BS1 demo's speech and logic work now.

But there's something wrong with the SFX, which can lead to crashes.

svn-id: r15813

4 files changed, 47 insertions, 31 deletions

diff --git a/sword1/logic.cpp b/sword1/logic.cpp
index 1d7e85093c..8c4095b215 100644
--- a/sword1/logic.cpp
+++ b/sword1/logic.cpp
@@ -474,6 +474,7 @@ int Logic::interpretScript(Object *compact, int id, Header *scriptModule, int sc
 	int32 a, b, c, d, e, f;
 	int mCodeReturn = 0;
 	int32 mCodeNumber = 0, mCodeArguments = 0;
+	uint32 varNum = 0;
 	while (1) {
 		assert((stackIdx >= 0) && (stackIdx <= MAX_STACK_SIZE));
 		switch (scriptCode[pc++]) {
@@ -504,7 +505,14 @@ int Logic::interpretScript(Object *compact, int id, Header *scriptModule, int sc
 				break;
 			case IT_PUSHVARIABLE:
 				debug(9, "IT_PUSHVARIABLE: ScriptVar[%d] => %d", scriptCode[pc], _scriptVars[scriptCode[pc]]);
-				stack[stackIdx++] = _scriptVars[scriptCode[pc++]];
+				varNum = scriptCode[pc++];
+				if (SwordEngine::_systemVars.isDemo) {
+					if (varNum >= 397) // BS1 Demo has different number of script variables
+						varNum++;
+					if (varNum >= 699)
+						varNum++;
+				}
+				stack[stackIdx++] = _scriptVars[varNum];
 				break;
 			case IT_NOTEQUAL:
 				stackIdx--;
@@ -588,7 +596,14 @@ int Logic::interpretScript(Object *compact, int id, Header *scriptModule, int sc
 				return 0;
 			case IT_POPVAR:         // pop a variable
 				debug(9, "IT_POPVAR: ScriptVars[%d] = %d", scriptCode[pc], stack[stackIdx-1]);
-				_scriptVars[scriptCode[pc++]] = stack[--stackIdx];
+				varNum = scriptCode[pc++];
+				if (SwordEngine::_systemVars.isDemo) {
+					if (varNum >= 397) // BS1 Demo has different number of script variables
+						varNum++;
+					if (varNum >= 699)
+						varNum++;
+				}
+				_scriptVars[varNum] = stack[--stackIdx];
 				break;
 			case IT_POPLONGOFFSET:
 				offset = scriptCode[pc++];
diff --git a/sword1/sound.cpp b/sword1/sound.cpp
index 550d8dd54b..fde2a402cc 100644
--- a/sword1/sound.cpp
+++ b/sword1/sound.cpp
@@ -218,36 +218,28 @@ int16 *Sound::uncompressSpeech(uint32 index, uint32 cSize, uint32 *size) {
 		headerPos++;
 	if (headerPos < 100) {
 		int32 resSize;
-		if (_cowMode == CowDemo) { // Demo uses slightly different headers
-			resSize = READ_LE_UINT32(fBuf + headerPos + 6) >> 1;
-			headerPos += 2;
-		} else
-			resSize = READ_LE_UINT32(fBuf + headerPos + 4) >> 1;
-		int16 *srcData = (int16*)(fBuf + headerPos + 8);
-		uint32 srcPos = 0;
-		uint32 dstPos = 0;
-		cSize = (cSize - (headerPos + 8)) / 2;
-		if (_cowMode == CowDemo) {
-			// FIXME: Until someone figures out how to really
-			//        calculate the uncompressed buffer size, use
-			//        brute force to avoid crashes.
-			debug(1, "old resSize = %d", resSize);
-			resSize = 0;
-			while (srcPos < cSize) {
-				int16 length = (int16)READ_LE_UINT16(srcData + srcPos);
-				srcPos++;
-				if (length < 0) {
-					length = -length;
-					srcPos++;
-				} else {
-					srcPos += length;
-				}
-				resSize += length;
-			}
-			debug(1, "new resSize = %d", resSize);
+		headerPos += 4; // skip 'data' tag
+		if (_cowMode != CowDemo) {
+			resSize = READ_LE_UINT32(fBuf + headerPos) >> 1;
+			headerPos += 4;
+		} else {
+			// the demo speech files have the uncompressed size embedded
+			// in the compressed stream *sigh*
+			if (READ_LE_UINT16(fBuf + headerPos) == 1) {				
+				resSize = READ_LE_UINT16(fBuf + headerPos + 2);
+				resSize |= READ_LE_UINT16(fBuf + headerPos + 6) << 16;
+				resSize >>= 1;
+			} else
+				resSize = READ_LE_UINT32(fBuf + headerPos + 2) >> 1;
 		}
-		int16 *dstData = (int16*)malloc(resSize * 2);
-		srcPos = 0;
+		assert(!(headerPos & 1));
+		int16 *srcData = (int16*)fBuf;
+		uint32 srcPos = headerPos >> 1;
+		cSize /= 2;
+		uint32 dstPos = 0;
+		/* alloc 200 additional bytes, as the demo sometimes has ASCII junk
+		   at the end of the wave data */
+		int16 *dstData = (int16*)malloc(resSize * 2 + 200);
 		while (srcPos < cSize) {
 			int16 length = (int16)READ_LE_UINT16(srcData + srcPos);
 			srcPos++;
@@ -262,6 +254,9 @@ int16 *Sound::uncompressSpeech(uint32 index, uint32 cSize, uint32 *size) {
 				srcPos += length;
 			}
 		}
+		assert(dstPos < (uint32)resSize + 100);
+		if (_cowMode == CowDemo) // demo has wave output size embedded in the compressed data
+			*(uint32*)dstData = 0;
 		free(fBuf);
 		*size = resSize * 2;
 		calcWaveVolume(dstData, resSize);
diff --git a/sword1/sword1.cpp b/sword1/sword1.cpp
index 82aa029f85..f9cbb2115d 100644
--- a/sword1/sword1.cpp
+++ b/sword1/sword1.cpp
@@ -1095,6 +1095,7 @@ void SwordEngine::checkCdFiles(void) { // check if we're running from cd, hdd or
 	File test;
 
 	_systemVars.playSpeech = true;
+	_systemVars.isDemo = false;
 
 	for (int i = 1; i <= 2; i++) {
 		for (int j = 0; j < ARRAYSIZE(speechFiles); j++) {
@@ -1113,6 +1114,10 @@ void SwordEngine::checkCdFiles(void) { // check if we're running from cd, hdd or
 		_systemVars.runningFromCd = false;
 		_systemVars.playSpeech = true;
 	} else { // speech1 & speech2 not present. are we running from cd?
+		if (test.open("cows.mad")) {
+			_systemVars.isDemo = true;
+			test.close();
+		}
 		if (test.open("cd1.id")) {
 			_systemVars.runningFromCd = true;
 			_systemVars.currentCD = 1;
diff --git a/sword1/sword1.h b/sword1/sword1.h
index 22a51960d5..330d47a38c 100644
--- a/sword1/sword1.h
+++ b/sword1/sword1.h
@@ -63,6 +63,7 @@ struct SystemVars {
 	uint8	playSpeech;
 	uint8	showText;
 	uint8	language;
+	bool    isDemo;
 };
 
 class SwordEngine : public Engine {