sdlpixel.h

Go to the documentation of this file.

/*
 * The ManaPlus Client
 * Copyright (C) 2011-2019 The ManaPlus Developers
 * Copyright (C) 2019-2021 Andrei Karas
 *
 * This file is part of The ManaPlus Client.
 *
 * This program 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; either version 2 of the License, or
 * any later version.
 *
 * This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
/* _______ __ __ __ ______ __ __ _______ __ __
 * / _____/\ / /\ / /\ / /\ / ____/\ / /\ / /\ / ___ /\ / |\/ /\
 * / /\____\// / // / // / // /\___\// /_// / // /\_/ / // , |/ / /
 * / / /__ / / // / // / // / / / ___ / // ___ / // /| ' / /
 * / /_// /\ / /_// / // / // /_/_ / / // / // /\_/ / // / | / /
 * /______/ //______/ //_/ //_____/\ /_/ //_/ //_/ //_/ //_/ /|_/ /
 * \______\/ \______\/ \_\/ \_____\/ \_\/ \_\/ \_\/ \_\/ \_\/ \_\/
 *
 * Copyright (c) 2004 - 2008 Olof Naessén and Per Larsson
 *
 *
 * Per Larsson a.k.a finalman
 * Olof Naessén a.k.a jansem/yakslem
 *
 * Visit: http://guichan.sourceforge.net
 *
 * License: (BSD)
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in
 * the documentation and/or other materials provided with the
 * distribution.
 * 3. Neither the name of Guichan nor the names of its contributors may
 * be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
#ifndef UTILS_SDLPIXEL_H
#define UTILS_SDLPIXEL_H
 
#include "gui/color.h"
 
PRAGMA48(GCC diagnostic push)
PRAGMA48(GCC diagnostic ignored "-Wshadow")
#include <SDL.h>
PRAGMA48(GCC diagnostic pop)
 
#ifndef SDL_BYTEORDER
#error missing SDL_endian.h
#endif // SDL_BYTEORDER
 
inline void SDLputPixel(SDL_Surface* surface, int x, int y,
 const Color& color)
{
 if (surface == nullptr)
 return;
 
 const int bpp = surface->format->BytesPerPixel;
 
 SDL_LockSurface(surface);
 
 Uint8 *const p = static_cast<uint8_t*>(surface->pixels)
 + CAST_SIZE(y * surface->pitch + x * bpp);
 
 const Uint32 pixel = SDL_MapRGB(surface->format,
 CAST_U8(color.r), CAST_U8(color.g),
 CAST_U8(color.b));
 
 switch (bpp)
 {
 case 1:
 *p = CAST_U8(pixel);
 break;
 
 case 2:
 *reinterpret_cast<uint16_t*>(p) = CAST_U16(pixel);
 break;
 
 case 3:
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
 p[0] = CAST_U8((pixel >> 16) & 0xff);
 p[1] = CAST_U8((pixel >> 8) & 0xff);
 p[2] = CAST_U8((pixel) & 0xff);
#else // SDL_BYTEORDER == SDL_BIG_ENDIAN
 
 p[0] = CAST_U8((pixel) & 0xff);
 p[1] = CAST_U8((pixel >> 8) & 0xff);
 p[2] = CAST_U8((pixel >> 16) & 0xff);
#endif // SDL_BYTEORDER == SDL_BIG_ENDIAN
 
 break;
 
 case 4:
 *reinterpret_cast<Uint32*>(p) = pixel;
 break;
 
 default:
 break;
 }
 
 SDL_UnlockSurface(surface);
}
 
inline unsigned int SDLAlpha32(const unsigned int src,
 const unsigned int dst,
 const unsigned char a)
{
 const unsigned int b = ((src & 0xff) * a + (dst & 0xff) * (255 - a)) >> 8;
 const unsigned int g = ((src & 0xff00) * a + (dst & 0xff00)
 * (255 - a)) >> 8;
 const unsigned int r = ((src & 0xff0000) * a + (dst & 0xff0000)
 * (255 - a)) >> 8;
 
 return (b & 0xff) | (g & 0xff00) | (r & 0xff0000);
}
 
inline unsigned short SDLAlpha16(const unsigned short src,
 const unsigned short dst,
 const unsigned char a,
 const SDL_PixelFormat *const f) A_NONNULL(4);
 
inline unsigned short SDLAlpha16(const unsigned short src,
 const unsigned short dst,
 const unsigned char a,
 const SDL_PixelFormat *const f)
{
 unsigned int b = ((src & f->Rmask) * a + (dst & f->Rmask)
 * (255 - a)) >> 8;
 unsigned int g = ((src & f->Gmask) * a + (dst & f->Gmask)
 * (255 - a)) >> 8;
 unsigned int r = ((src & f->Bmask) * a + (dst & f->Bmask)
 * (255 - a)) >> 8;
 
 return static_cast<unsigned short>((b & f->Rmask)
 | (g & f->Gmask) | (r & f->Bmask));
}
 
inline void SDLputPixelAlpha(SDL_Surface* surface, int x, int y,
 const Color& color)
{
 if (surface == nullptr)
 return;
 const int bpp = surface->format->BytesPerPixel;
 
 SDL_LockSurface(surface);
 
 Uint8 *const p = static_cast<uint8_t*>(surface->pixels)
 + CAST_SIZE(y * surface->pitch + x * bpp);
 
 const Uint32 pixel = SDL_MapRGB(surface->format,
 CAST_U8(color.r),
 CAST_U8(color.g),
 CAST_U8(color.b));
 
 switch (bpp)
 {
 case 1:
 *p = CAST_U8(pixel);
 break;
 
 case 2:
 *reinterpret_cast<Uint16*>(p) = SDLAlpha16(
 static_cast<unsigned short>(pixel),
 *reinterpret_cast<unsigned short*>(p),
 CAST_U8(color.a), surface->format);
 break;
 
 case 3:
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
 p[2] = CAST_U8((p[2] * (255 - color.a)
 + color.b * color.a) >> 8);
 p[1] = CAST_U8((p[1] * (255 - color.a)
 + color.g * color.a) >> 8);
 p[0] = CAST_U8((p[0] * (255 - color.a)
 + color.r * color.a) >> 8);
#else // SDL_BYTEORDER == SDL_BIG_ENDIAN
 
 p[0] = CAST_U8((p[0] * (255 - color.a)
 + color.b * color.a) >> 8);
 p[1] = CAST_U8((p[1] * (255 - color.a)
 + color.g * color.a) >> 8);
 p[2] = CAST_U8((p[2] * (255 - color.a)
 + color.r * color.a) >> 8);
#endif // SDL_BYTEORDER == SDL_BIG_ENDIAN
 
 break;
 
 case 4:
 *reinterpret_cast<Uint32*>(p) = SDLAlpha32(pixel,
 *reinterpret_cast<Uint32*>(p),
 CAST_U8(color.a));
 break;
 default:
 break;
 }
 
 SDL_UnlockSurface(surface);
}
 
#endif // UTILS_SDLPIXEL_H