Merge pull request #109 from kd7tck/develop

Added proto version of jar_xm

src/audio.c

@@ -42,6 +42,9 @@
 #include <string.h>         // Required for strcmp()
 #include <stdio.h>          // Used for .WAV loading
 
+#define JAR_XM_IMPLEMENTATION
+#include "jar_xm.h"         // For playing .xm files
+
 #if defined(AUDIO_STANDALONE)
     #include <stdarg.h>     // Used for functions with variable number of parameters (TraceLog())
 #else
@@ -73,6 +76,7 @@
 // NOTE: Anything longer than ~10 seconds should be streamed...
 typedef struct Music {
     stb_vorbis *stream;
+    jar_xm_context_t *chipctx; // Stores jar_xm context
 
     ALuint buffers[MUSIC_STREAM_BUFFERS];
     ALuint source;
@@ -82,7 +86,7 @@ typedef struct Music {
     int sampleRate;
     int totalSamplesLeft;
     bool loop;
-
+    bool chipTune; // True if chiptune is loaded
 } Music;
 
 #if defined(AUDIO_STANDALONE)
@@ -564,6 +568,22 @@ void PlayMusicStream(char *fileName)
             currentMusic.totalSamplesLeft = stb_vorbis_stream_length_in_samples(currentMusic.stream) * currentMusic.channels;
         }
     }
+    else if (strcmp(GetExtension(fileName),"xm") == 0)
+    {
+        currentMusic.chipTune = true;
+        currentMusic.channels = 2;
+        currentMusic.sampleRate = 48000;
+        currentMusic.loop = true;
+        
+        // only stereo/float is supported for xm
+        if(info.channels == 2 && !jar_xm_create_context_from_file(&currentMusic.chipctx, currentMusic.sampleRate, fileName))
+        {
+            currentMusic.format = AL_FORMAT_STEREO_FLOAT32;
+            jar_xm_set_max_loop_count(currentMusic.chipctx, 0); //infinite number of loops
+            //currentMusic.totalSamplesLeft =  ; // Unsure of how to calculate this
+            musicEnabled = true;
+        }
+    }
     else TraceLog(WARNING, "[%s] Music extension not recognized, it can't be loaded", fileName);
 }
 
@@ -573,13 +593,18 @@ void StopMusicStream(void)
     if (musicEnabled)
     {
         alSourceStop(currentMusic.source);
-
-        EmptyMusicStream();     // Empty music buffers
-
+        EmptyMusicStream(); // Empty music buffers
         alDeleteSources(1, &currentMusic.source);
         alDeleteBuffers(2, currentMusic.buffers);
-
-        stb_vorbis_close(currentMusic.stream);
+        
+        if (currentMusic.chipTune)
+        {
+            jar_xm_free_context(currentMusic.chipctx);
+        }
+        else
+        {
+            stb_vorbis_close(currentMusic.stream);
+        }
     }
 
     musicEnabled = false;
@@ -633,7 +658,15 @@ void SetMusicVolume(float volume)
 // Get current music time length (in seconds)
 float GetMusicTimeLength(void)
 {
-    float totalSeconds = stb_vorbis_stream_length_in_seconds(currentMusic.stream);
+    float totalSeconds;
+    if (currentMusic.chipTune)
+    {
+        //totalSeconds = (float)samples; // Need to figure out how toget this
+    }
+    else
+    {
+        totalSeconds = stb_vorbis_stream_length_in_seconds(currentMusic.stream);
+    }
 
     return totalSeconds;
 }
@@ -641,11 +674,20 @@ float GetMusicTimeLength(void)
 // Get current music time played (in seconds)
 float GetMusicTimePlayed(void)
 {
-    int totalSamples = stb_vorbis_stream_length_in_samples(currentMusic.stream) * currentMusic.channels;
-
-    int samplesPlayed = totalSamples - currentMusic.totalSamplesLeft;
-
-    float secondsPlayed = (float)samplesPlayed / (currentMusic.sampleRate * currentMusic.channels);
+    float secondsPlayed;
+    if (currentMusic.chipTune)
+    {
+        uint64_t samples;
+        jar_xm_get_position(currentMusic.chipctx, NULL, NULL, NULL, &samples); // Unsure if this is the desired value
+        secondsPlayed = (float)samples / (currentMusic.sampleRate * currentMusic.channels);
+    }
+    else
+    {
+        int totalSamples = stb_vorbis_stream_length_in_samples(currentMusic.stream) * currentMusic.channels;
+        int samplesPlayed = totalSamples - currentMusic.totalSamplesLeft;
+        secondsPlayed = (float)samplesPlayed / (currentMusic.sampleRate * currentMusic.channels);
+    }
+    
 
     return secondsPlayed;
 }
@@ -668,7 +710,15 @@ static bool BufferMusicStream(ALuint buffer)
     {
         while (size < MUSIC_BUFFER_SIZE)
         {
-            streamedBytes = stb_vorbis_get_samples_short_interleaved(currentMusic.stream, currentMusic.channels, pcm + size, MUSIC_BUFFER_SIZE - size);
+            if (currentMusic.chipTune)
+            {
+                jar_xm_generate_samples(currentMusic.chipctx, pcm + size, (MUSIC_BUFFER_SIZE - size) / 2);
+                streamedBytes = (MUSIC_BUFFER_SIZE - size)/2; // There is no end of stream for xmfiles, once the end is reached zeros are generated for non looped chiptunes.
+            }
+            else
+            {
+                streamedBytes = stb_vorbis_get_samples_short_interleaved(currentMusic.stream, currentMusic.channels, pcm + size, MUSIC_BUFFER_SIZE - size);
+            }
 
             if (streamedBytes > 0) size += (streamedBytes*currentMusic.channels);
             else break;

src/jar_xm.h

@@ -0,0 +1,2669 @@
+// jar_xm.h - v0.01 - public domain - Joshua Reisenauer, MAR 2016
+//
+// HISTORY:
+//
+//   v0.01  2016-02-22  Setup
+//
+//
+// USAGE:
+//
+// In ONE source file, put:
+//
+//    #define JAR_XM_IMPLEMENTATION
+//    #include "jar_xm.h"
+//
+// Other source files should just include jar_xm.h
+//
+// SAMPLE CODE:
+//
+// jar_xm_context_t *musicptr;
+// float musicBuffer[48000 / 60];
+// int intro_load(void)
+// {
+//     jar_xm_create_context_from_file(&musicptr, 48000, "Song.XM");
+//     return 1;
+// }
+// int intro_unload(void)
+// {
+//     jar_xm_free_context(musicptr);
+//     return 1;
+// }
+// int intro_tick(long counter)
+// {
+//     jar_xm_generate_samples(musicptr, musicBuffer, (48000 / 60) / 2);
+//     if(IsKeyDown(KEY_ENTER))
+//         return 1;
+//     return 0;
+// }
+//
+//
+// LISCENSE - FOR LIBXM:
+//
+// Author: Romain "Artefact2" Dalmaso <[email protected]>
+// Contributor: Dan Spencer <[email protected]>
+// Repackaged into jar_xm.h By: Joshua Adam Reisenauer <[email protected]>
+// This program is free software. It comes without any warranty, to the
+// extent permitted by applicable law. You can redistribute it and/or
+// modify it under the terms of the Do What The Fuck You Want To Public
+// License, Version 2, as published by Sam Hocevar. See
+// http://sam.zoy.org/wtfpl/COPYING for more details.
+
+#ifndef INCLUDE_JAR_XM_H
+#define INCLUDE_JAR_XM_H
+
+#define JAR_XM_DEBUG 0
+#define JAR_XM_LINEAR_INTERPOLATION 1 // speed increase with decrease in quality
+#define JAR_XM_DEFENSIVE 1
+#define JAR_XM_RAMPING 1
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <limits.h>
+#include <string.h>
+
+//-------------------------------------------------------------------------------
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct jar_xm_context_s;
+typedef struct jar_xm_context_s jar_xm_context_t;
+
+/** Create a XM context.
+ *
+ * @param moddata the contents of the module
+ * @param rate play rate in Hz, recommended value of 48000
+ *
+ * @returns 0 on success
+ * @returns 1 if module data is not sane
+ * @returns 2 if memory allocation failed
+ * @returns 3 unable to open input file
+ * @returns 4 fseek() failed
+ * @returns 5 fread() failed
+ * @returns 6 unkown error
+ *
+ * @deprecated This function is unsafe!
+ * @see jar_xm_create_context_safe()
+ */
+int jar_xm_create_context_from_file(jar_xm_context_t** ctx, uint32_t rate, const char* filename);
+
+/** Create a XM context.
+ *
+ * @param moddata the contents of the module
+ * @param rate play rate in Hz, recommended value of 48000
+ *
+ * @returns 0 on success
+ * @returns 1 if module data is not sane
+ * @returns 2 if memory allocation failed
+ *
+ * @deprecated This function is unsafe!
+ * @see jar_xm_create_context_safe()
+ */
+int jar_xm_create_context(jar_xm_context_t**, const char* moddata, uint32_t rate);
+
+/** Create a XM context.
+ *
+ * @param moddata the contents of the module
+ * @param moddata_length the length of the contents of the module, in bytes
+ * @param rate play rate in Hz, recommended value of 48000
+ *
+ * @returns 0 on success
+ * @returns 1 if module data is not sane
+ * @returns 2 if memory allocation failed
+ */
+int jar_xm_create_context_safe(jar_xm_context_t**, const char* moddata, size_t moddata_length, uint32_t rate);
+
+/** Free a XM context created by jar_xm_create_context(). */
+void jar_xm_free_context(jar_xm_context_t*);
+
+/** Play the module and put the sound samples in an output buffer.
+ *
+ * @param output buffer of 2*numsamples elements
+ * @param numsamples number of samples to generate
+ */
+void jar_xm_generate_samples(jar_xm_context_t*, float* output, size_t numsamples);
+
+/** Play the module, resample from 32 bit to 16 bit, and put the sound samples in an output buffer.
+ *
+ * @param output buffer of 2*numsamples elements
+ * @param numsamples number of samples to generate
+ */
+void jar_xm_generate_samples_16bit(jar_xm_context_t* ctx, short* output, size_t numsamples)
+{
+    float* musicBuffer = malloc((2*numsamples)*sizeof(float));
+    short* musicBuffer2 = malloc((2*numsamples)*sizeof(short));
+
+    jar_xm_generate_samples(ctx, musicBuffer, numsamples);
+
+    int x;
+    for(x=0;x<2*numsamples;x++)
+        musicBuffer2[x] = musicBuffer[x] * SHRT_MAX;
+
+    memcpy(output, musicBuffer2, (2*numsamples)*sizeof(short));
+    free(musicBuffer);
+    free(musicBuffer2);
+}
+
+/** Play the module, resample from 32 bit to 8 bit, and put the sound samples in an output buffer.
+ *
+ * @param output buffer of 2*numsamples elements
+ * @param numsamples number of samples to generate
+ */
+void jar_xm_generate_samples_8bit(jar_xm_context_t* ctx, char* output, size_t numsamples)
+{
+    float* musicBuffer = malloc((2*numsamples)*sizeof(float));
+    char* musicBuffer2 = malloc((2*numsamples)*sizeof(char));
+
+    jar_xm_generate_samples(ctx, musicBuffer, numsamples);
+
+    int x;
+    for(x=0;x<2*numsamples;x++)
+        musicBuffer2[x] = musicBuffer[x] * CHAR_MAX;
+
+    memcpy(output, musicBuffer2, (2*numsamples)*sizeof(char));
+    free(musicBuffer);
+    free(musicBuffer2);
+}
+
+
+
+/** Set the maximum number of times a module can loop. After the
+ * specified number of loops, calls to jar_xm_generate_samples will only
+ * generate silence. You can control the current number of loops with
+ * jar_xm_get_loop_count().
+ *
+ * @param loopcnt maximum number of loops. Use 0 to loop
+ * indefinitely. */
+void jar_xm_set_max_loop_count(jar_xm_context_t*, uint8_t loopcnt);
+
+/** Get the loop count of the currently playing module. This value is
+ * 0 when the module is still playing, 1 when the module has looped
+ * once, etc. */
+uint8_t jar_xm_get_loop_count(jar_xm_context_t*);
+
+
+
+/** Mute or unmute a channel.
+ *
+ * @note Channel numbers go from 1 to jar_xm_get_number_of_channels(...).
+ *
+ * @return whether the channel was muted.
+ */
+bool jar_xm_mute_channel(jar_xm_context_t*, uint16_t, bool);
+
+/** Mute or unmute an instrument.
+ *
+ * @note Instrument numbers go from 1 to
+ * jar_xm_get_number_of_instruments(...).
+ *
+ * @return whether the instrument was muted.
+ */
+bool jar_xm_mute_instrument(jar_xm_context_t*, uint16_t, bool);
+
+
+
+/** Get the module name as a NUL-terminated string. */
+const char* jar_xm_get_module_name(jar_xm_context_t*);
+
+/** Get the tracker name as a NUL-terminated string. */
+const char* jar_xm_get_tracker_name(jar_xm_context_t*);
+
+
+
+/** Get the number of channels. */
+uint16_t jar_xm_get_number_of_channels(jar_xm_context_t*);
+
+/** Get the module length (in patterns). */
+uint16_t jar_xm_get_module_length(jar_xm_context_t*);
+
+/** Get the number of patterns. */
+uint16_t jar_xm_get_number_of_patterns(jar_xm_context_t*);
+
+/** Get the number of rows of a pattern.
