Switch to RGB32 images for composition checker

Author: nyalldawson

python/core/qgsrenderchecker.sip

@@ -82,4 +82,11 @@ class QgsRenderChecker
     bool isKnownAnomaly( QString theDiffImageFile );
 
     QString expectedImageFile();
+    
+  protected:
+  
+    /**Draws a checkboard pattern for image backgrounds, so that transparency is visible
+     * without requiring a transparent background for the image
+     */
+    void drawBackround( QImage* image );
 };

src/core/qgsrenderchecker.cpp

@@ -78,6 +78,27 @@ void QgsRenderChecker::setMapSettings( const QgsMapSettings& mapSettings )
   mMapSettings = mapSettings;
 }
 
+void QgsRenderChecker::drawBackround( QImage* image )
+{
+  // create a 2x2 checker-board image
+  uchar pixDataRGB[] = { 255, 255, 255, 255,
+                         127, 127, 127, 255,
+                         127, 127, 127, 255,
+                         255, 255, 255, 255
+                       };
+
+  QImage img( pixDataRGB, 2, 2, 8, QImage::Format_ARGB32 );
+  QPixmap pix = QPixmap::fromImage( img.scaled( 20, 20 ) );
+
+  // fill image with texture
+  QBrush brush;
+  brush.setTexture( pix );
+  QPainter p( image );
+  p.setRenderHint( QPainter::Antialiasing, false );
+  p.fillRect( QRect( 0, 0, image->width(), image->height() ), brush );
+  p.end();
+}
+
 bool QgsRenderChecker::isKnownAnomaly( QString theDiffImageFile )
 {
   QString myControlImageDir = controlImagePath() + mControlName

src/core/qgsrenderchecker.h

@@ -136,6 +136,11 @@ class CORE_EXPORT QgsRenderChecker
     QString mRenderedImageFile;
     QString mExpectedImageFile;
 
+    /**Draws a checkboard pattern for image backgrounds, so that transparency is visible
+     * without requiring a transparent background for the image
+     */
+    void drawBackround( QImage* image );
+
   private:
     QString mControlName;
     unsigned int mMismatchCount;

tests/src/core/qgscompositionchecker.cpp

@@ -73,7 +73,7 @@ bool QgsCompositionChecker::testComposition( QString &theReport, int page, int p
 #if 0
   //fake mode to generate expected image
   //assume 96 dpi and size of the control image 1122 * 794
-  QImage newImage( QSize( 1122, 794 ), QImage::Format_ARGB32 );
+  QImage newImage( QSize( 1122, 794 ), QImage::Format_RGB32 );
   mComposition->setPlotStyle( QgsComposition::Print );
   newImage.setDotsPerMeterX( 96 / 25.4 * 1000 );
   newImage.setDotsPerMeterY( 96 / 25.4 * 1000 );
@@ -87,7 +87,7 @@ bool QgsCompositionChecker::testComposition( QString &theReport, int page, int p
   return true;
 #endif //0
 
-  QImage outputImage( mSize, QImage::Format_ARGB32 );
+  QImage outputImage( mSize, QImage::Format_RGB32 );
 
   mComposition->setPlotStyle( QgsComposition::Print );
   outputImage.setDotsPerMeterX( mDotsPerMeter );

tests/src/core/qgscompositionchecker.h

@@ -34,11 +34,6 @@ class QgsCompositionChecker : public QgsMultiRenderChecker
   private:
     QgsCompositionChecker(); //forbidden
 
-    /**Draws a checkboard pattern for image backgrounds, so that transparency is visible
-     * without requiring a transparent background for the image
-     */
-    void drawBackround( QImage* image );
-
     QString mTestName;
     QgsComposition* mComposition;
     QSize mSize;

tests/src/python/qgscompositionchecker.py

@@ -39,12 +39,12 @@ def testComposition(self, page=0, pixelDiff=0 ):
          #get width/height, create image and render the composition to it
         width = expectedImage.width();
         height = expectedImage.height();
-        outputImage = QImage( QSize( width, height ), QImage.Format_ARGB32 )
+        outputImage = QImage( QSize( width, height ), QImage.Format_RGB32 )
 
         self.mComposition.setPlotStyle( QgsComposition.Print )
         outputImage.setDotsPerMeterX( expectedImage.dotsPerMeterX() )
         outputImage.setDotsPerMeterY( expectedImage.dotsPerMeterX() )
-        outputImage.fill( 0 )
+        self.drawBackround( outputImage )
         p = QPainter( outputImage )
         self.mComposition.renderPage( p, page )
         p.end()