/* Scream Tracker 2 STM loader**** Note: Data sanitation is done in the last stage** of module loading, so you don't need to do that here.*/ #include <stdio.h>#include <stdint.h>#include <stdbool.h>#include "../ft2_header.h"#include "../ft2_module_loader.h"#include "../ft2_sample_ed.h"#include "../ft2_tables.h"#include "../ft2_sysreqs.h" #ifdef _MSC_VER // please don't mess with these structs!#pragma pack(push)#pragma pack(1)#endiftypedef struct stmSmpHdr_t{	char name[12];	uint8_t nul, junk1;	uint16_t junk2, length, loopStart, loopEnd;	uint8_t volume, junk3;	uint16_t midCFreq;	int32_t junk4;	uint16_t paraLen;}#ifdef __GNUC____attribute__ ((packed))#endifstmSmpHdr_t; typedef struct stmHdr_t{	char name[20], sig[8];	uint8_t x1A, type;	uint8_t verMajor, verMinor;	uint8_t tempo, numPatterns, volume, reserved[13];	stmSmpHdr_t smp[31];	uint8_t orders[128];}#ifdef __GNUC____attribute__ ((packed))#endifstmHdr_t;#ifdef _MSC_VER#pragma pack(pop)#endif static const uint8_t stmEfx[16] = { 0, 0, 11, 0, 10, 2, 1, 3, 4, 7, 0, 5, 6, 0, 0, 0 };static uint8_t pattBuff[64*4*4]; static uint16_t stmTempoToBPM(uint8_t tempo); bool loadSTM(FILE *f, uint32_t filesize){	int16_t i, j, k;	stmHdr_t hdr; 	tmpLinearPeriodsFlag = false; // use Amiga periods 	if (filesize < sizeof (hdr))	{		loaderMsgBox("Error: This file is either not a module, or is not supported.");		return false;	} 	if (fread(&hdr, 1, sizeof (hdr), f) != sizeof (hdr))	{		loaderMsgBox("Error: This file is either not a module, or is not supported.");		return false;	} 	if (hdr.verMinor == 0 || hdr.type != 2)	{		loaderMsgBox("Error loading STM: Incompatible module!");		return false;	} 	songTmp.numChannels = 4;	memcpy(songTmp.orders, hdr.orders, 128); 	i = 0;	while (i < 128 && songTmp.orders[i] < 99)		i++;	songTmp.songLength = i + (i == 0); 	if (songTmp.songLength < 255)		memset(&songTmp.orders[songTmp.songLength], 0, 256 - songTmp.songLength); 	memcpy(songTmp.name, hdr.name, 20); 	uint8_t tempo = hdr.tempo;	if (hdr.verMinor < 21)		tempo = ((tempo / 10) << 4) + (tempo % 10); 	if (tempo == 0)		tempo = 96; 	songTmp.BPM = stmTempoToBPM(tempo);	songTmp.speed = hdr.tempo >> 4; 	for (i = 0; i < hdr.numPatterns; i++)	{		if (!allocateTmpPatt(i, 64))		{			loaderMsgBox("Not enough memory!");			return false;		} 		if (fread(pattBuff, 64 * 4 * 4, 1, f) != 1)		{			loaderMsgBox("General I/O error during loading!");			return false;		} 		uint8_t *pattPtr = pattBuff;		for (j = 0; j < 64; j++)		{			for (k = 0; k < 4; k++, pattPtr += 4)			{				note_t *p = &patternTmp[i][(j * MAX_CHANNELS) + k];								if (pattPtr[0] == 254)				{					p->note = NOTE_OFF;				}				else if (pattPtr[0] < 96)				{					p->note = (12 * (pattPtr[0] >> 4)) + (25 + (pattPtr[0] & 0x0F));					if (p->note > 96)						p->note = 0;				}				else				{					p->note = 0;				} 				p->instr = pattPtr[1] >> 3; 				uint8_t vol = (pattPtr[1] & 7) + ((pattPtr[2] & 0xF0) >> 1);				if (vol <= 64)					p->vol = 0x10 + vol; 				p->efxData = pattPtr[3]; 				uint8_t efx = pattPtr[2] & 0x0F;				if (efx == 1)				{					p->efx = 15; 					if (hdr.verMinor < 21)						p->efxData = ((p->efxData / 10) << 4) + (p->efxData % 10);										p->efxData >>= 4;				}				else if (efx == 3)				{					p->efx = 13;					p->efxData = 0;				}				else if (efx == 2 || (efx >= 4 && efx <= 12))				{					p->efx = stmEfx[efx];					if (p->efx == 0xA)					{						if (p->efxData & 0x0F)							p->efxData &= 0x0F;						else							p->efxData &= 0xF0;					}				}				else				{					p->efxData = 0;				}			}		} 		if (tmpPatternEmpty(i))		{			if (patternTmp[i] != NULL)			{				free(patternTmp[i]);				patternTmp[i] = NULL;			}		}	} 	for (i = 0; i < 31; i++)	{		memcpy(&songTmp.instrName[1+i], hdr.smp[i].name, 12); 		if (hdr.smp[i].length > 0)		{			allocateTmpInstr(1 + i);			setNoEnvelope(instrTmp[i]); 			sample_t *s = &instrTmp[1+i]->smp[0]; 			if (!allocateSmpData(s, hdr.smp[i].length, false))			{				loaderMsgBox("Not enough memory!");				return false;			} 			s->length = hdr.smp[i].length;			s->volume = hdr.smp[i].volume;			s->loopStart = hdr.smp[i].loopStart;			s->loopLength = hdr.smp[i].loopEnd - hdr.smp[i].loopStart; 			memcpy(s->name, hdr.smp[i].name, 12);			tuneSample(s, hdr.smp[i].midCFreq, tmpLinearPeriodsFlag); 			if (s->loopStart < s->length && hdr.smp[i].loopEnd > s->loopStart && hdr.smp[i].loopEnd != 0xFFFF)			{				if (s->loopStart+s->loopLength > s->length)					s->loopLength = s->length - s->loopStart; 				s->flags |= LOOP_FWD; // enable loop			}			else			{				s->loopStart = 0;				s->loopLength = 0;			} 			if (fread(s->dataPtr, s->length, 1, f) != 1)			{				loaderMsgBox("General I/O error during loading! Possibly corrupt module?");				return false;			}		}	} 	return true;} static uint16_t stmTempoToBPM(uint8_t tempo) // ported from original ST2.3 replayer code{	const uint8_t slowdowns[16] = { 140, 50, 25, 15, 10, 7, 6, 4, 3, 3, 2, 2, 2, 2, 1, 1 };	uint16_t hz = 50; 	hz -= ((slowdowns[tempo >> 4] * (tempo & 15)) >> 4); // can and will underflow 	const uint16_t bpm = (hz << 1) + (hz >> 1); // BPM = hz * 2.5	return bpm; // result can be slightly off, but close enough...}