+ *
+ * @note Pattern numbers go from 0 to
+ * jar_xm_get_number_of_patterns(...)-1.
+ */
+uint16_t jar_xm_get_number_of_rows(jar_xm_context_t*, uint16_t);
+
+/** Get the number of instruments. */
+uint16_t jar_xm_get_number_of_instruments(jar_xm_context_t*);
+
+/** Get the number of samples of an instrument.
+ *
+ * @note Instrument numbers go from 1 to
+ * jar_xm_get_number_of_instruments(...).
+ */
+uint16_t jar_xm_get_number_of_samples(jar_xm_context_t*, uint16_t);
+
+
+
+/** Get the current module speed.
+ *
+ * @param bpm will receive the current BPM
+ * @param tempo will receive the current tempo (ticks per line)
+ */
+void jar_xm_get_playing_speed(jar_xm_context_t*, uint16_t* bpm, uint16_t* tempo);
+
+/** Get the current position in the module being played.
+ *
+ * @param pattern_index if not NULL, will receive the current pattern
+ * index in the POT (pattern order table)
+ *
+ * @param pattern if not NULL, will receive the current pattern number
+ *
+ * @param row if not NULL, will receive the current row
+ *
+ * @param samples if not NULL, will receive the total number of
+ * generated samples (divide by sample rate to get seconds of
+ * generated audio)
+ */
+void jar_xm_get_position(jar_xm_context_t*, uint8_t* pattern_index, uint8_t* pattern, uint8_t* row, uint64_t* samples);
+
+/** Get the latest time (in number of generated samples) when a
+ * particular instrument was triggered in any channel.
+ *
+ * @note Instrument numbers go from 1 to
+ * jar_xm_get_number_of_instruments(...).
+ */
+uint64_t jar_xm_get_latest_trigger_of_instrument(jar_xm_context_t*, uint16_t);
+
+/** Get the latest time (in number of generated samples) when a
+ * particular sample was triggered in any channel.
+ *
+ * @note Instrument numbers go from 1 to
+ * jar_xm_get_number_of_instruments(...).
+ *
+ * @note Sample numbers go from 0 to
+ * jar_xm_get_nubmer_of_samples(...,instr)-1.
+ */
+uint64_t jar_xm_get_latest_trigger_of_sample(jar_xm_context_t*, uint16_t instr, uint16_t sample);
+
+/** Get the latest time (in number of generated samples) when any
+ * instrument was triggered in a given channel.
+ *
+ * @note Channel numbers go from 1 to jar_xm_get_number_of_channels(...).
+ */
+uint64_t jar_xm_get_latest_trigger_of_channel(jar_xm_context_t*, uint16_t);
+
+/** Get the number of remaining samples. Divide by 2 to get the number of individual LR data samples.
+ *
+ * @note This is the remaining number of samples before the loop starts module again, or halts if on last pass.
+ * @note This function is very slow and should only be run once, if at all.
+ */
+uint64_t jar_xm_get_remaining_samples(jar_xm_context_t*);
+
+#ifdef __cplusplus
+}
+#endif
+//-------------------------------------------------------------------------------
+
+
+
+
+
+
+//Function Definitions-----------------------------------------------------------
+#ifdef JAR_XM_IMPLEMENTATION
+
+#include <math.h>
+#include <string.h>
+
+#if JAR_XM_DEBUG
+#include <stdio.h>
+#define DEBUG(fmt, ...) do {                                        \
+        fprintf(stderr, "%s(): " fmt "\n", __func__, __VA_ARGS__);    \
+        fflush(stderr);                                                \
+    } while(0)
+#else
+#define DEBUG(...)
+#endif
+
+#if jar_xm_BIG_ENDIAN
+#error "Big endian platforms are not yet supported, sorry"
+/* Make sure the compiler stops, even if #error is ignored */
+extern int __fail[-1];
+#endif
+
+/* ----- XM constants ----- */
+
+#define SAMPLE_NAME_LENGTH 22
+#define INSTRUMENT_NAME_LENGTH 22
+#define MODULE_NAME_LENGTH 20
+#define TRACKER_NAME_LENGTH 20
+#define PATTERN_ORDER_TABLE_LENGTH 256
+#define NUM_NOTES 96
+#define NUM_ENVELOPE_POINTS 12
+#define MAX_NUM_ROWS 256
+
+#if JAR_XM_RAMPING
+#define jar_xm_SAMPLE_RAMPING_POINTS 0x20
+#endif
+
+/* ----- Data types ----- */
+
+enum jar_xm_waveform_type_e {
+    jar_xm_SINE_WAVEFORM = 0,
+    jar_xm_RAMP_DOWN_WAVEFORM = 1,
+    jar_xm_SQUARE_WAVEFORM = 2,
+    jar_xm_RANDOM_WAVEFORM = 3,
+    jar_xm_RAMP_UP_WAVEFORM = 4,
+};
+typedef enum jar_xm_waveform_type_e jar_xm_waveform_type_t;
+
+enum jar_xm_loop_type_e {
+    jar_xm_NO_LOOP,
+    jar_xm_FORWARD_LOOP,
+    jar_xm_PING_PONG_LOOP,
+};
+typedef enum jar_xm_loop_type_e jar_xm_loop_type_t;
+
+enum jar_xm_frequency_type_e {
+    jar_xm_LINEAR_FREQUENCIES,
+    jar_xm_AMIGA_FREQUENCIES,
+};
+typedef enum jar_xm_frequency_type_e jar_xm_frequency_type_t;
+
+struct jar_xm_envelope_point_s {
+    uint16_t frame;
+    uint16_t value;
+};
+typedef struct jar_xm_envelope_point_s jar_xm_envelope_point_t;
+
+struct jar_xm_envelope_s {
+    jar_xm_envelope_point_t points[NUM_ENVELOPE_POINTS];
+    uint8_t num_points;
+    uint8_t sustain_point;
+    uint8_t loop_start_point;
+    uint8_t loop_end_point;
+    bool enabled;
+    bool sustain_enabled;
+    bool loop_enabled;
+};
+typedef struct jar_xm_envelope_s jar_xm_envelope_t;
+
+struct jar_xm_sample_s {
+    char name[SAMPLE_NAME_LENGTH + 1];
+    int8_t bits; /* Either 8 or 16 */
+
+    uint32_t length;
+    uint32_t loop_start;
+    uint32_t loop_length;
+    uint32_t loop_end;
+    float volume;
+    int8_t finetune;
+    jar_xm_loop_type_t loop_type;
+    float panning;
+    int8_t relative_note;
+    uint64_t latest_trigger;
+
+    float* data;
+ };
+ typedef struct jar_xm_sample_s jar_xm_sample_t;
+
+ struct jar_xm_instrument_s {
+     char name[INSTRUMENT_NAME_LENGTH + 1];
+     uint16_t num_samples;
+     uint8_t sample_of_notes[NUM_NOTES];
+     jar_xm_envelope_t volume_envelope;
+     jar_xm_envelope_t panning_envelope;
+     jar_xm_waveform_type_t vibrato_type;
+     uint8_t vibrato_sweep;
+     uint8_t vibrato_depth;
+     uint8_t vibrato_rate;
+     uint16_t volume_fadeout;
+     uint64_t latest_trigger;
+     bool muted;
+
+     jar_xm_sample_t* samples;
+ };
+ typedef struct jar_xm_instrument_s jar_xm_instrument_t;
+
+ struct jar_xm_pattern_slot_s {
+     uint8_t note; /* 1-96, 97 = Key Off note */
+     uint8_t instrument; /* 1-128 */
+     uint8_t volume_column;
+     uint8_t effect_type;
+     uint8_t effect_param;
+ };
+ typedef struct jar_xm_pattern_slot_s jar_xm_pattern_slot_t;
+
+ struct jar_xm_pattern_s {
+     uint16_t num_rows;
+     jar_xm_pattern_slot_t* slots; /* Array of size num_rows * num_channels */
+ };
+ typedef struct jar_xm_pattern_s jar_xm_pattern_t;
+
+ struct jar_xm_module_s {
+     char name[MODULE_NAME_LENGTH + 1];
+     char trackername[TRACKER_NAME_LENGTH + 1];
+     uint16_t length;
+     uint16_t restart_position;
+     uint16_t num_channels;
+     uint16_t num_patterns;
+     uint16_t num_instruments;
+     jar_xm_frequency_type_t frequency_type;
+     uint8_t pattern_table[PATTERN_ORDER_TABLE_LENGTH];
+
+     jar_xm_pattern_t* patterns;
+     jar_xm_instrument_t* instruments; /* Instrument 1 has index 0,
+                                    * instrument 2 has index 1, etc. */
+ };
+ typedef struct jar_xm_module_s jar_xm_module_t;
+
+ struct jar_xm_channel_context_s {
+     float note;
+     float orig_note; /* The original note before effect modifications, as read in the pattern. */
+     jar_xm_instrument_t* instrument; /* Could be NULL */
+     jar_xm_sample_t* sample; /* Could be NULL */
+     jar_xm_pattern_slot_t* current;
+
+     float sample_position;
+     float period;
+     float frequency;
+     float step;
+     bool ping; /* For ping-pong samples: true is -->, false is <-- */
+
+     float volume; /* Ideally between 0 (muted) and 1 (loudest) */
+     float panning; /* Between 0 (left) and 1 (right); 0.5 is centered */
+
+     uint16_t autovibrato_ticks;
+
+     bool sustained;
+     float fadeout_volume;
+     float volume_envelope_volume;
+     float panning_envelope_panning;
+     uint16_t volume_envelope_frame_count;
+     uint16_t panning_envelope_frame_count;
+
+     float autovibrato_note_offset;
+
+     bool arp_in_progress;
+     uint8_t arp_note_offset;
+     uint8_t volume_slide_param;
+     uint8_t fine_volume_slide_param;
+     uint8_t global_volume_slide_param;
+     uint8_t panning_slide_param;
+     uint8_t portamento_up_param;
+     uint8_t portamento_down_param;
+     uint8_t fine_portamento_up_param;
+     uint8_t fine_portamento_down_param;
+     uint8_t extra_fine_portamento_up_param;
+     uint8_t extra_fine_portamento_down_param;
+     uint8_t tone_portamento_param;
+     float tone_portamento_target_period;
+     uint8_t multi_retrig_param;
+     uint8_t note_delay_param;
+     uint8_t pattern_loop_origin; /* Where to restart a E6y loop */
+     uint8_t pattern_loop_count; /* How many loop passes have been done */
+     bool vibrato_in_progress;
+     jar_xm_waveform_type_t vibrato_waveform;
+     bool vibrato_waveform_retrigger; /* True if a new note retriggers the waveform */
+     uint8_t vibrato_param;
+     uint16_t vibrato_ticks; /* Position in the waveform */
+     float vibrato_note_offset;
+     jar_xm_waveform_type_t tremolo_waveform;
+     bool tremolo_waveform_retrigger;
+     uint8_t tremolo_param;
+     uint8_t tremolo_ticks;
+     float tremolo_volume;
+     uint8_t tremor_param;
+     bool tremor_on;
+
+     uint64_t latest_trigger;
+     bool muted;
+
+#if JAR_XM_RAMPING
+     /* These values are updated at the end of each tick, to save
+      * a couple of float operations on every generated sample. */
+     float target_panning;
+     float target_volume;
+
+     unsigned long frame_count;
+     float end_of_previous_sample[jar_xm_SAMPLE_RAMPING_POINTS];
+#endif
+
+     float actual_panning;
+     float actual_volume;
+ };
+ typedef struct jar_xm_channel_context_s jar_xm_channel_context_t;
+
+ struct jar_xm_context_s {
+     void* allocated_memory;
+     jar_xm_module_t module;
+     uint32_t rate;
+
+     uint16_t tempo;
+     uint16_t bpm;
+     float global_volume;
+     float amplification;
+
+#if JAR_XM_RAMPING
+     /* How much is a channel final volume allowed to change per
+      * sample; this is used to avoid abrubt volume changes which
+      * manifest as "clicks" in the generated sound. */
+     float volume_ramp;
+     float panning_ramp; /* Same for panning. */
+#endif
+
+     uint8_t current_table_index;
+     uint8_t current_row;
+     uint16_t current_tick; /* Can go below 255, with high tempo and a pattern delay */
+     float remaining_samples_in_tick;
+     uint64_t generated_samples;
+
+     bool position_jump;
+     bool pattern_break;
+     uint8_t jump_dest;
+     uint8_t jump_row;
+
+     /* Extra ticks to be played before going to the next row -
+      * Used for EEy effect */
+     uint16_t extra_ticks;
+
+     uint8_t* row_loop_count; /* Array of size MAX_NUM_ROWS * module_length */
+     uint8_t loop_count;
+     uint8_t max_loop_count;
+
+     jar_xm_channel_context_t* channels;
+};
+
+/* ----- Internal API ----- */
+
+#if JAR_XM_DEFENSIVE
+
+/** Check the module data for errors/inconsistencies.
+ *
+ * @returns 0 if everything looks OK. Module should be safe to load.
+ */
+int jar_xm_check_sanity_preload(const char*, size_t);
+
+/** Check a loaded module for errors/inconsistencies.
+ *
+ * @returns 0 if everything looks OK.
