godot/modules/chibi/cp_loader_it_patterns.cpp

/*************************************************************************/
/*  cp_loader_it_patterns.cpp                                            */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
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#include "cp_loader_it.h"

CPLoader::Error CPLoader_IT::load_patterns() {

	for (int i = 0; i < header.patnum; i++) {

		if (i >= CPSong::MAX_PATTERNS)
			break;

		/* Position where pattern offsets are stored */
		file->seek(0xC0 + header.ordnum + header.insnum * 4 + header.smpnum * 4 + i * 4);
		uint32_t pattern_offset = file->get_dword();

		if (pattern_offset == 0) {

			continue;
		}

		uint16_t pat_size;
		uint16_t pat_length;

		int row = 0, flag, channel, j;
		uint8_t aux_byte;
		uint32_t reserved;
		uint8_t chan_mask[64]; //mask cache for each
		CPNote last_value[64]; //last value of each

		for (j = 0; j < 64; j++) {

			chan_mask[j] = 0;
			last_value[j].clear();
		}

		file->seek(pattern_offset);

		pat_size = file->get_word();
		pat_length = file->get_word();
		reserved = file->get_dword();

		song->get_pattern(i)->set_length(pat_length);

		do {

			aux_byte = file->get_byte();
			flag = aux_byte;

			if (flag == 0) {

				row++;
			} else {

				channel = (flag - 1) & 63;

				if (flag & 128) {

					aux_byte = file->get_byte();
					chan_mask[channel] = aux_byte;
				}

				CPNote note; //note used for reading

				if (chan_mask[channel] & 1) { // read note

					aux_byte = file->get_byte();

					if (aux_byte < 120)
						note.note = aux_byte;
					else if (aux_byte == 255)
						note.note = CPNote::OFF;
					else if (aux_byte == 254)
						note.note = CPNote::CUT;

					last_value[channel].note = note.note;
				}

				if (chan_mask[channel] & 2) {

					aux_byte = file->get_byte();
					if (aux_byte < 100)
						note.instrument = aux_byte - 1;

					last_value[channel].instrument = note.instrument;
				}
				if (chan_mask[channel] & 4) {

					aux_byte = file->get_byte();
					if (aux_byte < 213)
						note.volume = aux_byte;

					last_value[channel].volume = note.volume;
				}
				if (chan_mask[channel] & 8) {

					aux_byte = file->get_byte();
					if (aux_byte > 0)
						note.command = aux_byte - 1;

					last_value[channel].command = note.command;

					note.parameter = file->get_byte();

					last_value[channel].parameter = note.parameter;
				}

				if (chan_mask[channel] & 16) {

					note.note = last_value[channel].note;
				}

				if (chan_mask[channel] & 32) {

					note.instrument = last_value[channel].instrument;
				}
				if (chan_mask[channel] & 64) {

					note.volume = last_value[channel].volume;
				}
				if (chan_mask[channel] & 128) {

					note.command = last_value[channel].command;
					note.parameter = last_value[channel].parameter;
				}

				song->get_pattern(i)->set_note(channel, row, note);
			}

		} while (row < pat_length);
	}

	return FILE_OK;
}