ref: 7377a142451ecea51eaa51b6047b5537f8926ef4
dir: /src/gfx/rgba.cpp/
/* * This file is part of RGBDS. * * Copyright (c) 2022, Eldred Habert and RGBDS contributors. * * SPDX-License-Identifier: MIT */ #include "gfx/rgba.hpp" #include <assert.h> #include <stdint.h> #include "gfx/main.hpp" // options /* * based on the Gaussian-like curve used by SameBoy since commit * 65dd02cc52f531dbbd3a7e6014e99d5b24e71a4c (Oct 2017) * with ties resolved by comparing the difference of the squares. */ static std::array<uint8_t, 256> reverse_curve{ 0, 0, 1, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, // These 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, // comments 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, // prevent 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, // clang-format 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, // from 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, // reflowing 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, // these 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, // sixteen 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, // 16-item 17, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, // lines, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, // which, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21, 21, 21, 21, // in 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 22, // my 22, 23, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, // opinion, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, // help 26, 27, 27, 27, 27, 27, 28, 28, 28, 28, 29, 29, 29, 30, 30, 31, // visualization! }; uint16_t Rgba::cgbColor() const { if (isTransparent()) { return transparent; } assert(isOpaque()); uint8_t r = red, g = green, b = blue; if (options.useColorCurve) { g = g * 4 < b ? 0 : (g * 4 - b) / 3; r = reverse_curve[r]; g = reverse_curve[g]; b = reverse_curve[b]; } return (r >> 3) | (g >> 3) << 5 | (b >> 3) << 10; } uint8_t Rgba::grayIndex() const { assert(isGray()); // Convert from [0; 256[ to [0; maxOpaqueColors[ return static_cast<uint16_t>(255 - red) * options.maxOpaqueColors() / 256; }