Image filters: implement SkImage::makeWithFilter().

tests/ImageFilterTest.cpp

Index: tests/ImageFilterTest.cpp
diff --git a/tests/ImageFilterTest.cpp b/tests/ImageFilterTest.cpp
index ed98ef4ab99a4ee69b7b037dbc8c2ec43190fe8b..475b76abfa5e6ff13e7c32a524abb189f20e867e 100644
--- a/tests/ImageFilterTest.cpp
+++ b/tests/ImageFilterTest.cpp
@@ -377,6 +377,18 @@ static sk_sp<SkSpecialSurface> create_empty_special_surface(GrContext* context,
     }
 }
 
+static sk_sp<SkSurface> create_surface(GrContext* context, int width, int height) {
+    const SkImageInfo info = SkImageInfo::MakeN32(width, height, kOpaque_SkAlphaType);
+#if SK_SUPPORT_GPU
+    if (context) {
+        return SkSurface::MakeRenderTarget(context, SkBudgeted::kNo, info);
+    } else
+#endif
+    {
+        return SkSurface::MakeRaster(info);
+    }
+}
+
 static sk_sp<SkSpecialImage> create_empty_special_image(GrContext* context, int widthHeight) {
     sk_sp<SkSpecialSurface> surf(create_empty_special_surface(context, widthHeight));
 
@@ -1669,6 +1681,57 @@ DEF_TEST(ImageFilterBlurLargeImage, reporter) {
     test_large_blur_input(reporter, surface->getCanvas());
 }
 
+static void test_make_with_filter(skiatest::Reporter* reporter, GrContext* context) {
+    sk_sp<SkSurface> surface(create_surface(context, 100, 100));
+    surface->getCanvas()->clear(SK_ColorRED);
+    SkPaint greenPaint;
+    greenPaint.setColor(SK_ColorBLUE);
+    SkIRect subset = SkIRect::MakeXYWH(25, 20, 50, 50);
+    surface->getCanvas()->drawRect(SkRect::Make(subset), greenPaint);
+    sk_sp<SkImage> sourceImage = surface->makeImageSnapshot();
+
+    sk_sp<SkImageFilter> filter = make_grayscale(nullptr, nullptr);
+    SkIRect clipBounds = SkIRect::MakeWH(100, 100);
+    SkIRect outSubset;
+    SkIPoint offset;
+    sk_sp<SkImage> result;
+
+    result = sourceImage->makeWithFilter(nullptr, subset, clipBounds, &outSubset, &offset);
+    REPORTER_ASSERT(reporter, !result);
+
+    result = sourceImage->makeWithFilter(filter.get(), subset, clipBounds, nullptr, &offset);
+    REPORTER_ASSERT(reporter, !result);
+
+    result = sourceImage->makeWithFilter(filter.get(), subset, clipBounds, &outSubset, nullptr);
+    REPORTER_ASSERT(reporter, !result);
+
+    SkIRect bigSubset = SkIRect::MakeXYWH(-10000, -10000, 20000, 20000);
+    result = sourceImage->makeWithFilter(filter.get(), bigSubset, clipBounds, &outSubset, nullptr);
+    REPORTER_ASSERT(reporter, !result);
+
+    SkIRect emptySubset = SkIRect::MakeEmpty();
+    result = sourceImage->makeWithFilter(filter.get(), emptySubset, clipBounds, &outSubset, nullptr);
+    REPORTER_ASSERT(reporter, !result);
+
+    result = sourceImage->makeWithFilter(filter.get(), subset, clipBounds, &outSubset, &offset);
+
+    REPORTER_ASSERT(reporter, result);

[reed1, 2016/05/19 16:33:34]

What are the pre and post conditions for the api (w.r.t. rects)?

preconditions:
- src->contains(inSubset) /* else we return null? */

postconditions:
- dst->contains(outSubset)
- clipBounds.contains(outSubset)

1. are there others?
2. can we tests for these here?

[Stephen White, 2016/05/19 17:20:06]

Done. (Test was there, but buggy.)
Test was already there. Made it more explicit.
Not quite -- outSubset is relative to the image origin, not the coordinate space
origin. Added the appropriate check.

+    REPORTER_ASSERT(reporter, outSubset.width() == subset.width());
+    REPORTER_ASSERT(reporter, outSubset.height() == subset.height());
+    REPORTER_ASSERT(reporter, outSubset.width() <= result->width());
+    REPORTER_ASSERT(reporter, outSubset.height() <= result->height());
+}
+
+DEF_TEST(ImageFilterMakeWithFilter, reporter) {
+    test_make_with_filter(reporter, nullptr);
+}
+
+#if SK_SUPPORT_GPU
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(ImageFilterMakeWithFilter_Gpu, reporter, ctxInfo) {
+    test_make_with_filter(reporter, ctxInfo.grContext());
+}
+#endif
+
 #if SK_SUPPORT_GPU
 
 DEF_GPUTEST_FOR_RENDERING_CONTEXTS(ImageFilterHugeBlur_Gpu, reporter, ctxInfo) {