add experimental test for blending math (disabled for now)
git-svn-id: http://skia.googlecode.com/svn/trunk@2648 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/MathTest.cpp b/tests/MathTest.cpp
index 1539cd7..fef93cd 100644
--- a/tests/MathTest.cpp
+++ b/tests/MathTest.cpp
@@ -16,6 +16,59 @@
return dst + (src - dst) * unit;
}
+static int blend31(int src, int dst, int a31) {
+ return dst + ((src - dst) * a31 * 2114 >> 16);
+ // return dst + ((src - dst) * a31 * 33 >> 10);
+}
+
+static int blend31_slow(int src, int dst, int a31) {
+ int prod = src * a31 + (31 - a31) * dst + 16;
+ prod = (prod + (prod >> 5)) >> 5;
+ return prod;
+}
+
+static int blend31_round(int src, int dst, int a31) {
+ int prod = (src - dst) * a31 + 16;
+ prod = (prod + (prod >> 5)) >> 5;
+ return dst + prod;
+}
+
+static int blend31_old(int src, int dst, int a31) {
+ a31 += a31 >> 4;
+ return dst + ((src - dst) * a31 >> 5);
+}
+
+static void test_blend31() {
+ int failed = 0;
+ int death = 0;
+ for (int src = 0; src <= 255; src++) {
+ for (int dst = 0; dst <= 255; dst++) {
+ for (int a = 0; a <= 31; a++) {
+// int r0 = blend31(src, dst, a);
+// int r0 = blend31_round(src, dst, a);
+// int r0 = blend31_old(src, dst, a);
+ int r0 = blend31_slow(src, dst, a);
+
+ float f = float_blend(src, dst, a / 31.f);
+ int r1 = (int)f;
+ int r2 = SkScalarRoundToInt(SkFloatToScalar(f));
+
+ if (r0 != r1 && r0 != r2) {
+ printf("src:%d dst:%d a:%d result:%d float:%g\n",
+ src, dst, a, r0, f);
+ failed += 1;
+ }
+ if (r0 > 255) {
+ death += 1;
+ printf("death src:%d dst:%d a:%d result:%d float:%g\n",
+ src, dst, a, r0, f);
+ }
+ }
+ }
+ }
+ SkDebugf("---- failed %d death %d\n", failed, death);
+}
+
static void test_blend(skiatest::Reporter* reporter) {
for (int src = 0; src <= 255; src++) {
for (int dst = 0; dst <= 255; dst++) {
@@ -499,6 +552,9 @@
#ifdef SK_SCALAR_IS_FLOAT
test_blend(reporter);
#endif
+
+ // disable for now
+// test_blend31();
}
#include "TestClassDef.h"