juce_use_CGContextDrawXYZGradient_on_osx_10_5_plus.diff

gistfile1.diff

diff --git a/modules/juce_graphics/native/juce_mac_CoreGraphicsContext.h b/modules/juce_graphics/native/juce_mac_CoreGraphicsContext.h
index bf26ce8..41a8571 100644
--- a/modules/juce_graphics/native/juce_mac_CoreGraphicsContext.h
+++ b/modules/juce_graphics/native/juce_mac_CoreGraphicsContext.h
@@ -77,7 +77,9 @@ private:
     const CGFloat flipHeight;
     float targetScale;
     CGColorSpaceRef rgbColourSpace, greyColourSpace;
+    #if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
     CGFunctionCallbacks gradientCallbacks;
+    #endif
     mutable Rectangle<int> lastClipRect;
     mutable bool lastClipRectIsValid;
 
@@ -88,9 +90,12 @@ private:
         ~SavedState();
 
         void setFill (const FillType& newFill);
+        #if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
         CGShadingRef getShading (CoreGraphicsContext& owner);
-
         static void gradientCallback (void* info, const CGFloat* inData, CGFloat* outData);
+        #else
+        CGGradientRef getGradient(CGColorSpaceRef colourSpace);
+        #endif
 
         FillType fillType;
         Font font;
@@ -98,9 +103,13 @@ private:
         CGAffineTransform fontTransform;
 
     private:
+        #if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
         CGShadingRef shading;
         HeapBlock <PixelARGB> gradientLookupTable;
         int numGradientLookupEntries;
+        #else
+        CGGradientRef gradient;
+        #endif
     };
 
     ScopedPointer <SavedState> state;
diff --git a/modules/juce_graphics/native/juce_mac_CoreGraphicsContext.mm b/modules/juce_graphics/native/juce_mac_CoreGraphicsContext.mm
index 309a02a..c968295 100644
--- a/modules/juce_graphics/native/juce_mac_CoreGraphicsContext.mm
+++ b/modules/juce_graphics/native/juce_mac_CoreGraphicsContext.mm
@@ -178,9 +178,11 @@ CoreGraphicsContext::CoreGraphicsContext (CGContextRef c, const float h, const f
     CGContextSetBlendMode (context, kCGBlendModeNormal);
     rgbColourSpace = CGColorSpaceCreateDeviceRGB();
     greyColourSpace = CGColorSpaceCreateDeviceGray();
+    #if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
     gradientCallbacks.version = 0;
     gradientCallbacks.evaluate = SavedState::gradientCallback;
     gradientCallbacks.releaseInfo = 0;
+    #endif
     setFont (Font());
 }
 
@@ -679,36 +681,62 @@ bool CoreGraphicsContext::drawTextLayout (const AttributedString& text, const Re
 
 CoreGraphicsContext::SavedState::SavedState()
     : font (1.0f), fontRef (0), fontTransform (CGAffineTransformIdentity),
-      shading (0), numGradientLookupEntries (0)
+#if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
+      shading (0),
+      numGradientLookupEntries (0)
+#else
+      gradient(0)
+#endif
 {
 }
 
 CoreGraphicsContext::SavedState::SavedState (const SavedState& other)
     : fillType (other.fillType), font (other.font), fontRef (other.fontRef),
-      fontTransform (other.fontTransform), shading (0),
+      fontTransform (other.fontTransform),
+#if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
+      shading (0),
       gradientLookupTable ((size_t) other.numGradientLookupEntries),
       numGradientLookupEntries (other.numGradientLookupEntries)
+#else
+      gradient(0)
+#endif
 {
+    #if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
     memcpy (gradientLookupTable, other.gradientLookupTable, sizeof (PixelARGB) * (size_t) numGradientLookupEntries);
+    #endif
 }
 
 CoreGraphicsContext::SavedState::~SavedState()
 {
+#if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
     if (shading != 0)
         CGShadingRelease (shading);
+#else
+    if (gradient != 0)
+        CGGradientRelease(gradient);
+#endif
 }
 
 void CoreGraphicsContext::SavedState::setFill (const FillType& newFill)
 {
     fillType = newFill;
 
