| /* |
| * Copyright 2016 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkSRGB.h" |
| #include "SkTypes.h" |
| #include "Test.h" |
| #include <math.h> |
| |
| static uint8_t linear_to_srgb(float l) { |
| // Round float to int, truncate that to uint8_t. |
| return (uint8_t)Sk4f_round( sk_linear_to_srgb(Sk4f{l}) )[0]; |
| } |
| |
| DEF_TEST(sk_linear_to_srgb, r) { |
| // Should map 0 -> 0 and 1 -> 1. |
| REPORTER_ASSERT(r, 0 == linear_to_srgb(0.0f)); |
| REPORTER_ASSERT(r, 255 == linear_to_srgb(1.0f)); |
| |
| // Should be monotonic between 0 and 1. |
| // We don't bother checking denorm values. |
| int tolerated_regressions = 0; |
| #if defined(SK_ARM_HAS_NEON) |
| // Values around 0.166016 are usually 72 but drop briefly (41 floats) down to 71. |
| tolerated_regressions = 1; |
| #endif |
| uint8_t prev = 0; |
| for (float f = FLT_MIN; f <= 1.0f; ) { |
| uint8_t srgb = linear_to_srgb(f); |
| |
| REPORTER_ASSERT(r, srgb >= prev || tolerated_regressions > 0); |
| if (srgb < prev) { tolerated_regressions--; } |
| prev = srgb; |
| |
| union { float flt; uint32_t bits; } pun = { f }; |
| pun.bits++; |
| f = pun.flt; |
| } |
| } |