GOB: Add constants for different surfaces/sprites

Add
static const int kFrontSurface   = 20;
static const int kBackSurface    = 21;
static const int kAnimSurface    = 22;
static const int kCursorSurface  = 23;
static const int kCaptureSurface = 30;
to class Draw and substitute the raw numbers in other files with
those aliases, for readability.

svn-id: r51852

17 files changed, 92 insertions, 87 deletions

diff --git a/engines/gob/draw.cpp b/engines/gob/draw.cpp
index ff6d558998..36b75dc2eb 100644
--- a/engines/gob/draw.cpp
+++ b/engines/gob/draw.cpp
@@ -914,7 +914,7 @@ void Draw::winDraw(int16 fct) {
 	int table[10];
 	SurfaceDescPtr tempSrf;
 
-	if (_destSurface == 21) {
+	if (_destSurface == kBackSurface) {
 
 		if (_vm->_global->_curWinId) {
 			if (_fascinWin[_vm->_global->_curWinId].id == -1)
@@ -1032,7 +1032,7 @@ void Draw::winDraw(int16 fct) {
 					table[_fascinWin[i].id] = i;
 				}
 
-	if ((_sourceSurface == 21) && (fct == 0)) {
+	if ((_sourceSurface == kBackSurface) && (fct == 0)) {
 		_vm->_video->drawSprite(*_spritesArray[_sourceSurface], *_spritesArray[_destSurface],
 								_spriteLeft, _spriteTop, _spriteLeft + _spriteRight - 1,
 								_spriteTop + _spriteBottom - 1, _destSpriteX, _destSpriteY, _transparency);
@@ -1267,11 +1267,11 @@ void Draw::winDraw(int16 fct) {
 	}
 
 	if (_renderFlags & 16) {
-		if (_sourceSurface == 21) {
+		if (_sourceSurface == kBackSurface) {
 			_spriteLeft -= _backDeltaX;
 			_spriteTop -= _backDeltaY;
 		}
-		if (_destSurface == 21) {
+		if (_destSurface == kBackSurface) {
 			_destSpriteX -= _backDeltaX;
 			_destSpriteY -= _backDeltaY;
 		}
@@ -1323,9 +1323,9 @@ void Draw::forceBlit(bool backwards) {
 		return;
 	if (_frontSurface == _backSurface)
 		return;
-	if (_spritesArray[20] != _frontSurface)
+	if (_spritesArray[kFrontSurface] != _frontSurface)
 		return;
-	if (_spritesArray[21] != _backSurface)
+	if (_spritesArray[kBackSurface] != _backSurface)
 		return;
 
 	if (!backwards) {
diff --git a/engines/gob/draw.h b/engines/gob/draw.h
index 8997c53362..fa3cbb84cc 100644
--- a/engines/gob/draw.h
+++ b/engines/gob/draw.h
@@ -45,7 +45,12 @@ namespace Gob {
 
 class Draw {
 public:
-	static const int kFontCount = 8;
+	static const int kFontCount      =  8;
+	static const int kFrontSurface   = 20;
+	static const int kBackSurface    = 21;
+	static const int kAnimSurface    = 22;
+	static const int kCursorSurface  = 23;
+	static const int kCaptureSurface = 30;
 
 	struct FontToSprite {
 		int8 sprite;
diff --git a/engines/gob/draw_fascin.cpp b/engines/gob/draw_fascin.cpp
index 9d30faa972..1e01db7dfb 100644
--- a/engines/gob/draw_fascin.cpp
+++ b/engines/gob/draw_fascin.cpp
@@ -53,12 +53,12 @@ void Draw_Fascination::spriteOperation(int16 operation) {
 		_destSurface -= 80;
 
 	if ((_renderFlags & RENDERFLAG_USEDELTAS) && !deltaVeto) {
-		if ((_sourceSurface == 21) && (operation != DRAW_LOADSPRITE)) {
+		if ((_sourceSurface == kBackSurface) && (operation != DRAW_LOADSPRITE)) {
 			_spriteLeft += _backDeltaX;
 			_spriteTop += _backDeltaY;
 		}
 