+ */
+int jar_xm_check_sanity_postload(jar_xm_context_t*);
+
+#endif
+
+/** Get the number of bytes needed to store the module data in a
+ * dynamically allocated blank context.
+ *
+ * Things that are dynamically allocated:
+ * - sample data
+ * - sample structures in instruments
+ * - pattern data
+ * - row loop count arrays
+ * - pattern structures in module
+ * - instrument structures in module
+ * - channel contexts
+ * - context structure itself
+
+ * @returns 0 if everything looks OK.
+ */
+size_t jar_xm_get_memory_needed_for_context(const char*, size_t);
+
+/** Populate the context from module data.
+ *
+ * @returns pointer to the memory pool
+ */
+char* jar_xm_load_module(jar_xm_context_t*, const char*, size_t, char*);
+
+int jar_xm_create_context(jar_xm_context_t** ctxp, const char* moddata, uint32_t rate) {
+    return jar_xm_create_context_safe(ctxp, moddata, SIZE_MAX, rate);
+}
+
+int jar_xm_create_context_safe(jar_xm_context_t** ctxp, const char* moddata, size_t moddata_length, uint32_t rate) {
+#if JAR_XM_DEFENSIVE
+    int ret;
+#endif
+    size_t bytes_needed;
+    char* mempool;
+    jar_xm_context_t* ctx;
+
+#if JAR_XM_DEFENSIVE
+    if((ret = jar_xm_check_sanity_preload(moddata, moddata_length))) {
+        DEBUG("jar_xm_check_sanity_preload() returned %i, module is not safe to load", ret);
+        return 1;
+    }
+#endif
+
+    bytes_needed = jar_xm_get_memory_needed_for_context(moddata, moddata_length);
+    mempool = malloc(bytes_needed);
+    if(mempool == NULL && bytes_needed > 0) {
+        /* malloc() failed, trouble ahead */
+        DEBUG("call to malloc() failed, returned %p", (void*)mempool);
+        return 2;
+    }
+
+    /* Initialize most of the fields to 0, 0.f, NULL or false depending on type */
+    memset(mempool, 0, bytes_needed);
+
+    ctx = (*ctxp = (jar_xm_context_t*)mempool);
+    ctx->allocated_memory = mempool; /* Keep original pointer for free() */
+    mempool += sizeof(jar_xm_context_t);
+
+    ctx->rate = rate;
+    mempool = jar_xm_load_module(ctx, moddata, moddata_length, mempool);
+
+    ctx->channels = (jar_xm_channel_context_t*)mempool;
+    mempool += ctx->module.num_channels * sizeof(jar_xm_channel_context_t);
+
+    ctx->global_volume = 1.f;
+    ctx->amplification = .25f; /* XXX: some bad modules may still clip. Find out something better. */
+
+#if JAR_XM_RAMPING
+    ctx->volume_ramp = (1.f / 128.f);
+    ctx->panning_ramp = (1.f / 128.f);
+#endif
+
+    for(uint8_t i = 0; i < ctx->module.num_channels; ++i) {
+        jar_xm_channel_context_t* ch = ctx->channels + i;
+
+        ch->ping = true;
+        ch->vibrato_waveform = jar_xm_SINE_WAVEFORM;
+        ch->vibrato_waveform_retrigger = true;
+        ch->tremolo_waveform = jar_xm_SINE_WAVEFORM;
+        ch->tremolo_waveform_retrigger = true;
+
+        ch->volume = ch->volume_envelope_volume = ch->fadeout_volume = 1.0f;
+        ch->panning = ch->panning_envelope_panning = .5f;
+        ch->actual_volume = .0f;
+        ch->actual_panning = .5f;
+    }
+
+    ctx->row_loop_count = (uint8_t*)mempool;
+    mempool += MAX_NUM_ROWS * sizeof(uint8_t);
+
+#if JAR_XM_DEFENSIVE
+    if((ret = jar_xm_check_sanity_postload(ctx))) {
+        DEBUG("jar_xm_check_sanity_postload() returned %i, module is not safe to play", ret);
+        jar_xm_free_context(ctx);
+        return 1;
+    }
+#endif
+
+    return 0;
+}
+
+void jar_xm_free_context(jar_xm_context_t* context) {
+    free(context->allocated_memory);
+}
+
+void jar_xm_set_max_loop_count(jar_xm_context_t* context, uint8_t loopcnt) {
+    context->max_loop_count = loopcnt;
+}
+
+uint8_t jar_xm_get_loop_count(jar_xm_context_t* context) {
+    return context->loop_count;
+}
+
+
+
+bool jar_xm_mute_channel(jar_xm_context_t* ctx, uint16_t channel, bool mute) {
+    bool old = ctx->channels[channel - 1].muted;
+    ctx->channels[channel - 1].muted = mute;
+    return old;
+}
+
+bool jar_xm_mute_instrument(jar_xm_context_t* ctx, uint16_t instr, bool mute) {
+    bool old = ctx->module.instruments[instr - 1].muted;
+    ctx->module.instruments[instr - 1].muted = mute;
+    return old;
+}
+
+
+
+const char* jar_xm_get_module_name(jar_xm_context_t* ctx) {
+    return ctx->module.name;
+}
+
+const char* jar_xm_get_tracker_name(jar_xm_context_t* ctx) {
+    return ctx->module.trackername;
+}
+
+
+
+uint16_t jar_xm_get_number_of_channels(jar_xm_context_t* ctx) {
+    return ctx->module.num_channels;
+}
+
+uint16_t jar_xm_get_module_length(jar_xm_context_t* ctx) {
+    return ctx->module.length;
+}
+
+uint16_t jar_xm_get_number_of_patterns(jar_xm_context_t* ctx) {
+    return ctx->module.num_patterns;
+}
+
+uint16_t jar_xm_get_number_of_rows(jar_xm_context_t* ctx, uint16_t pattern) {
+    return ctx->module.patterns[pattern].num_rows;
+}
+
+uint16_t jar_xm_get_number_of_instruments(jar_xm_context_t* ctx) {
+    return ctx->module.num_instruments;
+}
+
+uint16_t jar_xm_get_number_of_samples(jar_xm_context_t* ctx, uint16_t instrument) {
+    return ctx->module.instruments[instrument - 1].num_samples;
+}
+
+
+
+void jar_xm_get_playing_speed(jar_xm_context_t* ctx, uint16_t* bpm, uint16_t* tempo) {
+    if(bpm) *bpm = ctx->bpm;
+    if(tempo) *tempo = ctx->tempo;
+}
+
+void jar_xm_get_position(jar_xm_context_t* ctx, uint8_t* pattern_index, uint8_t* pattern, uint8_t* row, uint64_t* samples) {
+    if(pattern_index) *pattern_index = ctx->current_table_index;
+    if(pattern) *pattern = ctx->module.pattern_table[ctx->current_table_index];
+    if(row) *row = ctx->current_row;
+    if(samples) *samples = ctx->generated_samples;
+}
+
+uint64_t jar_xm_get_latest_trigger_of_instrument(jar_xm_context_t* ctx, uint16_t instr) {
+    return ctx->module.instruments[instr - 1].latest_trigger;
+}
+
+uint64_t jar_xm_get_latest_trigger_of_sample(jar_xm_context_t* ctx, uint16_t instr, uint16_t sample) {
+    return ctx->module.instruments[instr - 1].samples[sample].latest_trigger;
+}
+
+uint64_t jar_xm_get_latest_trigger_of_channel(jar_xm_context_t* ctx, uint16_t chn) {
+    return ctx->channels[chn - 1].latest_trigger;
+}
+
+/* .xm files are little-endian. (XXX: Are they really?) */
+
+/* Bounded reader macros.
+ * If we attempt to read the buffer out-of-bounds, pretend that the buffer is
+ * infinitely padded with zeroes.
+ */
+#define READ_U8(offset) (((offset) < moddata_length) ? (*(uint8_t*)(moddata + (offset))) : 0)
+#define READ_U16(offset) ((uint16_t)READ_U8(offset) | ((uint16_t)READ_U8((offset) + 1) << 8))
+#define READ_U32(offset) ((uint32_t)READ_U16(offset) | ((uint32_t)READ_U16((offset) + 2) << 16))
+#define READ_MEMCPY(ptr, offset, length) memcpy_pad(ptr, length, moddata, moddata_length, offset)
+
+static inline void memcpy_pad(void* dst, size_t dst_len, const void* src, size_t src_len, size_t offset) {
+    uint8_t* dst_c = dst;
+    const uint8_t* src_c = src;
+
+    /* how many bytes can be copied without overrunning `src` */
+    size_t copy_bytes = (src_len >= offset) ? (src_len - offset) : 0;
+    copy_bytes = copy_bytes > dst_len ? dst_len : copy_bytes;
+
+    memcpy(dst_c, src_c + offset, copy_bytes);
+    /* padded bytes */
+    memset(dst_c + copy_bytes, 0, dst_len - copy_bytes);
+}
+
+#if JAR_XM_DEFENSIVE
+
+int jar_xm_check_sanity_preload(const char* module, size_t module_length) {
+    if(module_length < 60) {
+        return 4;
+    }
+
+    if(memcmp("Extended Module: ", module, 17) != 0) {
+        return 1;
+    }
+
+    if(module[37] != 0x1A) {
+        return 2;
+    }
+
+    if(module[59] != 0x01 || module[58] != 0x04) {
+        /* Not XM 1.04 */
+        return 3;
+    }
+
+    return 0;
+}
+
+int jar_xm_check_sanity_postload(jar_xm_context_t* ctx) {
+    /* @todo: plenty of stuff to do here… */
+
+    /* Check the POT */
+    for(uint8_t i = 0; i < ctx->module.length; ++i) {
+        if(ctx->module.pattern_table[i] >= ctx->module.num_patterns) {
+            if(i+1 == ctx->module.length && ctx->module.length > 1) {
+                /* Cheap fix */
+                --ctx->module.length;
+                DEBUG("trimming invalid POT at pos %X", i);
+            } else {
+                DEBUG("module has invalid POT, pos %X references nonexistent pattern %X",
+                      i,
+                      ctx->module.pattern_table[i]);
+                return 1;
+            }
+        }
+    }
+
+    return 0;
+}
+
+#endif
+
+size_t jar_xm_get_memory_needed_for_context(const char* moddata, size_t moddata_length) {
+    size_t memory_needed = 0;
+    size_t offset = 60; /* Skip the first header */
+    uint16_t num_channels;
+    uint16_t num_patterns;
+    uint16_t num_instruments;
+
+    /* Read the module header */
+
+    num_channels = READ_U16(offset + 8);
+    num_channels = READ_U16(offset + 8);
+
+    num_patterns = READ_U16(offset + 10);
+    memory_needed += num_patterns * sizeof(jar_xm_pattern_t);
+
+    num_instruments = READ_U16(offset + 12);
+    memory_needed += num_instruments * sizeof(jar_xm_instrument_t);
+
+    memory_needed += MAX_NUM_ROWS * READ_U16(offset + 4) * sizeof(uint8_t); /* Module length */
+
+    /* Header size */
+    offset += READ_U32(offset);
+
+    /* Read pattern headers */
+    for(uint16_t i = 0; i < num_patterns; ++i) {
+        uint16_t num_rows;
+
+        num_rows = READ_U16(offset + 5);
+        memory_needed += num_rows * num_channels * sizeof(jar_xm_pattern_slot_t);
+
+        /* Pattern header length + packed pattern data size */
+        offset += READ_U32(offset) + READ_U16(offset + 7);
+    }
+
+    /* Read instrument headers */
+    for(uint16_t i = 0; i < num_instruments; ++i) {
+        uint16_t num_samples;
+        uint32_t sample_header_size = 0;
+        uint32_t sample_size_aggregate = 0;
+
+        num_samples = READ_U16(offset + 27);
+        memory_needed += num_samples * sizeof(jar_xm_sample_t);
+
+        if(num_samples > 0) {
+            sample_header_size = READ_U32(offset + 29);
+        }
+
+        /* Instrument header size */
+        offset += READ_U32(offset);
+
+        for(uint16_t j = 0; j < num_samples; ++j) {
+            uint32_t sample_size;
+            uint8_t flags;
+
+            sample_size = READ_U32(offset);
+            flags = READ_U8(offset + 14);
+            sample_size_aggregate += sample_size;
+
+            if(flags & (1 << 4)) {
+                /* 16 bit sample */
+                memory_needed += sample_size * (sizeof(float) >> 1);
+            } else {
+                /* 8 bit sample */
+                memory_needed += sample_size * sizeof(float);
+            }
+
+            offset += sample_header_size;
+        }
+
+        offset += sample_size_aggregate;
+    }
+
+    memory_needed += num_channels * sizeof(jar_xm_channel_context_t);
+    memory_needed += sizeof(jar_xm_context_t);
+
+    return memory_needed;
+}
+
+char* jar_xm_load_module(jar_xm_context_t* ctx, const char* moddata, size_t moddata_length, char* mempool) {
+    size_t offset = 0;
+    jar_xm_module_t* mod = &(ctx->module);
+
+    /* Read XM header */
+    READ_MEMCPY(mod->name, offset + 17, MODULE_NAME_LENGTH);
+    READ_MEMCPY(mod->trackername, offset + 38, TRACKER_NAME_LENGTH);
+    offset += 60;
+
+    /* Read module header */
+    uint32_t header_size = READ_U32(offset);
+
+    mod->length = READ_U16(offset + 4);
+    mod->restart_position = READ_U16(offset + 6);
+    mod->num_channels = READ_U16(offset + 8);
+    mod->num_patterns = READ_U16(offset + 10);
+    mod->num_instruments = READ_U16(offset + 12);
+
+    mod->patterns = (jar_xm_pattern_t*)mempool;
+    mempool += mod->num_patterns * sizeof(jar_xm_pattern_t);
+
+    mod->instruments = (jar_xm_instrument_t*)mempool;
+    mempool += mod->num_instruments * sizeof(jar_xm_instrument_t);
+
+    uint16_t flags = READ_U32(offset + 14);
+    mod->frequency_type = (flags & (1 << 0)) ? jar_xm_LINEAR_FREQUENCIES : jar_xm_AMIGA_FREQUENCIES;
+
+    ctx->tempo = READ_U16(offset + 16);
+    ctx->bpm = READ_U16(offset + 18);
+
