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

 // Copyright (c) 2011 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"

 #include <time.h>

 #include "base/mac/mac_util.h"
 #include "base/memory/ref_counted.h"
 #include "skia/ext/bitmap_platform_device_data.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "third_party/skia/include/core/SkMatrix.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.
   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

 SkDevice* BitmapPlatformDeviceFactory::newDevice(SkCanvas* ignored,
                                                  SkBitmap::Config config,
                                                  int width, int height,
                                                  bool isOpaque,
                                                  bool isForLayer) {
   SkASSERT(config == SkBitmap::kARGB_8888_Config);
   return BitmapPlatformDevice::Create(NULL, width, height, isOpaque);
 }

 BitmapPlatformDevice::BitmapPlatformDeviceData::BitmapPlatformDeviceData(
     CGContextRef bitmap)
     : bitmap_context_(bitmap),
       config_dirty_(true) {  // Want to load the config next time.
   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);
   transform_.reset();
   CGContextRetain(bitmap_context_);
   // We must save the state once so that we can use the restore/save trick
   // in LoadConfig().
   CGContextSaveGState(bitmap_context_);
 }

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

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

 void BitmapPlatformDevice::BitmapPlatformDeviceData::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) {
   SkBitmap bitmap;
   bitmap.setConfig(SkBitmap::kARGB_8888_Config, width, height);
   if (bitmap.allocPixels() != true)
     return NULL;

   void* data = NULL;
   if (context) {
     data = CGBitmapContextGetData(context);
     bitmap.setPixels(data);
   } else {
     data = bitmap.getPixels();

     // Note: The Windows implementation clears the Bitmap later on.
     // This bears mentioning since removal of this line makes the
     // unit tests only fail periodically (or when MallocPreScribble is set).
     bitmap.eraseARGB(0, 0, 0, 0);
   }

   bitmap.setIsOpaque(is_opaque);

   // 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);
   else
     CGContextRetain(context);

   BitmapPlatformDevice* rv = new BitmapPlatformDevice(
       new BitmapPlatformDeviceData(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);

   // 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 SkDevice's bitmap.
 BitmapPlatformDevice::BitmapPlatformDevice(
     BitmapPlatformDeviceData* data, const SkBitmap& bitmap)
     : PlatformDevice(bitmap),
       data_(data) {
 }

 // The copy constructor just adds another reference to the underlying data.
 // We use a const cast since the default Skia definitions don't define the
 // proper constedness that we expect (accessBitmap should really be const).
 BitmapPlatformDevice::BitmapPlatformDevice(
     const BitmapPlatformDevice& other)
     : PlatformDevice(
           const_cast<BitmapPlatformDevice&>(other).accessBitmap(true)),
       data_(other.data_) {
   data_->ref();
 }

 BitmapPlatformDevice::~BitmapPlatformDevice() {
   data_->unref();
 }

 SkDeviceFactory* BitmapPlatformDevice::getDeviceFactory() {
   return SkNEW(BitmapPlatformDeviceFactory);
 }

 BitmapPlatformDevice& BitmapPlatformDevice::operator=(
     const BitmapPlatformDevice& other) {
   data_ = other.data_;
   data_->ref();
   return *this;
 }

 CGContextRef BitmapPlatformDevice::GetBitmapContext() {
   data_->LoadConfig();
   return data_->bitmap_context();
 }

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

 void BitmapPlatformDevice::DrawToContext(CGContextRef context, int x, int y,
                                          const CGRect* src_rect) {
   bool created_dc = false;
   if (!data_->bitmap_context()) {
     created_dc = true;
     GetBitmapContext();
   }

   // this should not make a copy of the bits, since we're not doing
   // anything to trigger copy on write
   CGImageRef image = CGBitmapContextCreateImage(data_->bitmap_context());
   CGRect bounds;
   bounds.origin.x = x;
   bounds.origin.y = y;
   if (src_rect) {
     bounds.size.width = src_rect->size.width;
     bounds.size.height = src_rect->size.height;
     CGImageRef sub_image = CGImageCreateWithImageInRect(image, *src_rect);
     CGContextDrawImage(context, bounds, sub_image);
     CGImageRelease(sub_image);
   } else {
     bounds.size.width = width();
     bounds.size.height = height();
     CGContextDrawImage(context, bounds, image);
   }
   CGImageRelease(image);

   if (created_dc)
     data_->ReleaseBitmapContext();
 }

 bool BitmapPlatformDevice::IsVectorial() {
   return false;
 }

 // Returns the color value at the specified location.
 SkColor BitmapPlatformDevice::getColorAt(int x, int y) {
   const SkBitmap& bitmap = accessBitmap(true);
   SkAutoLockPixels lock(bitmap);
   uint32_t* data = bitmap.getAddr32(0, 0);
   return static_cast<SkColor>(data[x + y * width()]);
 }

 void BitmapPlatformDevice::onAccessBitmap(SkBitmap*) {
   // Not needed in CoreGraphics
 }

 }  // namespace skia
	// Copyright (c) 2011 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"