-		if (_destSurface == 21) {
+		if (_destSurface == kBackSurface) {
 			_destSpriteX += _backDeltaX;
 			_destSpriteY += _backDeltaY;
 			if ((operation == DRAW_DRAWLINE) ||
@@ -70,7 +70,7 @@ void Draw_Fascination::spriteOperation(int16 operation) {
 	}
 
 	if (_renderFlags & 0x20) {
-		if (_destSurface == 21 || (operation == 0 && _sourceSurface == 21)) {
+		if (_destSurface == kBackSurface || (operation == 0 && _sourceSurface == kBackSurface)) {
 			winDraw(operation);
 			return;
 		}
@@ -86,7 +86,7 @@ void Draw_Fascination::spriteOperation(int16 operation) {
 	int16 destSurface = _destSurface;
 	int16 sourceSurface = _sourceSurface;
 
-	if (_vm->_video->_splitSurf && ((_destSurface == 20) || (_destSurface == 21))) {
+	if (_vm->_video->_splitSurf && ((_destSurface == kFrontSurface) || (_destSurface == kBackSurface))) {
 		if ((_destSpriteY >= _vm->_video->_splitStart)) {
 			_destSpriteY -= _vm->_video->_splitStart;
 			if ((operation == DRAW_DRAWLINE) ||
@@ -340,12 +340,12 @@ void Draw_Fascination::spriteOperation(int16 operation) {
 	}
 
 	if ((_renderFlags & RENDERFLAG_USEDELTAS) && !deltaVeto) {
-		if (_sourceSurface == 21) {
+		if (_sourceSurface == kBackSurface) {
 			_spriteLeft -= _backDeltaX;
 			_spriteTop -= _backDeltaY;
 		}
 
-		if (_destSurface == 21) {
+		if (_destSurface == kBackSurface) {
 			_destSpriteX -= _backDeltaX;
 			_destSpriteY -= _backDeltaY;
 		}
diff --git a/engines/gob/draw_playtoons.cpp b/engines/gob/draw_playtoons.cpp
index 862cdd33eb..583d13986e 100644
--- a/engines/gob/draw_playtoons.cpp
+++ b/engines/gob/draw_playtoons.cpp
@@ -53,12 +53,12 @@ void Draw_Playtoons::spriteOperation(int16 operation) {
 		_destSurface -= 80;
 
 	if ((_renderFlags & RENDERFLAG_USEDELTAS) && !deltaVeto) {
-		if ((_sourceSurface == 21) && (operation != DRAW_LOADSPRITE)) {
+		if ((_sourceSurface == kBackSurface) && (operation != DRAW_LOADSPRITE)) {
 			_spriteLeft += _backDeltaX;
 			_spriteTop += _backDeltaY;
 		}
 
-		if (_destSurface == 21) {
+		if (_destSurface == kBackSurface) {
 			_destSpriteX += _backDeltaX;
 			_destSpriteY += _backDeltaY;
 			if ((operation == DRAW_DRAWLINE) ||
@@ -78,7 +78,7 @@ void Draw_Playtoons::spriteOperation(int16 operation) {
 	int16 destSurface = _destSurface;
 	int16 sourceSurface = _sourceSurface;
 
-	if (_vm->_video->_splitSurf && ((_destSurface == 20) || (_destSurface == 21))) {
+	if (_vm->_video->_splitSurf && ((_destSurface == kFrontSurface) || (_destSurface == kBackSurface))) {
 		if ((_destSpriteY >= _vm->_video->_splitStart)) {
 			_destSpriteY -= _vm->_video->_splitStart;
 			if ((operation == DRAW_DRAWLINE) ||
@@ -409,12 +409,12 @@ void Draw_Playtoons::spriteOperation(int16 operation) {
 	}
 
 	if ((_renderFlags & RENDERFLAG_USEDELTAS) && !deltaVeto) {
-		if (_sourceSurface == 21) {
+		if (_sourceSurface == kBackSurface) {
 			_spriteLeft -= _backDeltaX;
 			_spriteTop -= _backDeltaY;
 		}
 
-		if (_destSurface == 21) {
+		if (_destSurface == kBackSurface) {
 			_destSpriteX -= _backDeltaX;
 			_destSpriteY -= _backDeltaY;
 		}
diff --git a/engines/gob/draw_v1.cpp b/engines/gob/draw_v1.cpp
index 719945fd6f..1cec15ce04 100644
--- a/engines/gob/draw_v1.cpp
+++ b/engines/gob/draw_v1.cpp
@@ -184,7 +184,7 @@ void Draw_v1::printTotText(int16 id) {
 	_destSpriteY = destY;
 	_spriteRight = spriteRight;
 	_spriteBottom = spriteBottom;
-	_destSurface = 21;
+	_destSurface = kBackSurface;
 
