/* Ultimate SoundTracker (or compatible) STK 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 this struct!#pragma pack(push)#pragma pack(1)#endiftypedef struct stkHdr_t{	char name[20];	modSmpHdr_t smp[15];	uint8_t numOrders, CIAVal, orders[128];}#ifdef __GNUC____attribute__ ((packed))#endifstkHdr_t;#ifdef _MSC_VER#pragma pack(pop)#endif bool loadSTK(FILE *f, uint32_t filesize){	uint8_t bytes[4];	int16_t i, j, k;	uint16_t a, b;	sample_t *s;	stkHdr_t h; 	tmpLinearPeriodsFlag = false; // use Amiga periods 	bool veryLateSTKVerFlag = false; // "DFJ SoundTracker III" nad later	bool lateSTKVerFlag = false; // "TJC SoundTracker II" and later 	if (filesize < sizeof (h))	{		loaderMsgBox("Error: This file is either not a module, or is not supported.");		return false;	} 	memset(&h, 0, sizeof (stkHdr_t));	if (fread(&h, 1, sizeof (h), f) != sizeof (h))	{		loaderMsgBox("Error: This file is either not a module, or is not supported.");		return false;	} 	if (h.CIAVal == 0) // a CIA value of 0 results in 120		h.CIAVal = 120; 	if (h.numOrders < 1 || h.numOrders > 128 || h.CIAVal > 220)	{		loaderMsgBox("Error: This file is either not a module, or is not supported.");		return false;	} 	memcpy(songTmp.orders, h.orders, 128); 	songTmp.numChannels = 4;	songTmp.songLength = h.numOrders;	songTmp.BPM = 125;	songTmp.speed = 6; 	for (a = 0; a < 15; a++)	{		modSmpHdr_t *modSmp = &h.smp[a];		memcpy(songTmp.instrName[1+a], modSmp->name, 22); 		/* Only late versions of Ultimate SoundTracker supports samples larger than 9999 bytes.		** If found, we know for sure that this is a late STK module.		*/		const int32_t sampleLen = 2*SWAP16(modSmp->length);		if (sampleLen > 9999)			lateSTKVerFlag = true;	} 	// jjk55.mod by Jesper Kyd has a bogus STK tempo value that should be ignored (hackish!)	if (!strcmp("jjk55", h.name))		h.CIAVal = 120; 	if (h.CIAVal != 120) // 120 is a special case and means 50Hz (125BPM)	{		// convert UST tempo to BPM		uint16_t ciaPeriod = (240 - h.CIAVal) * 122;		double dHz = 709379.0 / ciaPeriod;		int32_t BPM = (int32_t)((dHz * 2.5) + 0.5); 		songTmp.BPM = (uint16_t)BPM;	} 	memcpy(songTmp.name, h.name, 20); 	// count number of patterns	b = 0;	for (a = 0; a < 128; a++)	{		if (songTmp.orders[a] > b)			b = songTmp.orders[a];	}	b++; 	for (a = 0; a < b; a++)	{		if (!allocateTmpPatt(a, 64))		{			loaderMsgBox("Not enough memory!");			return false;		} 		for (j = 0; j < 64; j++)		{			for (k = 0; k < songTmp.numChannels; k++)			{				note_t *p = &patternTmp[a][(j * MAX_CHANNELS) + k]; 				if (fread(bytes, 1, 4, f) != 4)				{					loaderMsgBox("Error: This file is either not a module, or is not supported.");					return false;				} 				// period to note				uint16_t period = ((bytes[0] & 0x0F) << 8) | bytes[1];				for (i = 0; i < 3*12; i++)				{					if (period >= ptPeriods[i])					{						p->note = 1 + (3*12) + (uint8_t)i;						break;					}				} 				p->instr = (bytes[0] & 0xF0) | (bytes[2] >> 4);				p->efx = bytes[2] & 0x0F;				p->efxData = bytes[3]; 				if (p->efx == 0xC || p->efx == 0xD || p->efx == 0xE)				{					// "TJC SoundTracker II" and later					lateSTKVerFlag = true;				} 				if (p->efx == 0xF)				{					// "DFJ SoundTracker III" and later					lateSTKVerFlag = true;					veryLateSTKVerFlag = true;				} 				if (p->efx == 0xC)				{					if (p->efxData > 64)						p->efxData = 64;				}				else if (p->efx == 0x1)				{					if (p->efxData == 0)						p->efxData = 0;				}				else if (p->efx == 0x2)				{					if (p->efxData == 0)						p->efxData = 0;				}				else if (p->efx == 0x5)				{					if (p->efxData == 0)						p->efxData = 0x3;				}				else if (p->efx == 0x6)				{					if (p->efxData == 0)						p->efxData = 0x4;				}				else if (p->efx == 0xA)				{					if (p->efxData == 0)						p->efxData = 0;				}				else if (p->efx == 0xE)				{					// check if certain E commands are empty					if (p->efxData == 0x10 || p->efxData == 0x20 || p->efxData == 0xA0 || p->efxData == 0xB0)					{						p->efx = 0;						p->efxData = 0;					}				}			}		} 		if (tmpPatternEmpty(a))		{			if (patternTmp[a] != NULL)			{				free(patternTmp[a]);				patternTmp[a] = NULL;			}		}	} 	// pattern command conversion for non-PT formats	for (a = 0; a < b; a++)	{		if (patternTmp[a] == NULL)			continue; 		for (j = 0; j < 64; j++)		{			for (k = 0; k < songTmp.numChannels; k++)			{				note_t *p = &patternTmp[a][(j * MAX_CHANNELS) + k]; 				// convert STK effects to PT effects 				if (!lateSTKVerFlag)				{					// old SoundTracker 1.x commands 					if (p->efx == 1)					{						// arpeggio						p->efx = 0;					}					else if (p->efx == 2)					{						// pitch slide						if (p->efxData & 0xF0)						{							// pitch slide down							p->efx = 2;							p->efxData >>= 4;						}						else if (p->efxData & 0x0F)						{							// pitch slide up							p->efx = 1;						}					}				}				else				{					// "DFJ SoundTracker II" or later 					if (p->efx == 0xD)					{						if (veryLateSTKVerFlag) // "DFJ SoundTracker III" or later						{							// pattern break w/ no param (param must be cleared to fix some songs)							p->efxData = 0;						}						else						{							// volume slide							p->efx = 0xA;						}					}				} 				// effect F with param 0x00 does nothing in UST/STK (I think)				if (p->efx == 0xF && p->efxData == 0)					p->efx = 0;			}		}	} 	for (a = 0; a < 15; a++)	{		if (h.smp[a].length == 0)			continue; 		if (!allocateTmpInstr(1+a))		{			loaderMsgBox("Not enough memory!");			return false;		} 		setNoEnvelope(instrTmp[1+a]); 		s = &instrTmp[1+a]->smp[0];		s->volume = h.smp[a].volume;		s->length = 2 * SWAP16(h.smp[a].length);		s->loopStart = SWAP16(h.smp[a].loopStart); // in STK, loopStart = bytes, not words		s->loopLength = 2 * SWAP16(h.smp[a].loopLength); 		if (s->loopLength < 2)			s->loopLength = 2; 		// fix overflown loop		if (s->loopStart+s->loopLength > s->length)		{			if (s->loopStart >= s->length)			{				s->loopStart = 0;				s->loopLength = 0;			}			else			{				s->loopLength = s->length - s->loopStart;			}		} 		if (s->loopStart+s->loopLength > 2)		{			s->flags |= LOOP_FWD; // enable loop		}		else		{			s->loopLength = 0;			s->loopStart = 0;		} 		/* In STK, only the loop area of a looped sample is played.		** Skip loading of eventual data present before loop start.		*/		if (s->loopStart > 0 && s->loopLength < s->length)		{			s->length -= s->loopStart;			fseek(f, s->loopStart, SEEK_CUR);			s->loopStart = 0;		} 		if (!allocateSmpData(s, s->length, false))		{			loaderMsgBox("Not enough memory!");			return false;		} 		int32_t bytesRead = (int32_t)fread(s->dataPtr, 1, s->length, f);		if (bytesRead < s->length)		{			int32_t bytesToClear = s->length - bytesRead;			memset(&s->dataPtr[bytesRead], 0, bytesToClear);		}	} 	return true;}