Merge branch 'master' of https://github.com/BSVino/stb into test

stb_image_resize.h

@@ -2229,8 +2229,8 @@ static void stbir__calculate_transform(stbir__info *info, float s0, float t0, fl
         info->horizontal_scale = ((float)info->output_w / info->input_w) / (s1 - s0);
         info->vertical_scale = ((float)info->output_h / info->input_h) / (t1 - t0);
 
-        info->horizontal_shift = s0 * info->input_w / (s1 - s0);
-        info->vertical_shift = t0 * info->input_h / (t1 - t0);
+        info->horizontal_shift = s0 * info->output_w / (s1 - s0);
+        info->vertical_shift = t0 * info->output_h / (t1 - t0);
     }
 }
 

stb_truetype.h

@@ -706,6 +706,18 @@ STBTT_DEF int  stbtt_GetGlyphKernAdvance(const stbtt_fontinfo *info, int glyph1,
 STBTT_DEF int  stbtt_GetGlyphBox(const stbtt_fontinfo *info, int glyph_index, int *x0, int *y0, int *x1, int *y1);
 // as above, but takes one or more glyph indices for greater efficiency
 
+typedef struct stbtt_kerningentry
+{
+   int glyph1; // use stbtt_FindGlyphIndex
+   int glyph2;
+   int advance;
+} stbtt_kerningentry;
+
+STBTT_DEF int  stbtt_GetKerningTableLength(const stbtt_fontinfo *info);
+STBTT_DEF int  stbtt_GetKerningTable(const stbtt_fontinfo *info, stbtt_kerningentry* table, int table_length);
+// Retrieves a complete list of all of the kerning pairs provided by the font
+// stbtt_GetKerningTable never writes more than table_length entries and returns how many entries it did write.
+// The table will be sorted by (a.glyph1 == b.glyph1)?(a.glyph2 < b.glyph2):(a.glyph1 < b.glyph1)
 
 //////////////////////////////////////////////////////////////////////////////
 //
@@ -1478,6 +1490,48 @@ STBTT_DEF void stbtt_GetGlyphHMetrics(const stbtt_fontinfo *info, int glyph_inde
    }
 }
 
+STBTT_DEF int  stbtt_GetKerningTableLength(const stbtt_fontinfo *info)
+{
+   stbtt_uint8 *data = info->data + info->kern;
+
+   // we only look at the first table. it must be 'horizontal' and format 0.
+   if (!info->kern)
+      return 0;
+   if (ttUSHORT(data+2) < 1) // number of tables, need at least 1
+      return 0;
+   if (ttUSHORT(data+8) != 1) // horizontal flag must be set in format
+      return 0;
+
+   return ttUSHORT(data+10);
+}
+
+STBTT_DEF int stbtt_GetKerningTable(const stbtt_fontinfo *info, stbtt_kerningentry* table, int table_length)
+{
+   stbtt_uint8 *data = info->data + info->kern;
+   int k, length;
+
+   // we only look at the first table. it must be 'horizontal' and format 0.
+   if (!info->kern)
+      return 0;
+   if (ttUSHORT(data+2) < 1) // number of tables, need at least 1
+      return 0;
+   if (ttUSHORT(data+8) != 1) // horizontal flag must be set in format
+      return 0;
+
+   length = ttUSHORT(data+10);
+   if (table_length < length)
+      length = table_length;
+
+   for (k = 0; k < length; k++)
+   {
+      table[k].glyph1 = ttUSHORT(data+18+(k*6));
+      table[k].glyph2 = ttUSHORT(data+20+(k*6));
+      table[k].advance = ttSHORT(data+22+(k*6));
+   }
+
+   return length;
+}
+
 STBTT_DEF int  stbtt_GetGlyphKernAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2)
 {
    stbtt_uint8 *data = info->data + info->kern;

tests/resample_test.cpp

@@ -1,4 +1,5 @@
-#include <malloc.h>
+#include <stdlib.h>
+#include <stdio.h>
 
 #if defined(_WIN32) && _MSC_VER > 1200
 #define STBIR_ASSERT(x) \
@@ -356,6 +357,54 @@ void test_subpixel(const char* file, float width_percent, float height_percent,
 	free(output_data);
 }
 