 	_backColor = *ptr++;
 	_transparency = 1;
@@ -326,12 +326,12 @@ void Draw_v1::spriteOperation(int16 operation) {
 		_destSurface -= 80;
 
 	if (_renderFlags & RENDERFLAG_USEDELTAS) {
-		if (_sourceSurface == 21) {
+		if (_sourceSurface == kBackSurface) {
 			_spriteLeft += _backDeltaX;
 			_spriteTop += _backDeltaY;
 		}
 
-		if (_destSurface == 21) {
+		if (_destSurface == kBackSurface) {
 			_destSpriteX += _backDeltaX;
 			_destSpriteY += _backDeltaY;
 			if ((operation == DRAW_DRAWLINE) ||
@@ -508,12 +508,12 @@ void Draw_v1::spriteOperation(int16 operation) {
 	}
 
 	if (_renderFlags & RENDERFLAG_USEDELTAS) {
-		if (_sourceSurface == 21) {
+		if (_sourceSurface == kBackSurface) {
 			_spriteLeft -= _backDeltaX;
 			_spriteTop -= _backDeltaY;
 		}
 
-		if (_destSurface == 21) {
+		if (_destSurface == kBackSurface) {
 			_destSpriteX -= _backDeltaX;
 			_destSpriteY -= _backDeltaY;
 		}
diff --git a/engines/gob/draw_v2.cpp b/engines/gob/draw_v2.cpp
index 985f84aaef..5d001f4b59 100644
--- a/engines/gob/draw_v2.cpp
+++ b/engines/gob/draw_v2.cpp
@@ -51,30 +51,30 @@ void Draw_v2::initScreen() {
 	_scrollOffsetX = 0;
 	_scrollOffsetY = 0;
 
-	initSpriteSurf(21, _vm->_video->_surfWidth, _vm->_video->_surfHeight, 0);
-	_backSurface = _spritesArray[21];
+	initSpriteSurf(kBackSurface, _vm->_video->_surfWidth, _vm->_video->_surfHeight, 0);
+	_backSurface = _spritesArray[kBackSurface];
 	_vm->_video->clearSurf(*_backSurface);
 
-	if (!_spritesArray[23]) {
-		initSpriteSurf(23, 32, 16, 2);
-		_cursorSpritesBack = _spritesArray[23];
+	if (!_spritesArray[kCursorSurface]) {
+		initSpriteSurf(kCursorSurface, 32, 16, 2);
+		_cursorSpritesBack = _spritesArray[kCursorSurface];
 		_cursorSprites = _cursorSpritesBack;
 		_scummvmCursor =
 			_vm->_video->initSurfDesc(_vm->_global->_videoMode, 16, 16, SCUMMVM_CURSOR);
 	}
 
-	_spritesArray[20] = _frontSurface;
-	_spritesArray[21] = _backSurface;
+	_spritesArray[kFrontSurface] = _frontSurface;
+	_spritesArray[kBackSurface ] = _backSurface;
 
 	_vm->_video->dirtyRectsAll();
 }
 
 void Draw_v2::closeScreen() {
-	//freeSprite(23);
+	//freeSprite(kCursorSurface);
 	//_cursorSprites = 0;
 	//_cursorSpritesBack = 0;
 	//_scummvmCursor = 0;
-	freeSprite(21);
+	freeSprite(kBackSurface);
 }
 
 void Draw_v2::blitCursor() {
@@ -273,7 +273,7 @@ void Draw_v2::printTotText(int16 id) {
 	_destSpriteY = destY;
 	_spriteRight = spriteRight;
 	_spriteBottom = spriteBottom;
-	_destSurface = 21;
+	_destSurface = kBackSurface;
 
 	_backColor = *ptr++;
 	_transparency = 1;
@@ -629,12 +629,12 @@ void Draw_v2::spriteOperation(int16 operation) {
 		_destSurface -= 80;
 
 	if ((_renderFlags & RENDERFLAG_USEDELTAS) && !deltaVeto) {
-		if ((_sourceSurface == 21) && (operation != DRAW_LOADSPRITE)) {
+		if ((_sourceSurface == kBackSurface) && (operation != DRAW_LOADSPRITE)) {
 			_spriteLeft += _backDeltaX;
 			_spriteTop += _backDeltaY;
 		}
 
