1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "skia/ext/bitmap_platform_device_mac.h"
7 #import <ApplicationServices/ApplicationServices.h>
10 #include "base/mac/mac_util.h"
11 #include "base/memory/ref_counted.h"
12 #include "skia/ext/bitmap_platform_device.h"
13 #include "skia/ext/platform_canvas.h"
14 #include "skia/ext/skia_utils_mac.h"
15 #include "third_party/skia/include/core/SkMatrix.h"
16 #include "third_party/skia/include/core/SkRegion.h"
17 #include "third_party/skia/include/core/SkTypes.h"
18 #include "third_party/skia/include/core/SkUtils.h"
24 static CGContextRef CGContextForData(void* data, int width, int height) {
25 #define HAS_ARGB_SHIFTS(a, r, g, b) \
26 (SK_A32_SHIFT == (a) && SK_R32_SHIFT == (r) \
27 && SK_G32_SHIFT == (g) && SK_B32_SHIFT == (b))
28 #if defined(SK_CPU_LENDIAN) && HAS_ARGB_SHIFTS(24, 16, 8, 0)
29 // Allocate a bitmap context with 4 components per pixel (BGRA). Apple
30 // recommends these flags for improved CG performance.
32 // CGBitmapContextCreate returns NULL if width/height are 0. However, our
33 // callers expect to get a canvas back (which they later resize/reallocate)
34 // so we pin the dimensions here.
35 width = SkMax32(1, width);
36 height = SkMax32(1, height);
37 CGContextRef context =
38 CGBitmapContextCreate(data, width, height, 8, width * 4,
39 base::mac::GetSystemColorSpace(),
40 kCGImageAlphaPremultipliedFirst |
41 kCGBitmapByteOrder32Host);
43 #error We require that Skia's and CoreGraphics's recommended \
44 image memory layout match.
46 #undef HAS_ARGB_SHIFTS
51 // Change the coordinate system to match WebCore's
52 CGContextTranslateCTM(context, 0, height);
53 CGContextScaleCTM(context, 1.0, -1.0);
60 void BitmapPlatformDevice::ReleaseBitmapContext() {
61 SkASSERT(bitmap_context_);
62 CGContextRelease(bitmap_context_);
63 bitmap_context_ = NULL;
66 void BitmapPlatformDevice::SetMatrixClip(
67 const SkMatrix& transform,
68 const SkRegion& region) {
69 transform_ = transform;
70 clip_region_ = region;
74 void BitmapPlatformDevice::LoadConfig() {
75 if (!config_dirty_ || !bitmap_context_)
76 return; // Nothing to do.
77 config_dirty_ = false;
79 // We must restore and then save the state of the graphics context since the
80 // calls to Load the clipping region to the context are strictly cummulative,
81 // i.e., you can't replace a clip rect, other than with a save/restore.
82 // But this implies that no other changes to the state are done elsewhere.
83 // If we ever get to need to change this, then we must replace the clip rect
84 // calls in LoadClippingRegionToCGContext() with an image mask instead.
85 CGContextRestoreGState(bitmap_context_);
86 CGContextSaveGState(bitmap_context_);
87 LoadTransformToCGContext(bitmap_context_, transform_);
88 LoadClippingRegionToCGContext(bitmap_context_, clip_region_, transform_);
92 // We use this static factory function instead of the regular constructor so
93 // that we can create the pixel data before calling the constructor. This is
94 // required so that we can call the base class' constructor with the pixel
96 BitmapPlatformDevice* BitmapPlatformDevice::Create(CGContextRef context,
100 if (RasterDeviceTooBigToAllocate(width, height))
104 // TODO: verify that the CG Context's pixels will have tight rowbytes or pass in the correct
105 // rowbytes for the case when context != NULL.
106 bitmap.setConfig(SkBitmap::kARGB_8888_Config, width, height, 0,
107 is_opaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType);
111 data = CGBitmapContextGetData(context);
112 bitmap.setPixels(data);
114 if (!bitmap.allocPixels())
116 data = bitmap.getPixels();
119 // If we were given data, then don't clobber it!
121 if (!context && is_opaque) {
122 // To aid in finding bugs, we set the background color to something
123 // obviously wrong so it will be noticable when it is not cleared
124 bitmap.eraseARGB(255, 0, 255, 128); // bright bluish green
129 context = CGContextForData(data, width, height);
133 CGContextRetain(context);
135 BitmapPlatformDevice* rv = new BitmapPlatformDevice(context, bitmap);
137 // The device object took ownership of the graphics context with its own
138 // CGContextRetain call.
