skia/ext/bitmap_platform_device_mac.cc - chromium/src - Git at Google

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "skia/ext/bitmap_platform_device_mac.h"

 #import <ApplicationServices/ApplicationServices.h>
 #include <stddef.h>
 #include <time.h>

 #include "base/mac/mac_util.h"
 #include "base/memory/ref_counted.h"
 #include "skia/ext/bitmap_platform_device.h"
 #include "skia/ext/platform_canvas.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "third_party/skia/include/core/SkMatrix.h"
 #include "third_party/skia/include/core/SkPath.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "third_party/skia/include/core/SkTypes.h"
 #include "third_party/skia/include/core/SkUtils.h"

 namespace skia {

 namespace {

 static CGContextRef CGContextForData(void* data, int width, int height) {
 #define HAS_ARGB_SHIFTS(a, r, g, b) \
             (SK_A32_SHIFT == (a) && SK_R32_SHIFT == (r) \
              && SK_G32_SHIFT == (g) && SK_B32_SHIFT == (b))
 #if defined(SK_CPU_LENDIAN) && HAS_ARGB_SHIFTS(24, 16, 8, 0)
   // Allocate a bitmap context with 4 components per pixel (BGRA).  Apple
   // recommends these flags for improved CG performance.

   // CGBitmapContextCreate returns NULL if width/height are 0. However, our
   // callers expect to get a canvas back (which they later resize/reallocate)
   // so we pin the dimensions here.
   width = SkMax32(1, width);
   height = SkMax32(1, height);
   CGContextRef context =
       CGBitmapContextCreate(data, width, height, 8, width * 4,
                             base::mac::GetSystemColorSpace(),
                             kCGImageAlphaPremultipliedFirst |
                                 kCGBitmapByteOrder32Host);
 #else
 #error We require that Skia's and CoreGraphics's recommended \
        image memory layout match.
 #endif
 #undef HAS_ARGB_SHIFTS

   if (!context)
     return NULL;

   // Change the coordinate system to match WebCore's
   CGContextTranslateCTM(context, 0, height);
   CGContextScaleCTM(context, 1.0, -1.0);

   return context;
 }

 }  // namespace

 void BitmapPlatformDevice::ReleaseBitmapContext() {
   SkASSERT(bitmap_context_);
   CGContextRelease(bitmap_context_);
   bitmap_context_ = NULL;
 }

 void BitmapPlatformDevice::SetMatrixClip(
     const SkMatrix& transform,
     const SkRegion& region) {
   transform_ = transform;
   clip_region_ = region;
   config_dirty_ = true;
 }

 // Loads the specified Skia transform into the device context
 static void LoadTransformToCGContext(CGContextRef context,
                                      const SkMatrix& matrix) {
   // CoreGraphics can concatenate transforms, but not reset the current one.
   // So in order to get the required behavior here, we need to first make
   // the current transformation matrix identity and only then load the new one.

   // Reset matrix to identity.
   CGAffineTransform orig_cg_matrix = CGContextGetCTM(context);
   CGAffineTransform orig_cg_matrix_inv =
       CGAffineTransformInvert(orig_cg_matrix);
   CGContextConcatCTM(context, orig_cg_matrix_inv);

   // assert that we have indeed returned to the identity Matrix.
   SkASSERT(CGAffineTransformIsIdentity(CGContextGetCTM(context)));

   // Convert xform to CG-land.
   // Our coordinate system is flipped to match WebKit's so we need to modify
   // the xform to match that.
   SkMatrix transformed_matrix = matrix;
   SkScalar sy = -matrix.getScaleY();
   transformed_matrix.setScaleY(sy);
   size_t height = CGBitmapContextGetHeight(context);
   SkScalar ty = -matrix.getTranslateY();  // y axis is flipped.
   transformed_matrix.setTranslateY(ty + (SkScalar)height);

   CGAffineTransform cg_matrix =
       skia::SkMatrixToCGAffineTransform(transformed_matrix);

   // Load final transform into context.
   CGContextConcatCTM(context, cg_matrix);
 }