-		if (_destSurface == 21) {
+		if (_destSurface == kBackSurface) {
 			_destSpriteX += _backDeltaX;
 			_destSpriteY += _backDeltaY;
 			if ((operation == DRAW_DRAWLINE) ||
@@ -654,7 +654,7 @@ void Draw_v2::spriteOperation(int16 operation) {
 	int16 destSurface = _destSurface;
 	int16 sourceSurface = _sourceSurface;
 
-	if (_vm->_video->_splitSurf && ((_destSurface == 20) || (_destSurface == 21))) {
+	if (_vm->_video->_splitSurf && ((_destSurface == kFrontSurface) || (_destSurface == kBackSurface))) {
 		if ((_destSpriteY >= _vm->_video->_splitStart)) {
 			_destSpriteY -= _vm->_video->_splitStart;
 			if ((operation == DRAW_DRAWLINE) ||
@@ -908,12 +908,12 @@ void Draw_v2::spriteOperation(int16 operation) {
 	}
 
 	if ((_renderFlags & RENDERFLAG_USEDELTAS) && !deltaVeto) {
-		if (_sourceSurface == 21) {
+		if (_sourceSurface == kBackSurface) {
 			_spriteLeft -= _backDeltaX;
 			_spriteTop -= _backDeltaY;
 		}
 
-		if (_destSurface == 21) {
+		if (_destSurface == kBackSurface) {
 			_destSpriteX -= _backDeltaX;
 			_destSpriteY -= _backDeltaY;
 		}
diff --git a/engines/gob/game.cpp b/engines/gob/game.cpp
index ddf095a5d1..1e6f078499 100644
--- a/engines/gob/game.cpp
+++ b/engines/gob/game.cpp
@@ -286,8 +286,8 @@ void Game::playTot(int16 skipPlay) {
 				_vm->_mult->initAll();
 				_vm->_mult->zeroMultData();
 
-				_vm->_draw->_spritesArray[20] = _vm->_draw->_frontSurface;
-				_vm->_draw->_spritesArray[21] = _vm->_draw->_backSurface;
+				_vm->_draw->_spritesArray[Draw::kFrontSurface] = _vm->_draw->_frontSurface;
+				_vm->_draw->_spritesArray[Draw::kBackSurface ] = _vm->_draw->_backSurface;
 				_vm->_draw->_cursorSpritesBack = _vm->_draw->_cursorSprites;
 			} else
 				_vm->_inter->initControlVars(0);
@@ -397,10 +397,10 @@ void Game::capturePush(int16 left, int16 top, int16 width, int16 height) {
 	left &= 0xFFF0;
 	right |= 0xF;
 
-	_vm->_draw->initSpriteSurf(30 + _captureCount, right - left + 1, height, 0);
+	_vm->_draw->initSpriteSurf(Draw::kCaptureSurface + _captureCount, right - left + 1, height, 0);
 
-	_vm->_draw->_sourceSurface = 21;
-	_vm->_draw->_destSurface = 30 + _captureCount;
+	_vm->_draw->_sourceSurface = Draw::kBackSurface;
+	_vm->_draw->_destSurface = Draw::kCaptureSurface + _captureCount;
 
 	_vm->_draw->_spriteLeft = left;
 	_vm->_draw->_spriteRight = right - left + 1;
@@ -425,13 +425,13 @@ void Game::capturePop(char doDraw) {
 		    _captureStack[_captureCount].height();
 
 		_vm->_draw->_transparency = 0;
-		_vm->_draw->_sourceSurface = 30 + _captureCount;
-		_vm->_draw->_destSurface = 21;
+		_vm->_draw->_sourceSurface = Draw::kCaptureSurface + _captureCount;
+		_vm->_draw->_destSurface = Draw::kBackSurface;
 		_vm->_draw->_spriteLeft = _vm->_draw->_destSpriteX & 0xF;
 		_vm->_draw->_spriteTop = 0;
 		_vm->_draw->spriteOperation(0);
 	}
-	_vm->_draw->freeSprite(30 + _captureCount);
+	_vm->_draw->freeSprite(Draw::kCaptureSurface + _captureCount);
 }
 
 void Game::freeSoundSlot(int16 slot) {
diff --git a/engines/gob/hotspots.cpp b/engines/gob/hotspots.cpp
index abdf513393..396d9f0a22 100644
--- a/engines/gob/hotspots.cpp
+++ b/engines/gob/hotspots.cpp
@@ -2082,7 +2082,7 @@ void Hotspots::getTextCursorPos(const Font &font, const char *str,
 }
 
