[Scummvm-cvs-logs] SF.net SVN: scummvm:[42220] scummvm/branches/gsoc2009-16bit/graphics/jpeg. cpp

[scott_t at users.sourceforge.net]

Revision: 42220
          http://scummvm.svn.sourceforge.net/scummvm/?rev=42220&view=rev
Author:   scott_t
Date:     2009-07-07 14:04:18 +0000 (Tue, 07 Jul 2009)

Log Message:
-----------
Properly handle odd-sized JPEG files (ie, those not a multiple of 8 pixels)

Modified Paths:
--------------
    scummvm/branches/gsoc2009-16bit/graphics/jpeg.cpp

Modified: scummvm/branches/gsoc2009-16bit/graphics/jpeg.cpp
===================================================================
--- scummvm/branches/gsoc2009-16bit/graphics/jpeg.cpp	2009-07-07 13:39:24 UTC (rev 42219)
+++ scummvm/branches/gsoc2009-16bit/graphics/jpeg.cpp	2009-07-07 14:04:18 UTC (rev 42220)
@@ -354,6 +354,13 @@
 	// Read all the scan MCUs
 	uint16 xMCU = _w / (_maxFactorH * 8);
 	uint16 yMCU = _h / (_maxFactorV * 8);
+
+	// Check for non- multiple-of-8 dimensions
+	if (_w % 8 != 0)
+		xMCU++;
+	if (_h % 8 != 0)
+		yMCU++;
+
 	bool ok = true;
 	for (int y = 0; ok && (y < yMCU); y++) 
 		for (int x = 0; ok && (x < xMCU); x++)
@@ -478,12 +485,21 @@
 	// Convert coordinates from MCU blocks to pixels
 	x <<= 3;
 	y <<= 3;
-	for (int j = 0; j < 8; j++) {
+
+	// Handle non- multiple-of-8 dimensions
+	byte xLim = 8;
+	byte yLim = 8;
+	if (x*scalingH + 8 > _w)
+		xLim -= (x*scalingH + 8 - _w);
+	if (y*scalingV + 8 > _h)
+		yLim -= (y*scalingV + 8 - _h);
+
+	for (int j = 0; j < yLim; j++) {
 		for (int sV = 0; sV < scalingV; sV++) {
 			// Get the beginning of the block line
 			byte *ptr = (byte *)_currentComp->surface.getBasePtr(x * scalingH, (y + j) * scalingV + sV);
 
-			for (int i = 0; i < 8; i++) {
+			for (int i = 0; i < xLim; i++) {
 				for (uint8 sH = 0; sH < scalingH; sH++) {
 					*ptr = (byte)(result[j * 8 + i]);
 					ptr++;


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