Source/WebCore/platform/graphics/win/GraphicsContextCGWin.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2010, 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "GraphicsContextCG.h"

 #if USE(CG)

 #include "AffineTransform.h"
 #include "GraphicsContextImpl.h"
 #include "GraphicsContextPlatformPrivateCG.h"
 #include "Path.h"

 #include <pal/spi/cg/CoreGraphicsSPI.h>
 #include <wtf/win/GDIObject.h>


 namespace WebCore {

 static CGContextRef CGContextWithHDC(HDC hdc, bool hasAlpha)
 {
     HBITMAP bitmap = static_cast<HBITMAP>(GetCurrentObject(hdc, OBJ_BITMAP));

     DIBPixelData pixelData(bitmap);

     // FIXME: We can get here because we asked for a bitmap that is too big
     // when we have a tiled layer and we're compositing. In that case
     // bmBitsPixel will be 0. This seems to be benign, so for now we will
     // exit gracefully and look at it later:
     //  https://bugs.webkit.org/show_bug.cgi?id=52041
     // ASSERT(bitmapBits.bitsPerPixel() == 32);
     if (pixelData.bitsPerPixel() != 32)
         return 0;

     CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Little | (hasAlpha ? kCGImageAlphaPremultipliedFirst : kCGImageAlphaNoneSkipFirst);
     CGContextRef context = CGBitmapContextCreate(pixelData.buffer(), pixelData.size().width(), pixelData.size().height(), 8,
                                                  pixelData.bytesPerRow(), sRGBColorSpaceRef(), bitmapInfo);

     // Flip coords
     CGContextTranslateCTM(context, 0, pixelData.size().height());
     CGContextScaleCTM(context, 1, -1);

     // Put the HDC In advanced mode so it will honor affine transforms.
     SetGraphicsMode(hdc, GM_ADVANCED);

     return context;
 }

 GraphicsContext::GraphicsContext(HDC hdc, bool hasAlpha)
 {
     platformInit(hdc, hasAlpha);
 }

 void GraphicsContext::platformInit(HDC hdc, bool hasAlpha)
 {
     if (!hdc)
         return;

     m_data = new GraphicsContextPlatformPrivate(CGContextWithHDC(hdc, hasAlpha));
     CGContextRelease(m_data->m_cgContext.get());
     m_data->m_hdc = hdc;
     if (m_data->m_cgContext) {
         // Make sure the context starts in sync with our state.
         setPlatformFillColor(fillColor());
         setPlatformStrokeColor(strokeColor());
     }
 }

 // FIXME: Is it possible to merge getWindowsContext and createWindowsBitmap into a single API
 // suitable for all clients?
 void GraphicsContext::releaseWindowsContext(HDC hdc, const IntRect& dstRect, bool supportAlphaBlend)
 {
     bool createdBitmap = m_impl || !m_data->m_hdc || isInTransparencyLayer();
     if (!createdBitmap) {
         m_data->restore();
         return;
     }

     if (dstRect.isEmpty())
         return;

     auto bitmap = adoptGDIObject(static_cast<HBITMAP>(::GetCurrentObject(hdc, OBJ_BITMAP)));

     DIBPixelData pixelData(bitmap.get());

     ASSERT(pixelData.bitsPerPixel() == 32);

     CGContextRef bitmapContext = CGBitmapContextCreate(pixelData.buffer(), pixelData.size().width(), pixelData.size().height(), 8,
                                                        pixelData.bytesPerRow(), sRGBColorSpaceRef(), kCGBitmapByteOrder32Little |
                                                        (supportAlphaBlend ? kCGImageAlphaPremultipliedFirst : kCGImageAlphaNoneSkipFirst));

     CGImageRef image = CGBitmapContextCreateImage(bitmapContext);
     CGContextDrawImage(m_data->m_cgContext.get(), dstRect, image);

