Add AGI256 picture resource decoding support to PictureMgr::decodePicture.

svn-id: r27568

2 files changed, 17 insertions, 5 deletions

diff --git a/engines/agi/picture.cpp b/engines/agi/picture.cpp
index 9a16d4ab20..7a30d9c094 100644
--- a/engines/agi/picture.cpp
+++ b/engines/agi/picture.cpp
@@ -619,8 +619,9 @@ uint8 *PictureMgr::convertV3Pic(uint8 *src, uint32 len) {
  * drawing.
  * @param n      AGI picture resource number
  * @param clear  clear AGI screen before drawing
+ * @param agi256 load an AGI256 picture resource
  */
-int PictureMgr::decodePicture(int n, int clear) {
+int PictureMgr::decodePicture(int n, int clear, bool agi256) {
 	debugC(8, kDebugLevelResources, "(%d)", n);
 
 	patCode = 0;
@@ -633,10 +634,21 @@ int PictureMgr::decodePicture(int n, int clear) {
 	flen = _vm->_game.dirPic[n].len;
 	foffs = 0;
 
-	if (clear)
-		memset(_vm->_game.sbuf, 0x4f, _WIDTH * _HEIGHT);
+	if (clear && !agi256) // 256 color pictures should always fill the whole screen, so no clearing for them.
+		memset(_vm->_game.sbuf16c, 0x4f, _WIDTH * _HEIGHT); // Clear 16 color AGI screen (Priority 4, color white).
 
-	drawPicture();
+	if (!agi256) {
+		drawPicture(); // Draw 16 color picture.
+	} else {
+		const uint32 maxFlen = _WIDTH * _HEIGHT;
+		memcpy(_vm->_game.sbuf256c, data, MIN(flen, maxFlen)); // Draw 256 color picture.
+
+		if (flen < maxFlen) {
+			warning("Undersized AGI256 picture resource %d, using it anyway. Filling rest with white.", n);
+			memset(_vm->_game.sbuf256c + flen, 0x0f, maxFlen - flen); // Fill missing area with white.
+		} else if (flen > maxFlen)
+			warning("Oversized AGI256 picture resource %d, decoding only %ux%u part of it", n, _WIDTH, _HEIGHT);
+	}
 
 	if (clear)
 		_vm->clearImageStack();
diff --git a/engines/agi/picture.h b/engines/agi/picture.h
index 6a3f641eca..0f8584f3b2 100644
--- a/engines/agi/picture.h
+++ b/engines/agi/picture.h
@@ -68,7 +68,7 @@ public:
 		_gfx = gfx;
 	}
 
-	int decodePicture(int, int);
+	int decodePicture(int n, int clear, bool agi256 = false);
 	int unloadPicture(int);
 	void showPic();
 	uint8 *convertV3Pic(uint8 *src, uint32 len);