 // Loads a SkRegion into the CG context.
 static void LoadClippingRegionToCGContext(CGContextRef context,
                                           const SkRegion& region,
                                           const SkMatrix& transformation) {
   if (region.isEmpty()) {
     // region can be empty, in which case everything will be clipped.
     SkRect rect;
     rect.setEmpty();
     CGContextClipToRect(context, skia::SkRectToCGRect(rect));
   } else if (region.isRect()) {
     // CoreGraphics applies the current transform to clip rects, which is
     // unwanted. Inverse-transform the rect before sending it to CG. This only
     // works for translations and scaling, but not for rotations (but the
     // viewport is never rotated anyway).
     SkMatrix t;
     bool did_invert = transformation.invert(&t);
     if (!did_invert)
       t.reset();
     // Do the transformation.
     SkRect rect;
     rect.set(region.getBounds());
     t.mapRect(&rect);
     SkIRect irect;
     rect.round(&irect);
     CGContextClipToRect(context, skia::SkIRectToCGRect(irect));
   } else {
     // It is complex.
     SkPath path;
     region.getBoundaryPath(&path);
     // Clip. Note that windows clipping regions are not affected by the
     // transform so apply it manually.
     path.transform(transformation);
     // TODO(playmobil): Implement.
     SkASSERT(false);
     // LoadPathToDC(context, path);
     // hrgn = PathToRegion(context);
   }
 }

 void BitmapPlatformDevice::LoadConfig() {
   if (!config_dirty_ || !bitmap_context_)
     return;  // Nothing to do.
   config_dirty_ = false;

   // We must restore and then save the state of the graphics context since the
   // calls to Load the clipping region to the context are strictly cummulative,
   // i.e., you can't replace a clip rect, other than with a save/restore.
   // But this implies that no other changes to the state are done elsewhere.
   // If we ever get to need to change this, then we must replace the clip rect
   // calls in LoadClippingRegionToCGContext() with an image mask instead.
   CGContextRestoreGState(bitmap_context_);
   CGContextSaveGState(bitmap_context_);
   LoadTransformToCGContext(bitmap_context_, transform_);
   LoadClippingRegionToCGContext(bitmap_context_, clip_region_, transform_);
 }


 // We use this static factory function instead of the regular constructor so
 // that we can create the pixel data before calling the constructor. This is
 // required so that we can call the base class' constructor with the pixel
 // data.
 BitmapPlatformDevice* BitmapPlatformDevice::Create(CGContextRef context,
                                                    int width,
                                                    int height,
                                                    bool is_opaque,
                                                    bool do_clear) {
   if (RasterDeviceTooBigToAllocate(width, height))
     return NULL;

   SkBitmap bitmap;
   // TODO: verify that the CG Context's pixels will have tight rowbytes or pass in the correct
   // rowbytes for the case when context != NULL.
   bitmap.setInfo(SkImageInfo::MakeN32(width, height, is_opaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType));

   void* data;
   if (context) {
     data = CGBitmapContextGetData(context);
     bitmap.setPixels(data);
   } else {
     if (!bitmap.tryAllocPixels())
       return NULL;
     data = bitmap.getPixels();
   }
   if (do_clear)
     memset(data, 0, bitmap.getSafeSize());

   // If we were given data, then don't clobber it!
 #ifndef NDEBUG
   if (!context && is_opaque) {
     // To aid in finding bugs, we set the background color to something
     // obviously wrong so it will be noticable when it is not cleared
     bitmap.eraseARGB(255, 0, 255, 128);  // bright bluish green
   }
 #endif

   if (!context) {
     context = CGContextForData(data, width, height);
     if (!context)
       return NULL;
   } else
     CGContextRetain(context);

   BitmapPlatformDevice* rv = new BitmapPlatformDevice(context, bitmap);

   // The device object took ownership of the graphics context with its own
   // CGContextRetain call.
   CGContextRelease(context);

   return rv;
 }

 BitmapPlatformDevice* BitmapPlatformDevice::CreateWithData(uint8_t* data,
                                                            int width,
                                                            int height,
                                                            bool is_opaque) {
   CGContextRef context = NULL;
   if (data)
     context = CGContextForData(data, width, height);

   BitmapPlatformDevice* rv = Create(context, width, height, is_opaque, false);

   // The device object took ownership of the graphics context with its own
   // CGContextRetain call.
   if (context)
     CGContextRelease(context);

   return rv;
 }

 // The device will own the bitmap, which corresponds to also owning the pixel
 // data. Therefore, we do not transfer ownership to the SkBitmapDevice's bitmap.
 BitmapPlatformDevice::BitmapPlatformDevice(
     CGContextRef context, const SkBitmap& bitmap)
     : SkBitmapDevice(bitmap),
       bitmap_context_(context),
       config_dirty_(true),  // Want to load the config next time.
       transform_(SkMatrix::I()) {
   SetPlatformDevice(this, this);
   SkASSERT(bitmap_context_);
   // Initialize the clip region to the entire bitmap.