     // Delete all our junk.
     CGImageRelease(image);
     CGContextRelease(bitmapContext);
     ::DeleteDC(hdc);
 }

 void GraphicsContext::drawWindowsBitmap(WindowsBitmap* image, const IntPoint& point)
 {
     // FIXME: Creating CFData is non-optimal, but needed to avoid crashing when printing.  Ideally we should
     // make a custom CGDataProvider that controls the WindowsBitmap lifetime.  see <rdar://6394455>
     RetainPtr<CFDataRef> imageData = adoptCF(CFDataCreate(kCFAllocatorDefault, image->buffer(), image->bufferLength()));
     RetainPtr<CGDataProviderRef> dataProvider = adoptCF(CGDataProviderCreateWithCFData(imageData.get()));
     RetainPtr<CGImageRef> cgImage = adoptCF(CGImageCreate(image->size().width(), image->size().height(), 8, 32, image->bytesPerRow(), sRGBColorSpaceRef(),
                                                          kCGBitmapByteOrder32Little | kCGImageAlphaFirst, dataProvider.get(), 0, true, kCGRenderingIntentDefault));
     CGContextDrawImage(m_data->m_cgContext.get(), CGRectMake(point.x(), point.y(), image->size().width(), image->size().height()), cgImage.get());
 }

 void GraphicsContext::drawFocusRing(const Path& path, float width, float offset, const Color& color)
 {
     // FIXME: implement
 }

 // FIXME: This is nearly identical to the GraphicsContext::drawFocusRing function in GraphicsContextMac.mm.
 // The code could move to GraphicsContextCG.cpp and be shared.
 void GraphicsContext::drawFocusRing(const Vector<FloatRect>& rects, float width, float offset, const Color& color)
 {
     if (paintingDisabled())
         return;

     float radius = (width - 1) / 2.0f;
     offset += radius;
     CGColorRef colorRef = color.isValid() ? cachedCGColor(color) : nullptr;

     CGMutablePathRef focusRingPath = CGPathCreateMutable();
     unsigned rectCount = rects.size();
     for (unsigned i = 0; i < rectCount; i++)
         CGPathAddRect(focusRingPath, 0, CGRectInset(rects[i], -offset, -offset));

     CGContextRef context = platformContext();
     CGContextSaveGState(context);

     CGContextBeginPath(context);
     CGContextAddPath(context, focusRingPath);

     // FIXME: We clear the fill color here to avoid getting a black fill when drawing the focus ring.
     // Find out from CG if this is their bug.
     CGContextSetRGBFillColor(context, 0, 0, 0, 0);

     CGContextSetFocusRingWithColor(context, radius, colorRef, 0, (CFDictionaryRef)0);
     CGContextFillPath(context);

     CGPathRelease(focusRingPath);

     CGContextRestoreGState(context);
 }

 // Pulled from GraphicsContextCG
 static void setCGStrokeColor(CGContextRef context, const Color& color)
 {
     CGFloat red, green, blue, alpha;
     color.getRGBA(red, green, blue, alpha);
     CGContextSetRGBStrokeColor(context, red, green, blue, alpha);
 }

 static const Color& spellingPatternColor() {
     static const Color spellingColor(255, 0, 0);
     return spellingColor;
 }

 static const Color& grammarPatternColor() {
     static const Color grammarColor(0, 128, 0);
     return grammarColor;
 }

 void GraphicsContext::drawDotsForDocumentMarker(const FloatRect& rect, DocumentMarkerLineStyle style)
 {
     if (paintingDisabled())
         return;

     if (style.mode != DocumentMarkerLineStyle::Mode::Spelling && style.mode != DocumentMarkerLineStyle::Mode::Grammar)
         return;

     auto point = rect.location();
     auto width = rect.width();
     auto lineThickness = rect.height();
     auto patternGapWidth = lineThickness / 3;
     auto patternWidth = lineThickness + patternGapWidth;

     // Make sure to draw only complete dots.
     // NOTE: Code here used to shift the underline to the left and increase the width
     // to make sure everything gets underlined, but that results in drawing out of
     // bounds (e.g. when at the edge of a view) and could make it appear that the
     // space between adjacent misspelled words was underlined.
     // allow slightly more considering that the pattern ends with a transparent pixel
     float widthMod = fmodf(width, patternWidth);
     if (patternWidth - widthMod > patternGapWidth)
         width -= widthMod;

     // Draw the underline
     CGContextRef context = platformContext();
     CGContextSaveGState(context);

     const Color& patternColor = style.mode == DocumentMarkerLineStyle::Mode::Grammar ? grammarPatternColor() : spellingPatternColor();
     setCGStrokeColor(context, patternColor);

     CGAffineTransform userToBase = getUserToBaseCTM(context);
     CGPoint phase = CGPointApplyAffineTransform(point, userToBase);

     CGContextSetPatternPhase(context, CGSizeMake(phase.x, phase.y));
     CGContextSetBlendMode(context, kCGBlendModeNormal);

