# 32bpp_base.hpp

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    00001 /* $Id$ */
    00002
    00003 /*
    00004  * This file is part of OpenTTD.
    00005  * 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.
    00006  * 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.
    00007  * 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/>.
    00008  */
    00009
    00012 #ifndef BLITTER_32BPP_BASE_HPP
    00013 #define BLITTER_32BPP_BASE_HPP
    00014
    00015 #include "base.hpp"
    00016 #include "../core/bitmath_func.hpp"
    00017 #include "../gfx_func.h"
    00018
    00020 class Blitter_32bppBase : public Blitter {
    00021 public:
    00022   /* virtual */ uint8 GetScreenDepth() { return 32; }
    00023   /* virtual */ void *MoveTo(const void *video, int x, int y);
    00024   /* virtual */ void SetPixel(void *video, int x, int y, uint8 colour);
    00025   /* virtual */ void DrawRect(void *video, int width, int height, uint8 colour);
    00026   /* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height);
    00027   /* virtual */ void CopyToBuffer(const void *video, void *dst, int width, int height);
    00028   /* virtual */ void CopyImageToBuffer(const void *video, void *dst, int width, int height, int dst_pitch);
    00029   /* virtual */ void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y);
    00030   /* virtual */ int BufferSize(int width, int height);
    00031   /* virtual */ void PaletteAnimate(uint start, uint count);
    00032   /* virtual */ Blitter::PaletteAnimation UsePaletteAnimation();
    00033   /* virtual */ int GetBytesPerPixel() { return 4; }
    00034
    00038   static inline uint32 ComposeColour(uint a, uint r, uint g, uint b)
    00039   {
    00040     return (((a) << 24) & 0xFF000000) | (((r) << 16) & 0x00FF0000) | (((g) << 8) & 0x0000FF00) | ((b) & 0x000000FF);
    00041   }
    00042
    00046   static inline uint32 LookupColourInPalette(uint index)
    00047   {
    00048     return _cur_palette[index].data;
    00049   }
    00050
    00054   static inline uint32 ComposeColourRGBANoCheck(uint r, uint g, uint b, uint a, uint32 current)
    00055   {
    00056     uint cr = GB(current, 16, 8);
    00057     uint cg = GB(current, 8,  8);
    00058     uint cb = GB(current, 0,  8);
    00059
    00060     /* The 256 is wrong, it should be 255, but 256 is much faster... */
    00061     return ComposeColour(0xFF,
    00062               ((int)(r - cr) * a) / 256 + cr,
    00063               ((int)(g - cg) * a) / 256 + cg,
    00064               ((int)(b - cb) * a) / 256 + cb);
    00065   }
    00066
    00071   static inline uint32 ComposeColourRGBA(uint r, uint g, uint b, uint a, uint32 current)
    00072   {
    00073     if (a == 0) return current;
    00074     if (a >= 255) return ComposeColour(0xFF, r, g, b);
    00075
    00076     return ComposeColourRGBANoCheck(r, g, b, a, current);
    00077   }
    00078
    00082   static inline uint32 ComposeColourPANoCheck(uint32 colour, uint a, uint32 current)
    00083   {
    00084     uint r  = GB(colour,  16, 8);
    00085     uint g  = GB(colour,  8,  8);
    00086     uint b  = GB(colour,  0,  8);
    00087
    00088     return ComposeColourRGBANoCheck(r, g, b, a, current);
    00089   }
    00090
    00095   static inline uint32 ComposeColourPA(uint32 colour, uint a, uint32 current)
    00096   {
    00097     if (a == 0) return current;
    00098     if (a >= 255) return (colour | 0xFF000000);
    00099
    00100     return ComposeColourPANoCheck(colour, a, current);
    00101   }
    00102
    00110   static inline uint32 MakeTransparent(uint32 colour, uint nom, uint denom = 256)
    00111   {
    00112     uint r = GB(colour, 16, 8);
    00113     uint g = GB(colour, 8,  8);
    00114     uint b = GB(colour, 0,  8);
    00115
    00116     return ComposeColour(0xFF, r * nom / denom, g * nom / denom, b * nom / denom);
    00117   }
    00118
    00124   static inline uint32 MakeGrey(uint32 colour)
    00125   {
    00126     uint r = GB(colour, 16, 8);
    00127     uint g = GB(colour, 8,  8);
    00128     uint b = GB(colour, 0,  8);
    00129
    00130     /* To avoid doubles and stuff, multiple it with a total of 65536 (16bits), then
    00131      *  divide by it to normalize the value to a byte again. See heightmap.cpp for
    00132      *  information about the formula. */
    00133     colour = ((r * 19595) + (g * 38470) + (b * 7471)) / 65536;
    00134
    00135     return ComposeColour(0xFF, colour, colour, colour);
    00136   }
    00137 };
    00138
    00139 #endif /* BLITTER_32BPP_BASE_HPP */