+    READ_MEMCPY(mod->pattern_table, offset + 20, PATTERN_ORDER_TABLE_LENGTH);
+    offset += header_size;
+
+    /* Read patterns */
+    for(uint16_t i = 0; i < mod->num_patterns; ++i) {
+        uint16_t packed_patterndata_size = READ_U16(offset + 7);
+        jar_xm_pattern_t* pat = mod->patterns + i;
+
+        pat->num_rows = READ_U16(offset + 5);
+
+        pat->slots = (jar_xm_pattern_slot_t*)mempool;
+        mempool += mod->num_channels * pat->num_rows * sizeof(jar_xm_pattern_slot_t);
+
+        /* Pattern header length */
+        offset += READ_U32(offset);
+
+        if(packed_patterndata_size == 0) {
+            /* No pattern data is present */
+            memset(pat->slots, 0, sizeof(jar_xm_pattern_slot_t) * pat->num_rows * mod->num_channels);
+        } else {
+            /* This isn't your typical for loop */
+            for(uint16_t j = 0, k = 0; j < packed_patterndata_size; ++k) {
+                uint8_t note = READ_U8(offset + j);
+                jar_xm_pattern_slot_t* slot = pat->slots + k;
+
+                if(note & (1 << 7)) {
+                    /* MSB is set, this is a compressed packet */
+                    ++j;
+
+                    if(note & (1 << 0)) {
+                        /* Note follows */
+                        slot->note = READ_U8(offset + j);
+                        ++j;
+                    } else {
+                        slot->note = 0;
+                    }
+
+                    if(note & (1 << 1)) {
+                        /* Instrument follows */
+                        slot->instrument = READ_U8(offset + j);
+                        ++j;
+                    } else {
+                        slot->instrument = 0;
+                    }
+
+                    if(note & (1 << 2)) {
+                        /* Volume column follows */
+                        slot->volume_column = READ_U8(offset + j);
+                        ++j;
+                    } else {
+                        slot->volume_column = 0;
+                    }
+
+                    if(note & (1 << 3)) {
+                        /* Effect follows */
+                        slot->effect_type = READ_U8(offset + j);
+                        ++j;
+                    } else {
+                        slot->effect_type = 0;
+                    }
+
+                    if(note & (1 << 4)) {
+                        /* Effect parameter follows */
+                        slot->effect_param = READ_U8(offset + j);
+                        ++j;
+                    } else {
+                        slot->effect_param = 0;
+                    }
+                } else {
+                    /* Uncompressed packet */
+                    slot->note = note;
+                    slot->instrument = READ_U8(offset + j + 1);
+                    slot->volume_column = READ_U8(offset + j + 2);
+                    slot->effect_type = READ_U8(offset + j + 3);
+                    slot->effect_param = READ_U8(offset + j + 4);
+                    j += 5;
+                }
+            }
+        }
+
+        offset += packed_patterndata_size;
+    }
+
+    /* Read instruments */
+    for(uint16_t i = 0; i < ctx->module.num_instruments; ++i) {
+        uint32_t sample_header_size = 0;
+        jar_xm_instrument_t* instr = mod->instruments + i;
+
+        READ_MEMCPY(instr->name, offset + 4, INSTRUMENT_NAME_LENGTH);
+        instr->num_samples = READ_U16(offset + 27);
+
+        if(instr->num_samples > 0) {
+            /* Read extra header properties */
+            sample_header_size = READ_U32(offset + 29);
+            READ_MEMCPY(instr->sample_of_notes, offset + 33, NUM_NOTES);
+
+            instr->volume_envelope.num_points = READ_U8(offset + 225);
+            instr->panning_envelope.num_points = READ_U8(offset + 226);
+
+            for(uint8_t j = 0; j < instr->volume_envelope.num_points; ++j) {
+                instr->volume_envelope.points[j].frame = READ_U16(offset + 129 + 4 * j);
+                instr->volume_envelope.points[j].value = READ_U16(offset + 129 + 4 * j + 2);
+            }
+
+            for(uint8_t j = 0; j < instr->panning_envelope.num_points; ++j) {
+                instr->panning_envelope.points[j].frame = READ_U16(offset + 177 + 4 * j);
+                instr->panning_envelope.points[j].value = READ_U16(offset + 177 + 4 * j + 2);
+            }
+
+            instr->volume_envelope.sustain_point = READ_U8(offset + 227);
+            instr->volume_envelope.loop_start_point = READ_U8(offset + 228);
+            instr->volume_envelope.loop_end_point = READ_U8(offset + 229);
+
+            instr->panning_envelope.sustain_point = READ_U8(offset + 230);
+            instr->panning_envelope.loop_start_point = READ_U8(offset + 231);
+            instr->panning_envelope.loop_end_point = READ_U8(offset + 232);
+
+            uint8_t flags = READ_U8(offset + 233);
+            instr->volume_envelope.enabled = flags & (1 << 0);
+            instr->volume_envelope.sustain_enabled = flags & (1 << 1);
+            instr->volume_envelope.loop_enabled = flags & (1 << 2);
+
+            flags = READ_U8(offset + 234);
+            instr->panning_envelope.enabled = flags & (1 << 0);
+            instr->panning_envelope.sustain_enabled = flags & (1 << 1);
+            instr->panning_envelope.loop_enabled = flags & (1 << 2);
+
+            instr->vibrato_type = READ_U8(offset + 235);
+            if(instr->vibrato_type == 2) {
+                instr->vibrato_type = 1;
+            } else if(instr->vibrato_type == 1) {
+                instr->vibrato_type = 2;
+            }
+            instr->vibrato_sweep = READ_U8(offset + 236);
+            instr->vibrato_depth = READ_U8(offset + 237);
+            instr->vibrato_rate = READ_U8(offset + 238);
+            instr->volume_fadeout = READ_U16(offset + 239);
+
+            instr->samples = (jar_xm_sample_t*)mempool;
+            mempool += instr->num_samples * sizeof(jar_xm_sample_t);
+        } else {
+            instr->samples = NULL;
+        }
+
+        /* Instrument header size */
+        offset += READ_U32(offset);
+
+        for(uint16_t j = 0; j < instr->num_samples; ++j) {
+            /* Read sample header */
+            jar_xm_sample_t* sample = instr->samples + j;
+
+            sample->length = READ_U32(offset);
+            sample->loop_start = READ_U32(offset + 4);
+            sample->loop_length = READ_U32(offset + 8);
+            sample->loop_end = sample->loop_start + sample->loop_length;
+            sample->volume = (float)READ_U8(offset + 12) / (float)0x40;
+            sample->finetune = (int8_t)READ_U8(offset + 13);
+
+            uint8_t flags = READ_U8(offset + 14);
+            if((flags & 3) == 0) {
+                sample->loop_type = jar_xm_NO_LOOP;
+            } else if((flags & 3) == 1) {
+                sample->loop_type = jar_xm_FORWARD_LOOP;
+            } else {
+                sample->loop_type = jar_xm_PING_PONG_LOOP;
+            }
+
+            sample->bits = (flags & (1 << 4)) ? 16 : 8;
+
+            sample->panning = (float)READ_U8(offset + 15) / (float)0xFF;
+            sample->relative_note = (int8_t)READ_U8(offset + 16);
+            READ_MEMCPY(sample->name, 18, SAMPLE_NAME_LENGTH);
+            sample->data = (float*)mempool;
+
+            if(sample->bits == 16) {
+                /* 16 bit sample */
+                mempool += sample->length * (sizeof(float) >> 1);
+                sample->loop_start >>= 1;
+                sample->loop_length >>= 1;
+                sample->loop_end >>= 1;
+                sample->length >>= 1;
+            } else {
+                /* 8 bit sample */
+                mempool += sample->length * sizeof(float);
+            }
+
+            offset += sample_header_size;
+        }
+
+        for(uint16_t j = 0; j < instr->num_samples; ++j) {
+            /* Read sample data */
+            jar_xm_sample_t* sample = instr->samples + j;
+            uint32_t length = sample->length;
+
+            if(sample->bits == 16) {
+                int16_t v = 0;
+                for(uint32_t k = 0; k < length; ++k) {
+                    v = v + (int16_t)READ_U16(offset + (k << 1));
+                    sample->data[k] = (float)v / (float)(1 << 15);
+                }
+                offset += sample->length << 1;
+            } else {
+                int8_t v = 0;
+                for(uint32_t k = 0; k < length; ++k) {
+                    v = v + (int8_t)READ_U8(offset + k);
+                    sample->data[k] = (float)v / (float)(1 << 7);
+                }
+                offset += sample->length;
+            }
+        }
+    }
+
+    return mempool;
+}
+
+//-------------------------------------------------------------------------------
+//THE FOLLOWING IS FOR PLAYING
+//-------------------------------------------------------------------------------
+
+/* ----- Static functions ----- */
+
+static float jar_xm_waveform(jar_xm_waveform_type_t, uint8_t);
+static void jar_xm_autovibrato(jar_xm_context_t*, jar_xm_channel_context_t*);
+static void jar_xm_vibrato(jar_xm_context_t*, jar_xm_channel_context_t*, uint8_t, uint16_t);
+static void jar_xm_tremolo(jar_xm_context_t*, jar_xm_channel_context_t*, uint8_t, uint16_t);
+static void jar_xm_arpeggio(jar_xm_context_t*, jar_xm_channel_context_t*, uint8_t, uint16_t);
+static void jar_xm_tone_portamento(jar_xm_context_t*, jar_xm_channel_context_t*);
+static void jar_xm_pitch_slide(jar_xm_context_t*, jar_xm_channel_context_t*, float);
+static void jar_xm_panning_slide(jar_xm_channel_context_t*, uint8_t);
+static void jar_xm_volume_slide(jar_xm_channel_context_t*, uint8_t);
+
+static float jar_xm_envelope_lerp(jar_xm_envelope_point_t*, jar_xm_envelope_point_t*, uint16_t);
+static void jar_xm_envelope_tick(jar_xm_channel_context_t*, jar_xm_envelope_t*, uint16_t*, float*);
+static void jar_xm_envelopes(jar_xm_channel_context_t*);
+
+static float jar_xm_linear_period(float);
+static float jar_xm_linear_frequency(float);
+static float jar_xm_amiga_period(float);
+static float jar_xm_amiga_frequency(float);
+static float jar_xm_period(jar_xm_context_t*, float);
+static float jar_xm_frequency(jar_xm_context_t*, float, float);
+static void jar_xm_update_frequency(jar_xm_context_t*, jar_xm_channel_context_t*);
+
+static void jar_xm_handle_note_and_instrument(jar_xm_context_t*, jar_xm_channel_context_t*, jar_xm_pattern_slot_t*);
+static void jar_xm_trigger_note(jar_xm_context_t*, jar_xm_channel_context_t*, unsigned int flags);
+static void jar_xm_cut_note(jar_xm_channel_context_t*);
+static void jar_xm_key_off(jar_xm_channel_context_t*);
+
+static void jar_xm_post_pattern_change(jar_xm_context_t*);
+static void jar_xm_row(jar_xm_context_t*);
+static void jar_xm_tick(jar_xm_context_t*);
+
+static float jar_xm_next_of_sample(jar_xm_channel_context_t*);
+static void jar_xm_sample(jar_xm_context_t*, float*, float*);
+
+/* ----- Other oddities ----- */
+
+#define jar_xm_TRIGGER_KEEP_VOLUME (1 << 0)
+#define jar_xm_TRIGGER_KEEP_PERIOD (1 << 1)
+#define jar_xm_TRIGGER_KEEP_SAMPLE_POSITION (1 << 2)
+
+static const uint16_t amiga_frequencies[] = {
+    1712, 1616, 1525, 1440, /* C-2, C#2, D-2, D#2 */
+    1357, 1281, 1209, 1141, /* E-2, F-2, F#2, G-2 */
+    1077, 1017,  961,  907, /* G#2, A-2, A#2, B-2 */
+    856,                    /* C-3 */
+};
+
+static const float multi_retrig_add[] = {
+     0.f,  -1.f,  -2.f,  -4.f,  /* 0, 1, 2, 3 */
+    -8.f, -16.f,   0.f,   0.f,  /* 4, 5, 6, 7 */
+     0.f,   1.f,   2.f,   4.f,  /* 8, 9, A, B */
+     8.f,  16.f,   0.f,   0.f   /* C, D, E, F */
+};
+
+static const float multi_retrig_multiply[] = {
+    1.f,   1.f,  1.f,        1.f,  /* 0, 1, 2, 3 */
+    1.f,   1.f,   .6666667f,  .5f, /* 4, 5, 6, 7 */
+    1.f,   1.f,  1.f,        1.f,  /* 8, 9, A, B */
+    1.f,   1.f,  1.5f,       2.f   /* C, D, E, F */
+};
+
+#define jar_xm_CLAMP_UP1F(vol, limit) do {            \
+        if((vol) > (limit)) (vol) = (limit);    \
