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authorGravatar reed <reed@google.com>2015-12-04 12:44:24 -0800
committerGravatar Commit bot <commit-bot@chromium.org>2015-12-04 12:44:24 -0800
commit95f53fbc5ddf14ddb1e51c7ebced2b80fb069f81 (patch)
tree107b0119489a7dd84e6ab3d2701451af3340128a
parent5123eb760fcb1684394b73c2fc6bfad270b29baf (diff)
clarify diff manually, showing black where they differ
BUG=skia: TBR=robertphilips@google.com Review URL: https://codereview.chromium.org/1498243002
-rw-r--r--gm/spritebitmap.cpp34
1 files changed, 30 insertions, 4 deletions
diff --git a/gm/spritebitmap.cpp b/gm/spritebitmap.cpp
index b11763b5f9..b199371e89 100644
--- a/gm/spritebitmap.cpp
+++ b/gm/spritebitmap.cpp
@@ -228,6 +228,34 @@ DEF_GM( return new ApplyFilterGM; )
#include "SkDisplacementMapEffect.h"
#include "SkMatrixConvolutionImageFilter.h"
+static SkPMColor max_component(SkPMColor a, SkPMColor b) {
+ int dr = SkAbs32(SkGetPackedR32(a) - SkGetPackedR32(b));
+ int dg = SkAbs32(SkGetPackedG32(a) - SkGetPackedG32(b));
+ int db = SkAbs32(SkGetPackedB32(a) - SkGetPackedB32(b));
+ int d = SkTMax(dr, SkTMax(dg, db));
+ d = 0xFF - d;
+ return SkPackARGB32(0xFF, d, d, d);
+}
+
+static SkImage* compute_diff(SkImage* a, SkImage* b) {
+ SkASSERT(a->width() == b->width() && a->height() == b->height());
+ const SkImageInfo info = SkImageInfo::MakeN32Premul(a->width(), a->height());
+ SkBitmap bma, bmb, bmdiff;
+ bma.allocPixels(info);
+ bmb.allocPixels(info);
+ bmdiff.allocPixels(info);
+
+ a->readPixels(info, bma.getPixels(), bma.rowBytes(), 0, 0);
+ b->readPixels(info, bmb.getPixels(), bmb.rowBytes(), 0, 0);
+ for (int y = 0; y < info.height(); ++y) {
+ for (int x = 0; x < info.width(); ++x) {
+ *bmdiff.getAddr32(x, y) = max_component(*bma.getAddr32(x, y), *bmb.getAddr32(x, y));
+ }
+ }
+ bmdiff.setImmutable(); // avoid the copy
+ return SkImage::NewFromBitmap(bmdiff);
+}
+
static SkImage* make_native_red_oval(SkCanvas* rootCanvas) {
SkImageInfo info = SkImageInfo::MakeN32Premul(160, 90);
SkAutoTUnref<SkSurface> surface(rootCanvas->newSurface(info));
@@ -329,10 +357,8 @@ protected:
canvas->drawImage(snap1, dx, 0);
SkAutoTUnref<SkImage> diff(snapshot(canvas, info, [&](SkCanvas* c) {
- c->drawImage(snap0, 0, 0);
- SkPaint p;
- p.setXfermodeMode(SkXfermode::kDifference_Mode);
- c->drawImage(snap1, 0, 0, &p);
+ SkAutoTUnref<SkImage> diff(compute_diff(snap0, snap1));
+ c->drawImage(diff, 0, 0);
}));
canvas->drawImage(diff, 2*dx, 0);