1 files changed, 92 insertions, 0 deletions
diff --git a/examples/canvas/makeimg.cpp b/examples/canvas/makeimg.cpp
new file mode 100644
index 0000000..c90ce8c
--- /dev/null
+++ b/examples/canvas/makeimg.cpp
@@ -0,0 +1,92 @@
+#include <qimage.h>
+#include <qcolor.h>
+
+static inline int blendComponent( int v, int av, int s, int as )
+{
+    //shadow gets a color inversely proportional to the
+    //alpha value
+    s = (s*(255-as))/255;
+    //then do standard blending
+    return as*s + av*v -(av*as*s)/255;  
+}
+    
+static inline QRgb blendShade( QRgb v, QRgb s )
+{
+    //pick a number: shadow is 1/3 of object
+    int as = qAlpha(s)/3; 
+    int av = qAlpha(v);
+    if ( as == 0 || av == 255 )
+	return v;
+
+    int a = as + av -(as*av)/255;
+
+    
+    int r = blendComponent( qRed(v),av, qRed(s), as)/a;
+    int g = blendComponent( qGreen(v),av, qGreen(s), as)/a;
+    int b = blendComponent( qBlue(v),av, qBlue(s), as)/a;
+
+    return qRgba(r,g,b,a);
+}
+
+int main( int*, char**)
+{
+    QImage *img;
+
+    img = new QImage( "in.png" );
+    int w,h;
+    int y;
+    img->setAlphaBuffer( TRUE );
+    *img = img->convertDepth( 32 );
+    w = img->width();
+    h = img->height();
+#if 0
+    for ( y = 0; y < h; y ++ ) {
+	uint *line = (uint*)img->scanLine( y );
+	for ( int x = 0; x < w; x++ ) {
+	    uint pixel = line[x];
+	    int r = qRed(pixel);
+	    int g = qGreen(pixel);
+	    int b = qBlue(pixel);
+	    int min = QMIN( r, QMIN( g, b ) );
+	    int max = QMAX( r, QMAX( g, b ) );
+	    r -= min;
+	    g -= min;
+	    b -= min;
+	    if ( max !=min ) {
+		r = (r*255)/(max-min);
+		g = (g*255)/(max-min);
+		b = (b*255)/(max-min);
+	    }
+	    int a = 255-min;
+	    a -=  (max-min)/3; //hack more transparency for colors.
+	    line[x] = qRgba( r, g, b, a );
+	}
+    }
+#endif    
+    *img = img->smoothScale( w/2, h/2 );
+
+    qDebug( "saving out.png");
+    img->save( "out.png", "PNG" );
+    
+    w = img->width();
+    h = img->height();
+    
+    QImage *img2 = new QImage( w, h, 32 );
+    img2->setAlphaBuffer( TRUE );
+    for ( y = 0; y < h; y++ ) {
+	for ( int x = 0; x < w; x++ ) {
+	    QRgb shader = img->pixel( x, y );
+
+	    int as = qAlpha(shader)/3;
+
+	    int r = (qRed(shader)*(255-as))/255;
+	    int g = (qGreen(shader)*(255-as))/255;
+	    int b = (qBlue(shader)*(255-as))/255;
+
+	    img2->setPixel( x, y, qRgba(r,g,b,as) ); 
+	}
+    }
+
+    img2->save( "outshade.png", "PNG" );
+
+}