SkSurface_Raster.cpp revision 02d91d187324cd0f014a78eab1ca09ec71a9b356
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 void (*releaseProc)(void* pixels, void* context), void* context, 22 const SkSurfaceProps*); 23 SkSurface_Raster(SkPixelRef*, const SkSurfaceProps*); 24 25 SkCanvas* onNewCanvas() override; 26 SkSurface* onNewSurface(const SkImageInfo&) override; 27 SkImage* onNewImageSnapshot(Budgeted) override; 28 void onDraw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*) override; 29 void onCopyOnWrite(ContentChangeMode) override; 30 void onRestoreBackingMutability() override; 31 32private: 33 SkBitmap fBitmap; 34 bool fWeOwnThePixels; 35 36 typedef SkSurface_Base INHERITED; 37}; 38 39/////////////////////////////////////////////////////////////////////////////// 40 41bool SkSurface_Raster::Valid(const SkImageInfo& info, size_t rowBytes) { 42 if (info.isEmpty()) { 43 return false; 44 } 45 46 static const size_t kMaxTotalSize = SK_MaxS32; 47 48 int shift = 0; 49 switch (info.colorType()) { 50 case kAlpha_8_SkColorType: 51 shift = 0; 52 break; 53 case kRGB_565_SkColorType: 54 shift = 1; 55 break; 56 case kN32_SkColorType: 57 shift = 2; 58 break; 59 default: 60 return false; 61 } 62 63 if (kIgnoreRowBytesValue == rowBytes) { 64 return true; 65 } 66 67 uint64_t minRB = (uint64_t)info.width() << shift; 68 if (minRB > rowBytes) { 69 return false; 70 } 71 72 size_t alignedRowBytes = rowBytes >> shift << shift; 73 if (alignedRowBytes != rowBytes) { 74 return false; 75 } 76 77 uint64_t size = sk_64_mul(info.height(), rowBytes); 78 if (size > kMaxTotalSize) { 79 return false; 80 } 81 82 return true; 83} 84 85SkSurface_Raster::SkSurface_Raster(const SkImageInfo& info, void* pixels, size_t rb, 86 void (*releaseProc)(void* pixels, void* context), void* context, 87 const SkSurfaceProps* props) 88 : INHERITED(info, props) 89{ 90 fBitmap.installPixels(info, pixels, rb, NULL, releaseProc, context); 91 fWeOwnThePixels = false; // We are "Direct" 92} 93 94SkSurface_Raster::SkSurface_Raster(SkPixelRef* pr, const SkSurfaceProps* props) 95 : INHERITED(pr->info().width(), pr->info().height(), props) 96{ 97 const SkImageInfo& info = pr->info(); 98 99 fBitmap.setInfo(info, info.minRowBytes()); 100 fBitmap.setPixelRef(pr); 101 fWeOwnThePixels = true; 102 103 if (!info.isOpaque()) { 104 fBitmap.eraseColor(SK_ColorTRANSPARENT); 105 } 106} 107 108SkCanvas* SkSurface_Raster::onNewCanvas() { 109 return SkNEW_ARGS(SkCanvas, (fBitmap, this->props())); 110} 111 112SkSurface* SkSurface_Raster::onNewSurface(const SkImageInfo& info) { 113 return SkSurface::NewRaster(info, &this->props()); 114} 115 116void SkSurface_Raster::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y, 117 const SkPaint* paint) { 118 canvas->drawBitmap(fBitmap, x, y, paint); 119} 120 121SkImage* SkSurface_Raster::onNewImageSnapshot(Budgeted) { 122 if (fWeOwnThePixels) { 123 // SkImage_raster requires these pixels are immutable for its full lifetime. 124 // We'll undo this via onRestoreBackingMutability() if we can avoid the COW. 125 if (SkPixelRef* pr = fBitmap.pixelRef()) { 126 pr->setTemporarilyImmutable(); 127 } 128 } 129 // Our pixels are in memory, so read access on the snapshot SkImage could be cheap. 130 // Lock the shared pixel ref to ensure peekPixels() is usable. 131 return SkNewImageFromRasterBitmap(fBitmap, &this->props(), 132 fWeOwnThePixels ? kNo_ForceCopyMode : kYes_ForceCopyMode); 133} 134 135void SkSurface_Raster::onRestoreBackingMutability() { 136 SkASSERT(!this->hasCachedImage()); // Shouldn't be any snapshots out there. 137 if (SkPixelRef* pr = fBitmap.pixelRef()) { 138 pr->restoreMutability(); 139 } 140} 141 142void SkSurface_Raster::onCopyOnWrite(ContentChangeMode mode) { 143 // are we sharing pixelrefs with the image? 144 SkASSERT(this->getCachedImage(kNo_Budgeted)); 145 if (SkBitmapImageGetPixelRef(this->getCachedImage(kNo_Budgeted)) == fBitmap.pixelRef()) { 146 SkASSERT(fWeOwnThePixels); 147 if (kDiscard_ContentChangeMode == mode) { 148 fBitmap.setPixelRef(NULL); 149 fBitmap.allocPixels(); 150 } else { 151 SkBitmap prev(fBitmap); 152 prev.deepCopyTo(&fBitmap); 153 } 154 // Now fBitmap is a deep copy of itself (and therefore different from 155 // what is being used by the image. Next we update the canvas to use 156 // this as its backend, so we can't modify the image's pixels anymore. 157 SkASSERT(this->getCachedCanvas()); 158 this->getCachedCanvas()->getDevice()->replaceBitmapBackendForRasterSurface(fBitmap); 159 } 160} 161 162/////////////////////////////////////////////////////////////////////////////// 163 164SkSurface* SkSurface::NewRasterDirectReleaseProc(const SkImageInfo& info, void* pixels, size_t rb, 165 void (*releaseProc)(void* pixels, void* context), 166 void* context, const SkSurfaceProps* props) { 167 if (NULL == releaseProc) { 168 context = NULL; 169 } 170 if (!SkSurface_Raster::Valid(info, rb)) { 171 return NULL; 172 } 173 if (NULL == pixels) { 174 return NULL; 175 } 176 177 return SkNEW_ARGS(SkSurface_Raster, (info, pixels, rb, releaseProc, context, props)); 178} 179 180SkSurface* SkSurface::NewRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes, 181 const SkSurfaceProps* props) { 182 return NewRasterDirectReleaseProc(info, pixels, rowBytes, NULL, NULL, props); 183} 184 185SkSurface* SkSurface::NewRaster(const SkImageInfo& info, const SkSurfaceProps* props) { 186 if (!SkSurface_Raster::Valid(info)) { 187 return NULL; 188 } 189 190 SkAutoTUnref<SkPixelRef> pr(SkMallocPixelRef::NewAllocate(info, 0, NULL)); 191 if (NULL == pr.get()) { 192 return NULL; 193 } 194 return SkNEW_ARGS(SkSurface_Raster, (pr, props)); 195} 196