limit alpha

jef-n · jef-n · commit 78e59c96cd82 · 2014-04-02T23:50:21.000+02:00
diff --git a/src/gui/qgshighlight.cpp b/src/gui/qgshighlight.cpp
@@ -380,7 +380,7 @@ void QgsHighlight::paint( QPainter* p )
       imagePainter->end();
 
       QColor color( mPen.color() );  // true output color
-      // coeficient to subtract alpha using green (temporary fill)
+      // coefficient to subtract alpha using green (temporary fill)
       double k = ( 255. - mBrush.color().alpha() ) / 255.;
       for ( int r = 0; r < image.height(); r++ )
       {
@@ -391,7 +391,7 @@ void QgsHighlight::paint( QPainter* p )
           if ( alpha > 0 )
           {
             int green = qGreen( rgba );
-            color.setAlpha( alpha - ( green * k ) );
+            color.setAlpha( qBound<int>( 0, alpha - ( green * k ), 255 ) );
 
             image.setPixel( c, r, color.rgba() );
           }

Original file line number	Diff line number	Diff line change
`@@ -380,7 +380,7 @@ void QgsHighlight::paint( QPainter* p )`
`380`	`380`	`imagePainter->end();`
`381`	`381`
`382`	`382`	`QColor color( mPen.color() ); // true output color`
`383`		`- // coeficient to subtract alpha using green (temporary fill)`
	`383`	`+ // coefficient to subtract alpha using green (temporary fill)`
`384`	`384`	`double k = ( 255. - mBrush.color().alpha() ) / 255.;`
`385`	`385`	`for ( int r = 0; r < image.height(); r++ )`
`386`	`386`	`{`
`@@ -391,7 +391,7 @@ void QgsHighlight::paint( QPainter* p )`
`391`	`391`	`if ( alpha > 0 )`
`392`	`392`	`{`
`393`	`393`	`int green = qGreen( rgba );`
`394`		`- color.setAlpha( alpha - ( green * k ) );`
	`394`	`+ color.setAlpha( qBound<int>( 0, alpha - ( green * k ), 255 ) );`
`395`	`395`
`396`	`396`	`image.setPixel( c, r, color.rgba() );`
`397`	`397`	`}`