1 files changed, 76 insertions, 0 deletions
diff --git a/tests/NonlinearBlendingTest.cpp b/tests/NonlinearBlendingTest.cpp
new file mode 100644
index 0000000000..10c12aa280
--- /dev/null
+++ b/tests/NonlinearBlendingTest.cpp
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "Test.h"
+#include "SkHalf.h"
+#include "SkSurface.h"
+#include "SkCanvas.h"
+
+DEF_TEST(NonlinearBlending, r) {
+
+    // First check our familiar basics with linear F16.
+    {
+        auto info = SkImageInfo::Make(1,1, kRGBA_F16_SkColorType, kPremul_SkAlphaType,
+                                      SkColorSpace::MakeSRGBLinear());
+
+        auto surface = SkSurface::MakeRaster(info);
+        surface->getCanvas()->clear(0xff808080);
+        uint64_t pix;
+        REPORTER_ASSERT(r, surface->readPixels(info, &pix, sizeof(pix),0,0));
+
+        // 0x80 in sRGB is ≈ 0.22 linear.
+        REPORTER_ASSERT(r, SkHalfToFloat(pix & 0xffff) < 0.25f);
+    }
+
+    // Test that we support sRGB-encoded F16.  This is somewhat new.
+    {
+        auto info = SkImageInfo::Make(1,1, kRGBA_F16_SkColorType, kPremul_SkAlphaType,
+                                      SkColorSpace::MakeSRGB());
+
+        auto surface = SkSurface::MakeRaster(info);
+        surface->getCanvas()->clear(0xff808080);
+        uint64_t pix;
+        REPORTER_ASSERT(r, surface->readPixels(info, &pix, sizeof(pix),0,0));
+
+        // 0x80 sRGB is ≈ 0.501.
+        REPORTER_ASSERT(r, SkHalfToFloat(pix & 0xffff) >= 0.5f);
+    }
+
+    // Since we're only clear()ing, this should work the same as the last block.
+    {
+        auto info = SkImageInfo::Make(1,1, kRGBA_F16_SkColorType, kPremul_SkAlphaType,
+                                      SkColorSpace::MakeSRGB()->makeNonlinearBlending());
+
+        auto surface = SkSurface::MakeRaster(info);
+        surface->getCanvas()->clear(0xff808080);
+        uint64_t pix;
+        REPORTER_ASSERT(r, surface->readPixels(info, &pix, sizeof(pix),0,0));
+
+        // 0x80 sRGB is ≈ 0.501.
+        REPORTER_ASSERT(r, SkHalfToFloat(pix & 0xffff) >= 0.5f);
+    }
+
+    // This won't work until we actually support color spaces with non-linear blending.
+    if (0) {
+        auto info = SkImageInfo::Make(1,1, kRGBA_F16_SkColorType, kPremul_SkAlphaType,
+                                      SkColorSpace::MakeSRGB()->makeNonlinearBlending());
+
+        auto surface = SkSurface::MakeRaster(info);
+
+        surface->getCanvas()->clear(SK_ColorWHITE);
+        SkPaint p;
+        p.setColor(0x80000000);
+        surface->getCanvas()->drawPaint(p);
+
+        uint64_t pix;
+        REPORTER_ASSERT(r, surface->readPixels(info, &pix, sizeof(pix),0,0));
+
+        // 0x80 sRGB is ≈ 0.501.  A likely failure here is ~0.75, linear blending.
+        REPORTER_ASSERT(r, SkHalfToFloat(pix & 0xffff) >= 0.45f &&
+                           SkHalfToFloat(pix & 0xffff) <= 0.55f);
+    }
+}