+    } while(0)
+#define jar_xm_CLAMP_UP(vol) jar_xm_CLAMP_UP1F((vol), 1.f)
+
+#define jar_xm_CLAMP_DOWN1F(vol, limit) do {        \
+        if((vol) < (limit)) (vol) = (limit);    \
+    } while(0)
+#define jar_xm_CLAMP_DOWN(vol) jar_xm_CLAMP_DOWN1F((vol), .0f)
+
+#define jar_xm_CLAMP2F(vol, up, down) do {            \
+        if((vol) > (up)) (vol) = (up);            \
+        else if((vol) < (down)) (vol) = (down); \
+    } while(0)
+#define jar_xm_CLAMP(vol) jar_xm_CLAMP2F((vol), 1.f, .0f)
+
+#define jar_xm_SLIDE_TOWARDS(val, goal, incr) do {        \
+        if((val) > (goal)) {                        \
+            (val) -= (incr);                        \
+            jar_xm_CLAMP_DOWN1F((val), (goal));            \
+        } else if((val) < (goal)) {                    \
+            (val) += (incr);                        \
+            jar_xm_CLAMP_UP1F((val), (goal));            \
+        }                                            \
+    } while(0)
+
+#define jar_xm_LERP(u, v, t) ((u) + (t) * ((v) - (u)))
+#define jar_xm_INVERSE_LERP(u, v, lerp) (((lerp) - (u)) / ((v) - (u)))
+
+#define HAS_TONE_PORTAMENTO(s) ((s)->effect_type == 3 \
+                                 || (s)->effect_type == 5 \
+                                 || ((s)->volume_column >> 4) == 0xF)
+#define HAS_ARPEGGIO(s) ((s)->effect_type == 0 \
+                          && (s)->effect_param != 0)
+#define HAS_VIBRATO(s) ((s)->effect_type == 4 \
+                         || (s)->effect_param == 6 \
+                         || ((s)->volume_column >> 4) == 0xB)
+#define NOTE_IS_VALID(n) ((n) > 0 && (n) < 97)
+
+/* ----- Function definitions ----- */
+
+static float jar_xm_waveform(jar_xm_waveform_type_t waveform, uint8_t step) {
+    static unsigned int next_rand = 24492;
+    step %= 0x40;
+
+    switch(waveform) {
+
+    case jar_xm_SINE_WAVEFORM:
+        /* Why not use a table? For saving space, and because there's
+         * very very little actual performance gain. */
+        return -sinf(2.f * 3.141592f * (float)step / (float)0x40);
+
+    case jar_xm_RAMP_DOWN_WAVEFORM:
+        /* Ramp down: 1.0f when step = 0; -1.0f when step = 0x40 */
+        return (float)(0x20 - step) / 0x20;
+
+    case jar_xm_SQUARE_WAVEFORM:
+        /* Square with a 50% duty */
+        return (step >= 0x20) ? 1.f : -1.f;
+
+    case jar_xm_RANDOM_WAVEFORM:
+        /* Use the POSIX.1-2001 example, just to be deterministic
+         * across different machines */
+        next_rand = next_rand * 1103515245 + 12345;
+        return (float)((next_rand >> 16) & 0x7FFF) / (float)0x4000 - 1.f;
+
+    case jar_xm_RAMP_UP_WAVEFORM:
+        /* Ramp up: -1.f when step = 0; 1.f when step = 0x40 */
+        return (float)(step - 0x20) / 0x20;
+
+    default:
+        break;
+
+    }
+
+    return .0f;
+}
+
+static void jar_xm_autovibrato(jar_xm_context_t* ctx, jar_xm_channel_context_t* ch) {
+    if(ch->instrument == NULL || ch->instrument->vibrato_depth == 0) return;
+    jar_xm_instrument_t* instr = ch->instrument;
+    float sweep = 1.f;
+
+    if(ch->autovibrato_ticks < instr->vibrato_sweep) {
+        /* No idea if this is correct, but it sounds close enough… */
+        sweep = jar_xm_LERP(0.f, 1.f, (float)ch->autovibrato_ticks / (float)instr->vibrato_sweep);
+    }
+
+    unsigned int step = ((ch->autovibrato_ticks++) * instr->vibrato_rate) >> 2;
+    ch->autovibrato_note_offset = .25f * jar_xm_waveform(instr->vibrato_type, step)
+        * (float)instr->vibrato_depth / (float)0xF * sweep;
+    jar_xm_update_frequency(ctx, ch);
+}
+
+static void jar_xm_vibrato(jar_xm_context_t* ctx, jar_xm_channel_context_t* ch, uint8_t param, uint16_t pos) {
+    unsigned int step = pos * (param >> 4);
+    ch->vibrato_note_offset =
+        2.f
+        * jar_xm_waveform(ch->vibrato_waveform, step)
+        * (float)(param & 0x0F) / (float)0xF;
+    jar_xm_update_frequency(ctx, ch);
+}
+
+static void jar_xm_tremolo(jar_xm_context_t* ctx, jar_xm_channel_context_t* ch, uint8_t param, uint16_t pos) {
+    unsigned int step = pos * (param >> 4);
+    /* Not so sure about this, it sounds correct by ear compared with
+     * MilkyTracker, but it could come from other bugs */
+    ch->tremolo_volume = -1.f * jar_xm_waveform(ch->tremolo_waveform, step)
+        * (float)(param & 0x0F) / (float)0xF;
+}
+
+static void jar_xm_arpeggio(jar_xm_context_t* ctx, jar_xm_channel_context_t* ch, uint8_t param, uint16_t tick) {
+    switch(tick % 3) {
+    case 0:
+        ch->arp_in_progress = false;
+        ch->arp_note_offset = 0;
+        break;
+    case 2:
+        ch->arp_in_progress = true;
+        ch->arp_note_offset = param >> 4;
+        break;
+    case 1:
+        ch->arp_in_progress = true;
+        ch->arp_note_offset = param & 0x0F;
+        break;
+    }
+
+    jar_xm_update_frequency(ctx, ch);
+}
+
+static void jar_xm_tone_portamento(jar_xm_context_t* ctx, jar_xm_channel_context_t* ch) {
+    /* 3xx called without a note, wait until we get an actual
+     * target note. */
+    if(ch->tone_portamento_target_period == 0.f) return;
+
+    if(ch->period != ch->tone_portamento_target_period) {
+        jar_xm_SLIDE_TOWARDS(ch->period,
+                         ch->tone_portamento_target_period,
+                         (ctx->module.frequency_type == jar_xm_LINEAR_FREQUENCIES ?
+                          4.f : 1.f) * ch->tone_portamento_param
+        );
+        jar_xm_update_frequency(ctx, ch);
+    }
+}
+
+static void jar_xm_pitch_slide(jar_xm_context_t* ctx, jar_xm_channel_context_t* ch, float period_offset) {
+    /* Don't ask about the 4.f coefficient. I found mention of it
+     * nowhere. Found by ear™. */
+    if(ctx->module.frequency_type == jar_xm_LINEAR_FREQUENCIES) {
+        period_offset *= 4.f;
+    }
+
+    ch->period += period_offset;
+    jar_xm_CLAMP_DOWN(ch->period);
+    /* XXX: upper bound of period ? */
+
+    jar_xm_update_frequency(ctx, ch);
+}
+
+static void jar_xm_panning_slide(jar_xm_channel_context_t* ch, uint8_t rawval) {
+    float f;
+
+    if((rawval & 0xF0) && (rawval & 0x0F)) {
+        /* Illegal state */
+        return;
+    }
+
+    if(rawval & 0xF0) {
+        /* Slide right */
+        f = (float)(rawval >> 4) / (float)0xFF;
+        ch->panning += f;
+        jar_xm_CLAMP_UP(ch->panning);
+    } else {
+        /* Slide left */
+        f = (float)(rawval & 0x0F) / (float)0xFF;
+        ch->panning -= f;
+        jar_xm_CLAMP_DOWN(ch->panning);
+    }
+}
+
+static void jar_xm_volume_slide(jar_xm_channel_context_t* ch, uint8_t rawval) {
+    float f;
+
+    if((rawval & 0xF0) && (rawval & 0x0F)) {
+        /* Illegal state */
+        return;
+    }
+
+    if(rawval & 0xF0) {
+        /* Slide up */
+        f = (float)(rawval >> 4) / (float)0x40;
+        ch->volume += f;
+        jar_xm_CLAMP_UP(ch->volume);
+    } else {
+        /* Slide down */
+        f = (float)(rawval & 0x0F) / (float)0x40;
+        ch->volume -= f;
+        jar_xm_CLAMP_DOWN(ch->volume);
+    }
+}
+
+static float jar_xm_envelope_lerp(jar_xm_envelope_point_t* restrict a, jar_xm_envelope_point_t* restrict b, uint16_t pos) {
+    /* Linear interpolation between two envelope points */
+    if(pos <= a->frame) return a->value;
+    else if(pos >= b->frame) return b->value;
+    else {
+        float p = (float)(pos - a->frame) / (float)(b->frame - a->frame);
+        return a->value * (1 - p) + b->value * p;
+    }
+}
+
+static void jar_xm_post_pattern_change(jar_xm_context_t* ctx) {
+    /* Loop if necessary */
+    if(ctx->current_table_index >= ctx->module.length) {
+        ctx->current_table_index = ctx->module.restart_position;
+    }
+}
+
+static float jar_xm_linear_period(float note) {
+    return 7680.f - note * 64.f;
+}
+
+static float jar_xm_linear_frequency(float period) {
+    return 8363.f * powf(2.f, (4608.f - period) / 768.f);
+}
+
+static float jar_xm_amiga_period(float note) {
+    unsigned int intnote = note;
+    uint8_t a = intnote % 12;
+    int8_t octave = note / 12.f - 2;
+    uint16_t p1 = amiga_frequencies[a], p2 = amiga_frequencies[a + 1];
+
+    if(octave > 0) {
+        p1 >>= octave;
+        p2 >>= octave;
+    } else if(octave < 0) {
+        p1 <<= (-octave);
+        p2 <<= (-octave);
+    }
+
+    return jar_xm_LERP(p1, p2, note - intnote);
+}
+
+static float jar_xm_amiga_frequency(float period) {
+    if(period == .0f) return .0f;
+
+    /* This is the PAL value. No reason to choose this one over the
+     * NTSC value. */
+    return 7093789.2f / (period * 2.f);
+}
+
+static float jar_xm_period(jar_xm_context_t* ctx, float note) {
+    switch(ctx->module.frequency_type) {
+    case jar_xm_LINEAR_FREQUENCIES:
+        return jar_xm_linear_period(note);
+    case jar_xm_AMIGA_FREQUENCIES:
+        return jar_xm_amiga_period(note);
+    }
+    return .0f;
+}
+
+static float jar_xm_frequency(jar_xm_context_t* ctx, float period, float note_offset) {
+    uint8_t a;
+    int8_t octave;
+    float note;
+    uint16_t p1, p2;
+
+    switch(ctx->module.frequency_type) {
+
+    case jar_xm_LINEAR_FREQUENCIES:
+        return jar_xm_linear_frequency(period - 64.f * note_offset);
+
+    case jar_xm_AMIGA_FREQUENCIES:
+        if(note_offset == 0) {
+            /* A chance to escape from insanity */
+            return jar_xm_amiga_frequency(period);
+        }
+
+        /* FIXME: this is very crappy at best */
+        a = octave = 0;
+
+        /* Find the octave of the current period */
+        if(period > amiga_frequencies[0]) {
+            --octave;
+            while(period > (amiga_frequencies[0] << (-octave))) --octave;
+        } else if(period < amiga_frequencies[12]) {
+            ++octave;
+            while(period < (amiga_frequencies[12] >> octave)) ++octave;
+        }
+
+        /* Find the smallest note closest to the current period */
+        for(uint8_t i = 0; i < 12; ++i) {
+            p1 = amiga_frequencies[i], p2 = amiga_frequencies[i + 1];
+
+            if(octave > 0) {
+                p1 >>= octave;
+                p2 >>= octave;
+            } else if(octave < 0) {
+                p1 <<= (-octave);
+                p2 <<= (-octave);
+            }
+
+            if(p2 <= period && period <= p1) {
+                a = i;
+                break;
+            }
+        }
+
+        if(JAR_XM_DEBUG && (p1 < period || p2 > period)) {
+            DEBUG("%i <= %f <= %i should hold but doesn't, this is a bug", p2, period, p1);
+        }
+
+        note = 12.f * (octave + 2) + a + jar_xm_INVERSE_LERP(p1, p2, period);
+
+        return jar_xm_amiga_frequency(jar_xm_amiga_period(note + note_offset));
+
+    }
+
+    return .0f;
+}
+
+static void jar_xm_update_frequency(jar_xm_context_t* ctx, jar_xm_channel_context_t* ch) {
+    ch->frequency = jar_xm_frequency(
+        ctx, ch->period,
+        (ch->arp_note_offset > 0 ? ch->arp_note_offset : (
+            ch->vibrato_note_offset + ch->autovibrato_note_offset
+        ))
+    );
+    ch->step = ch->frequency / ctx->rate;
+}
+
+static void jar_xm_handle_note_and_instrument(jar_xm_context_t* ctx, jar_xm_channel_context_t* ch,
+                                          jar_xm_pattern_slot_t* s) {
+    if(s->instrument > 0) {
+        if(HAS_TONE_PORTAMENTO(ch->current) && ch->instrument != NULL && ch->sample != NULL) {
+            /* Tone portamento in effect, unclear stuff happens */
+            jar_xm_trigger_note(ctx, ch, jar_xm_TRIGGER_KEEP_PERIOD | jar_xm_TRIGGER_KEEP_SAMPLE_POSITION);
+        } else if(s->instrument > ctx->module.num_instruments) {
+            /* Invalid instrument, Cut current note */
+            jar_xm_cut_note(ch);
+            ch->instrument = NULL;
+            ch->sample = NULL;
+        } else {
+            ch->instrument = ctx->module.instruments + (s->instrument - 1);
+            if(s->note == 0 && ch->sample != NULL) {
+                /* Ghost instrument, trigger note */
