add applyFilter() to SkImage
Result:
- clients can get a filtered version of an image without having to setup a temp drawing environment
- for some cases, the process is more efficient even than (deprecated) drawSprite, since there is no need to draw/copy the result
Impl:
- made Proxy virtual so we don't need to have an existing device to use it
This, in conjunction with LocalMatrixImageFilter, should allow us to simplify and optimize ApplyImageFilter() in cc/output/gl_renderer.cc
BUG=skia:
Review URL: https://codereview.chromium.org/1390913005
diff --git a/gm/spritebitmap.cpp b/gm/spritebitmap.cpp
index ceed50a..0d467ea 100644
--- a/gm/spritebitmap.cpp
+++ b/gm/spritebitmap.cpp
@@ -97,3 +97,121 @@
};
DEF_GM( return new SpriteBitmapGM; )
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+#include "SkColorFilterImageFilter.h"
+#include "SkModeColorFilter.h"
+#include "SkMorphologyImageFilter.h"
+#include "SkOffsetImageFilter.h"
+
+static SkImage* make_image(SkCanvas* rootCanvas) {
+ SkImageInfo info = SkImageInfo::MakeN32Premul(100, 100);
+ SkAutoTUnref<SkSurface> surface(rootCanvas->newSurface(info));
+ if (!surface) {
+ surface.reset(SkSurface::NewRaster(info));
+ }
+
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setColor(SK_ColorRED);
+ surface->getCanvas()->drawCircle(50, 50, 50, paint);
+ return surface->newImageSnapshot();
+}
+
+static void show_image(SkCanvas* canvas, SkImage* image, const SkIPoint& offset) {
+ SkScalar x = SkIntToScalar(offset.x());
+ SkScalar y = SkIntToScalar(offset.y());
+
+ SkPaint paint;
+ paint.setStyle(SkPaint::kStroke_Style);
+
+ SkRect r = SkRect::MakeIWH(image->width(), image->height());
+ r.offset(x, y);
+ // get on pixel-centers to make the hairline land on a numerical stable boundary
+ r.outset(SK_ScalarHalf, SK_ScalarHalf);
+ canvas->drawRect(r, paint);
+
+ canvas->drawImage(image, x, y, nullptr);
+}
+
+typedef SkImageFilter* (*ImageFilterFactory)();
+
+// +[]{...} did not work on windows (VS)
+// (ImageFilterFactory)[]{...} did not work on linux (gcc)
+// hence this cast function
+template <typename T> ImageFilterFactory IFCCast(T arg) { return arg; }
+
+/**
+ * Compare output of drawSprite and drawBitmap (esp. clipping and imagefilters)
+ */
+class ApplyFilterGM : public skiagm::GM {
+public:
+ ApplyFilterGM() {}
+
+protected:
+ SkString onShortName() override {
+ return SkString("apply-filter");
+ }
+
+ SkISize onISize() override {
+ return SkISize::Make(640, 480);
+ }
+
+ void onDraw(SkCanvas* canvas) override {
+ SkAutoTUnref<SkImage> image0(make_image(canvas));
+
+ const ImageFilterFactory factories[] = {
+ IFCCast([]{ return SkBlurImageFilter::Create(8, 8); }),
+ IFCCast([]{ SkAutoTUnref<SkColorFilter> cf(SkModeColorFilter::Create(SK_ColorBLUE,
+ SkXfermode::kSrcIn_Mode));
+ return SkColorFilterImageFilter::Create(cf);
+ }),
+ IFCCast([]{ return SkDilateImageFilter::Create(8, 8); }),
+ IFCCast([]{ return SkErodeImageFilter::Create(8, 8); }),
+ IFCCast([]{ return SkOffsetImageFilter::Create(8, 8); }),
+ };
+
+ const SkScalar spacer = image0->width() * 3.0f / 2;
+
+ for (auto&& factory : factories) {
+ SkAutoTUnref<SkImageFilter> filter(factory());
+
+ SkIPoint offset1, offset2;
+ SkAutoTUnref<SkImage> image1(image0->applyFilter(filter, &offset1, true));
+ SkAutoTUnref<SkImage> image2(image0->applyFilter(filter, &offset2, false));
+
+ canvas->save();
+ canvas->translate(30, 30);
+ show_image(canvas, image0, SkIPoint::Make(0, 0)); // original
+ canvas->translate(spacer, 0);
+ show_image(canvas, image1, offset1); // snug
+ canvas->translate(spacer, 0);
+ show_image(canvas, image2, offset2); // not snug
+
+ // Try drawing the original w/ the filter, to see that it "draws" the same as
+ // when we have manually applied the filter (above).
+ {
+ SkPaint paint;
+ paint.setImageFilter(filter);
+
+ SkBitmap bm;
+ image0->asLegacyBitmap(&bm, SkImage::kRO_LegacyBitmapMode);
+ SkPoint loc = { 0, 0 };
+ canvas->translate(spacer, 0);
+ canvas->getTotalMatrix().mapPoints(&loc, 1);
+ canvas->drawSprite(bm, (int)loc.x(), (int)loc.y(), &paint); // like snug
+
+ canvas->translate(spacer, 0);
+ canvas->drawImage(image0, 0, 0, &paint); // like not snug
+ }
+ canvas->restore();
+
+ canvas->translate(0, spacer);
+ }
+ }
+
+private:
+ typedef GM INHERITED;
+};
+DEF_GM( return new ApplyFilterGM; )
+