     // 3 rows, each offset by half a pixel for blending purposes
     const CGPoint upperPoints[] = {{ point.x(), point.y() + lineThickness - 2.5 }, {point.x() + width, point.y() + lineThickness - 2.5 }};
     const CGPoint middlePoints[] = {{ point.x(), point.y() + lineThickness - 1.5 }, {point.x() + width, point.y() + lineThickness - 1.5 }};
     const CGPoint lowerPoints[] = {{ point.x(), point.y() + lineThickness - 0.5 }, {point.x() + width, point.y() + lineThickness - 0.5 }};

     // Dash lengths for the top and bottom of the error underline are the same.
     // These are magic.
     static const CGFloat edge_dash_lengths[] = {2.0f, 2.0f};
     static const CGFloat middle_dash_lengths[] = { 2.76f, 1.24f };
     static const CGFloat edge_offset = -(edge_dash_lengths[1] - 1.0f) / 2.0f;
     static const CGFloat middle_offset = -(middle_dash_lengths[1] - 1.0f) / 2.0f;

     // Line opacities.  Once again, these are magic.
     const float upperOpacity = 0.33f;
     const float middleOpacity = 0.75f;
     const float lowerOpacity = 0.88f;

     //Top line
     CGContextSetLineDash(context, edge_offset, edge_dash_lengths, WTF_ARRAY_LENGTH(edge_dash_lengths));
     CGContextSetAlpha(context, upperOpacity);
     CGContextStrokeLineSegments(context, upperPoints, 2);

     // Middle line
     CGContextSetLineDash(context, middle_offset, middle_dash_lengths, WTF_ARRAY_LENGTH(middle_dash_lengths));
     CGContextSetAlpha(context, middleOpacity);
     CGContextStrokeLineSegments(context, middlePoints, 2);

     // Bottom line
     CGContextSetLineDash(context, edge_offset, edge_dash_lengths, WTF_ARRAY_LENGTH(edge_dash_lengths));
     CGContextSetAlpha(context, lowerOpacity);
     CGContextStrokeLineSegments(context, lowerPoints, 2);

     CGContextRestoreGState(context);
 }

 void GraphicsContextPlatformPrivate::flush()
 {
     CGContextFlush(m_cgContext.get());
 }

 }
 #endif
	/*
	* Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2010, 2013 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "GraphicsContextCG.h"

	#if USE(CG)

	#include "AffineTransform.h"
	#include "GraphicsContextImpl.h"
	#include "GraphicsContextPlatformPrivateCG.h"
	#include "Path.h"

	#include <pal/spi/cg/CoreGraphicsSPI.h>
	#include <wtf/win/GDIObject.h>


	namespace WebCore {

	static CGContextRef CGContextWithHDC(HDC hdc, bool hasAlpha)
	{
	HBITMAP bitmap = static_cast<HBITMAP>(GetCurrentObject(hdc, OBJ_BITMAP));

	DIBPixelData pixelData(bitmap);

	// FIXME: We can get here because we asked for a bitmap that is too big
	// when we have a tiled layer and we're compositing. In that case
	// bmBitsPixel will be 0. This seems to be benign, so for now we will
	// exit gracefully and look at it later:
	// https://bugs.webkit.org/show_bug.cgi?id=52041
	// ASSERT(bitmapBits.bitsPerPixel() == 32);
	if (pixelData.bitsPerPixel() != 32)
	return 0;

	CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Little \| (hasAlpha ? kCGImageAlphaPremultipliedFirst : kCGImageAlphaNoneSkipFirst);
	CGContextRef context = CGBitmapContextCreate(pixelData.buffer(), pixelData.size().width(), pixelData.size().height(), 8,
	pixelData.bytesPerRow(), sRGBColorSpaceRef(), bitmapInfo);

	// Flip coords
	CGContextTranslateCTM(context, 0, pixelData.size().height());
	CGContextScaleCTM(context, 1, -1);

	// Put the HDC In advanced mode so it will honor affine transforms.
	SetGraphicsMode(hdc, GM_ADVANCED);

	return context;
	}

	GraphicsContext::GraphicsContext(HDC hdc, bool hasAlpha)
	{
	platformInit(hdc, hasAlpha);
	}

	void GraphicsContext::platformInit(HDC hdc, bool hasAlpha)
	{
	if (!hdc)
	return;

	m_data = new GraphicsContextPlatformPrivate(CGContextWithHDC(hdc, hasAlpha));
	CGContextRelease(m_data->m_cgContext.get());
	m_data->m_hdc = hdc;
	if (m_data->m_cgContext) {
	// Make sure the context starts in sync with our state.
	setPlatformFillColor(fillColor());
	setPlatformStrokeColor(strokeColor());
	}
	}