+                /* Sample position is kept, but envelopes are reset */
+                jar_xm_trigger_note(ctx, ch, jar_xm_TRIGGER_KEEP_SAMPLE_POSITION);
+            }
+        }
+    }
+
+    if(NOTE_IS_VALID(s->note)) {
+        /* Yes, the real note number is s->note -1. Try finding
+         * THAT in any of the specs! :-) */
+
+        jar_xm_instrument_t* instr = ch->instrument;
+
+        if(HAS_TONE_PORTAMENTO(ch->current) && instr != NULL && ch->sample != NULL) {
+            /* Tone portamento in effect */
+            ch->note = s->note + ch->sample->relative_note + ch->sample->finetune / 128.f - 1.f;
+            ch->tone_portamento_target_period = jar_xm_period(ctx, ch->note);
+        } else if(instr == NULL || ch->instrument->num_samples == 0) {
+            /* Bad instrument */
+            jar_xm_cut_note(ch);
+        } else {
+            if(instr->sample_of_notes[s->note - 1] < instr->num_samples) {
+#if JAR_XM_RAMPING
+                for(unsigned int z = 0; z < jar_xm_SAMPLE_RAMPING_POINTS; ++z) {
+                    ch->end_of_previous_sample[z] = jar_xm_next_of_sample(ch);
+                }
+                ch->frame_count = 0;
+#endif
+                ch->sample = instr->samples + instr->sample_of_notes[s->note - 1];
+                ch->orig_note = ch->note = s->note + ch->sample->relative_note
+                    + ch->sample->finetune / 128.f - 1.f;
+                if(s->instrument > 0) {
+                    jar_xm_trigger_note(ctx, ch, 0);
+                } else {
+                    /* Ghost note: keep old volume */
+                    jar_xm_trigger_note(ctx, ch, jar_xm_TRIGGER_KEEP_VOLUME);
+                }
+            } else {
+                /* Bad sample */
+                jar_xm_cut_note(ch);
+            }
+        }
+    } else if(s->note == 97) {
+        /* Key Off */
+        jar_xm_key_off(ch);
+    }
+
+    switch(s->volume_column >> 4) {
+
+    case 0x5:
+        if(s->volume_column > 0x50) break;
+    case 0x1:
+    case 0x2:
+    case 0x3:
+    case 0x4:
+        /* Set volume */
+        ch->volume = (float)(s->volume_column - 0x10) / (float)0x40;
+        break;
+
+    case 0x8: /* Fine volume slide down */
+        jar_xm_volume_slide(ch, s->volume_column & 0x0F);
+        break;
+
+    case 0x9: /* Fine volume slide up */
+        jar_xm_volume_slide(ch, s->volume_column << 4);
+        break;
+
+    case 0xA: /* Set vibrato speed */
+        ch->vibrato_param = (ch->vibrato_param & 0x0F) | ((s->volume_column & 0x0F) << 4);
+        break;
+
+    case 0xC: /* Set panning */
+        ch->panning = (float)(
+            ((s->volume_column & 0x0F) << 4) | (s->volume_column & 0x0F)
+            ) / (float)0xFF;
+        break;
+
+    case 0xF: /* Tone portamento */
+        if(s->volume_column & 0x0F) {
+            ch->tone_portamento_param = ((s->volume_column & 0x0F) << 4)
+                | (s->volume_column & 0x0F);
+        }
+        break;
+
+    default:
+        break;
+
+    }
+
+    switch(s->effect_type) {
+
+    case 1: /* 1xx: Portamento up */
+        if(s->effect_param > 0) {
+            ch->portamento_up_param = s->effect_param;
+        }
+        break;
+
+    case 2: /* 2xx: Portamento down */
+        if(s->effect_param > 0) {
+            ch->portamento_down_param = s->effect_param;
+        }
+        break;
+
+    case 3: /* 3xx: Tone portamento */
+        if(s->effect_param > 0) {
+            ch->tone_portamento_param = s->effect_param;
+        }
+        break;
+
+    case 4: /* 4xy: Vibrato */
+        if(s->effect_param & 0x0F) {
+            /* Set vibrato depth */
+            ch->vibrato_param = (ch->vibrato_param & 0xF0) | (s->effect_param & 0x0F);
+        }
+        if(s->effect_param >> 4) {
+            /* Set vibrato speed */
+            ch->vibrato_param = (s->effect_param & 0xF0) | (ch->vibrato_param & 0x0F);
+        }
+        break;
+
+    case 5: /* 5xy: Tone portamento + Volume slide */
+        if(s->effect_param > 0) {
+            ch->volume_slide_param = s->effect_param;
+        }
+        break;
+
+    case 6: /* 6xy: Vibrato + Volume slide */
+        if(s->effect_param > 0) {
+            ch->volume_slide_param = s->effect_param;
+        }
+        break;
+
+    case 7: /* 7xy: Tremolo */
+        if(s->effect_param & 0x0F) {
+            /* Set tremolo depth */
+            ch->tremolo_param = (ch->tremolo_param & 0xF0) | (s->effect_param & 0x0F);
+        }
+        if(s->effect_param >> 4) {
+            /* Set tremolo speed */
+            ch->tremolo_param = (s->effect_param & 0xF0) | (ch->tremolo_param & 0x0F);
+        }
+        break;
+
+    case 8: /* 8xx: Set panning */
+        ch->panning = (float)s->effect_param / (float)0xFF;
+        break;
+
+    case 9: /* 9xx: Sample offset */
+        if(ch->sample != NULL && NOTE_IS_VALID(s->note)) {
+            uint32_t final_offset = s->effect_param << (ch->sample->bits == 16 ? 7 : 8);
+            if(final_offset >= ch->sample->length) {
+                /* Pretend the sample dosen't loop and is done playing */
+                ch->sample_position = -1;
+                break;
+            }
+            ch->sample_position = final_offset;
+        }
+        break;
+
+    case 0xA: /* Axy: Volume slide */
+        if(s->effect_param > 0) {
+            ch->volume_slide_param = s->effect_param;
+        }
+        break;
+
+    case 0xB: /* Bxx: Position jump */
+        if(s->effect_param < ctx->module.length) {
+            ctx->position_jump = true;
+            ctx->jump_dest = s->effect_param;
+        }
+        break;
+
+    case 0xC: /* Cxx: Set volume */
+        ch->volume = (float)((s->effect_param > 0x40)
+                             ? 0x40 : s->effect_param) / (float)0x40;
+        break;
+
+    case 0xD: /* Dxx: Pattern break */
+        /* Jump after playing this line */
+        ctx->pattern_break = true;
+        ctx->jump_row = (s->effect_param >> 4) * 10 + (s->effect_param & 0x0F);
+        break;
+
+    case 0xE: /* EXy: Extended command */
+        switch(s->effect_param >> 4) {
+
+        case 1: /* E1y: Fine portamento up */
+            if(s->effect_param & 0x0F) {
+                ch->fine_portamento_up_param = s->effect_param & 0x0F;
+            }
+            jar_xm_pitch_slide(ctx, ch, -ch->fine_portamento_up_param);
+            break;
+
+        case 2: /* E2y: Fine portamento down */
+            if(s->effect_param & 0x0F) {
+                ch->fine_portamento_down_param = s->effect_param & 0x0F;
+            }
+            jar_xm_pitch_slide(ctx, ch, ch->fine_portamento_down_param);
+            break;
+
+        case 4: /* E4y: Set vibrato control */
+            ch->vibrato_waveform = s->effect_param & 3;
+            ch->vibrato_waveform_retrigger = !((s->effect_param >> 2) & 1);
+            break;
+
+        case 5: /* E5y: Set finetune */
+            if(NOTE_IS_VALID(ch->current->note) && ch->sample != NULL) {
+                ch->note = ch->current->note + ch->sample->relative_note +
+                    (float)(((s->effect_param & 0x0F) - 8) << 4) / 128.f - 1.f;
+                ch->period = jar_xm_period(ctx, ch->note);
+                jar_xm_update_frequency(ctx, ch);
+            }
+            break;
+
+        case 6: /* E6y: Pattern loop */
+            if(s->effect_param & 0x0F) {
+                if((s->effect_param & 0x0F) == ch->pattern_loop_count) {
+                    /* Loop is over */
+                    ch->pattern_loop_count = 0;
+                    break;
+                }
+
+                /* Jump to the beginning of the loop */
+                ch->pattern_loop_count++;
+                ctx->position_jump = true;
+                ctx->jump_row = ch->pattern_loop_origin;
+                ctx->jump_dest = ctx->current_table_index;
+            } else {
+                /* Set loop start point */
+                ch->pattern_loop_origin = ctx->current_row;
+                /* Replicate FT2 E60 bug */
+                ctx->jump_row = ch->pattern_loop_origin;
+            }
+            break;
+
+        case 7: /* E7y: Set tremolo control */
+            ch->tremolo_waveform = s->effect_param & 3;
+            ch->tremolo_waveform_retrigger = !((s->effect_param >> 2) & 1);
+            break;
+
+        case 0xA: /* EAy: Fine volume slide up */
+            if(s->effect_param & 0x0F) {
+                ch->fine_volume_slide_param = s->effect_param & 0x0F;
+            }
+            jar_xm_volume_slide(ch, ch->fine_volume_slide_param << 4);
+            break;
+
+        case 0xB: /* EBy: Fine volume slide down */
+            if(s->effect_param & 0x0F) {
+                ch->fine_volume_slide_param = s->effect_param & 0x0F;
+            }
+            jar_xm_volume_slide(ch, ch->fine_volume_slide_param);
+            break;
+
+        case 0xD: /* EDy: Note delay */
+            /* XXX: figure this out better. EDx triggers
+             * the note even when there no note and no
+             * instrument. But ED0 acts like like a ghost
+             * note, EDx (x ≠ 0) does not. */
+            if(s->note == 0 && s->instrument == 0) {
+                unsigned int flags = jar_xm_TRIGGER_KEEP_VOLUME;
+
+                if(ch->current->effect_param & 0x0F) {
+                    ch->note = ch->orig_note;
+                    jar_xm_trigger_note(ctx, ch, flags);
+                } else {
+                    jar_xm_trigger_note(
+                        ctx, ch,
+                        flags
+                        | jar_xm_TRIGGER_KEEP_PERIOD
+                        | jar_xm_TRIGGER_KEEP_SAMPLE_POSITION
+                        );
+                }
+            }
+            break;
+
+        case 0xE: /* EEy: Pattern delay */
+            ctx->extra_ticks = (ch->current->effect_param & 0x0F) * ctx->tempo;
+            break;
+
+        default:
+            break;
+
+        }
+        break;
+
+    case 0xF: /* Fxx: Set tempo/BPM */
+        if(s->effect_param > 0) {
+            if(s->effect_param <= 0x1F) {
+                ctx->tempo = s->effect_param;
+            } else {
+                ctx->bpm = s->effect_param;
+            }
+        }
+        break;
+
+    case 16: /* Gxx: Set global volume */
+        ctx->global_volume = (float)((s->effect_param > 0x40)
+                                     ? 0x40 : s->effect_param) / (float)0x40;
+        break;
+
+    case 17: /* Hxy: Global volume slide */
+        if(s->effect_param > 0) {
+            ch->global_volume_slide_param = s->effect_param;
+        }
+        break;
+
+    case 21: /* Lxx: Set envelope position */
+        ch->volume_envelope_frame_count = s->effect_param;
+        ch->panning_envelope_frame_count = s->effect_param;
+        break;
+
+    case 25: /* Pxy: Panning slide */
+        if(s->effect_param > 0) {
+            ch->panning_slide_param = s->effect_param;
+        }
+        break;
+
+    case 27: /* Rxy: Multi retrig note */
+        if(s->effect_param > 0) {
+            if((s->effect_param >> 4) == 0) {
+                /* Keep previous x value */
+                ch->multi_retrig_param = (ch->multi_retrig_param & 0xF0) | (s->effect_param & 0x0F);
+            } else {
+                ch->multi_retrig_param = s->effect_param;
+            }
+        }
+        break;
+
+    case 29: /* Txy: Tremor */
+        if(s->effect_param > 0) {
+            /* Tremor x and y params do not appear to be separately
+             * kept in memory, unlike Rxy */
+            ch->tremor_param = s->effect_param;
+        }
+        break;
+
+    case 33: /* Xxy: Extra stuff */
+        switch(s->effect_param >> 4) {
+
+        case 1: /* X1y: Extra fine portamento up */
+            if(s->effect_param & 0x0F) {
+                ch->extra_fine_portamento_up_param = s->effect_param & 0x0F;
+            }
+            jar_xm_pitch_slide(ctx, ch, -1.0f * ch->extra_fine_portamento_up_param);
+            break;
+
