PRINCE: plotTracePoint(), plotTraceLine(), tracePath(), approxPath() update

3 files changed, 82 insertions, 60 deletions

diff --git a/engines/prince/prince.cpp b/engines/prince/prince.cpp
index db72e01223..a1d1f2d30c 100644
--- a/engines/prince/prince.cpp
+++ b/engines/prince/prince.cpp
@@ -90,10 +90,10 @@ PrinceEngine::PrinceEngine(OSystem *syst, const PrinceGameDescription *gameDesc)
 	_dialogWidth(600), _dialogHeight(0), _dialogLineSpace(10), _dialogColor1(220), _dialogColor2(223),
 	_dialogFlag(false), _dialogLines(0), _dialogText(nullptr), _mouseFlag(1),
 	_roomPathBitmap(nullptr), _roomPathBitmapTemp(nullptr), _coordsBufEnd(nullptr), _coordsBuf(nullptr), _coords(nullptr),
-	_traceLineLen(0), _traceLineFlag(0), _rembBitmapTemp(nullptr), _rembBitmap(nullptr), _rembMask(0), _rembX(0), _rembY(0),
+	_traceLineLen(0), _rembBitmapTemp(nullptr), _rembBitmap(nullptr), _rembMask(0), _rembX(0), _rembY(0),
 	_checkBitmapTemp(nullptr), _checkBitmap(nullptr), _checkMask(0), _checkX(0), _checkY(0), _traceLineFirstPointFlag(false),
 	_tracePointFirstPointFlag(false), _coordsBuf2(nullptr), _coords2(nullptr), _coordsBuf3(nullptr), _coords3(nullptr),
-	_tracePointFlag(0), _shanLen1(0), _directionTable(nullptr) {
+	_shanLen1(0), _directionTable(nullptr) {
 
 	// Debug/console setup
 	DebugMan.addDebugChannel(DebugChannel::kScript, "script", "Prince Script debug channel");
@@ -1466,6 +1466,10 @@ void PrinceEngine::clearBackAnimList() {
 	}
 }
 
+void PrinceEngine::grabMap() {
+	//TODO
+}
+
 void PrinceEngine::initZoomIn(int slot) {
 	//TODO
 }
@@ -1616,8 +1620,6 @@ void PrinceEngine::drawScreen() {
 
 		runDrawNodes();
 
-		testDrawPath();
-
 		freeDrawNodes();
 
 		if (_mainHero->_visible) {
@@ -2761,6 +2763,47 @@ void PrinceEngine::freeAllNormAnims() {
 	_normAnimList.clear();
 }
 
+// Modified version of Graphics::drawLine() to allow breaking the loop and return value
+int PrinceEngine::drawLine(int x0, int y0, int x1, int y1, int (*plotProc)(int, int, void *), void *data) {
+	// Bresenham's line algorithm, as described by Wikipedia
+	const bool steep = ABS(y1 - y0) > ABS(x1 - x0);
+
+	if (steep) {
+		SWAP(x0, y0);
+		SWAP(x1, y1);
+	}
+
+	const int delta_x = ABS(x1 - x0);
+	const int delta_y = ABS(y1 - y0);
+	const int delta_err = delta_y;
+	int x = x0;
+	int y = y0;
+	int err = 0;
+
+	const int x_step = (x0 < x1) ? 1 : -1;
+	const int y_step = (y0 < y1) ? 1 : -1;
+
+	int stopFlag = 0;
+	if (steep)
+		stopFlag = (*plotProc)(y, x, data);
+	else
+		stopFlag = (*plotProc)(x, y, data);
+
+	while (x != x1 && !stopFlag) {
+		x += x_step;
+		err += delta_err;
+		if (2 * err > delta_x) {
+			y += y_step;
+			err -= delta_x;
+		}
+		if (steep)
+			stopFlag = (*plotProc)(y, x, data);
+		else
+			stopFlag = (*plotProc)(x, y, data);
+	}
+	return stopFlag;
+}
+
 int PrinceEngine::getPixelAddr(byte *pathBitmap, int x, int y) {
 	int mask = 128 >> (x & 7);
 	byte value = pathBitmap[x / 8 + y * 80];
@@ -2924,25 +2967,23 @@ void PrinceEngine::specialPlotInside(int x, int y) {
 	}
 }
 