   SkIRect rect;
   rect.set(0, 0,
            CGBitmapContextGetWidth(bitmap_context_),
            CGBitmapContextGetHeight(bitmap_context_));
   clip_region_ = SkRegion(rect);
   CGContextRetain(bitmap_context_);
   // We must save the state once so that we can use the restore/save trick
   // in LoadConfig().
   CGContextSaveGState(bitmap_context_);
 }

 BitmapPlatformDevice::~BitmapPlatformDevice() {
   if (bitmap_context_)
     CGContextRelease(bitmap_context_);
 }

 CGContextRef BitmapPlatformDevice::GetBitmapContext() {
   LoadConfig();
   return bitmap_context_;
 }

 void BitmapPlatformDevice::setMatrixClip(const SkMatrix& transform,
                                          const SkRegion& region,
                                          const SkClipStack&) {
   SetMatrixClip(transform, region);
 }

 SkBaseDevice* BitmapPlatformDevice::onCreateDevice(const CreateInfo& cinfo,
                                                    const SkPaint*) {
   const SkImageInfo& info = cinfo.fInfo;
   const bool do_clear = !info.isOpaque();
   SkASSERT(info.colorType() == kN32_SkColorType);
   return Create(NULL, info.width(), info.height(), info.isOpaque(), do_clear);
 }

 // PlatformCanvas impl

 SkCanvas* CreatePlatformCanvas(CGContextRef ctx, int width, int height,
                                bool is_opaque, OnFailureType failureType) {
   const bool do_clear = false;
   skia::RefPtr<SkBaseDevice> dev = skia::AdoptRef(
       BitmapPlatformDevice::Create(ctx, width, height, is_opaque, do_clear));
   return CreateCanvas(dev, failureType);
 }

 SkCanvas* CreatePlatformCanvas(int width, int height, bool is_opaque,
                                uint8_t* data, OnFailureType failureType) {
   skia::RefPtr<SkBaseDevice> dev = skia::AdoptRef(
       BitmapPlatformDevice::CreateWithData(data, width, height, is_opaque));
   return CreateCanvas(dev, failureType);
 }

 }  // namespace skia
	// Copyright (c) 2012 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "skia/ext/bitmap_platform_device_mac.h"

	#import <ApplicationServices/ApplicationServices.h>
	#include <stddef.h>
	#include <time.h>

	#include "base/mac/mac_util.h"
	#include "base/memory/ref_counted.h"
	#include "skia/ext/bitmap_platform_device.h"
	#include "skia/ext/platform_canvas.h"
	#include "skia/ext/skia_utils_mac.h"
	#include "third_party/skia/include/core/SkMatrix.h"
	#include "third_party/skia/include/core/SkPath.h"
	#include "third_party/skia/include/core/SkRegion.h"
	#include "third_party/skia/include/core/SkTypes.h"
	#include "third_party/skia/include/core/SkUtils.h"

	namespace skia {

	namespace {

	static CGContextRef CGContextForData(void* data, int width, int height) {
	#define HAS_ARGB_SHIFTS(a, r, g, b) \
	(SK_A32_SHIFT == (a) && SK_R32_SHIFT == (r) \
	&& SK_G32_SHIFT == (g) && SK_B32_SHIFT == (b))
	#if defined(SK_CPU_LENDIAN) && HAS_ARGB_SHIFTS(24, 16, 8, 0)
	// Allocate a bitmap context with 4 components per pixel (BGRA). Apple
	// recommends these flags for improved CG performance.

	// CGBitmapContextCreate returns NULL if width/height are 0. However, our
	// callers expect to get a canvas back (which they later resize/reallocate)
	// so we pin the dimensions here.
	width = SkMax32(1, width);
	height = SkMax32(1, height);
	CGContextRef context =
	CGBitmapContextCreate(data, width, height, 8, width * 4,
	base::mac::GetSystemColorSpace(),
	kCGImageAlphaPremultipliedFirst \|
	kCGBitmapByteOrder32Host);
	#else
	#error We require that Skia's and CoreGraphics's recommended \
	image memory layout match.
	#endif
	#undef HAS_ARGB_SHIFTS

	if (!context)
	return NULL;