+        case 2: /* X2y: Extra fine portamento down */
+            if(s->effect_param & 0x0F) {
+                ch->extra_fine_portamento_down_param = s->effect_param & 0x0F;
+            }
+            jar_xm_pitch_slide(ctx, ch, ch->extra_fine_portamento_down_param);
+            break;
+
+        default:
+            break;
+
+        }
+        break;
+
+    default:
+        break;
+
+    }
+}
+
+static void jar_xm_trigger_note(jar_xm_context_t* ctx, jar_xm_channel_context_t* ch, unsigned int flags) {
+    if(!(flags & jar_xm_TRIGGER_KEEP_SAMPLE_POSITION)) {
+        ch->sample_position = 0.f;
+        ch->ping = true;
+    }
+
+    if(ch->sample != NULL) {
+        if(!(flags & jar_xm_TRIGGER_KEEP_VOLUME)) {
+            ch->volume = ch->sample->volume;
+        }
+
+        ch->panning = ch->sample->panning;
+    }
+
+    ch->sustained = true;
+    ch->fadeout_volume = ch->volume_envelope_volume = 1.0f;
+    ch->panning_envelope_panning = .5f;
+    ch->volume_envelope_frame_count = ch->panning_envelope_frame_count = 0;
+    ch->vibrato_note_offset = 0.f;
+    ch->tremolo_volume = 0.f;
+    ch->tremor_on = false;
+
+    ch->autovibrato_ticks = 0;
+
+    if(ch->vibrato_waveform_retrigger) {
+        ch->vibrato_ticks = 0; /* XXX: should the waveform itself also
+                                * be reset to sine? */
+    }
+    if(ch->tremolo_waveform_retrigger) {
+        ch->tremolo_ticks = 0;
+    }
+
+    if(!(flags & jar_xm_TRIGGER_KEEP_PERIOD)) {
+        ch->period = jar_xm_period(ctx, ch->note);
+        jar_xm_update_frequency(ctx, ch);
+    }
+
+    ch->latest_trigger = ctx->generated_samples;
+    if(ch->instrument != NULL) {
+        ch->instrument->latest_trigger = ctx->generated_samples;
+    }
+    if(ch->sample != NULL) {
+        ch->sample->latest_trigger = ctx->generated_samples;
+    }
+}
+
+static void jar_xm_cut_note(jar_xm_channel_context_t* ch) {
+    /* NB: this is not the same as Key Off */
+    ch->volume = .0f;
+}
+
+static void jar_xm_key_off(jar_xm_channel_context_t* ch) {
+    /* Key Off */
+    ch->sustained = false;
+
+    /* If no volume envelope is used, also cut the note */
+    if(ch->instrument == NULL || !ch->instrument->volume_envelope.enabled) {
+        jar_xm_cut_note(ch);
+    }
+}
+
+static void jar_xm_row(jar_xm_context_t* ctx) {
+    if(ctx->position_jump) {
+        ctx->current_table_index = ctx->jump_dest;
+        ctx->current_row = ctx->jump_row;
+        ctx->position_jump = false;
+        ctx->pattern_break = false;
+        ctx->jump_row = 0;
+        jar_xm_post_pattern_change(ctx);
+    } else if(ctx->pattern_break) {
+        ctx->current_table_index++;
+        ctx->current_row = ctx->jump_row;
+        ctx->pattern_break = false;
+        ctx->jump_row = 0;
+        jar_xm_post_pattern_change(ctx);
+    }
+
+    jar_xm_pattern_t* cur = ctx->module.patterns + ctx->module.pattern_table[ctx->current_table_index];
+    bool in_a_loop = false;
+
+    /* Read notes… */
+    for(uint8_t i = 0; i < ctx->module.num_channels; ++i) {
+        jar_xm_pattern_slot_t* s = cur->slots + ctx->current_row * ctx->module.num_channels + i;
+        jar_xm_channel_context_t* ch = ctx->channels + i;
+
+        ch->current = s;
+
+        if(s->effect_type != 0xE || s->effect_param >> 4 != 0xD) {
+            jar_xm_handle_note_and_instrument(ctx, ch, s);
+        } else {
+            ch->note_delay_param = s->effect_param & 0x0F;
+        }
+
+        if(!in_a_loop && ch->pattern_loop_count > 0) {
+            in_a_loop = true;
+        }
+    }
+
+    if(!in_a_loop) {
+        /* No E6y loop is in effect (or we are in the first pass) */
+        ctx->loop_count = (ctx->row_loop_count[MAX_NUM_ROWS * ctx->current_table_index + ctx->current_row]++);
+    }
+
+    ctx->current_row++; /* Since this is an uint8, this line can
+                         * increment from 255 to 0, in which case it
+                         * is still necessary to go the next
+                         * pattern. */
+    if(!ctx->position_jump && !ctx->pattern_break &&
+       (ctx->current_row >= cur->num_rows || ctx->current_row == 0)) {
+        ctx->current_table_index++;
+        ctx->current_row = ctx->jump_row; /* This will be 0 most of
+                                           * the time, except when E60
+                                           * is used */
+        ctx->jump_row = 0;
+        jar_xm_post_pattern_change(ctx);
+    }
+}
+
+static void jar_xm_envelope_tick(jar_xm_channel_context_t* ch,
+                             jar_xm_envelope_t* env,
+                             uint16_t* counter,
+                             float* outval) {
+    if(env->num_points < 2) {
+        /* Don't really know what to do… */
+        if(env->num_points == 1) {
+            /* XXX I am pulling this out of my ass */
+            *outval = (float)env->points[0].value / (float)0x40;
+            if(*outval > 1) {
+                *outval = 1;
+            }
+        }
+
+        return;
+    } else {
+        uint8_t j;
+
+        if(env->loop_enabled) {
+            uint16_t loop_start = env->points[env->loop_start_point].frame;
+            uint16_t loop_end = env->points[env->loop_end_point].frame;
+            uint16_t loop_length = loop_end - loop_start;
+
+            if(*counter >= loop_end) {
+                *counter -= loop_length;
+            }
+        }
+
+        for(j = 0; j < (env->num_points - 2); ++j) {
+            if(env->points[j].frame <= *counter &&
+               env->points[j+1].frame >= *counter) {
+                break;
+            }
+        }
+
+        *outval = jar_xm_envelope_lerp(env->points + j, env->points + j + 1, *counter) / (float)0x40;
+
+        /* Make sure it is safe to increment frame count */
+        if(!ch->sustained || !env->sustain_enabled ||
+           *counter != env->points[env->sustain_point].frame) {
+            (*counter)++;
+        }
+    }
+}
+
+static void jar_xm_envelopes(jar_xm_channel_context_t* ch) {
+    if(ch->instrument != NULL) {
+        if(ch->instrument->volume_envelope.enabled) {
+            if(!ch->sustained) {
+                ch->fadeout_volume -= (float)ch->instrument->volume_fadeout / 65536.f;
+                jar_xm_CLAMP_DOWN(ch->fadeout_volume);
+            }
+
+            jar_xm_envelope_tick(ch,
+                             &(ch->instrument->volume_envelope),
+                             &(ch->volume_envelope_frame_count),
+                             &(ch->volume_envelope_volume));
+        }
+
+        if(ch->instrument->panning_envelope.enabled) {
+            jar_xm_envelope_tick(ch,
+                             &(ch->instrument->panning_envelope),
+                             &(ch->panning_envelope_frame_count),
+                             &(ch->panning_envelope_panning));
+        }
+    }
+}
+
+static void jar_xm_tick(jar_xm_context_t* ctx) {
+    if(ctx->current_tick == 0) {
+        jar_xm_row(ctx);
+    }
+
+    for(uint8_t i = 0; i < ctx->module.num_channels; ++i) {
+        jar_xm_channel_context_t* ch = ctx->channels + i;
+
+        jar_xm_envelopes(ch);
+        jar_xm_autovibrato(ctx, ch);
+
+        if(ch->arp_in_progress && !HAS_ARPEGGIO(ch->current)) {
+            ch->arp_in_progress = false;
+            ch->arp_note_offset = 0;
+            jar_xm_update_frequency(ctx, ch);
+        }
+        if(ch->vibrato_in_progress && !HAS_VIBRATO(ch->current)) {
+            ch->vibrato_in_progress = false;
+            ch->vibrato_note_offset = 0.f;
+            jar_xm_update_frequency(ctx, ch);
+        }
+
+        switch(ch->current->volume_column >> 4) {
+
+        case 0x6: /* Volume slide down */
+            if(ctx->current_tick == 0) break;
+            jar_xm_volume_slide(ch, ch->current->volume_column & 0x0F);
+            break;
+
+        case 0x7: /* Volume slide up */
+            if(ctx->current_tick == 0) break;
+            jar_xm_volume_slide(ch, ch->current->volume_column << 4);
+            break;
+
+        case 0xB: /* Vibrato */
+            if(ctx->current_tick == 0) break;
+            ch->vibrato_in_progress = false;
+            jar_xm_vibrato(ctx, ch, ch->vibrato_param, ch->vibrato_ticks++);
+            break;
+
+        case 0xD: /* Panning slide left */
+            if(ctx->current_tick == 0) break;
+            jar_xm_panning_slide(ch, ch->current->volume_column & 0x0F);
+            break;
+
+        case 0xE: /* Panning slide right */
+            if(ctx->current_tick == 0) break;
+            jar_xm_panning_slide(ch, ch->current->volume_column << 4);
+            break;
+
+        case 0xF: /* Tone portamento */
+            if(ctx->current_tick == 0) break;
+            jar_xm_tone_portamento(ctx, ch);
+            break;
+
+        default:
+            break;
+
+        }
+
+        switch(ch->current->effect_type) {
+
+        case 0: /* 0xy: Arpeggio */
+            if(ch->current->effect_param > 0) {
+                char arp_offset = ctx->tempo % 3;
+                switch(arp_offset) {
+                case 2: /* 0 -> x -> 0 -> y -> x -> … */
+                    if(ctx->current_tick == 1) {
+                        ch->arp_in_progress = true;
+                        ch->arp_note_offset = ch->current->effect_param >> 4;
+                        jar_xm_update_frequency(ctx, ch);
+                        break;
+                    }
+                    /* No break here, this is intended */
+                case 1: /* 0 -> 0 -> y -> x -> … */
+                    if(ctx->current_tick == 0) {
+                        ch->arp_in_progress = false;
+                        ch->arp_note_offset = 0;
+                        jar_xm_update_frequency(ctx, ch);
+                        break;
+                    }
+                    /* No break here, this is intended */
+                case 0: /* 0 -> y -> x -> … */
+                    jar_xm_arpeggio(ctx, ch, ch->current->effect_param, ctx->current_tick - arp_offset);
+                default:
+                    break;
+                }
+            }
+            break;
+
+        case 1: /* 1xx: Portamento up */
+            if(ctx->current_tick == 0) break;
+            jar_xm_pitch_slide(ctx, ch, -ch->portamento_up_param);
+            break;
+
+        case 2: /* 2xx: Portamento down */
+            if(ctx->current_tick == 0) break;
+            jar_xm_pitch_slide(ctx, ch, ch->portamento_down_param);
+            break;
+
+        case 3: /* 3xx: Tone portamento */
+            if(ctx->current_tick == 0) break;
+            jar_xm_tone_portamento(ctx, ch);
+            break;
+
+        case 4: /* 4xy: Vibrato */
+            if(ctx->current_tick == 0) break;
+            ch->vibrato_in_progress = true;
+            jar_xm_vibrato(ctx, ch, ch->vibrato_param, ch->vibrato_ticks++);
+            break;
+
+        case 5: /* 5xy: Tone portamento + Volume slide */
+            if(ctx->current_tick == 0) break;
+            jar_xm_tone_portamento(ctx, ch);
+            jar_xm_volume_slide(ch, ch->volume_slide_param);
+            break;
+
+        case 6: /* 6xy: Vibrato + Volume slide */
+            if(ctx->current_tick == 0) break;
+            ch->vibrato_in_progress = true;
+            jar_xm_vibrato(ctx, ch, ch->vibrato_param, ch->vibrato_ticks++);
+            jar_xm_volume_slide(ch, ch->volume_slide_param);
+            break;
+
+        case 7: /* 7xy: Tremolo */
+            if(ctx->current_tick == 0) break;
+            jar_xm_tremolo(ctx, ch, ch->tremolo_param, ch->tremolo_ticks++);
+            break;
+
+        case 0xA: /* Axy: Volume slide */
+            if(ctx->current_tick == 0) break;
+            jar_xm_volume_slide(ch, ch->volume_slide_param);
+            break;
+
+        case 0xE: /* EXy: Extended command */
+            switch(ch->current->effect_param >> 4) {
+
+            case 0x9: /* E9y: Retrigger note */
+                if(ctx->current_tick != 0 && ch->current->effect_param & 0x0F) {
