src/skia/ext/platform_canvas.cc

   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