	// Change the coordinate system to match WebCore's
	CGContextTranslateCTM(context, 0, height);
	CGContextScaleCTM(context, 1.0, -1.0);

	return context;
	}

	} // namespace

	void BitmapPlatformDevice::ReleaseBitmapContext() {
	SkASSERT(bitmap_context_);
	CGContextRelease(bitmap_context_);
	bitmap_context_ = NULL;
	}

	void BitmapPlatformDevice::SetMatrixClip(
	const SkMatrix& transform,
	const SkRegion& region) {
	transform_ = transform;
	clip_region_ = region;
	config_dirty_ = true;
	}

	// Loads the specified Skia transform into the device context
	static void LoadTransformToCGContext(CGContextRef context,
	const SkMatrix& matrix) {
	// CoreGraphics can concatenate transforms, but not reset the current one.
	// So in order to get the required behavior here, we need to first make
	// the current transformation matrix identity and only then load the new one.

	// Reset matrix to identity.
	CGAffineTransform orig_cg_matrix = CGContextGetCTM(context);
	CGAffineTransform orig_cg_matrix_inv =
	CGAffineTransformInvert(orig_cg_matrix);
	CGContextConcatCTM(context, orig_cg_matrix_inv);

	// assert that we have indeed returned to the identity Matrix.
	SkASSERT(CGAffineTransformIsIdentity(CGContextGetCTM(context)));

	// Convert xform to CG-land.
	// Our coordinate system is flipped to match WebKit's so we need to modify
	// the xform to match that.
	SkMatrix transformed_matrix = matrix;
	SkScalar sy = -matrix.getScaleY();
	transformed_matrix.setScaleY(sy);
	size_t height = CGBitmapContextGetHeight(context);
	SkScalar ty = -matrix.getTranslateY(); // y axis is flipped.
	transformed_matrix.setTranslateY(ty + (SkScalar)height);

	CGAffineTransform cg_matrix =
	skia::SkMatrixToCGAffineTransform(transformed_matrix);

	// Load final transform into context.
	CGContextConcatCTM(context, cg_matrix);
	}

	// Loads a SkRegion into the CG context.
	static void LoadClippingRegionToCGContext(CGContextRef context,
	const SkRegion& region,
	const SkMatrix& transformation) {
	if (region.isEmpty()) {
	// region can be empty, in which case everything will be clipped.
	SkRect rect;
	rect.setEmpty();
	CGContextClipToRect(context, skia::SkRectToCGRect(rect));
	} else if (region.isRect()) {
	// CoreGraphics applies the current transform to clip rects, which is
	// unwanted. Inverse-transform the rect before sending it to CG. This only
	// works for translations and scaling, but not for rotations (but the
	// viewport is never rotated anyway).
	SkMatrix t;
	bool did_invert = transformation.invert(&t);
	if (!did_invert)
	t.reset();
	// Do the transformation.
	SkRect rect;
	rect.set(region.getBounds());
	t.mapRect(&rect);
	SkIRect irect;
	rect.round(&irect);
	CGContextClipToRect(context, skia::SkIRectToCGRect(irect));
	} else {
	// It is complex.
	SkPath path;
	region.getBoundaryPath(&path);
	// Clip. Note that windows clipping regions are not affected by the
	// transform so apply it manually.
	path.transform(transformation);
	// TODO(playmobil): Implement.
	SkASSERT(false);
	// LoadPathToDC(context, path);
	// hrgn = PathToRegion(context);
	}
	}

	void BitmapPlatformDevice::LoadConfig() {
	if (!config_dirty_ \|\| !bitmap_context_)
	return; // Nothing to do.
	config_dirty_ = false;

	// We must restore and then save the state of the graphics context since the
	// calls to Load the clipping region to the context are strictly cummulative,
	// i.e., you can't replace a clip rect, other than with a save/restore.
	// But this implies that no other changes to the state are done elsewhere.
	// If we ever get to need to change this, then we must replace the clip rect
	// calls in LoadClippingRegionToCGContext() with an image mask instead.
	CGContextRestoreGState(bitmap_context_);
	CGContextSaveGState(bitmap_context_);
	LoadTransformToCGContext(bitmap_context_, transform_);
	LoadClippingRegionToCGContext(bitmap_context_, clip_region_, transform_);
	}


	// We use this static factory function instead of the regular constructor so
	// that we can create the pixel data before calling the constructor. This is
	// required so that we can call the base class' constructor with the pixel
	// data.
	BitmapPlatformDevice* BitmapPlatformDevice::Create(CGContextRef context,
	int width,
	int height,
	bool is_opaque,
	bool do_clear) {
	if (RasterDeviceTooBigToAllocate(width, height))
	return NULL;