+                    if(!(ctx->current_tick % (ch->current->effect_param & 0x0F))) {
+                        jar_xm_trigger_note(ctx, ch, 0);
+                        jar_xm_envelopes(ch);
+                    }
+                }
+                break;
+
+            case 0xC: /* ECy: Note cut */
+                if((ch->current->effect_param & 0x0F) == ctx->current_tick) {
+                    jar_xm_cut_note(ch);
+                }
+                break;
+
+            case 0xD: /* EDy: Note delay */
+                if(ch->note_delay_param == ctx->current_tick) {
+                    jar_xm_handle_note_and_instrument(ctx, ch, ch->current);
+                    jar_xm_envelopes(ch);
+                }
+                break;
+
+            default:
+                break;
+
+            }
+            break;
+
+        case 17: /* Hxy: Global volume slide */
+            if(ctx->current_tick == 0) break;
+            if((ch->global_volume_slide_param & 0xF0) &&
+               (ch->global_volume_slide_param & 0x0F)) {
+                /* Illegal state */
+                break;
+            }
+            if(ch->global_volume_slide_param & 0xF0) {
+                /* Global slide up */
+                float f = (float)(ch->global_volume_slide_param >> 4) / (float)0x40;
+                ctx->global_volume += f;
+                jar_xm_CLAMP_UP(ctx->global_volume);
+            } else {
+                /* Global slide down */
+                float f = (float)(ch->global_volume_slide_param & 0x0F) / (float)0x40;
+                ctx->global_volume -= f;
+                jar_xm_CLAMP_DOWN(ctx->global_volume);
+            }
+            break;
+
+        case 20: /* Kxx: Key off */
+            /* Most documentations will tell you the parameter has no
+             * use. Don't be fooled. */
+            if(ctx->current_tick == ch->current->effect_param) {
+                jar_xm_key_off(ch);
+            }
+            break;
+
+        case 25: /* Pxy: Panning slide */
+            if(ctx->current_tick == 0) break;
+            jar_xm_panning_slide(ch, ch->panning_slide_param);
+            break;
+
+        case 27: /* Rxy: Multi retrig note */
+            if(ctx->current_tick == 0) break;
+            if(((ch->multi_retrig_param) & 0x0F) == 0) break;
+            if((ctx->current_tick % (ch->multi_retrig_param & 0x0F)) == 0) {
+                float v = ch->volume * multi_retrig_multiply[ch->multi_retrig_param >> 4]
+                    + multi_retrig_add[ch->multi_retrig_param >> 4];
+                jar_xm_CLAMP(v);
+                jar_xm_trigger_note(ctx, ch, 0);
+                ch->volume = v;
+            }
+            break;
+
+        case 29: /* Txy: Tremor */
+            if(ctx->current_tick == 0) break;
+            ch->tremor_on = (
+                (ctx->current_tick - 1) % ((ch->tremor_param >> 4) + (ch->tremor_param & 0x0F) + 2)
+                >
+                (ch->tremor_param >> 4)
+            );
+            break;
+
+        default:
+            break;
+
+        }
+
+        float panning, volume;
+
+        panning = ch->panning +
+            (ch->panning_envelope_panning - .5f) * (.5f - fabsf(ch->panning - .5f)) * 2.0f;
+
+        if(ch->tremor_on) {
+                volume = .0f;
+        } else {
+            volume = ch->volume + ch->tremolo_volume;
+            jar_xm_CLAMP(volume);
+            volume *= ch->fadeout_volume * ch->volume_envelope_volume;
+        }
+
+#if JAR_XM_RAMPING
+        ch->target_panning = panning;
+        ch->target_volume = volume;
+#else
+        ch->actual_panning = panning;
+        ch->actual_volume = volume;
+#endif
+    }
+
+    ctx->current_tick++;
+    if(ctx->current_tick >= ctx->tempo + ctx->extra_ticks) {
+        ctx->current_tick = 0;
+        ctx->extra_ticks = 0;
+    }
+
+    /* FT2 manual says number of ticks / second = BPM * 0.4 */
+    ctx->remaining_samples_in_tick += (float)ctx->rate / ((float)ctx->bpm * 0.4f);
+}
+
+static float jar_xm_next_of_sample(jar_xm_channel_context_t* ch) {
+    if(ch->instrument == NULL || ch->sample == NULL || ch->sample_position < 0) {
+#if JAR_XM_RAMPING
+        if(ch->frame_count < jar_xm_SAMPLE_RAMPING_POINTS) {
+            return jar_xm_LERP(ch->end_of_previous_sample[ch->frame_count], .0f,
+                           (float)ch->frame_count / (float)jar_xm_SAMPLE_RAMPING_POINTS);
+        }
+#endif
+        return .0f;
+    }
+    if(ch->sample->length == 0) {
+        return .0f;
+    }
+
+    float u, v, t;
+    uint32_t a, b;
+    a = (uint32_t)ch->sample_position; /* This cast is fine,
+                                        * sample_position will not
+                                        * go above integer
+                                        * ranges */
+    if(JAR_XM_LINEAR_INTERPOLATION) {
+        b = a + 1;
+        t = ch->sample_position - a; /* Cheaper than fmodf(., 1.f) */
+    }
+    u = ch->sample->data[a];
+
+    switch(ch->sample->loop_type) {
+
+    case jar_xm_NO_LOOP:
+        if(JAR_XM_LINEAR_INTERPOLATION) {
+            v = (b < ch->sample->length) ? ch->sample->data[b] : .0f;
+        }
+        ch->sample_position += ch->step;
+        if(ch->sample_position >= ch->sample->length) {
+            ch->sample_position = -1;
+        }
+        break;
+
+    case jar_xm_FORWARD_LOOP:
+        if(JAR_XM_LINEAR_INTERPOLATION) {
+            v = ch->sample->data[
+                (b == ch->sample->loop_end) ? ch->sample->loop_start : b
+            ];
+        }
+        ch->sample_position += ch->step;
+        while(ch->sample_position >= ch->sample->loop_end) {
+            ch->sample_position -= ch->sample->loop_length;
+        }
+        break;
+
+    case jar_xm_PING_PONG_LOOP:
+        if(ch->ping) {
+            ch->sample_position += ch->step;
+        } else {
+            ch->sample_position -= ch->step;
+        }
+        /* XXX: this may not work for very tight ping-pong loops
+         * (ie switches direction more than once per sample */
+        if(ch->ping) {
+            if(JAR_XM_LINEAR_INTERPOLATION) {
+                v = (b >= ch->sample->loop_end) ? ch->sample->data[a] : ch->sample->data[b];
+            }
+            if(ch->sample_position >= ch->sample->loop_end) {
+                ch->ping = false;
+                ch->sample_position = (ch->sample->loop_end << 1) - ch->sample_position;
+            }
+            /* sanity checking */
+            if(ch->sample_position >= ch->sample->length) {
+                ch->ping = false;
+                ch->sample_position -= ch->sample->length - 1;
+            }
+        } else {
+            if(JAR_XM_LINEAR_INTERPOLATION) {
+                v = u;
+                u = (b == 1 || b - 2 <= ch->sample->loop_start) ? ch->sample->data[a] : ch->sample->data[b - 2];
+            }
+            if(ch->sample_position <= ch->sample->loop_start) {
+                ch->ping = true;
+                ch->sample_position = (ch->sample->loop_start << 1) - ch->sample_position;
+            }
+            /* sanity checking */
+            if(ch->sample_position <= .0f) {
+                ch->ping = true;
+                ch->sample_position = .0f;
+            }
+        }
+        break;
+
+    default:
+        v = .0f;
+        break;
+    }
+
+    float endval = JAR_XM_LINEAR_INTERPOLATION ? jar_xm_LERP(u, v, t) : u;
+
+#if JAR_XM_RAMPING
+    if(ch->frame_count < jar_xm_SAMPLE_RAMPING_POINTS) {
+        /* Smoothly transition between old and new sample. */
+        return jar_xm_LERP(ch->end_of_previous_sample[ch->frame_count], endval,
+                       (float)ch->frame_count / (float)jar_xm_SAMPLE_RAMPING_POINTS);
+    }
+#endif
+
+    return endval;
+}
+
+static void jar_xm_sample(jar_xm_context_t* ctx, float* left, float* right) {
+    if(ctx->remaining_samples_in_tick <= 0) {
+        jar_xm_tick(ctx);
+    }
+    ctx->remaining_samples_in_tick--;
+
+    *left = 0.f;
+    *right = 0.f;
+
+    if(ctx->max_loop_count > 0 && ctx->loop_count >= ctx->max_loop_count) {
+        return;
+    }
+
+    for(uint8_t i = 0; i < ctx->module.num_channels; ++i) {
+        jar_xm_channel_context_t* ch = ctx->channels + i;
+
+        if(ch->instrument == NULL || ch->sample == NULL || ch->sample_position < 0) {
+            continue;
+        }
+
+        const float fval = jar_xm_next_of_sample(ch);
+
+        if(!ch->muted && !ch->instrument->muted) {
+            *left += fval * ch->actual_volume * (1.f - ch->actual_panning);
+            *right += fval * ch->actual_volume * ch->actual_panning;
+        }
+
+#if JAR_XM_RAMPING
+        ch->frame_count++;
+        jar_xm_SLIDE_TOWARDS(ch->actual_volume, ch->target_volume, ctx->volume_ramp);
+        jar_xm_SLIDE_TOWARDS(ch->actual_panning, ch->target_panning, ctx->panning_ramp);
+#endif
+    }
+
+    const float fgvol = ctx->global_volume * ctx->amplification;
+    *left *= fgvol;
+    *right *= fgvol;
+
+#if JAR_XM_DEBUG
+    if(fabs(*left) > 1 || fabs(*right) > 1) {
+        DEBUG("clipping frame: %f %f, this is a bad module or a libxm bug", *left, *right);
+    }
+#endif
+}
+
+void jar_xm_generate_samples(jar_xm_context_t* ctx, float* output, size_t numsamples) {
+    if(ctx && output) {
+        ctx->generated_samples += numsamples;
+        for(size_t i = 0; i < numsamples; i++) {
+            jar_xm_sample(ctx, output + (2 * i), output + (2 * i + 1));
+        }
+    }
+}
+
+uint64_t jar_xm_get_remaining_samples(jar_xm_context_t* ctx)
+{
+    uint64_t total = 0;
+    uint8_t currentLoopCount = jar_xm_get_loop_count(ctx);
+    jar_xm_set_max_loop_count(ctx, 0);
+    
+    while(jar_xm_get_loop_count(ctx) == currentLoopCount)
+    {
+        total += ctx->remaining_samples_in_tick;
+        ctx->remaining_samples_in_tick = 0;
+        jar_xm_tick(ctx);
+    }
+    
+    ctx->loop_count = currentLoopCount;
+    return total;
+}
+
+
+
+
+
+//--------------------------------------------
+//FILE LOADER - TODO - NEEDS TO BE CLEANED UP
+//--------------------------------------------
+
+
+
+#undef DEBUG
+#define DEBUG(...) do {      \
+        fprintf(stderr, __VA_ARGS__); \
+        fflush(stderr); \
+    } while(0)
+
+#define DEBUG_ERR(...) do {      \
+        fprintf(stderr, __VA_ARGS__); \
+        fflush(stderr); \
+    } while(0)
+
+#define FATAL(...) do {      \
+        fprintf(stderr, __VA_ARGS__); \
+        fflush(stderr); \
+        exit(1); \
+    } while(0)
+
+#define FATAL_ERR(...) do {      \
+        fprintf(stderr, __VA_ARGS__); \
+        fflush(stderr); \
+        exit(1); \
+    } while(0)
+
+
+int jar_xm_create_context_from_file(jar_xm_context_t** ctx, uint32_t rate, const char* filename) {
+    FILE* xmf;
+    int size;
+
+    xmf = fopen(filename, "rb");
+    if(xmf == NULL) {
+        DEBUG_ERR("Could not open input file");
+        *ctx = NULL;
+        return 3;
+    }
+
+    fseek(xmf, 0, SEEK_END);
+    size = ftell(xmf);
+    rewind(xmf);
+    if(size == -1) {
+        fclose(xmf);
+        DEBUG_ERR("fseek() failed");
+        *ctx = NULL;
+        return 4;
+    }
+
+    char* data = malloc(size + 1);
+    if(fread(data, 1, size, xmf) < size) {
+        fclose(xmf);
+        DEBUG_ERR("fread() failed");
+        *ctx = NULL;
+        return 5;
+    }
+
+    fclose(xmf);
+
+    switch(jar_xm_create_context_safe(ctx, data, size, rate)) {
+    case 0:
+        break;
+
+    case 1:
+        DEBUG("could not create context: module is not sane\n");
+        *ctx = NULL;
+        return 1;
+        break;
+
+    case 2:
+        FATAL("could not create context: malloc failed\n");
+        return 2;
+        break;
+
+    default:
+        FATAL("could not create context: unknown error\n");
+        return 6;
+        break;
+
+    }
+
+    return 0;
+}
+
+
+
+
+#endif//end of JAR_XM_IMPLEMENTATION
+//-------------------------------------------------------------------------------
+
+
+
+
+#endif//end of INCLUDE_JAR_XM_H