139 CGContextRelease(context);
144 BitmapPlatformDevice* BitmapPlatformDevice::CreateAndClear(int width,
147 BitmapPlatformDevice* device = Create(NULL, width, height, is_opaque);
153 BitmapPlatformDevice* BitmapPlatformDevice::CreateWithData(uint8_t* data,
157 CGContextRef context = NULL;
159 context = CGContextForData(data, width, height);
161 BitmapPlatformDevice* rv = Create(context, width, height, is_opaque);
163 // The device object took ownership of the graphics context with its own
164 // CGContextRetain call.
166 CGContextRelease(context);
171 // The device will own the bitmap, which corresponds to also owning the pixel
172 // data. Therefore, we do not transfer ownership to the SkBitmapDevice's bitmap.
173 BitmapPlatformDevice::BitmapPlatformDevice(
174 CGContextRef context, const SkBitmap& bitmap)
175 : SkBitmapDevice(bitmap),
176 bitmap_context_(context),
177 config_dirty_(true), // Want to load the config next time.
178 transform_(SkMatrix::I()) {
179 SetPlatformDevice(this, this);
180 SkASSERT(bitmap_context_);
181 // Initialize the clip region to the entire bitmap.
185 CGBitmapContextGetWidth(bitmap_context_),
186 CGBitmapContextGetHeight(bitmap_context_));
187 clip_region_ = SkRegion(rect);
188 CGContextRetain(bitmap_context_);
189 // We must save the state once so that we can use the restore/save trick
191 CGContextSaveGState(bitmap_context_);
194 BitmapPlatformDevice::~BitmapPlatformDevice() {
196 CGContextRelease(bitmap_context_);
199 CGContextRef BitmapPlatformDevice::GetBitmapContext() {
201 return bitmap_context_;
204 void BitmapPlatformDevice::setMatrixClip(const SkMatrix& transform,
205 const SkRegion& region,
206 const SkClipStack&) {
207 SetMatrixClip(transform, region);
210 void BitmapPlatformDevice::DrawToNativeContext(CGContextRef context, int x,
211 int y, const CGRect* src_rect) {
212 bool created_dc = false;
213 if (!bitmap_context_) {
218 // this should not make a copy of the bits, since we're not doing
219 // anything to trigger copy on write
220 CGImageRef image = CGBitmapContextCreateImage(bitmap_context_);
225 bounds.size.width = src_rect->size.width;
226 bounds.size.height = src_rect->size.height;
227 CGImageRef sub_image = CGImageCreateWithImageInRect(image, *src_rect);
228 CGContextDrawImage(context, bounds, sub_image);
229 CGImageRelease(sub_image);
231 bounds.size.width = width();
232 bounds.size.height = height();
233 CGContextDrawImage(context, bounds, image);
235 CGImageRelease(image);
238 ReleaseBitmapContext();
241 SkBaseDevice* BitmapPlatformDevice::onCreateCompatibleDevice(
242 SkBitmap::Config config, int width, int height, bool isOpaque,
244 SkASSERT(config == SkBitmap::kARGB_8888_Config);
245 SkBaseDevice* bitmap_device = BitmapPlatformDevice::CreateAndClear(width,
248 return bitmap_device;
251 // PlatformCanvas impl
253 SkCanvas* CreatePlatformCanvas(CGContextRef ctx, int width, int height,
254 bool is_opaque, OnFailureType failureType) {
255 skia::RefPtr<SkBaseDevice> dev = skia::AdoptRef(
256 BitmapPlatformDevice::Create(ctx, width, height, is_opaque));
257 return CreateCanvas(dev, failureType);
260 SkCanvas* CreatePlatformCanvas(int width, int height, bool is_opaque,
261 uint8_t* data, OnFailureType failureType) {
262 skia::RefPtr<SkBaseDevice> dev = skia::AdoptRef(
263 BitmapPlatformDevice::CreateWithData(data, width, height, is_opaque));
264 return CreateCanvas(dev, failureType);
267 // Port of PlatformBitmap to mac
269 PlatformBitmap::~PlatformBitmap() {
271 CGContextRelease(surface_);
274 bool PlatformBitmap::Allocate(int width, int height, bool is_opaque) {
275 if (RasterDeviceTooBigToAllocate(width, height))
278 bitmap_.setConfig(SkBitmap::kARGB_8888_Config, width, height, width * 4,
279 is_opaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType);
280 if (!bitmap_.allocPixels())
284 bitmap_.eraseColor(0);
286 surface_ = CGContextForData(bitmap_.getPixels(), bitmap_.width(),