	SkBitmap bitmap;
	// TODO: verify that the CG Context's pixels will have tight rowbytes or pass in the correct
	// rowbytes for the case when context != NULL.
	bitmap.setInfo(SkImageInfo::MakeN32(width, height, is_opaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType));

	void* data;
	if (context) {
	data = CGBitmapContextGetData(context);
	bitmap.setPixels(data);
	} else {
	if (!bitmap.tryAllocPixels())
	return NULL;
	data = bitmap.getPixels();
	}
	if (do_clear)
	memset(data, 0, bitmap.getSafeSize());

	// If we were given data, then don't clobber it!
	#ifndef NDEBUG
	if (!context && is_opaque) {
	// To aid in finding bugs, we set the background color to something
	// obviously wrong so it will be noticable when it is not cleared
	bitmap.eraseARGB(255, 0, 255, 128); // bright bluish green
	}
	#endif

	if (!context) {
	context = CGContextForData(data, width, height);
	if (!context)
	return NULL;
	} else
	CGContextRetain(context);

	BitmapPlatformDevice* rv = new BitmapPlatformDevice(context, bitmap);

	// The device object took ownership of the graphics context with its own
	// CGContextRetain call.
	CGContextRelease(context);

	return rv;
	}

	BitmapPlatformDevice* BitmapPlatformDevice::CreateWithData(uint8_t* data,
	int width,
	int height,
	bool is_opaque) {
	CGContextRef context = NULL;
	if (data)
	context = CGContextForData(data, width, height);

	BitmapPlatformDevice* rv = Create(context, width, height, is_opaque, false);

	// The device object took ownership of the graphics context with its own
	// CGContextRetain call.
	if (context)
	CGContextRelease(context);

	return rv;
	}

	// The device will own the bitmap, which corresponds to also owning the pixel
	// data. Therefore, we do not transfer ownership to the SkBitmapDevice's bitmap.
	BitmapPlatformDevice::BitmapPlatformDevice(
	CGContextRef context, const SkBitmap& bitmap)
	: SkBitmapDevice(bitmap),
	bitmap_context_(context),
	config_dirty_(true), // Want to load the config next time.
	transform_(SkMatrix::I()) {
	SetPlatformDevice(this, this);
	SkASSERT(bitmap_context_);
	// Initialize the clip region to the entire bitmap.

	SkIRect rect;
	rect.set(0, 0,
	CGBitmapContextGetWidth(bitmap_context_),
	CGBitmapContextGetHeight(bitmap_context_));
	clip_region_ = SkRegion(rect);
	CGContextRetain(bitmap_context_);
	// We must save the state once so that we can use the restore/save trick
	// in LoadConfig().
	CGContextSaveGState(bitmap_context_);
	}

	BitmapPlatformDevice::~BitmapPlatformDevice() {
	if (bitmap_context_)
	CGContextRelease(bitmap_context_);
	}

	CGContextRef BitmapPlatformDevice::GetBitmapContext() {
	LoadConfig();
	return bitmap_context_;
	}

	void BitmapPlatformDevice::setMatrixClip(const SkMatrix& transform,
	const SkRegion& region,
	const SkClipStack&) {
	SetMatrixClip(transform, region);
	}

	SkBaseDevice* BitmapPlatformDevice::onCreateDevice(const CreateInfo& cinfo,
	const SkPaint*) {
	const SkImageInfo& info = cinfo.fInfo;
	const bool do_clear = !info.isOpaque();
	SkASSERT(info.colorType() == kN32_SkColorType);
	return Create(NULL, info.width(), info.height(), info.isOpaque(), do_clear);
	}

	// PlatformCanvas impl

	SkCanvas* CreatePlatformCanvas(CGContextRef ctx, int width, int height,
	bool is_opaque, OnFailureType failureType) {
	const bool do_clear = false;
	skia::RefPtr<SkBaseDevice> dev = skia::AdoptRef(
	BitmapPlatformDevice::Create(ctx, width, height, is_opaque, do_clear));
	return CreateCanvas(dev, failureType);
	}

	SkCanvas* CreatePlatformCanvas(int width, int height, bool is_opaque,
	uint8_t* data, OnFailureType failureType) {
	skia::RefPtr<SkBaseDevice> dev = skia::AdoptRef(
	BitmapPlatformDevice::CreateWithData(data, width, height, is_opaque));
	return CreateCanvas(dev, failureType);
	}

	} // namespace skia