WINTERMUTE: Add binary alpha-blitting.

For now, no RLE, or anything, but the infrastructure for it
is put in place here.

6 files changed, 71 insertions, 23 deletions

diff --git a/engines/wintermute/base/gfx/osystem/base_surface_osystem.cpp b/engines/wintermute/base/gfx/osystem/base_surface_osystem.cpp
index aed0129b3a..6506abd29c 100644
--- a/engines/wintermute/base/gfx/osystem/base_surface_osystem.cpp
+++ b/engines/wintermute/base/gfx/osystem/base_surface_osystem.cpp
@@ -48,7 +48,7 @@ namespace Wintermute {
 BaseSurfaceOSystem::BaseSurfaceOSystem(BaseGame *inGame) : BaseSurface(inGame) {
 	_surface = new Graphics::Surface();
 	_alphaMask = nullptr;
-	_alphaType = ALPHA_FULL;
+	_alphaType = TransparentSurface::ALPHA_FULL;
 	_lockPixels = nullptr;
 	_lockPitch = 0;
 	_loaded = false;
@@ -71,10 +71,10 @@ BaseSurfaceOSystem::~BaseSurfaceOSystem() {
 	renderer->invalidateTicketsFromSurface(this);
 }
 
-AlphaType hasTransparencyType(const Graphics::Surface *surf) {
+TransparentSurface::AlphaType hasTransparencyType(const Graphics::Surface *surf) {
 	if (surf->format.bytesPerPixel != 4) {
 		warning("hasTransparencyType:: non 32 bpp surface passed as argument");
-		return ALPHA_OPAQUE;
+		return TransparentSurface::ALPHA_OPAQUE;
 	}
 	uint8 r, g, b, a;
 	bool seenAlpha = false;
@@ -96,11 +96,11 @@ AlphaType hasTransparencyType(const Graphics::Surface *surf) {
 		}
 	}
 	if (seenFullAlpha) {
-		return ALPHA_FULL;
+		return TransparentSurface::ALPHA_FULL;
 	} else if (seenAlpha) {
-		return ALPHA_BINARY;
+		return TransparentSurface::ALPHA_BINARY;
 	} else {
-		return ALPHA_OPAQUE;
+		return TransparentSurface::ALPHA_OPAQUE;
 	}
 }
 
@@ -438,7 +438,7 @@ bool BaseSurfaceOSystem::drawSprite(int x, int y, Rect32 *rect, Rect32 *newRect,
 	// But no checking is in place for that yet.
 
 	// Optimize by not doing alpha-blits if we lack alpha
-	if (_alphaType == ALPHA_OPAQUE && !transform._alphaDisable) {
+	if (_alphaType == TransparentSurface::ALPHA_OPAQUE && !transform._alphaDisable) {
 		transform._alphaDisable = true;
 	}
 
@@ -457,9 +457,9 @@ bool BaseSurfaceOSystem::putSurface(const Graphics::Surface &surface, bool hasAl
 	_surface->free();
 	_surface->copyFrom(surface);
 	if (hasAlpha) {
-		_alphaType = ALPHA_FULL;
+		_alphaType = TransparentSurface::ALPHA_FULL;
 	} else {
-		_alphaType = ALPHA_OPAQUE;
+		_alphaType = TransparentSurface::ALPHA_OPAQUE;
 	}
 	BaseRenderOSystem *renderer = static_cast<BaseRenderOSystem *>(_gameRef->_renderer);
 	renderer->invalidateTicketsFromSurface(this);
diff --git a/engines/wintermute/base/gfx/osystem/base_surface_osystem.h b/engines/wintermute/base/gfx/osystem/base_surface_osystem.h
index ad1e9cf737..6cf19d00fb 100644
--- a/engines/wintermute/base/gfx/osystem/base_surface_osystem.h
+++ b/engines/wintermute/base/gfx/osystem/base_surface_osystem.h
@@ -30,6 +30,7 @@
 #define WINTERMUTE_BASE_SURFACESDL_H
 