+void test_subpixel_region(const char* file, float width_percent, float height_percent, float s0, float t0, float s1, float t1)
+{
+	int w, h, n;
+	unsigned char* input_data = stbi_load(file, &w, &h, &n, 0);
+
+	if (input_data == NULL)
+		return;
+
+	int new_w = (int)(w * width_percent);
+	int new_h = (int)(h * height_percent);
+
+	unsigned char* output_data = (unsigned char*)malloc(new_w * new_h * n * sizeof(unsigned char));
+
+	stbir_resize_region(input_data, w, h, 0, output_data, new_w, new_h, 0, STBIR_TYPE_UINT8, n, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_BOX, STBIR_FILTER_CATMULLROM, STBIR_COLORSPACE_SRGB, &g_context, s0, t0, s1, t1);
+
+	stbi_image_free(input_data);
+
+	char output[200];
+	sprintf(output, "test-output/subpixel-region-%d-%d-%f-%f-%f-%f-%s", new_w, new_h, s0, t0, s1, t1, file);
+	stbi_write_png(output, new_w, new_h, n, output_data, 0);
+
+	free(output_data);
+}
+
+void test_subpixel_command(const char* file, float width_percent, float height_percent, float x_scale, float y_scale, float x_offset, float y_offset)
+{
+	int w, h, n;
+	unsigned char* input_data = stbi_load(file, &w, &h, &n, 0);
+
+	if (input_data == NULL)
+		return;
+
+	int new_w = (int)(w * width_percent);
+	int new_h = (int)(h * height_percent);
+
+	unsigned char* output_data = (unsigned char*)malloc(new_w * new_h * n * sizeof(unsigned char));
+
+	stbir_resize_subpixel(input_data, w, h, 0, output_data, new_w, new_h, 0, STBIR_TYPE_UINT8, n, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_BOX, STBIR_FILTER_CATMULLROM, STBIR_COLORSPACE_SRGB, &g_context, x_scale, y_scale, x_offset, y_offset);
+
+	stbi_image_free(input_data);
+
+	char output[200];
+	sprintf(output, "test-output/subpixel-command-%d-%d-%f-%f-%f-%f-%s", new_w, new_h, x_scale, y_scale, x_offset, y_offset, file);
+	stbi_write_png(output, new_w, new_h, n, output_data, 0);
+
+	free(output_data);
+}
+
 unsigned int* pixel(unsigned int* buffer, int x, int y, int c, int w, int n)
 {
 	return &buffer[y*w*n + x*n + c];
@@ -461,6 +510,18 @@ void test_subpixel_1()
 			STBIR_ASSERT(output_data[y * 16 + x + 8] == output_right[y * 8 + x]);
 		}
 	}
+
+	stbir_resize_subpixel(image, 8, 8, 0, output_left, 8, 16, 0, STBIR_TYPE_UINT8, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_CATMULLROM, STBIR_FILTER_CATMULLROM, STBIR_COLORSPACE_SRGB, &g_context, 2, 2, 0, 0);
+	stbir_resize_subpixel(image, 8, 8, 0, output_right, 8, 16, 0, STBIR_TYPE_UINT8, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_CATMULLROM, STBIR_FILTER_CATMULLROM, STBIR_COLORSPACE_SRGB, &g_context, 2, 2, 8, 0);
+
+	for (int x = 0; x < 8; x++)
+	{
+		for (int y = 0; y < 16; y++)
+		{
+			STBIR_ASSERT(output_data[y * 16 + x] == output_left[y * 8 + x]);
+			STBIR_ASSERT(output_data[y * 16 + x + 8] == output_right[y * 8 + x]);
+		}
+	}
 }
 
 // test that replicating an image and using a subtile of it produces same results as wraparound
@@ -498,6 +559,14 @@ void test_subpixel_2()
 		for (int y = 0; y < 16; y++)
 			STBIR_ASSERT(output_data_1[y * 16 + x] == output_data_2[y * 16 + x]);
 	}}
+
+	stbir_resize_subpixel(large_image, 32, 32, 0, output_data_2, 16, 16, 0, STBIR_TYPE_UINT8, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_WRAP, STBIR_EDGE_WRAP, STBIR_FILTER_CATMULLROM, STBIR_FILTER_CATMULLROM, STBIR_COLORSPACE_SRGB, &g_context, 2, 2, 16, 16);
+
+	{for (int x = 0; x < 16; x++)
+	{
+		for (int y = 0; y < 16; y++)
+			STBIR_ASSERT(output_data_1[y * 16 + x] == output_data_2[y * 16 + x]);
+	}}
 }
 
