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OpenTTD/src/spriteloader/makeindexed.cpp

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2.4 KiB
C++

/*
* This file is part of OpenTTD.
* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
* OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file makeindexed.cpp Implementation for converting sprites from another source from 32bpp RGBA to indexed 8bpp. */
#include "../stdafx.h"
#include "../core/bitmath_func.hpp"
#include "../core/math_func.hpp"
#include "../gfx_func.h"
#include "../palette_func.h"
#include "makeindexed.h"
#include "../safeguards.h"
/**
* Convert in place a 32bpp sprite to 8bpp.
* @param sprite Sprite to convert.
*/
static void Convert32bppTo8bpp(SpriteLoader::Sprite &sprite)
{
const auto *pixel_end = sprite.data + sprite.width * sprite.height;
for (auto *pixel = sprite.data; pixel != pixel_end; ++pixel) {
if (pixel->m != 0) {
/* Pixel has 8bpp mask, test if should be reshaded. */
uint8_t brightness = std::max({pixel->r, pixel->g, pixel->b});
if (brightness == 0 || brightness == 128) continue;
/* Update RGB component with reshaded palette colour, and enabled reshade. */
Colour c = AdjustBrightness(_cur_palette.palette[pixel->m], brightness);
if (IsInsideMM(pixel->m, 0xC6, 0xCE)) {
/* Dumb but simple brightness conversion. */
pixel->m = GetNearestColourReshadeIndex((c.r + c.g + c.b) / 3);
} else {
pixel->m = GetNearestColourIndex(c.r, c.g, c.b);
}
} else if (pixel->a < 128) {
/* Transparent pixel. */
pixel->m = 0;
} else {
/* Find nearest match from palette. */
pixel->m = GetNearestColourIndex(pixel->r, pixel->g, pixel->b);
}
}
}
uint8_t SpriteLoaderMakeIndexed::LoadSprite(SpriteLoader::SpriteCollection &sprite, SpriteFile &file, size_t file_pos, SpriteType sprite_type, bool, uint8_t control_flags, uint8_t &avail_8bpp, uint8_t &avail_32bpp)
{
uint8_t avail = this->baseloader.LoadSprite(sprite, file, file_pos, sprite_type, true, control_flags, avail_8bpp, avail_32bpp);
for (ZoomLevel zoom = ZOOM_LVL_NORMAL; zoom != ZOOM_LVL_END; zoom++) {
if (HasBit(avail, zoom)) Convert32bppTo8bpp(sprite[zoom]);
}
return avail;
}