	#include <time.h>

	#include "base/mac/mac_util.h"
	#include "base/memory/ref_counted.h"
	#include "skia/ext/bitmap_platform_device_data.h"
	#include "skia/ext/skia_utils_mac.h"
	#include "third_party/skia/include/core/SkMatrix.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.
	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

	SkDevice* BitmapPlatformDeviceFactory::newDevice(SkCanvas* ignored,
	SkBitmap::Config config,
	int width, int height,
	bool isOpaque,
	bool isForLayer) {
	SkASSERT(config == SkBitmap::kARGB_8888_Config);
	return BitmapPlatformDevice::Create(NULL, width, height, isOpaque);
	}

	BitmapPlatformDevice::BitmapPlatformDeviceData::BitmapPlatformDeviceData(
	CGContextRef bitmap)
	: bitmap_context_(bitmap),
	config_dirty_(true) { // Want to load the config next time.
	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);
	transform_.reset();
	CGContextRetain(bitmap_context_);
	// We must save the state once so that we can use the restore/save trick
	// in LoadConfig().
	CGContextSaveGState(bitmap_context_);
	}

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

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

	void BitmapPlatformDevice::BitmapPlatformDeviceData::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) {
	SkBitmap bitmap;
	bitmap.setConfig(SkBitmap::kARGB_8888_Config, width, height);
	if (bitmap.allocPixels() != true)
	return NULL;

	void* data = NULL;
	if (context) {
	data = CGBitmapContextGetData(context);
	bitmap.setPixels(data);
	} else {
	data = bitmap.getPixels();

	// Note: The Windows implementation clears the Bitmap later on.
	// This bears mentioning since removal of this line makes the
	// unit tests only fail periodically (or when MallocPreScribble is set).
	bitmap.eraseARGB(0, 0, 0, 0);
	}

	bitmap.setIsOpaque(is_opaque);

	// 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);
	else
	CGContextRetain(context);

	BitmapPlatformDevice* rv = new BitmapPlatformDevice(
	new BitmapPlatformDeviceData(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);

	// 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 SkDevice's bitmap.
	BitmapPlatformDevice::BitmapPlatformDevice(
	BitmapPlatformDeviceData* data, const SkBitmap& bitmap)
	: PlatformDevice(bitmap),
	data_(data) {
	}

	// The copy constructor just adds another reference to the underlying data.
	// We use a const cast since the default Skia definitions don't define the
	// proper constedness that we expect (accessBitmap should really be const).
	BitmapPlatformDevice::BitmapPlatformDevice(
	const BitmapPlatformDevice& other)
	: PlatformDevice(
	const_cast<BitmapPlatformDevice&>(other).accessBitmap(true)),
	data_(other.data_) {
	data_->ref();
	}

	BitmapPlatformDevice::~BitmapPlatformDevice() {
	data_->unref();
	}

	SkDeviceFactory* BitmapPlatformDevice::getDeviceFactory() {
	return SkNEW(BitmapPlatformDeviceFactory);
	}

	BitmapPlatformDevice& BitmapPlatformDevice::operator=(
	const BitmapPlatformDevice& other) {
	data_ = other.data_;
	data_->ref();
	return *this;
	}

	CGContextRef BitmapPlatformDevice::GetBitmapContext() {
	data_->LoadConfig();
	return data_->bitmap_context();
	}

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

	void BitmapPlatformDevice::DrawToContext(CGContextRef context, int x, int y,
	const CGRect* src_rect) {
	bool created_dc = false;
	if (!data_->bitmap_context()) {
	created_dc = true;
	GetBitmapContext();
	}

	// this should not make a copy of the bits, since we're not doing
	// anything to trigger copy on write
	CGImageRef image = CGBitmapContextCreateImage(data_->bitmap_context());
	CGRect bounds;
	bounds.origin.x = x;
	bounds.origin.y = y;
	if (src_rect) {
	bounds.size.width = src_rect->size.width;
	bounds.size.height = src_rect->size.height;
	CGImageRef sub_image = CGImageCreateWithImageInRect(image, *src_rect);
	CGContextDrawImage(context, bounds, sub_image);
	CGImageRelease(sub_image);
	} else {
	bounds.size.width = width();
	bounds.size.height = height();
	CGContextDrawImage(context, bounds, image);
	}
	CGImageRelease(image);

	if (created_dc)
	data_->ReleaseBitmapContext();
	}

	bool BitmapPlatformDevice::IsVectorial() {
	return false;
	}

	// Returns the color value at the specified location.
	SkColor BitmapPlatformDevice::getColorAt(int x, int y) {
	const SkBitmap& bitmap = accessBitmap(true);
	SkAutoLockPixels lock(bitmap);
	uint32_t* data = bitmap.getAddr32(0, 0);
	return static_cast<SkColor>(data[x + y * width()]);
	}

	void BitmapPlatformDevice::onAccessBitmap(SkBitmap*) {
	// Not needed in CoreGraphics
	}

	} // namespace skia