 void Hotspots::fillRect(uint16 x, uint16 y, uint16 width, uint16 height, uint16 color) const {
-	_vm->_draw->_destSurface  = 21;
+	_vm->_draw->_destSurface  = Draw::kBackSurface;
 	_vm->_draw->_destSpriteX  = x;
 	_vm->_draw->_destSpriteY  = y;
 	_vm->_draw->_spriteRight  = width;
diff --git a/engines/gob/inter_playtoons.cpp b/engines/gob/inter_playtoons.cpp
index 142467b47f..befed4b1c2 100644
--- a/engines/gob/inter_playtoons.cpp
+++ b/engines/gob/inter_playtoons.cpp
@@ -107,7 +107,7 @@ bool Inter_Playtoons::oPlaytoons_printText(OpFuncParams &params) {
 	_vm->_draw->_backColor = _vm->_game->_script->readValExpr();
 	_vm->_draw->_frontColor = _vm->_game->_script->readValExpr();
 	_vm->_draw->_fontIndex = _vm->_game->_script->readValExpr();
-	_vm->_draw->_destSurface = 21;
+	_vm->_draw->_destSurface = Draw::kBackSurface;
 	_vm->_draw->_textToPrint = buf;
 	_vm->_draw->_transparency = 0;
 
diff --git a/engines/gob/inter_v1.cpp b/engines/gob/inter_v1.cpp
index 9e841e7e68..11fe0c9c5e 100644
--- a/engines/gob/inter_v1.cpp
+++ b/engines/gob/inter_v1.cpp
@@ -328,7 +328,7 @@ void Inter_v1::o1_initCursor() {
 			(height != _vm->_draw->_cursorHeight) ||
 	    (_vm->_draw->_cursorSprites->getWidth() != (width * count))) {
 
-		_vm->_draw->freeSprite(23);
+		_vm->_draw->freeSprite(Draw::kCursorSurface);
 		_vm->_draw->_cursorSprites.reset();
 		_vm->_draw->_cursorSpritesBack.reset();
 		_vm->_draw->_scummvmCursor.reset();
@@ -344,9 +344,9 @@ void Inter_v1::o1_initCursor() {
 		if (count > 0x80)
 			count -= 0x80;
 
-		_vm->_draw->initSpriteSurf(23, _vm->_draw->_cursorWidth * count,
+		_vm->_draw->initSpriteSurf(Draw::kCursorSurface, _vm->_draw->_cursorWidth * count,
 				_vm->_draw->_cursorHeight, 2);
-		_vm->_draw->_cursorSpritesBack = _vm->_draw->_spritesArray[23];
+		_vm->_draw->_cursorSpritesBack = _vm->_draw->_spritesArray[Draw::kCursorSurface];
 		_vm->_draw->_cursorSprites = _vm->_draw->_cursorSpritesBack;
 
 		_vm->_draw->_scummvmCursor =
@@ -482,14 +482,14 @@ void Inter_v1::o1_initMult() {
 	if (_vm->_mult->_animSurf &&
 	    ((oldAnimWidth != _vm->_mult->_animWidth) ||
 			 (oldAnimHeight != _vm->_mult->_animHeight))) {
-		_vm->_draw->freeSprite(22);
+		_vm->_draw->freeSprite(Draw::kAnimSurface);
 		_vm->_mult->_animSurf.reset();
 	}
 
 	if (!_vm->_mult->_animSurf) {
-		_vm->_draw->initSpriteSurf(22, _vm->_mult->_animWidth,
+		_vm->_draw->initSpriteSurf(Draw::kAnimSurface, _vm->_mult->_animWidth,
 				_vm->_mult->_animHeight, 0);
-		_vm->_mult->_animSurf = _vm->_draw->_spritesArray[22];
+		_vm->_mult->_animSurf = _vm->_draw->_spritesArray[Draw::kAnimSurface];
 	}
 