	// FIXME: Is it possible to merge getWindowsContext and createWindowsBitmap into a single API
	// suitable for all clients?
	void GraphicsContext::releaseWindowsContext(HDC hdc, const IntRect& dstRect, bool supportAlphaBlend)
	{
	bool createdBitmap = m_impl \|\| !m_data->m_hdc \|\| isInTransparencyLayer();
	if (!createdBitmap) {
	m_data->restore();
	return;
	}

	if (dstRect.isEmpty())
	return;

	auto bitmap = adoptGDIObject(static_cast<HBITMAP>(::GetCurrentObject(hdc, OBJ_BITMAP)));

	DIBPixelData pixelData(bitmap.get());

	ASSERT(pixelData.bitsPerPixel() == 32);

	CGContextRef bitmapContext = CGBitmapContextCreate(pixelData.buffer(), pixelData.size().width(), pixelData.size().height(), 8,
	pixelData.bytesPerRow(), sRGBColorSpaceRef(), kCGBitmapByteOrder32Little \|
	(supportAlphaBlend ? kCGImageAlphaPremultipliedFirst : kCGImageAlphaNoneSkipFirst));

	CGImageRef image = CGBitmapContextCreateImage(bitmapContext);
	CGContextDrawImage(m_data->m_cgContext.get(), dstRect, image);

	// Delete all our junk.
	CGImageRelease(image);
	CGContextRelease(bitmapContext);
	::DeleteDC(hdc);
	}

	void GraphicsContext::drawWindowsBitmap(WindowsBitmap* image, const IntPoint& point)
	{
	// FIXME: Creating CFData is non-optimal, but needed to avoid crashing when printing. Ideally we should
	// make a custom CGDataProvider that controls the WindowsBitmap lifetime. see <rdar://6394455>
	RetainPtr<CFDataRef> imageData = adoptCF(CFDataCreate(kCFAllocatorDefault, image->buffer(), image->bufferLength()));
	RetainPtr<CGDataProviderRef> dataProvider = adoptCF(CGDataProviderCreateWithCFData(imageData.get()));
	RetainPtr<CGImageRef> cgImage = adoptCF(CGImageCreate(image->size().width(), image->size().height(), 8, 32, image->bytesPerRow(), sRGBColorSpaceRef(),
	kCGBitmapByteOrder32Little \| kCGImageAlphaFirst, dataProvider.get(), 0, true, kCGRenderingIntentDefault));
	CGContextDrawImage(m_data->m_cgContext.get(), CGRectMake(point.x(), point.y(), image->size().width(), image->size().height()), cgImage.get());
	}

	void GraphicsContext::drawFocusRing(const Path& path, float width, float offset, const Color& color)
	{
	// FIXME: implement
	}

	// FIXME: This is nearly identical to the GraphicsContext::drawFocusRing function in GraphicsContextMac.mm.
	// The code could move to GraphicsContextCG.cpp and be shared.
	void GraphicsContext::drawFocusRing(const Vector<FloatRect>& rects, float width, float offset, const Color& color)
	{
	if (paintingDisabled())
	return;

	float radius = (width - 1) / 2.0f;
	offset += radius;
	CGColorRef colorRef = color.isValid() ? cachedCGColor(color) : nullptr;

	CGMutablePathRef focusRingPath = CGPathCreateMutable();
	unsigned rectCount = rects.size();
	for (unsigned i = 0; i < rectCount; i++)
	CGPathAddRect(focusRingPath, 0, CGRectInset(rects[i], -offset, -offset));

	CGContextRef context = platformContext();
	CGContextSaveGState(context);

	CGContextBeginPath(context);
	CGContextAddPath(context, focusRingPath);

	// FIXME: We clear the fill color here to avoid getting a black fill when drawing the focus ring.
	// Find out from CG if this is their bug.
	CGContextSetRGBFillColor(context, 0, 0, 0, 0);

	CGContextSetFocusRingWithColor(context, radius, colorRef, 0, (CFDictionaryRef)0);
	CGContextFillPath(context);

	CGPathRelease(focusRingPath);

