32bpp_base.hpp

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00001 /* $Id: 32bpp_base.hpp 18907 2010-01-23 22:37:14Z alberth $ */
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 
00019 class Blitter_32bppBase : public Blitter {
00020 public:
00021   /* virtual */ uint8 GetScreenDepth() { return 32; }
00022 //  /* virtual */ void Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom);
00023 //  /* virtual */ void DrawColourMappingRect(void *dst, int width, int height, PaletteID pal);
00024 //  /* virtual */ Sprite *Encode(SpriteLoader::Sprite *sprite, Blitter::AllocatorProc *allocator);
00025   /* virtual */ void *MoveTo(const void *video, int x, int y);
00026   /* virtual */ void SetPixel(void *video, int x, int y, uint8 colour);
00027   /* virtual */ void DrawRect(void *video, int width, int height, uint8 colour);
00028   /* virtual */ void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour);
00029   /* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height);
00030   /* virtual */ void CopyToBuffer(const void *video, void *dst, int width, int height);
00031   /* virtual */ void CopyImageToBuffer(const void *video, void *dst, int width, int height, int dst_pitch);
00032   /* virtual */ void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y);
00033   /* virtual */ int BufferSize(int width, int height);
00034   /* virtual */ void PaletteAnimate(uint start, uint count);
00035   /* virtual */ Blitter::PaletteAnimation UsePaletteAnimation();
00036   /* virtual */ int GetBytesPerPixel() { return 4; }
00037 
00041   static inline uint32 ComposeColour(uint a, uint r, uint g, uint b)
00042   {
00043     return (((a) << 24) & 0xFF000000) | (((r) << 16) & 0x00FF0000) | (((g) << 8) & 0x0000FF00) | ((b) & 0x000000FF);
00044   }
00045 
00049   static inline uint32 LookupColourInPalette(uint index)
00050   {
00051     return _cur_palette[index].data;
00052   }
00053 
00057   static inline uint32 ComposeColourRGBANoCheck(uint r, uint g, uint b, uint a, uint32 current)
00058   {
00059     uint cr = GB(current, 16, 8);
00060     uint cg = GB(current, 8,  8);
00061     uint cb = GB(current, 0,  8);
00062 
00063     /* The 256 is wrong, it should be 255, but 256 is much faster... */
00064     return ComposeColour(0xFF,
00065               ((int)(r - cr) * a) / 256 + cr,
00066               ((int)(g - cg) * a) / 256 + cg,
00067               ((int)(b - cb) * a) / 256 + cb);
00068   }
00069 
00074   static inline uint32 ComposeColourRGBA(uint r, uint g, uint b, uint a, uint32 current)
00075   {
00076     if (a == 0) return current;
00077     if (a >= 255) return ComposeColour(0xFF, r, g, b);
00078 
00079     return ComposeColourRGBANoCheck(r, g, b, a, current);
00080   }
00081 
00085   static inline uint32 ComposeColourPANoCheck(uint32 colour, uint a, uint32 current)
00086   {
00087     uint r  = GB(colour,  16, 8);
00088     uint g  = GB(colour,  8,  8);
00089     uint b  = GB(colour,  0,  8);
00090 
00091     return ComposeColourRGBANoCheck(r, g, b, a, current);
00092   }
00093 
00098   static inline uint32 ComposeColourPA(uint32 colour, uint a, uint32 current)
00099   {
00100     if (a == 0) return current;
00101     if (a >= 255) return (colour | 0xFF000000);
00102 
00103     return ComposeColourPANoCheck(colour, a, current);
00104   }
00105 
00113   static inline uint32 MakeTransparent(uint32 colour, uint nom, uint denom = 256)
00114   {
00115     uint r = GB(colour, 16, 8);
00116     uint g = GB(colour, 8,  8);
00117     uint b = GB(colour, 0,  8);
00118 
00119     return ComposeColour(0xFF, r * nom / denom, g * nom / denom, b * nom / denom);
00120   }
00121 
00127   static inline uint32 MakeGrey(uint32 colour)
00128   {
00129     uint r = GB(colour, 16, 8);
00130     uint g = GB(colour, 8,  8);
00131     uint b = GB(colour, 0,  8);
00132 
00133     /* To avoid doubles and stuff, multiple it with a total of 65536 (16bits), then
00134      *  divide by it to normalize the value to a byte again. See heightmap.cpp for
00135      *  information about the formula. */
00136     colour = ((r * 19595) + (g * 38470) + (b * 7471)) / 65536;
00137 
00138     return ComposeColour(0xFF, colour, colour, colour);
00139   }
00140 };
00141 
00142 #endif /* BLITTER_32BPP_BASE_HPP */

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