 	_vm->_video->drawSprite(*_vm->_draw->_backSurface, *_vm->_mult->_animSurf,
@@ -922,7 +922,7 @@ bool Inter_v1::o1_printText(OpFuncParams &params) {
 	_vm->_draw->_backColor = _vm->_game->_script->readValExpr();
 	_vm->_draw->_frontColor = _vm->_game->_script->readValExpr();
 	_vm->_draw->_fontIndex = _vm->_game->_script->readValExpr();
-	_vm->_draw->_destSurface = 21;
+	_vm->_draw->_destSurface = Draw::kBackSurface;
 	_vm->_draw->_textToPrint = buf;
 	_vm->_draw->_transparency = 0;
 
diff --git a/engines/gob/inter_v2.cpp b/engines/gob/inter_v2.cpp
index 72764eec8d..ffca639cc4 100644
--- a/engines/gob/inter_v2.cpp
+++ b/engines/gob/inter_v2.cpp
@@ -360,24 +360,24 @@ void Inter_v2::o2_initMult() {
 	if (_vm->_mult->_animSurf &&
 	    ((oldAnimWidth != _vm->_mult->_animWidth) ||
 			 (oldAnimHeight != _vm->_mult->_animHeight))) {
-		_vm->_draw->freeSprite(22);
+		_vm->_draw->freeSprite(Draw::kAnimSurface);
 		_vm->_mult->_animSurf.reset();
 	}
 
 	_vm->_draw->adjustCoords(0,
 			&_vm->_mult->_animWidth, &_vm->_mult->_animHeight);
 	if (!_vm->_mult->_animSurf) {
-		_vm->_draw->initSpriteSurf(22, _vm->_mult->_animWidth,
+		_vm->_draw->initSpriteSurf(Draw::kAnimSurface, _vm->_mult->_animWidth,
 				_vm->_mult->_animHeight, 0);
-		_vm->_mult->_animSurf = _vm->_draw->_spritesArray[22];
+		_vm->_mult->_animSurf = _vm->_draw->_spritesArray[Draw::kAnimSurface];
 		if (_terminate)
 			return;
 	}
 
 	_vm->_draw->adjustCoords(1,
 			&_vm->_mult->_animWidth, &_vm->_mult->_animHeight);
-	_vm->_draw->_sourceSurface = 21;
-	_vm->_draw->_destSurface = 22;
+	_vm->_draw->_sourceSurface = Draw::kBackSurface;
+	_vm->_draw->_destSurface = Draw::kAnimSurface;
 	_vm->_draw->_spriteLeft = _vm->_mult->_animLeft;
 	_vm->_draw->_spriteTop = _vm->_mult->_animTop;
 	_vm->_draw->_spriteRight = _vm->_mult->_animWidth;
@@ -1106,7 +1106,7 @@ bool Inter_v2::o2_printText(OpFuncParams &params) {
 	_vm->_draw->_backColor = _vm->_game->_script->readValExpr();
 	_vm->_draw->_frontColor = _vm->_game->_script->readValExpr();
 	_vm->_draw->_fontIndex = _vm->_game->_script->readValExpr();
-	_vm->_draw->_destSurface = 21;
+	_vm->_draw->_destSurface = Draw::kBackSurface;
 	_vm->_draw->_textToPrint = buf;
 	_vm->_draw->_transparency = 0;
 
diff --git a/engines/gob/inter_v3.cpp b/engines/gob/inter_v3.cpp
index beace1b7d8..10ed23619d 100644
--- a/engines/gob/inter_v3.cpp
+++ b/engines/gob/inter_v3.cpp
@@ -253,8 +253,8 @@ bool Inter_v3::o3_copySprite(OpFuncParams &params) {
 	o1_copySprite(params);
 
 	// For the close-up "fading" in the CD version
-	if (_vm->_draw->_destSurface == 20)
-		_vm->_video->sparseRetrace(20);
+	if (_vm->_draw->_destSurface == Draw::kFrontSurface)
+		_vm->_video->sparseRetrace(Draw::kFrontSurface);
 	return false;
 }
 
diff --git a/engines/gob/mult.cpp b/engines/gob/mult.cpp
index 327b3ed1bd..667cd0d758 100644
--- a/engines/gob/mult.cpp
+++ b/engines/gob/mult.cpp
@@ -146,7 +146,7 @@ void Mult::freeMult() {
 	_orderArray = 0;
 
 	_animSurf.reset();
-	_vm->_draw->freeSprite(22);
+	_vm->_draw->freeSprite(Draw::kAnimSurface);
 }
 
 void Mult::checkFreeMult() {
@@ -238,7 +238,7 @@ void Mult::playMult(int16 startFrame, int16 endFrame, char checkEscape,
 			_orderArray = 0;
 
 			_animSurf.reset();
-			_vm->_draw->freeSprite(22);
+			_vm->_draw->freeSprite(Draw::kAnimSurface);
 
