diff options
author | 2015-06-15 08:58:22 -0700 | |
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committer | 2015-06-15 08:58:22 -0700 | |
commit | ce9d11189a5924b47c3629063b72bae9d466c2c7 (patch) | |
tree | 5205d6ed5402bb55457777c0e9742ea1ee522762 /tests/SkNxTest.cpp | |
parent | c751ecb3681072fda53dd3cebeb2eb41fc73b314 (diff) |
Thorough tests for saturatedAdd and mulDiv255Round.
BUG=skia:
Review URL: https://codereview.chromium.org/1184113003
Diffstat (limited to 'tests/SkNxTest.cpp')
-rw-r--r-- | tests/SkNxTest.cpp | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/tests/SkNxTest.cpp b/tests/SkNxTest.cpp index 2463b46f08..eab625d41e 100644 --- a/tests/SkNxTest.cpp +++ b/tests/SkNxTest.cpp @@ -5,6 +5,7 @@ * found in the LICENSE file. */ +#include "Sk4px.h" #include "SkNx.h" #include "SkRandom.h" #include "Test.h" @@ -154,3 +155,38 @@ DEF_TEST(SkNi_min, r) { }} #endif } + +DEF_TEST(SkNi_saturatedAdd, r) { + for (int a = 0; a < (1<<8); a++) { + for (int b = 0; b < (1<<8); b++) { + int exact = a+b; + if (exact > 255) { exact = 255; } + if (exact < 0) { exact = 0; } + + REPORTER_ASSERT(r, Sk16b(a).saturatedAdd(Sk16b(b)).kth<0>() == exact); + } + } +} + +DEF_TEST(Sk4px_muldiv255round, r) { + for (int a = 0; a < (1<<8); a++) { + for (int b = 0; b < (1<<8); b++) { + int exact = (a*b+127)/255; + + // Duplicate a and b 16x each. + Sk4px av((SkAlpha)a), + bv((SkAlpha)b); + + // This way should always be exactly correct. + int correct = av.mulWiden(bv).div255RoundNarrow().kth<0>(); + REPORTER_ASSERT(r, correct == exact); + + // We're a bit more flexible on this method: correct for 0 or 255, otherwise off by <=1. + int fast = av.fastMulDiv255Round(bv).kth<0>(); + REPORTER_ASSERT(r, fast-exact >= -1 && fast-exact <= 1); + if (a == 0 || a == 255 || b == 0 || b == 255) { + REPORTER_ASSERT(r, fast == exact); + } + } + } +} |