 // test that 0,0,1,1 subpixel produces same result as no-rect
@@ -521,6 +590,14 @@ void test_subpixel_3()
 		for (int y = 0; y < 32; y++)
 			STBIR_ASSERT(output_data_1[y * 32 + x] == output_data_2[y * 32 + x]);
 	}
+
+	stbir_resize_subpixel(image, 8, 8, 0, output_data_1, 32, 32, 0, STBIR_TYPE_UINT8, 1, 0, STBIR_ALPHA_CHANNEL_NONE, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_CATMULLROM, STBIR_FILTER_CATMULLROM, STBIR_COLORSPACE_LINEAR, NULL, 4, 4, 0, 0);
+
+	for (int x = 0; x < 32; x++)
+	{
+		for (int y = 0; y < 32; y++)
+			STBIR_ASSERT(output_data_1[y * 32 + x] == output_data_2[y * 32 + x]);
+	}
 }
 
 // test that 1:1 resample using s,t=0,0,1,1 with bilinear produces original image
@@ -537,6 +614,9 @@ void test_subpixel_4()
 
 	stbir_resize_region(image, 8, 8, 0, output, 8, 8, 0, STBIR_TYPE_UINT8, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_TRIANGLE, STBIR_FILTER_TRIANGLE, STBIR_COLORSPACE_LINEAR, &g_context, 0, 0, 1, 1);
 	STBIR_ASSERT(memcmp(image, output, 8 * 8) == 0);
+
+	stbir_resize_subpixel(image, 8, 8, 0, output, 8, 8, 0, STBIR_TYPE_UINT8, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_TRIANGLE, STBIR_FILTER_TRIANGLE, STBIR_COLORSPACE_LINEAR, &g_context, 1, 1, 0, 0);
+	STBIR_ASSERT(memcmp(image, output, 8 * 8) == 0);
 }
 
 static unsigned int  image88_int[8][8];
@@ -880,6 +960,55 @@ void test_suite(int argc, char **argv)
 	stbir_resize(image88, 8, 8, 0, output88, 16, 4, 0, STBIR_TYPE_UINT8, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_BOX, STBIR_FILTER_CATMULLROM, STBIR_COLORSPACE_SRGB, &g_context);
 	stbir_resize(image88, 8, 8, 0, output88, 16, 4, 0, STBIR_TYPE_UINT8, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_CATMULLROM, STBIR_FILTER_BOX, STBIR_COLORSPACE_SRGB, &g_context);
 
+	int barbara_width, barbara_height, barbara_channels;
+	stbi_image_free(stbi_load(barbara, &barbara_width, &barbara_height, &barbara_channels, 0));
+
+	int res = 10;
+	// Downscaling
+	for (int i = 0; i <= res; i++)
+	{
+		float t = (float)i/res;
+		float scale = 0.5;
+		float out_scale = 2.0/3;
+		float x_shift = (barbara_width*out_scale - barbara_width*scale) * t;
+		float y_shift = (barbara_height*out_scale - barbara_height*scale) * t;
+
+		test_subpixel_command(barbara, scale, scale, out_scale, out_scale, x_shift, y_shift);
+	}
+
+	// Upscaling
+	for (int i = 0; i <= res; i++)
+	{
+		float t = (float)i/res;
+		float scale = 2;
+		float out_scale = 3;
+		float x_shift = (barbara_width*out_scale - barbara_width*scale) * t;
+		float y_shift = (barbara_height*out_scale - barbara_height*scale) * t;
+
+		test_subpixel_command(barbara, scale, scale, out_scale, out_scale, x_shift, y_shift);
+	}
+
+	// Downscaling
+	for (int i = 0; i <= res; i++)
+	{
+		float t = (float)i/res / 2;
+		test_subpixel_region(barbara, 0.25f, 0.25f, t, t, t+0.5f, t+0.5f);
+	}
+
+	// No scaling
+	for (int i = 0; i <= res; i++)
+	{
+		float t = (float)i/res / 2;
+		test_subpixel_region(barbara, 0.5f, 0.5f, t, t, t+0.5f, t+0.5f);
+	}
+
+	// Upscaling
+	for (int i = 0; i <= res; i++)
+	{
+		float t = (float)i/res / 2;
+		test_subpixel_region(barbara, 1, 1, t, t, t+0.5f, t+0.5f);
+	}
+
 	for (i = 0; i < 10; i++)
 		test_subpixel(barbara, 0.5f, 0.5f, (float)i / 10, 1);