 			_animDataAllocated = false;
 		}
diff --git a/engines/gob/mult_v1.cpp b/engines/gob/mult_v1.cpp
index 1bb162c789..84869066e1 100644
--- a/engines/gob/mult_v1.cpp
+++ b/engines/gob/mult_v1.cpp
@@ -236,7 +236,7 @@ void Mult_v1::freeMultKeys() {
 		_animArrayData = 0;
 
 		_animSurf.reset();
-		_vm->_draw->freeSprite(22);
+		_vm->_draw->freeSprite(Draw::kAnimSurface);
 
 		_animDataAllocated = false;
 	}
@@ -318,7 +318,7 @@ void Mult_v1::playMultInit() {
 
 		_animSurf = _vm->_video->initSurfDesc(_vm->_global->_videoMode,
 				320, 200, 0);
-		_vm->_draw->_spritesArray[22] = _animSurf;
+		_vm->_draw->_spritesArray[Draw::kAnimSurface] = _animSurf;
 
 		_vm->_video->drawSprite(*_vm->_draw->_backSurface,
 			*_animSurf, 0, 0, 319, 199, 0, 0, 0);
@@ -579,8 +579,8 @@ void Mult_v1::animate() {
 		if ((pNeedRedraw[i] == 0) || (_objects[i].lastLeft == -1))
 			continue;
 
-		_vm->_draw->_sourceSurface = 22;
-		_vm->_draw->_destSurface = 21;
+		_vm->_draw->_sourceSurface = Draw::kAnimSurface;
+		_vm->_draw->_destSurface = Draw::kBackSurface;
 		_vm->_draw->_spriteLeft = pDirtyLefts[i] - _animLeft;
 		_vm->_draw->_spriteTop = pDirtyTops[i] - _animTop;
 		_vm->_draw->_spriteRight = pDirtyRights[i] - pDirtyLefts[i] + 1;
diff --git a/engines/gob/mult_v2.cpp b/engines/gob/mult_v2.cpp
index 6dcc01f836..9faf446a5b 100644
--- a/engines/gob/mult_v2.cpp
+++ b/engines/gob/mult_v2.cpp
@@ -579,11 +579,11 @@ void Mult_v2::playMultInit() {
 		width = _animWidth;
 		height = _animHeight;
 		_vm->_draw->adjustCoords(0, &width, &height);
-		_vm->_draw->initSpriteSurf(22, width, height, 0);
-		_animSurf = _vm->_draw->_spritesArray[22];
+		_vm->_draw->initSpriteSurf(Draw::kAnimSurface, width, height, 0);
+		_animSurf = _vm->_draw->_spritesArray[Draw::kAnimSurface];
 
-		_vm->_video->drawSprite(*_vm->_draw->_spritesArray[21],
-				*_vm->_draw->_spritesArray[22], 0, 0,
+		_vm->_video->drawSprite(*_vm->_draw->_spritesArray[Draw::kBackSurface],
+				*_vm->_draw->_spritesArray[Draw::kAnimSurface], 0, 0,
 				_vm->_video->_surfWidth, _vm->_video->_surfHeight, 0, 0, 0);
 
 		for (_counter = 0; _counter < _objCount; _counter++)
@@ -633,14 +633,14 @@ void Mult_v2::drawStatics(bool &stop) {
 				READ_LE_UINT16(_multData->execPtr + layer * 2);
 			_vm->_draw->_destSpriteX = 0;
 			_vm->_draw->_destSpriteY = 0;
-			_vm->_draw->_destSurface = 21;
+			_vm->_draw->_destSurface = Draw::kBackSurface;
 			_vm->_draw->_transparency = 0;
 			_vm->_draw->spriteOperation(DRAW_LOADSPRITE);
 			_vm->_scenery->_curStatic = -1;
 		}
 
-		_vm->_video->drawSprite(*_vm->_draw->_spritesArray[21],
-				*_vm->_draw->_spritesArray[22], 0, 0,
+		_vm->_video->drawSprite(*_vm->_draw->_spritesArray[Draw::kBackSurface],
+				*_vm->_draw->_spritesArray[Draw::kAnimSurface], 0, 0,
 				_vm->_video->_surfWidth, _vm->_video->_surfHeight, 0, 0, 0);
 	}
 }
@@ -937,8 +937,8 @@ void Mult_v2::animate() {
 		if ((right <= 0) || (bottom <= 0))
 			continue;
 
