GRAPHICS: Serialize PixelFormat for thumbnails and allow 4Bpp surfaces.

This allows any 2Bpp/4Bpp Surfaces to be written via saveThumbnail
and loadThumbnail now. It furthermore will preserve the loaded Surface
in loadThumbnail.

2 files changed, 73 insertions, 25 deletions

diff --git a/graphics/thumbnail.cpp b/graphics/thumbnail.cpp
index db61d828d2..ddb377306d 100644
--- a/graphics/thumbnail.cpp
+++ b/graphics/thumbnail.cpp
@@ -30,17 +30,17 @@
 namespace Graphics {
 
 namespace {
-#define THMB_VERSION 1
+#define THMB_VERSION 2
 
 struct ThumbnailHeader {
 	uint32 type;
 	uint32 size;
 	byte version;
 	uint16 width, height;
-	byte bpp;
+	PixelFormat format;
 };
 
-#define ThumbnailHeaderSize (4+4+1+2+2+1)
+#define ThumbnailHeaderSize (4+4+1+2+2+(1+4+4))
 
 bool loadHeader(Common::SeekableReadStream &in, ThumbnailHeader &header, bool outputWarnings) {
 	header.type = in.readUint32BE();
@@ -64,7 +64,22 @@ bool loadHeader(Common::SeekableReadStream &in, ThumbnailHeader &header, bool ou
 
 	header.width = in.readUint16BE();
 	header.height = in.readUint16BE();
-	header.bpp = in.readByte();
+	header.format.bytesPerPixel = in.readByte();
+	// Starting from version 2 on we serialize the whole PixelFormat.
+	if (header.version >= 2) {
+		header.format.rLoss = in.readByte();
+		header.format.gLoss = in.readByte();
+		header.format.bLoss = in.readByte();
+		header.format.aLoss = in.readByte();
+
+		header.format.rShift = in.readByte();
+		header.format.gShift = in.readByte();
+		header.format.bShift = in.readByte();
+		header.format.aShift = in.readByte();
+	} else {
+		// Version 1 used a hardcoded RGB565.
+		header.format = createPixelFormat<565>();
+	}
 
 	return true;
 }
@@ -100,23 +115,32 @@ Graphics::Surface *loadThumbnail(Common::SeekableReadStream &in) {
 	if (!loadHeader(in, header, true))
 		return 0;
 
-	if (header.bpp != 2) {
-		warning("trying to load thumbnail with unsupported bit depth %d", header.bpp);
+	if (header.format.bytesPerPixel != 2 && header.format.bytesPerPixel != 4) {
+		warning("trying to load thumbnail with unsupported bit depth %d", header.format.bytesPerPixel);
 		return 0;
 	}
 
-	Graphics::PixelFormat format = g_system->getOverlayFormat();
 	Graphics::Surface *const to = new Graphics::Surface();
-	to->create(header.width, header.height, format);
+	to->create(header.width, header.height, header.format);
 
-	OverlayColor *pixels = (OverlayColor *)to->pixels;
 	for (int y = 0; y < to->h; ++y) {
-		for (int x = 0; x < to->w; ++x) {
-			uint8 r, g, b;
-			colorToRGB<ColorMasks<565> >(in.readUint16BE(), r, g, b);
-
-			// converting to current OSystem Color
-			*pixels++ = format.RGBToColor(r, g, b);
+		switch (header.format.bytesPerPixel) {
+		case 2: {
+			uint16 *pixels = (uint16 *)to->getBasePtr(0, y);
+			for (uint x = 0; x < to->w; ++x) {
+				*pixels++ = in.readUint16BE();
+			}
+			} break;
+
+		case 4: {
+			uint32 *pixels = (uint32 *)to->getBasePtr(0, y);
+			for (uint x = 0; x < to->w; ++x) {
+				*pixels++ = in.readUint32BE();
+			}
+			} break;
+
+		default:
+			assert(0);
 		}
 	}
 
@@ -138,8 +162,8 @@ bool saveThumbnail(Common::WriteStream &out) {
 }
 
 bool saveThumbnail(Common::WriteStream &out, const Graphics::Surface &thumb) {
-	if (thumb.format.bytesPerPixel != 2) {
-		warning("trying to save thumbnail with bpp different than 2");
+	if (thumb.format.bytesPerPixel != 2 && thumb.format.bytesPerPixel != 4) {
+		warning("trying to save thumbnail with bpp %u", thumb.format.bytesPerPixel);
 		return false;
 	}
 
@@ -149,19 +173,45 @@ bool saveThumbnail(Common::WriteStream &out, const Graphics::Surface &thumb) {
 	header.version = THMB_VERSION;
 	header.width = thumb.w;
 	header.height = thumb.h;
-	header.bpp = thumb.format.bytesPerPixel;
 
 	out.writeUint32BE(header.type);
 	out.writeUint32BE(header.size);
 	out.writeByte(header.version);
 	out.writeUint16BE(header.width);
 	out.writeUint16BE(header.height);
-	out.writeByte(header.bpp);
 
-	// TODO: for later this shouldn't be casted to uint16...
-	uint16 *pixels = (uint16 *)thumb.pixels;
-	for (uint16 p = 0; p < thumb.w*thumb.h; ++p, ++pixels)
-		out.writeUint16BE(*pixels);
+	// Serialize the PixelFormat
+	out.writeByte(thumb.format.bytesPerPixel);
+	out.writeByte(thumb.format.rLoss);
+	out.writeByte(thumb.format.gLoss);
+	out.writeByte(thumb.format.bLoss);
+	out.writeByte(thumb.format.aLoss);
+	out.writeByte(thumb.format.rShift);
+	out.writeByte(thumb.format.gShift);
+	out.writeByte(thumb.format.bShift);
+	out.writeByte(thumb.format.aShift);
+
+	// Serialize the pixel data
+	for (uint y = 0; y < thumb.h; ++y) {
+		switch (thumb.format.bytesPerPixel) {
+		case 2: {
+			const uint16 *pixels = (const uint16 *)thumb.getBasePtr(0, y);
+			for (uint x = 0; x < thumb.w; ++x) {
+				out.writeUint16BE(*pixels++);
+			}
+			} break;
+
+		case 4: {
+			const uint32 *pixels = (const uint32 *)thumb.getBasePtr(0, y);
+			for (uint x = 0; x < thumb.w; ++x) {
+				out.writeUint32BE(*pixels++);
+			}
+			} break;
+
+		default:
+			assert(0);
+		}
+	}
 
 	return true;
 }
diff --git a/graphics/thumbnail.h b/graphics/thumbnail.h
index df99568f42..45a0fdbf07 100644
--- a/graphics/thumbnail.h
+++ b/graphics/thumbnail.h
@@ -50,8 +50,6 @@ bool skipThumbnail(Common::SeekableReadStream &in);
 
 /**
  * Loads a thumbnail from the given input stream.
- * The loaded thumbnail will be automatically converted to the
- * current overlay pixelformat.
  */
 Graphics::Surface *loadThumbnail(Common::SeekableReadStream &in);