-void PrinceEngine::plotTraceLine(int x, int y, int color, void *data) {
+int PrinceEngine::plotTraceLine(int x, int y, void *data) {
 	PrinceEngine *traceLine = (PrinceEngine *)data;
-	if (!traceLine->_traceLineFlag) {
-		if (!traceLine->_traceLineFirstPointFlag) {
-			if (!traceLine->getPixelAddr(traceLine->_roomPathBitmapTemp, x, y)) {
-				if (traceLine->getPixelAddr(traceLine->_roomPathBitmap, x, y)) {
-					traceLine->specialPlotInside(x, y);
-					traceLine->_traceLineLen++;
-					traceLine->_traceLineFlag = 0;
-				} else {
-					traceLine->_traceLineFlag = -1;
-				}
+	if (!traceLine->_traceLineFirstPointFlag) {
+		if (!traceLine->getPixelAddr(traceLine->_roomPathBitmapTemp, x, y)) {
+			if (traceLine->getPixelAddr(traceLine->_roomPathBitmap, x, y)) {
+				traceLine->specialPlotInside(x, y);
+				traceLine->_traceLineLen++;
+				return 0;
 			} else {
-				traceLine->_traceLineFlag = 1;
+				return -1;
 			}
 		} else {
-			traceLine->_traceLineFirstPointFlag = false;
-			traceLine->_traceLineFlag = 0;
+			return 1;
 		}
+	} else {
+		traceLine->_traceLineFirstPointFlag = false;
+		return 0;
 	}
 }
 
@@ -3730,13 +3771,12 @@ bool PrinceEngine::tracePath(int x1, int y1, int x2, int y2) {
 					bcad = _coords;
 
 					_traceLineLen = 0;
-					_traceLineFlag = 0;
 					_traceLineFirstPointFlag = true;
-					Graphics::drawLine(x, y, x2, y2, 0, &this->plotTraceLine, this);
+					int drawLineFlag = drawLine(x, y, x2, y2, &this->plotTraceLine, this);
 
-					if (!_traceLineFlag) {
+					if (!drawLineFlag) {
 						return true;
-					} else if (_traceLineFlag == -1 && _traceLineLen >= 2) {
+					} else if (drawLineFlag == -1 && _traceLineLen >= 2) {
 						byte *tempCorrds = bcad;
 						while (tempCorrds != _coords) {
 							x = READ_UINT16(tempCorrds);
@@ -3846,20 +3886,18 @@ void PrinceEngine::specialPlotInside2(int x, int y) {
 	_coords2 += 2;
 }
 
-void PrinceEngine::plotTracePoint(int x, int y, int color, void *data) {
+int PrinceEngine::plotTracePoint(int x, int y, void *data) {
 	PrinceEngine *tracePoint = (PrinceEngine *)data;
-	if (!tracePoint->_tracePointFlag) {
-		if (!tracePoint->_tracePointFirstPointFlag) {
-			if (tracePoint->getPixelAddr(tracePoint->_roomPathBitmap, x, y)) {
-				tracePoint->specialPlotInside2(x, y);
-				tracePoint->_tracePointFlag = 0;
-			} else {
-				tracePoint->_tracePointFlag = -1;
-			}
+	if (!tracePoint->_tracePointFirstPointFlag) {
+		if (tracePoint->getPixelAddr(tracePoint->_roomPathBitmap, x, y)) {
+			tracePoint->specialPlotInside2(x, y);
+			return 0;
 		} else {
-			tracePoint->_tracePointFirstPointFlag = false;
-			tracePoint->_tracePointFlag = 0;
+			return -1;
 		}
+	} else {
+		tracePoint->_tracePointFirstPointFlag = false;
+		return 0;
 	}
 }
 
@@ -3892,10 +3930,9 @@ void PrinceEngine::approxPath() {
 					_coords2 += 4;
 				}
 			}
-			_tracePointFlag = 0;
 			_tracePointFirstPointFlag = true;
-			Graphics::drawLine(x1, y1, x2, y2, 0, &this->plotTracePoint, this);
-			if (!_tracePointFlag) {
+			bool drawLineFlag = drawLine(x1, y1, x2, y2, &this->plotTracePoint, this);
+			if (!drawLineFlag) {
 				tempCoords = tempCoordsBuf - 4;
 				tempCoordsBuf = _coordsBuf;
 			} else {
@@ -4197,22 +4234,6 @@ void PrinceEngine::freeCoords3() {
 	}
 }
 