 #include "graphics/surface.h"
+#include "engines/wintermute/graphics/transparent_surface.h"
 #include "engines/wintermute/base/gfx/base_surface.h"
 #include "common/list.h"
 
@@ -81,6 +82,7 @@ public:
 		return _height;
 	}
 
+	TransparentSurface::AlphaType getAlphaType() const { return _alphaType; }
 private:
 	Graphics::Surface *_surface;
 	bool _loaded;
@@ -90,7 +92,7 @@ private:
 	uint32 getPixelAt(Graphics::Surface *surface, int x, int y);
 
 	uint32 _rotation;
-	AlphaType _alphaType;
+	TransparentSurface::AlphaType _alphaType;
 	void *_lockPixels;
 	int _lockPitch;
 	byte *_alphaMask;
diff --git a/engines/wintermute/base/gfx/osystem/render_ticket.cpp b/engines/wintermute/base/gfx/osystem/render_ticket.cpp
index 98739e0778..b1720c1b0b 100644
--- a/engines/wintermute/base/gfx/osystem/render_ticket.cpp
+++ b/engines/wintermute/base/gfx/osystem/render_ticket.cpp
@@ -28,6 +28,7 @@
 
 
 #include "engines/wintermute/base/gfx/osystem/render_ticket.h"
+#include "engines/wintermute/base/gfx/osystem/base_surface_osystem.h"
 #include "engines/wintermute/graphics/transform_tools.h"
 #include "common/textconsole.h"
 
@@ -104,7 +105,13 @@ void RenderTicket::drawToSurface(Graphics::Surface *_targetSurface) const {
 	clipRect.setWidth(getSurface()->w);
 	clipRect.setHeight(getSurface()->h);
 
-	src._enableAlphaBlit = !_transform._alphaDisable;
+	if (_owner) {
+		if (_transform._alphaDisable) {
+			src._alphaMode = TransparentSurface::ALPHA_OPAQUE;
+		} else {
+			src._alphaMode = _owner->getAlphaType();
+		}
+	}
 	src.blit(*_targetSurface, _dstRect.left, _dstRect.top, _transform._flip, &clipRect, _transform._rgbaMod, clipRect.width(), clipRect.height());
 }
 
@@ -118,7 +125,13 @@ void RenderTicket::drawToSurface(Graphics::Surface *_targetSurface, Common::Rect
 		clipRect->setHeight(getSurface()->h);
 	}
 
-	src._enableAlphaBlit = !_transform._alphaDisable; 
+	if (_owner) {
+		if (_transform._alphaDisable) {
+			src._alphaMode = TransparentSurface::ALPHA_OPAQUE;
+		} else {
+			src._alphaMode = _owner->getAlphaType();
+		}
+	}
 	src.blit(*_targetSurface, dstRect->left, dstRect->top, _transform._flip, clipRect, _transform._rgbaMod, clipRect->width(), clipRect->height());
 	if (doDelete) {
 		delete clipRect;
diff --git a/engines/wintermute/graphics/transform_struct.h b/engines/wintermute/graphics/transform_struct.h
index f4f97d1ea9..a54c4cc5d0 100644
--- a/engines/wintermute/graphics/transform_struct.h
+++ b/engines/wintermute/graphics/transform_struct.h
@@ -42,12 +42,6 @@ const int32 kDefaultOffsetX = 0;
 const int32 kDefaultOffsetY = 0;
 const int32 kDefaultAngle = 0;
 
-enum AlphaType {
-	ALPHA_OPAQUE = 0,
-	ALPHA_BINARY = 1,
-	ALPHA_FULL = 2
-};
-
 struct TransformStruct {
 private:
 	void init(Point32 zoom, uint32 angle, Point32 hotspot, bool alphaDisable, TSpriteBlendMode blendMode, uint32 alpha, bool mirrorX, bool mirrorY, Point32 offset);
diff --git a/engines/wintermute/graphics/transparent_surface.cpp b/engines/wintermute/graphics/transparent_surface.cpp
index 9539b68c85..249d30f7d9 100644
--- a/engines/wintermute/graphics/transparent_surface.cpp
+++ b/engines/wintermute/graphics/transparent_surface.cpp
@@ -140,9 +140,9 @@ void TransparentSurface::copyPixelNearestNeighbor(float projX, float projY, int
 }
 #endif
 
