Added convertToPremultipliedAlpha() to KImageEffect

Fixed "glowing icons" when 32 bit ARGB visuals are in use


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdelibs@1247329 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

kdecore/kiconloader.cpp

@@ -51,6 +51,8 @@
 #include "svgicons/ksvgiconpainter.h"
 #endif
 
+#include <kimageeffect.h>
+
 #include "kiconloader_p.h"
 
 /*** KIconThemeNode: A node in the icon theme dependancy tree. ***/
@@ -855,7 +857,8 @@ TQPixmap KIconLoader::loadIcon(const TQString& _name, KIcon::Group group, int si
         }
     }
 
-    pix.convertFromImage(*img);
+    if (TQPaintDevice::x11AppDepth() == 32) pix.convertFromImage(KImageEffect::convertToPremultipliedAlpha( *img ));
+    else pix.convertFromImage(*img);
 
     delete img;
 

kdefx/kimageeffect.cpp

@@ -4937,3 +4937,40 @@ TQImage KImageEffect::bumpmap(TQImage &img, TQImage &map, double azimuth, double
     }
     return dst;
 }
+
+/**
+ * Convert an image with standard alpha to premultiplied alpha
+ *
+ * @param img the image you want convert
+ *
+ * @return The destination image (dst) containing the result.
+ * @author Timothy Pearson <kb9vqf@pearsoncomputing.net>
+ */
+TQImage KImageEffect::convertToPremultipliedAlpha(TQImage input) {
+	TQImage alphaImage = input;
+	if (!alphaImage.isNull()) alphaImage = alphaImage.convertDepth( 32 );
+
+	int w = alphaImage.width();
+	int h = alphaImage.height();
+
+	register int r;
+	register int g;
+	register int b;
+	register int a;
+	register float alpha_adjust;
+	register TQRgb l;
+	TQRgb *ls;
+	for (int y = 0; y < h; ++y) {
+		ls = (TQRgb *)alphaImage.scanLine( y );
+		for (int x = 0; x < w; ++x) {
+			l = ls[x];
+			alpha_adjust = (tqAlpha( l )/255.0);
+			r = int( tqRed( l ) * alpha_adjust );
+			g = int( tqGreen( l ) * alpha_adjust );
+			b = int( tqBlue( l ) * alpha_adjust );
+			a = int( tqAlpha( l ) * 1.0 );
+			ls[x] = tqRgba( r, g, b, a );
+		}
+	}
+	return alphaImage;
+}

kdefx/kimageeffect.h

@@ -773,6 +773,16 @@ public:
                           int ambient, bool compensate, bool invert,
                           BumpmapType type, bool tiled);
 
+    /**
+     * Convert an image with standard alpha to premultiplied alpha
+     *
+     * @param img the image you want convert
+     *
+     * @return The destination image (dst) containing the result.
+     * @author Timothy Pearson <kb9vqf@pearsoncomputing.net>
+     */
+    static TQImage convertToPremultipliedAlpha(TQImage input);
+
 private:
 
     /**