commit 98308fb081687970278dce2a7631005f9cb424a8
author Mike Reed <reed@google.com> Fri Jul 07 08:28:13 2017 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Fri Jul 07 13:19:57 2017 +0000
tree dd80baa860c991fc48847e82a16c1a5d8e9dc217
parent 6b65b98996ebc0a511aa46042607a291e6836bed

Plumb through need for unpremul/premul

Update unittest to build test image with legal premul pixels.

Bug: skia:
Change-Id: Iebd1d2f81cac77f8913bd79f6ac25983ed710641
Reviewed-on: https://skia-review.googlesource.com/21735
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Reed <reed@google.com>

tests/ApplyGammaTest.cpp

diff --git a/tests/ApplyGammaTest.cpp b/tests/ApplyGammaTest.cpp
index 79dbfc7..83b5968 100644
--- a/tests/ApplyGammaTest.cpp
+++ b/tests/ApplyGammaTest.cpp
@@ -44,10 +44,17 @@
         result = false;
     }
 
+    // need to unpremul before we can perform srgb magic
+    float invScale = 0;
+    float alpha = SkGetPackedA32(src);
+    if (alpha) {
+        invScale = 255.0f / alpha;
+    }
+
     for (int c = 0; c < 3; ++c) {
-        uint8_t srcComponent = (src & (0xff << (c * 8))) >> (c * 8);
-        float lower = SkTMax(0.f, (float)srcComponent - error);
-        float upper = SkTMin(255.f, (float)srcComponent + error);
+        float srcComponent = ((src & (0xff << (c * 8))) >> (c * 8)) * invScale;
+        float lower = SkTMax(0.f, srcComponent - error);
+        float upper = SkTMin(255.f, srcComponent + error);
         if (toSRGB) {
             lower = linear_to_srgb(lower / 255.f);
             upper = linear_to_srgb(upper / 255.f);
@@ -55,14 +62,16 @@
             lower = srgb_to_linear(lower / 255.f);
             upper = srgb_to_linear(upper / 255.f);
         }
+        lower *= alpha;
+        upper *= alpha;
         SkASSERT(lower >= 0.f && lower <= 255.f);
         SkASSERT(upper >= 0.f && upper <= 255.f);
         uint8_t dstComponent = (dst & (0xff << (c * 8))) >> (c * 8);
-        if (dstComponent < SkScalarFloorToInt(lower * 255.f) ||
-            dstComponent > SkScalarCeilToInt(upper * 255.f)) {
+        if (dstComponent < SkScalarFloorToInt(lower) ||
+            dstComponent > SkScalarCeilToInt(upper)) {
             result = false;
         }
-        uint8_t expectedComponent = SkScalarRoundToInt((lower + upper) * 127.5f);
+        uint8_t expectedComponent = SkScalarRoundToInt((lower + upper) * 0.5f);
         expectedColor |= expectedComponent << (c * 8);
     }
 
@@ -72,8 +81,8 @@
 
 DEF_GPUTEST_FOR_RENDERING_CONTEXTS(ApplyGamma, reporter, ctxInfo) {
     GrContext* context = ctxInfo.grContext();
-    static const int kW = 10;
-    static const int kH = 10;
+    static const int kW = 256;
+    static const int kH = 256;
     static const size_t kRowBytes = sizeof(uint32_t) * kW;
 
     GrSurfaceDesc baseDesc;
@@ -84,8 +93,10 @@
     const SkImageInfo ii = SkImageInfo::MakeN32Premul(kW, kH);
 
     SkAutoTMalloc<uint32_t> srcPixels(kW * kH);
-    for (int i = 0; i < kW * kH; ++i) {
-        srcPixels.get()[i] = i;
+    for (int y = 0; y < kH; ++y) {
+        for (int x = 0; x < kW; ++x) {
+            srcPixels.get()[y*kW+x] = SkPreMultiplyARGB(x, y, x, 0xFF);
+        }
     }
 
     SkBitmap bm;