-TransparentSurface::TransparentSurface() : Surface(), _enableAlphaBlit(true) {}
+TransparentSurface::TransparentSurface() : Surface(), _alphaMode(ALPHA_FULL) {}
 
-TransparentSurface::TransparentSurface(const Surface &surf, bool copyData) : Surface(), _enableAlphaBlit(true) {
+TransparentSurface::TransparentSurface(const Surface &surf, bool copyData) : Surface(), _alphaMode(ALPHA_FULL) {
 	if (copyData) {
 		copyFrom(surf);
 	} else {
@@ -179,6 +179,37 @@ void doBlitOpaque(byte *ino, byte *outo, uint32 width, uint32 height, uint32 pit
 	}
 }
 
+void doBlitBinary(byte *ino, byte *outo, uint32 width, uint32 height, uint32 pitch, int32 inStep, int32 inoStep) {
+	byte *in, *out;
+	
+#ifdef SCUMM_LITTLE_ENDIAN
+	const int aIndex = 0;
+#else
+	const int aIndex = 3;
+#endif
+	const int aShift = 0;//img->format.aShift;
+
+	for (uint32 i = 0; i < height; i++) {
+		out = outo;
+		in = ino;
+		for (uint32 j = 0; j < width; j++) {
+			uint32 pix = *(uint32 *)in;
+			int a = (pix >> aShift) & 0xff;
+			in += inStep;
+
+			if (a == 0) { // Full transparency
+				out += 4;
+			} else { // Full opacity (Any value not exactly 0 is Opaque here)
+				*(uint32 *)out = pix;
+				out[aIndex] = 0xFF;
+				out += 4;
+			}
+		}
+		outo += pitch;
+		ino += inoStep;
+	}
+}
+
 void doBlitAlpha(byte *ino, byte *outo, uint32 width, uint32 height, uint32 pitch, int32 inStep, int32 inoStep) {
 	byte *in, *out;
 
@@ -388,9 +419,11 @@ Common::Rect TransparentSurface::blit(Graphics::Surface &target, int posX, int p
 		const int rShiftTarget = 24;//target.format.rShift;
 
 		if (ca == 255 && cb == 255 && cg == 255 && cr == 255) {
-			if (_enableAlphaBlit) {
+			if (_alphaMode == ALPHA_FULL) {
 				doBlitAlpha(ino, outo, img->w, img->h, target.pitch, inStep, inoStep);
-			} else {
+			} else if (_alphaMode == ALPHA_BINARY) {
+				doBlitBinary(ino, outo, img->w, img->h, target.pitch, inStep, inoStep);
+			} else if (_alphaMode == ALPHA_OPAQUE) {
 				doBlitOpaque(ino, outo, img->w, img->h, target.pitch, inStep, inoStep);
 			}
 		} else {
diff --git a/engines/wintermute/graphics/transparent_surface.h b/engines/wintermute/graphics/transparent_surface.h
index 828c4dd9a9..598aaa55d7 100644
--- a/engines/wintermute/graphics/transparent_surface.h
+++ b/engines/wintermute/graphics/transparent_surface.h
@@ -75,7 +75,13 @@ struct TransparentSurface : public Graphics::Surface {
 		FLIP_VH = FLIP_H | FLIP_V
 	};
 
-	bool _enableAlphaBlit;
+	enum AlphaType {
+		ALPHA_OPAQUE = 0,
+		ALPHA_BINARY = 1,
+		ALPHA_FULL = 2
+	};
+
+	AlphaType _alphaMode;
 
 	/**
 	 @brief renders the surface to another surface