add experimental test for different 8888->565 blends (disabled)

git-svn-id: http://skia.googlecode.com/svn/trunk@5916 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 107 insertions, 0 deletions

diff --git a/tests/ColorTest.cpp b/tests/ColorTest.cpp
index 86729d2756..55fdd74f0a 100644
--- a/tests/ColorTest.cpp
+++ b/tests/ColorTest.cpp
@@ -12,6 +12,112 @@
 #include "SkRandom.h"
 #include "SkUnPreMultiply.h"
 
+#define GetPackedR16As32(packed)    (SkGetPackedR16(dc) << (8 - SK_R16_BITS))
+#define GetPackedG16As32(packed)    (SkGetPackedG16(dc) << (8 - SK_G16_BITS))
+#define GetPackedB16As32(packed)    (SkGetPackedB16(dc) << (8 - SK_B16_BITS))
+
+static bool S32A_D565_Blend_0(SkPMColor sc, uint16_t dc, U8CPU alpha) {
+    unsigned dst_scale = 255 - SkMulDiv255Round(SkGetPackedA32(sc), alpha);
+    unsigned dr = SkMulS16(SkPacked32ToR16(sc), alpha) + SkMulS16(SkGetPackedR16(dc), dst_scale);
+    unsigned dg = SkMulS16(SkPacked32ToG16(sc), alpha) + SkMulS16(SkGetPackedG16(dc), dst_scale);
+    
+    unsigned rr = SkDiv255Round(dr);
+    unsigned rg = SkDiv255Round(dg);
+    
+    if (rr <= 31 && rg <= 63) {
+        return true;
+    }
+    return false;
+}
+
+static bool S32A_D565_Blend_01(SkPMColor sc, uint16_t dc, U8CPU alpha) {
+    unsigned dst_scale = 255 - SkMulDiv255Round(SkGetPackedA32(sc), alpha);
+    unsigned dr = SkMulS16(SkGetPackedR32(sc), alpha) + SkMulS16(SkGetPackedR16(dc) << 3, dst_scale);
+    unsigned dg = SkMulS16(SkGetPackedG32(sc), alpha) + SkMulS16(SkGetPackedG16(dc) << 2, dst_scale);
+    
+    unsigned rr = SkDiv255Round(dr) >> 3;
+    unsigned rg = SkDiv255Round(dg) >> 2;
+    
+    if (rr <= 31 && rg <= 63) {
+        return true;
+    }
+    return false;
+}
+
+static bool S32A_D565_Blend_02(SkPMColor sc, uint16_t dc, U8CPU alpha) {
+    unsigned dst_scale = 255 - SkMulDiv255Round(SkGetPackedA32(sc), alpha);
+    unsigned dr = SkMulS16(SkGetPackedR32(sc), alpha) + SkMulS16(GetPackedR16As32(dc), dst_scale);
+    unsigned dg = SkMulS16(SkGetPackedG32(sc), alpha) + SkMulS16(GetPackedG16As32(dc), dst_scale);
+    unsigned db = SkMulS16(SkGetPackedB32(sc), alpha) + SkMulS16(GetPackedB16As32(dc), dst_scale);
+    int rc = SkPack888ToRGB16(SkDiv255Round(dr),
+                              SkDiv255Round(dg),
+                              SkDiv255Round(db));
+    
+    unsigned rr = SkGetPackedR16(rc);
+    unsigned rg = SkGetPackedG16(rc);
+    
+    if (rr <= 31 && rg <= 63) {
+        return true;
+    }
+    return false;
+}
+
+static bool S32A_D565_Blend_1(SkPMColor sc, uint16_t dc, U8CPU alpha) {
+    unsigned dst_scale = 255 - SkMulDiv255Round(SkGetPackedA32(sc), alpha);
+    unsigned dr = (SkMulS16(SkGetPackedR32(sc), alpha) >> 3) + SkMulS16(SkGetPackedR16(dc), dst_scale);
+    unsigned dg = (SkMulS16(SkGetPackedG32(sc), alpha) >> 2) + SkMulS16(SkGetPackedG16(dc), dst_scale);
+    
+    unsigned rr = SkDiv255Round(dr);
+    unsigned rg = SkDiv255Round(dg);
+    
+    if (rr <= 31 && rg <= 63) {
+        return true;
+    }
+    return false;
+}
+
+static int SkDiv65025Round(int x) {
+    return (x + 65025/2) / 65025;
+//    return x / 65025;
+}
+static bool S32A_D565_Blend_2(SkPMColor sc, uint16_t dc, U8CPU alpha) {
+    unsigned dst_scale = 255*255 - SkGetPackedA32(sc) * alpha;
+    alpha *= 255;
+    unsigned dr = (SkGetPackedR32(sc) >> 3) * alpha + SkGetPackedR16(dc) * dst_scale;
+    unsigned dg = (SkGetPackedG32(sc) >> 2) * alpha + SkGetPackedG16(dc) * dst_scale;
+    
+    unsigned rr = SkDiv65025Round(dr);
+    unsigned rg = SkDiv65025Round(dg);
+    
+    if (rr <= 31 && rg <= 63) {
+        return true;
+    }
+    return false;
+}
+
+static void test_565blend(skiatest::Reporter* reporter) {
+    int total_failures = 0;
+    for (int global_alpha = 0; global_alpha <= 255; ++global_alpha) {
+        int failures = 0;
+        int total = 0;
+        for (int src_a = 0; src_a <= 255; ++src_a) {
+            for (int src_c = 0; src_c <= src_a; ++src_c) {
+                SkPMColor sc = SkPackARGB32(src_a, src_c, src_c, src_c);
+                for (int dst_r = 0; dst_r <= 31; ++dst_r) {
+                    for (int dst_g = 0; dst_g <= 63; ++dst_g) {
+                        uint16_t dc = SkPackRGB16(dst_r, dst_g, dst_r);
+                        failures += !S32A_D565_Blend_0(sc, dc, global_alpha);
+                        total += 1;
+                    }
+                }
+            }
+        }
+        SkDebugf("global_alpha=%d failures=%d total=%d %g\n", global_alpha, failures, total, failures * 100.0 / total);
+        total_failures += failures;
+    }
+    SkDebugf("total failures %d\n", total_failures);
+}
+
 static void test_premul(skiatest::Reporter* reporter) {
     for (int a = 0; a <= 255; a++) {
         for (int x = 0; x <= 255; x++) {
@@ -76,6 +182,7 @@ static void TestColor(skiatest::Reporter* reporter) {
     test_premul(reporter);
     //test_interp(reporter);
     test_fast_interp(reporter);
+//    test_565blend(reporter);
 }
 
 #include "TestClassDef.h"