src/third_party/skia/src/effects/SkTestImageFilters.cpp

   1
   2 #include "SkTestImageFilters.h"
   3 #include "SkCanvas.h"
   4 #include "SkDevice.h"
   5 #include "SkReadBuffer.h"
   6 #include "SkWriteBuffer.h"
   7
   8 // Simple helper canvas that "takes ownership" of the provided device, so that
   9 // when this canvas goes out of scope, so will its device. Could be replaced
  10 // with the following:
  11 //
  12 //  SkCanvas canvas(device);
  13 //  SkAutoTUnref<SkBaseDevice> aur(device);
  14 //
  15 class OwnDeviceCanvas : public SkCanvas {
  16 public:
  17     OwnDeviceCanvas(SkBaseDevice* device) : SkCanvas(device) {
  18         SkSafeUnref(device);
  19     }
  20 };
  21
  22 ///////////////////////////////////////////////////////////////////////////////
  23
  24 bool SkDownSampleImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
  25                                             const Context&,
  26                                             SkBitmap* result, SkIPoint*) const {
  27     SkScalar scale = fScale;
  28     if (scale > SK_Scalar1 || scale <= 0) {
  29         return false;
  30     }
  31
  32     int dstW = SkScalarRoundToInt(src.width() * scale);
  33     int dstH = SkScalarRoundToInt(src.height() * scale);
  34     if (dstW < 1) {
  35         dstW = 1;
  36     }
  37     if (dstH < 1) {
  38         dstH = 1;
  39     }
  40
  41     SkBitmap tmp;
  42
  43     // downsample
  44     {
  45         SkBaseDevice* dev = proxy->createDevice(dstW, dstH);
  46         if (NULL == dev) {
  47             return false;
  48         }
  49         OwnDeviceCanvas canvas(dev);
  50         SkPaint paint;
  51
  52         paint.setFilterLevel(SkPaint::kLow_FilterLevel);
  53         canvas.scale(scale, scale);
  54         canvas.drawBitmap(src, 0, 0, &paint);
  55         tmp = dev->accessBitmap(false);
  56     }
  57
  58     // upscale
  59     {
  60         SkBaseDevice* dev = proxy->createDevice(src.width(), src.height());
  61         if (NULL == dev) {
  62             return false;
  63         }
  64         OwnDeviceCanvas canvas(dev);
  65
  66         SkRect r = SkRect::MakeWH(SkIntToScalar(src.width()),
  67                                   SkIntToScalar(src.height()));
  68         canvas.drawBitmapRect(tmp, NULL, r, NULL);
  69         *result = dev->accessBitmap(false);
  70     }
  71     return true;
  72 }
  73
  74 SkFlattenable* SkDownSampleImageFilter::CreateProc(SkReadBuffer& buffer) {
  75     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
  76     return Create(buffer.readScalar(), common.getInput(0));
  77 }
  78
  79 void SkDownSampleImageFilter::flatten(SkWriteBuffer& buffer) const {
  80     this->INHERITED::flatten(buffer);
  81     buffer.writeScalar(fScale);
  82 }
  83
  84 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
  85 SkDownSampleImageFilter::SkDownSampleImageFilter(SkReadBuffer& buffer)
  86   : INHERITED(1, buffer) {
  87     fScale = buffer.readScalar();
  88     buffer.validate(SkScalarIsFinite(fScale));
  89 }
  90 #endif