-		_vm->_draw->_sourceSurface = 22;
-		_vm->_draw->_destSurface = 21;
+		_vm->_draw->_sourceSurface = Draw::kAnimSurface;
+		_vm->_draw->_destSurface = Draw::kBackSurface;
 		_vm->_draw->_spriteLeft = maxleft - _animLeft;
 		_vm->_draw->_spriteTop = maxtop - _animTop;
 		_vm->_draw->_spriteRight = right;
diff --git a/engines/gob/scenery.cpp b/engines/gob/scenery.cpp
index edd2051f1a..89adffc5ea 100644
--- a/engines/gob/scenery.cpp
+++ b/engines/gob/scenery.cpp
@@ -261,10 +261,10 @@ void Scenery::renderStatic(int16 scenery, int16 layer) {
 
 	_vm->_draw->_spriteLeft = layerPtr->backResId;
 	if (_vm->_draw->_spriteLeft != -1) {
-		_vm->_draw->_destSpriteX  =  0;
-		_vm->_draw->_destSpriteY  =  0;
-		_vm->_draw->_destSurface  = 21;
-		_vm->_draw->_transparency =  0;
+		_vm->_draw->_destSpriteX  = 0;
+		_vm->_draw->_destSpriteY  = 0;
+		_vm->_draw->_destSurface  = Draw::kBackSurface;
+		_vm->_draw->_transparency = 0;
 		_vm->_draw->spriteOperation(DRAW_LOADSPRITE);
 	}
 
@@ -295,7 +295,7 @@ void Scenery::renderStatic(int16 scenery, int16 layer) {
 
 			_vm->_draw->_sourceSurface =
 			    _staticPictToSprite[scenery * 7 + pictIndex];
-			_vm->_draw->_destSurface   = 21;
+			_vm->_draw->_destSurface   = Draw::kBackSurface;
 			_vm->_draw->_spriteLeft    = left;
 			_vm->_draw->_spriteTop     = top;
 			_vm->_draw->_spriteRight   = right - left + 1;
@@ -392,7 +392,7 @@ void Scenery::updateStatic(int16 orderFrom, byte index, byte layer) {
 
 			_vm->_draw->_sourceSurface =
 			    _staticPictToSprite[index * 7 + pictIndex];
-			_vm->_draw->_destSurface   = 21;
+			_vm->_draw->_destSurface   = Draw::kBackSurface;
 			_vm->_draw->_transparency  = planePtr->transp ? 3 : 0;
 			_vm->_draw->spriteOperation(DRAW_BLITSURF);
 		}
@@ -880,7 +880,7 @@ void Scenery::updateAnim(int16 layer, int16 frame, int16 animation, int16 flags,
 		if (doDraw) {
 			_vm->_draw->_sourceSurface =
 			    _animPictToSprite[animation * 7 + pictIndex];
-			_vm->_draw->_destSurface   = 21;
+			_vm->_draw->_destSurface   = Draw::kBackSurface;
 
 			_vm->_draw->_spriteLeft   = left;
 			_vm->_draw->_spriteTop    = top;
diff --git a/engines/gob/videoplayer.cpp b/engines/gob/videoplayer.cpp
index bdab7fcac1..50cb64dfad 100644
--- a/engines/gob/videoplayer.cpp
+++ b/engines/gob/videoplayer.cpp
@@ -38,7 +38,7 @@
 
 namespace Gob {
 
-VideoPlayer::Properties::Properties() : type(kVideoTypeTry), sprite(20),
+VideoPlayer::Properties::Properties() : type(kVideoTypeTry), sprite(Draw::kFrontSurface),
 	x(-1), y(-1), width(-1), height(-1), flags(kFlagFrontSurface),
 	startFrame(-1), lastFrame(-1), breakKey(kShortKeyEscape),
 	palCmd(8), palStart(0), palEnd(255), palFrame(-1), fade(false) {
@@ -418,7 +418,7 @@ bool VideoPlayer::primaryOpen(const char *videoFile, int16 x, int16 y,
 				_vm->_draw->_spritesArray[0] = surf;
 			} else {
 				_backSurf = ((flags & kFlagFrontSurface) == 0);
-				surf = _vm->_draw->_spritesArray[_backSurf ? 21 : 20];
+				surf = _vm->_draw->_spritesArray[_backSurf ? Draw::kBackSurface : Draw::kFrontSurface];
 			}
 
 			/*