skia2/tests/ColorTest.cpp
Brian Osman 3b79aa3a5a On second thought, remove GrColor4s
We're going to use half-floats, which are far more future-proof.

Bug: skia:
Change-Id: I6e098017381256d6e750ac546c353072802282cb
Reviewed-on: https://skia-review.googlesource.com/c/165522
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2018-10-26 19:29:50 +00:00

87 lines
2.6 KiB
C++

/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkColor.h"
#include "SkColorData.h"
#include "SkColorPriv.h"
#include "SkMathPriv.h"
#include "SkRandom.h"
#include "SkTypes.h"
#include "SkUnPreMultiply.h"
#include "Test.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 inline void test_premul(skiatest::Reporter* reporter) {
for (int a = 0; a <= 255; a++) {
for (int x = 0; x <= 255; x++) {
SkColor c0 = SkColorSetARGB(a, x, x, x);
SkPMColor p0 = SkPreMultiplyColor(c0);
SkColor c1 = SkUnPreMultiply::PMColorToColor(p0);
SkPMColor p1 = SkPreMultiplyColor(c1);
// we can't promise that c0 == c1, since c0 -> p0 is a many to one
// function, however, we can promise that p0 -> c1 -> p1 : p0 == p1
REPORTER_ASSERT(reporter, p0 == p1);
{
int ax = SkMulDiv255Ceiling(x, a);
REPORTER_ASSERT(reporter, ax <= a);
}
}
}
}
/**
This test fails: SkFourByteInterp does *not* preserve opaque destinations.
SkAlpha255To256 implemented as (alpha + 1) is faster than
(alpha + (alpha >> 7)), but inaccurate, and Skia intends to phase it out.
*/
/*
static void test_interp(skiatest::Reporter* reporter) {
SkRandom r;
U8CPU a0 = 0;
U8CPU a255 = 255;
for (int i = 0; i < 200; i++) {
SkColor colorSrc = r.nextU();
SkColor colorDst = r.nextU();
SkPMColor src = SkPreMultiplyColor(colorSrc);
SkPMColor dst = SkPreMultiplyColor(colorDst);
REPORTER_ASSERT(reporter, SkFourByteInterp(src, dst, a0) == dst);
REPORTER_ASSERT(reporter, SkFourByteInterp(src, dst, a255) == src);
}
}
*/
static inline void test_fast_interp(skiatest::Reporter* reporter) {
SkRandom r;
U8CPU a0 = 0;
U8CPU a255 = 255;
for (int i = 0; i < 200; i++) {
SkColor colorSrc = r.nextU();
SkColor colorDst = r.nextU();
SkPMColor src = SkPreMultiplyColor(colorSrc);
SkPMColor dst = SkPreMultiplyColor(colorDst);
REPORTER_ASSERT(reporter, SkFastFourByteInterp(src, dst, a0) == dst);
REPORTER_ASSERT(reporter, SkFastFourByteInterp(src, dst, a255) == src);
}
}
DEF_TEST(Color, reporter) {
test_premul(reporter);
//test_interp(reporter);
test_fast_interp(reporter);
//test_565blend();
}