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      1 // Copyright (c) 2011 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.
      4 
      5 #include "skia/ext/platform_canvas.h"
      6 
      7 #include "skia/ext/bitmap_platform_device.h"
      8 #include "third_party/skia/include/core/SkTypes.h"
      9 
     10 namespace skia {
     11 
     12 SkBaseDevice* GetTopDevice(const SkCanvas& canvas) {
     13   return canvas.getTopDevice(true);
     14 }
     15 
     16 bool SupportsPlatformPaint(const SkCanvas* canvas) {
     17   PlatformDevice* platform_device = GetPlatformDevice(GetTopDevice(*canvas));
     18   return platform_device && platform_device->SupportsPlatformPaint();
     19 }
     20 
     21 PlatformSurface BeginPlatformPaint(SkCanvas* canvas) {
     22   PlatformDevice* platform_device = GetPlatformDevice(GetTopDevice(*canvas));
     23   if (platform_device)
     24     return platform_device->BeginPlatformPaint();
     25 
     26   return 0;
     27 }
     28 
     29 void EndPlatformPaint(SkCanvas* canvas) {
     30   PlatformDevice* platform_device = GetPlatformDevice(GetTopDevice(*canvas));
     31   if (platform_device)
     32     platform_device->EndPlatformPaint();
     33 }
     34 
     35 void DrawToNativeContext(SkCanvas* canvas, PlatformSurface context, int x,
     36                          int y, const PlatformRect* src_rect) {
     37   PlatformDevice* platform_device = GetPlatformDevice(GetTopDevice(*canvas));
     38   if (platform_device)
     39     platform_device->DrawToNativeContext(context, x, y, src_rect);
     40 }
     41 
     42 static SkPMColor MakeOpaqueXfermodeProc(SkPMColor src, SkPMColor dst) {
     43     return dst | (0xFF << SK_A32_SHIFT);
     44 }
     45 
     46 void MakeOpaque(SkCanvas* canvas, int x, int y, int width, int height) {
     47   if (width <= 0 || height <= 0)
     48     return;
     49 
     50   SkRect rect;
     51   rect.setXYWH(SkIntToScalar(x), SkIntToScalar(y),
     52                SkIntToScalar(width), SkIntToScalar(height));
     53   SkPaint paint;
     54   // so we don't draw anything on a device that ignores xfermodes
     55   paint.setColor(0);
     56   // install our custom mode
     57   skia::RefPtr<SkProcXfermode> xfermode =
     58       skia::AdoptRef(new SkProcXfermode(MakeOpaqueXfermodeProc));
     59   paint.setXfermode(xfermode.get());
     60   canvas->drawRect(rect, paint);
     61 }
     62 
     63 size_t PlatformCanvasStrideForWidth(unsigned width) {
     64   return 4 * width;
     65 }
     66 
     67 SkCanvas* CreateCanvas(const skia::RefPtr<SkBaseDevice>& device, OnFailureType failureType) {
     68   if (!device) {
     69     if (CRASH_ON_FAILURE == failureType)
     70       SK_CRASH();
     71     return NULL;
     72   }
     73   return new SkCanvas(device.get());
     74 }
     75 
     76 PlatformBitmap::PlatformBitmap() : surface_(0), platform_extra_(0) {}
     77 
     78 }  // namespace skia
     79