Make filters use SkImage instead of SkBitmap

src/effects/SkTestImageFilters.cpp

 
 #include "SkTestImageFilters.h"
 #include "SkCanvas.h"
 #include "SkDevice.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 
-// Simple helper canvas that "takes ownership" of the provided device, so that
-// when this canvas goes out of scope, so will its device. Could be replaced
-// with the following:
-//
-//  SkCanvas canvas(device);
-//  SkAutoTUnref<SkBaseDevice> aur(device);
-//
-class OwnDeviceCanvas : public SkCanvas {
-public:
-    OwnDeviceCanvas(SkBaseDevice* device) : SkCanvas(device) {
-        SkSafeUnref(device);
-    }
-};
-
-///////////////////////////////////////////////////////////////////////////////
-
-bool SkDownSampleImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
+bool SkDownSampleImageFilter::onFilterImage(Proxy* proxy, const SkImage* src,
                                             const Context&,
-                                            SkBitmap* result, SkIPoint*) const {
+                                            SkAutoTUnref<const SkImage>& result, SkIPoint*) const {
     SkScalar scale = fScale;
     if (scale > SK_Scalar1 || scale <= 0) {
         return false;
     }
 
-    int dstW = SkScalarRoundToInt(src.width() * scale);
-    int dstH = SkScalarRoundToInt(src.height() * scale);
+    int dstW = SkScalarRoundToInt(src->width() * scale);
+    int dstH = SkScalarRoundToInt(src->height() * scale);
     if (dstW < 1) {
         dstW = 1;
     }
     if (dstH < 1) {
         dstH = 1;
     }
 
-    SkBitmap tmp;
+    SkAutoTUnref<const SkImage> tmp;
 
     // downsample
     {
-        SkBaseDevice* dev = proxy->createDevice(dstW, dstH);
-        if (NULL == dev) {
+        SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(dstW, dstH));
+        if (NULL == device) {
             return false;
         }
-        OwnDeviceCanvas canvas(dev);
+        SkCanvas canvas(device);
         SkPaint paint;
 
         paint.setFilterQuality(kLow_SkFilterQuality);
         canvas.scale(scale, scale);
-        canvas.drawBitmap(src, 0, 0, &paint);
-        tmp = dev->accessBitmap(false);
+        canvas.drawImage(src, 0, 0, &paint);
+
+        tmp.reset(device->newImageSnapshot());
+        if (NULL == tmp) {
+            return false;
+        }
     }
 
     // upscale
     {
-        SkBaseDevice* dev = proxy->createDevice(src.width(), src.height());
-        if (NULL == dev) {
+        SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(src->width(), src->height()));
+        if (NULL == device) {
             return false;
         }
-        OwnDeviceCanvas canvas(dev);
-
-        SkRect r = SkRect::MakeWH(SkIntToScalar(src.width()),
-                                  SkIntToScalar(src.height()));
-        canvas.drawBitmapRect(tmp, NULL, r, NULL);
-        *result = dev->accessBitmap(false);
+        SkCanvas canvas(device);
+        SkScalar scaleX = SkIntToScalar(src->width()) / SkIntToScalar(dstW);
+        SkScalar scaleY = SkIntToScalar(src->height()) / SkIntToScalar(dstH);
+        canvas.scale(scaleX, scaleY);
+        canvas.drawImage(tmp, 0, 0, NULL);
+        SkImage* image = device->newImageSnapshot();
+        if (NULL == image) {
+            return false;
+        }
+        result.reset(image);
     }
     return true;
 }
 
 SkFlattenable* SkDownSampleImageFilter::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
     return Create(buffer.readScalar(), common.getInput(0));
 }
 
 void SkDownSampleImageFilter::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fScale);
 }
 
 #ifndef SK_IGNORE_TO_STRING
 void SkDownSampleImageFilter::toString(SkString* str) const {
     str->appendf("SkDownSampleImageFilter: (");
     str->append(")");
 }
 #endif