-void PrinceEngine::testDrawPath() {
-	byte *tempCoords = _mainHero->_coords;
-	if (tempCoords != nullptr) {
-		while (1) {
-			int flag = READ_UINT32(tempCoords);
-			if (flag == 0xFFFFFFFF) {
-				break;
-			}
-			int x = READ_UINT16(tempCoords);
-			int y = READ_UINT16(tempCoords + 2);
-			tempCoords += 4;
-			_graph->drawPixel(_graph->_frontScreen, x, y);
-		}
-	}
-}
-
 void PrinceEngine::mainLoop() {
 
 	changeCursor(0);
diff --git a/engines/prince/prince.h b/engines/prince/prince.h
index 2f7009517f..4bab84b1d0 100644
--- a/engines/prince/prince.h
+++ b/engines/prince/prince.h
@@ -330,6 +330,8 @@ public:
 	void showMask(int maskNr, Graphics::Surface *originalRoomSurface);
 	void clsMasks();
 
+	void grabMap();
+
 	int _selectedMob; // number of selected Mob / inventory item
 	int _selectedItem; // number of item on mouse cursor
 	int _selectedMode;
@@ -449,9 +451,7 @@ public:
 	byte *_coordsBuf3;
 	byte *_coords3;
 	int _traceLineLen;
-	int _traceLineFlag; // return value of plotTraceLine
 	bool _traceLineFirstPointFlag; // if plotTraceLine after first point
-	int _tracePointFlag; // return value of plotTracePoint
 	bool _tracePointFirstPointFlag; // if plotTracePoint after first point
 	byte *_directionTable;
 	int _shanLen1;
@@ -475,11 +475,12 @@ public:
 		int y2;
 	} _fpResult;
 
+	int drawLine(int x0, int y0, int x1, int y1, int (*plotProc)(int, int, void *), void *data);
 	bool loadPath(const char *resourceName);
 	byte *makePath(int destX, int destY);
 	void findPoint(int x1, int y1, int x2, int y2);
 	int getPixelAddr(byte *pathBitmap, int x, int y);
-	static void plotTraceLine(int x, int y, int color, void *data);
+	static int plotTraceLine(int x, int y, void *data);
 	void specialPlotInside(int x, int y);
 	bool tracePath(int x1, int y1, int x2, int y2);
 	Direction makeDirection(int x1, int y1, int x2, int y2);
@@ -488,7 +489,7 @@ public:
 	void allocCoords2();
 	void freeCoords2();
 	void freeCoords3();
-	static void plotTracePoint(int x, int y, int color, void *data);
+	static int plotTracePoint(int x, int y, void *data);
 	void specialPlotInside2(int x, int y);
 	void approxPath();
 	void freeDirectionTable();
@@ -498,8 +499,6 @@ public:
 	void walkTo();
 	void moveRunHero(int heroId, int x, int y, int dir, bool runHeroFlag);
 
-	void testDrawPath();
-
 	int leftDownDir();
 	int leftDir();
 	int leftUpDir();
diff --git a/engines/prince/script.cpp b/engines/prince/script.cpp
index 1badee0da1..f5b38cbe47 100644
--- a/engines/prince/script.cpp
+++ b/engines/prince/script.cpp
@@ -516,7 +516,7 @@ void Interpreter::O_WAITFOREVER() {
 	_vm->changeCursor(_vm->_currentPointerNumber);
 	_opcodeNF = 1;
 	_currentInstruction -= 2;
-	debugInterpreter("O_WAITFOREVER");
+	//debugInterpreter("O_WAITFOREVER");
 }
 
 void Interpreter::O_BLACKPALETTE() {
@@ -1306,7 +1306,8 @@ void Interpreter::O_TALKBACKANIM() {
 }
 
 void Interpreter::O_LOADPATH() {
-	int32 offset = readScript<uint32>();
+	readScript<uint32>();
+	//int32 offset = readScript<uint32>();
 	// simplifying, because used only once in Location 20
 	_vm->loadPath("path2");
 	debugInterpreter("O_LOADPATH - path2");
@@ -1744,6 +1745,7 @@ void Interpreter::O_HEROCOLOR() {
 }
 
 void Interpreter::O_GRABMAPA() {
+	_vm->grabMap();
 	debugInterpreter("O_GRABMAPA");
 }