	CGContextRestoreGState(context);
	}

	// Pulled from GraphicsContextCG
	static void setCGStrokeColor(CGContextRef context, const Color& color)
	{
	CGFloat red, green, blue, alpha;
	color.getRGBA(red, green, blue, alpha);
	CGContextSetRGBStrokeColor(context, red, green, blue, alpha);
	}

	static const Color& spellingPatternColor() {
	static const Color spellingColor(255, 0, 0);
	return spellingColor;
	}

	static const Color& grammarPatternColor() {
	static const Color grammarColor(0, 128, 0);
	return grammarColor;
	}

	void GraphicsContext::drawDotsForDocumentMarker(const FloatRect& rect, DocumentMarkerLineStyle style)
	{
	if (paintingDisabled())
	return;

	if (style.mode != DocumentMarkerLineStyle::Mode::Spelling && style.mode != DocumentMarkerLineStyle::Mode::Grammar)
	return;

	auto point = rect.location();
	auto width = rect.width();
	auto lineThickness = rect.height();
	auto patternGapWidth = lineThickness / 3;
	auto patternWidth = lineThickness + patternGapWidth;

	// Make sure to draw only complete dots.
	// NOTE: Code here used to shift the underline to the left and increase the width
	// to make sure everything gets underlined, but that results in drawing out of
	// bounds (e.g. when at the edge of a view) and could make it appear that the
	// space between adjacent misspelled words was underlined.
	// allow slightly more considering that the pattern ends with a transparent pixel
	float widthMod = fmodf(width, patternWidth);
	if (patternWidth - widthMod > patternGapWidth)
	width -= widthMod;

	// Draw the underline
	CGContextRef context = platformContext();
	CGContextSaveGState(context);

	const Color& patternColor = style.mode == DocumentMarkerLineStyle::Mode::Grammar ? grammarPatternColor() : spellingPatternColor();
	setCGStrokeColor(context, patternColor);

	CGAffineTransform userToBase = getUserToBaseCTM(context);
	CGPoint phase = CGPointApplyAffineTransform(point, userToBase);

	CGContextSetPatternPhase(context, CGSizeMake(phase.x, phase.y));
	CGContextSetBlendMode(context, kCGBlendModeNormal);

	// 3 rows, each offset by half a pixel for blending purposes
	const CGPoint upperPoints[] = {{ point.x(), point.y() + lineThickness - 2.5 }, {point.x() + width, point.y() + lineThickness - 2.5 }};
	const CGPoint middlePoints[] = {{ point.x(), point.y() + lineThickness - 1.5 }, {point.x() + width, point.y() + lineThickness - 1.5 }};
	const CGPoint lowerPoints[] = {{ point.x(), point.y() + lineThickness - 0.5 }, {point.x() + width, point.y() + lineThickness - 0.5 }};

	// Dash lengths for the top and bottom of the error underline are the same.
	// These are magic.
	static const CGFloat edge_dash_lengths[] = {2.0f, 2.0f};
	static const CGFloat middle_dash_lengths[] = { 2.76f, 1.24f };
	static const CGFloat edge_offset = -(edge_dash_lengths[1] - 1.0f) / 2.0f;
	static const CGFloat middle_offset = -(middle_dash_lengths[1] - 1.0f) / 2.0f;

	// Line opacities. Once again, these are magic.
	const float upperOpacity = 0.33f;
	const float middleOpacity = 0.75f;
	const float lowerOpacity = 0.88f;

	//Top line
	CGContextSetLineDash(context, edge_offset, edge_dash_lengths, WTF_ARRAY_LENGTH(edge_dash_lengths));
	CGContextSetAlpha(context, upperOpacity);
	CGContextStrokeLineSegments(context, upperPoints, 2);

	// Middle line
	CGContextSetLineDash(context, middle_offset, middle_dash_lengths, WTF_ARRAY_LENGTH(middle_dash_lengths));
	CGContextSetAlpha(context, middleOpacity);
	CGContextStrokeLineSegments(context, middlePoints, 2);

	// Bottom line
	CGContextSetLineDash(context, edge_offset, edge_dash_lengths, WTF_ARRAY_LENGTH(edge_dash_lengths));
	CGContextSetAlpha(context, lowerOpacity);
	CGContextStrokeLineSegments(context, lowerPoints, 2);

	CGContextRestoreGState(context);
	}

	void GraphicsContextPlatformPrivate::flush()
	{
	CGContextFlush(m_cgContext.get());
	}

	}
	#endif