add conversion.h and conversion.cpp into trunk (were present in working copy, but not added to svn control)

svn-id: r43582

1 files changed, 152 insertions, 0 deletions

diff --git a/graphics/conversion.cpp b/graphics/conversion.cpp
new file mode 100644
index 0000000000..1863814c1d
--- /dev/null
+++ b/graphics/conversion.cpp
@@ -0,0 +1,152 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ */
+
+#include "graphics/conversion.h"
+
+namespace Graphics {
+
+// TODO: YUV to RGB conversion function
+
+// Function to blit a rect from one color format to another
+bool crossBlit(byte *dst, const byte *src, int dstpitch, int srcpitch,
+						int w, int h, const Graphics::PixelFormat &dstFmt, const Graphics::PixelFormat &srcFmt) {
+	// Error out if conversion is impossible
+	if ((srcFmt.bytesPerPixel == 1) || (dstFmt.bytesPerPixel == 1)
+			 || (!srcFmt.bytesPerPixel) || (!dstFmt.bytesPerPixel)
+			 || (srcFmt.bytesPerPixel > dstFmt.bytesPerPixel))
+		return false;
+
+	// Don't perform unnecessary conversion
+	if (srcFmt == dstFmt) {
+		if (dst == src) 
+			return true;
+		if (dstpitch == srcpitch && ((w * dstFmt.bytesPerPixel) == dstpitch)) {
+			memcpy(dst,src,dstpitch * h);
+			return true;
+		} else {
+			for (int i = 0; i < h; i++) {
+				memcpy(dst,src,w * dstFmt.bytesPerPixel);
+				dst += dstpitch;
+				src += srcpitch;
+			}
+			return true;
+		}
+	}
+
+	// Faster, but larger, to provide optimized handling for each case.
+	int srcDelta, dstDelta;
+	srcDelta = (srcpitch - w * srcFmt.bytesPerPixel);
+	dstDelta = (dstpitch - w * dstFmt.bytesPerPixel);
+
+	// TODO: optimized cases for dstDelta of 0
+	uint8 r, g, b, a;
+	if (dstFmt.bytesPerPixel == 2) {
+		uint16 color;
+		for (int y = 0; y < h; y++) {
+			for (int x = 0; x < w; x++, src += 2, dst += 2) {
+				color = *(uint16 *) src;
+				srcFmt.colorToARGB(color, a, r, g, b);
+				color = dstFmt.ARGBToColor(a, r, g, b);
+				*(uint16 *) dst = color;
+			}
+			src += srcDelta;
+			dst += dstDelta;
+		}
+	} else if (dstFmt.bytesPerPixel == 3) {
+		uint32 color;
+		uint8 *col = (uint8 *) &color;
+#ifdef SCUMM_BIG_ENDIAN
+		col++;
+#endif
+		if (srcFmt.bytesPerPixel == 2) {
+			for (int y = 0; y < h; y++) {
+				for (int x = 0; x < w; x++, src += 2, dst += 3) {
+					color = *(uint16 *) src;
+					srcFmt.colorToARGB(color, a, r, g, b);
+					color = dstFmt.ARGBToColor(a, r, g, b);
+					memcpy(dst, col, 3);
+				}
+				src += srcDelta;
+				dst += dstDelta;
+			}
+		} else {
+			for (int y = 0; y < h; y++) {
+				for (int x = 0; x < w; x++, src += 3, dst += 3) {
+					uint8 r, g, b, a;
+					memcpy(col, src, 3);
+					srcFmt.colorToARGB(color, a, r, g, b);
+					color = dstFmt.ARGBToColor(a, r, g, b);
+					memcpy(dst, col, 3);
+				}
+				src += srcDelta;
+				dst += dstDelta;
+			}
+		}
+	} else if (dstFmt.bytesPerPixel == 4) {
+		uint32 color;
+		if (srcFmt.bytesPerPixel == 2) {
+			for (int y = 0; y < h; y++) {
+				for (int x = 0; x < w; x++, src += 2, dst += 4) {
+					color = *(uint16 *) src;
+					srcFmt.colorToARGB(color, a, r, g, b);
+					color = dstFmt.ARGBToColor(a, r, g, b);
+					*(uint32 *) dst = color;
+				}
+				src += srcDelta;
+				dst += dstDelta;
+			}
+		} else if (srcFmt.bytesPerPixel == 3) {
+			uint8 *col = (uint8 *)&color;
+#ifdef SCUMM_BIG_ENDIAN
+			col++;
+#endif
+			for (int y = 0; y < h; y++) {
+				for (int x = 0; x < w; x++, src += 2, dst += 4) {
+					memcpy(col, src, 3);
+					srcFmt.colorToARGB(color, a, r, g, b);
+					color = dstFmt.ARGBToColor(a, r, g, b);
+					*(uint32 *) dst = color;
+				}
+				src += srcDelta;
+				dst += dstDelta;
+			}
+		} else {
+			for (int y = 0; y < h; y++) {
+				for (int x = 0; x < w; x++, src += 4, dst += 4) {
+					color = *(uint32 *) src;
+					srcFmt.colorToARGB(color, a, r, g, b);
+					color = dstFmt.ARGBToColor(a, r, g, b);
+					*(uint32 *) dst = color;
+				}
+				src += srcDelta;
+				dst += dstDelta;
+			}
+		}
+	} else {
+		return false;
+	}
+	return true;
+}
+
+} // end of namespace Graphics