566ea9b9fc
I basically just ran a big 5-deep for-loop over the five constants here. This is the first set of coefficients I found that round trips all bytes. I suspect there are many such sets. BUG=skia: GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2162063003 CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot Review-Url: https://codereview.chromium.org/2162063003
39 lines
942 B
C++
39 lines
942 B
C++
/*
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* Copyright 2016 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "SkSRGB.h"
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#include "SkTypes.h"
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#include "Test.h"
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#include <math.h>
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static uint8_t linear_to_srgb(float l) {
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return (uint8_t)sk_linear_to_srgb(Sk4f{l})[0];
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}
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DEF_TEST(sk_linear_to_srgb, r) {
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// All bytes should round trip.
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for (int i = 0; i < 256; i++) {
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int actual = linear_to_srgb(sk_linear_from_srgb[i]);
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if (i != actual) {
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ERRORF(r, "%d -> %d\n", i, actual);
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}
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}
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// Should be monotonic between 0 and 1.
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uint8_t prev = 0;
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for (float f = FLT_MIN; f <= 1.0f; ) { // We don't bother checking denorm values.
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uint8_t srgb = linear_to_srgb(f);
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REPORTER_ASSERT(r, srgb >= prev);
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prev = srgb;
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union { float flt; uint32_t bits; } pun = { f };
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pun.bits++;
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f = pun.flt;
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}
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}
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