+#if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
     if (fillType.isGradient() && shading != 0)
     {
         CGShadingRelease (shading);
         shading = 0;
     }
+#else
+    if (fillType.isGradient() && gradient != 0)
+    {
+        CGGradientRelease (gradient);
+        gradient = 0;
+    }
+#endif
 }
 
+#if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
 CGShadingRef CoreGraphicsContext::SavedState::getShading (CoreGraphicsContext& owner)
 {
     if (shading == 0)
@@ -752,15 +780,76 @@ void CoreGraphicsContext::SavedState::gradientCallback (void* info, const CGFloa
     outData[3] = colour.getAlpha() / 255.0f;
 }
 
+#else
+
+CGGradientRef CoreGraphicsContext::SavedState::getGradient(CGColorSpaceRef colourSpace)
+{
+    if(gradient == 0)
+    {
+        ColourGradient& g = *(fillType.gradient);
+
+        //CGColorSpaceRef colourSpace = CGColorSpaceCreateDeviceRGB();
+
+        CGFloat* components = new CGFloat[g.getNumColours() * 4];
+        CGFloat* locations = new CGFloat[g.getNumColours()];
+
+        for(int i=0; i!=g.getNumColours(); ++i)
+        {
+            Colour colour = g.getColour(i);
+            components[i * 4 + 0] = colour.getFloatRed();
+            components[i * 4 + 1] = colour.getFloatGreen();
+            components[i * 4 + 2] = colour.getFloatBlue();
+            components[i * 4 + 3] = colour.getFloatAlpha();
+            locations[i] = g.getColourPosition(i);
+        }
+
+        gradient = CGGradientCreateWithColorComponents(colourSpace, components, locations, g.getNumColours());
+        //CGColorSpaceRelease(colourSpace);
+        delete[] components;
+        delete[] locations;
+    }
+
+    return gradient;
+}
+#endif
+
 void CoreGraphicsContext::drawGradient()
 {
     flip();
     applyTransform (state->fillType.transform);
+    CGContextSetAlpha (context, state->fillType.getOpacity());
 
+    #if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5
     CGContextSetInterpolationQuality (context, kCGInterpolationDefault); // (This is required for 10.4, where there's a crash if
                                                                          // you draw a gradient with high quality interp enabled).
-    CGContextSetAlpha (context, state->fillType.getOpacity());
     CGContextDrawShading (context, state->getShading (*this));
+    #else
+    ColourGradient& g = *(state->fillType.gradient);
+    CGPoint p1 (convertToCGPoint (g.point1));
+    CGPoint p2 (convertToCGPoint (g.point2));
+
+    state->fillType.transform.transformPoints(p1.x, p1.y, p2.x, p2.y);
+
+    CGGradientRef gradient = state->getGradient(rgbColourSpace);
+
+    if (g.isRadial)
+    {
+        CGFloat dx = p2.x-p1.x;
+        CGFloat dy = p2.y-p1.y;
+        CGFloat r = sqrt(dx*dx+dy*dy);
+
+        CGContextDrawRadialGradient(context, gradient,
+            p1, 0, p1, r,
+            kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation
+        );
+    }
+    else
+    {
+        CGContextDrawLinearGradient(context, gradient,
+            p1, p2,
+            kCGGradientDrawsBeforeStartLocation | kCGGradientDrawsAfterEndLocation);
+    }
+    #endif
 }
 
 void CoreGraphicsContext::createPath (const Path& path) const

This patch modifies the CoreGraphicsContext of Juce to use CGGradient instead of CGShading for drawing gradients. The code that uses CGGradient is only enabled, if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5 (because CGGradient did not exist back then).

This patch was necessary, because the SavedState object that is passed to CGFunctionCreate was already released when a page based CoreGraphics context starts to draw the gradients (indirectly via CGContextEndPage). Apparently drawing of gradients is deferred on page based Graphics Contexts (like CGPDFContextCreateWithURL).

Further Info:
http://www.juce.com/forum/topic/render-juce-screenshots-pdf-osx#comment-310182
https://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CGFunction/index.html#//apple_ref/c/func/CGFunctionCreate
https://developer.apple.com/library/mac/documentation/GraphicsImaging/Reference/CGShading/index.html