SkSurface_Raster.cpp revision 398337b3a5d66a7db5d36a3b5182e4407e2292f7
1/* 2 * Copyright 2012 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8#include "SkSurface_Base.h" 9#include "SkImagePriv.h" 10#include "SkCanvas.h" 11#include "SkDevice.h" 12#include "SkMallocPixelRef.h" 13 14static const size_t kIgnoreRowBytesValue = (size_t)~0; 15 16class SkSurface_Raster : public SkSurface_Base { 17public: 18 static bool Valid(const SkImageInfo&, size_t rb = kIgnoreRowBytesValue); 19 20 SkSurface_Raster(const SkImageInfo&, void*, size_t rb); 21 SkSurface_Raster(const SkImageInfo&, SkPixelRef*, size_t rb); 22 23 virtual SkCanvas* onNewCanvas() SK_OVERRIDE; 24 virtual SkSurface* onNewSurface(const SkImageInfo&) SK_OVERRIDE; 25 virtual SkImage* onNewImageSnapshot() SK_OVERRIDE; 26 virtual void onDraw(SkCanvas*, SkScalar x, SkScalar y, 27 const SkPaint*) SK_OVERRIDE; 28 virtual void onCopyOnWrite(ContentChangeMode) SK_OVERRIDE; 29 30private: 31 SkBitmap fBitmap; 32 bool fWeOwnThePixels; 33 34 typedef SkSurface_Base INHERITED; 35}; 36 37/////////////////////////////////////////////////////////////////////////////// 38 39bool SkSurface_Raster::Valid(const SkImageInfo& info, size_t rowBytes) { 40 static const size_t kMaxTotalSize = SK_MaxS32; 41 42 SkBitmap::Config config = SkImageInfoToBitmapConfig(info); 43 44 int shift = 0; 45 switch (config) { 46 case SkBitmap::kA8_Config: 47 shift = 0; 48 break; 49 case SkBitmap::kRGB_565_Config: 50 shift = 1; 51 break; 52 case SkBitmap::kARGB_8888_Config: 53 shift = 2; 54 break; 55 default: 56 return false; 57 } 58 59 // TODO: examine colorspace 60 61 if (kIgnoreRowBytesValue == rowBytes) { 62 return true; 63 } 64 65 uint64_t minRB = (uint64_t)info.fWidth << shift; 66 if (minRB > rowBytes) { 67 return false; 68 } 69 70 size_t alignedRowBytes = rowBytes >> shift << shift; 71 if (alignedRowBytes != rowBytes) { 72 return false; 73 } 74 75 uint64_t size = (uint64_t)info.fHeight * rowBytes; 76 if (size > kMaxTotalSize) { 77 return false; 78 } 79 80 return true; 81} 82 83SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, void* pixels, size_t rb) 84 : INHERITED(info.fWidth, info.fHeight) { 85 SkBitmap::Config config = SkImageInfoToBitmapConfig(info); 86 fBitmap.setConfig(config, info.fWidth, info.fHeight, rb, info.fAlphaType); 87 fBitmap.setPixels(pixels); 88 fWeOwnThePixels = false; // We are "Direct" 89} 90 91SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, SkPixelRef* pr, size_t rb) 92 : INHERITED(info.fWidth, info.fHeight) { 93 SkBitmap::Config config = SkImageInfoToBitmapConfig(info); 94 fBitmap.setConfig(config, info.fWidth, info.fHeight, rb, info.fAlphaType); 95 fBitmap.setPixelRef(pr); 96 fWeOwnThePixels = true; 97 98 if (!SkAlphaTypeIsOpaque(info.fAlphaType)) { 99 fBitmap.eraseColor(SK_ColorTRANSPARENT); 100 } 101} 102 103SkCanvas* SkSurface_Raster::onNewCanvas() { 104 return SkNEW_ARGS(SkCanvas, (fBitmap)); 105} 106 107SkSurface* SkSurface_Raster::onNewSurface(const SkImageInfo& info) { 108 return SkSurface::NewRaster(info); 109} 110 111void SkSurface_Raster::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y, 112 const SkPaint* paint) { 113 canvas->drawBitmap(fBitmap, x, y, paint); 114} 115 116SkImage* SkSurface_Raster::onNewImageSnapshot() { 117 return SkNewImageFromBitmap(fBitmap, fWeOwnThePixels); 118} 119 120void SkSurface_Raster::onCopyOnWrite(ContentChangeMode mode) { 121 // are we sharing pixelrefs with the image? 122 SkASSERT(NULL != this->getCachedImage()); 123 if (SkBitmapImageGetPixelRef(this->getCachedImage()) == fBitmap.pixelRef()) { 124 SkASSERT(fWeOwnThePixels); 125 if (kDiscard_ContentChangeMode == mode) { 126 fBitmap.setPixelRef(NULL, 0); 127 fBitmap.allocPixels(); 128 } else { 129 SkBitmap prev(fBitmap); 130 prev.deepCopyTo(&fBitmap, prev.config()); 131 } 132 // Now fBitmap is a deep copy of itself (and therefore different from 133 // what is being used by the image. Next we update the canvas to use 134 // this as its backend, so we can't modify the image's pixels anymore. 135 SkASSERT(NULL != this->getCachedCanvas()); 136 this->getCachedCanvas()->getDevice()->replaceBitmapBackendForRasterSurface(fBitmap); 137 } 138} 139 140/////////////////////////////////////////////////////////////////////////////// 141 142SkSurface* SkSurface::NewRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes) { 143 if (!SkSurface_Raster::Valid(info, rowBytes)) { 144 return NULL; 145 } 146 if (NULL == pixels) { 147 return NULL; 148 } 149 150 return SkNEW_ARGS(SkSurface_Raster, (info, pixels, rowBytes)); 151} 152 153SkSurface* SkSurface::NewRaster(const SkImageInfo& info) { 154 if (!SkSurface_Raster::Valid(info)) { 155 return NULL; 156 } 157 158 static const size_t kMaxTotalSize = SK_MaxS32; 159 size_t rowBytes = SkImageMinRowBytes(info); 160 uint64_t size64 = (uint64_t)info.fHeight * rowBytes; 161 if (size64 > kMaxTotalSize) { 162 return NULL; 163 } 164 165 size_t size = (size_t)size64; 166 void* pixels = sk_malloc_throw(size); 167 if (NULL == pixels) { 168 return NULL; 169 } 170 171 SkAutoTUnref<SkPixelRef> pr(SkNEW_ARGS(SkMallocPixelRef, (pixels, size, NULL, true))); 172 return SkNEW_ARGS(SkSurface_Raster, (info, pr, rowBytes)); 173} 174