Fix two bugs in GPU special image read-back
- We always read from (0, 0), even if the subset had a different origin
- We also cached the results ignoring the origin, so future reads of
same-sized but differently positioned subsets could return previous
and wrong bitmaps.
Added a unit test that checks for both behaviors. Originally, both
asserts triggered. Adjusting the origin in readPixels, the first assert
was fixed, but the second continued to trigger. Adding the full subset
rect to the bitmap cache key fixed the second assert.
Bug: skia:8448 skia:8449
Change-Id: Ic6e8c0976bd59e86827be89105bd02845ad0d7cd
Reviewed-on: https://skia-review.googlesource.com/c/159981
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/tests/SpecialImageTest.cpp b/tests/SpecialImageTest.cpp
index fc09b47..06cd7bf 100644
--- a/tests/SpecialImageTest.cpp
+++ b/tests/SpecialImageTest.cpp
@@ -293,3 +293,41 @@
test_image(subSImg2, reporter, context, true, kPad, kFullSize);
}
}
+
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SpecialImage_ReadbackAndCachingSubsets_Gpu, reporter, ctxInfo) {
+ GrContext* context = ctxInfo.grContext();
+ SkImageInfo ii = SkImageInfo::Make(50, 50, kN32_SkColorType, kPremul_SkAlphaType);
+ auto surface = SkSurface::MakeRenderTarget(context, SkBudgeted::kNo, ii);
+
+ // Fill out our surface:
+ // Green | Blue
+ // Red | Green
+ {
+ surface->getCanvas()->clear(SK_ColorGREEN);
+ SkPaint p;
+ p.setColor(SK_ColorRED);
+ surface->getCanvas()->drawRect(SkRect::MakeXYWH(0, 25, 25, 25), p);
+ p.setColor(SK_ColorBLUE);
+ surface->getCanvas()->drawRect(SkRect::MakeXYWH(25, 0, 25, 25), p);
+ }
+
+ auto image = surface->makeImageSnapshot();
+ auto redImg = SkSpecialImage::MakeFromImage(SkIRect::MakeXYWH(10, 30, 10, 10), image, nullptr);
+ auto blueImg = SkSpecialImage::MakeFromImage(SkIRect::MakeXYWH(30, 10, 10, 10), image, nullptr);
+
+ // This isn't necessary, but if it ever becomes false, then the cache collision bug that we're
+ // checking below is irrelevant.
+ REPORTER_ASSERT(reporter, redImg->uniqueID() == blueImg->uniqueID());
+
+ SkBitmap redBM, blueBM;
+ SkAssertResult(redImg->getROPixels(&redBM));
+ SkAssertResult(blueImg->getROPixels(&blueBM));
+
+ // Each image should read from the correct sub-rect. Past bugs (skbug.com/8448) have included:
+ // - Always reading back from (0, 0), producing green
+ // - Incorrectly hitting the cache on the 2nd read-back, causing blueBM to be red
+ REPORTER_ASSERT(reporter, redBM.getColor(0, 0) == SK_ColorRED,
+ "0x%08x != 0x%08x", redBM.getColor(0, 0), SK_ColorRED);
+ REPORTER_ASSERT(reporter, blueBM.getColor(0, 0) == SK_ColorBLUE,
+ "0x%08x != 0x%08x", blueBM.getColor(0, 0), SK_ColorBLUE);
+}