# 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 "../core/math_func.hpp"
    00018 #include "../gfx_func.h"
    00019
    00021 class Blitter_32bppBase : public Blitter {
    00022 public:
    00023   /* virtual */ uint8 GetScreenDepth() { return 32; }
    00024   /* virtual */ void *MoveTo(void *video, int x, int y);
    00025   /* virtual */ void SetPixel(void *video, int x, int y, uint8 colour);
    00026   /* virtual */ void DrawRect(void *video, int width, int height, uint8 colour);
    00027   /* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height);
    00028   /* virtual */ void CopyToBuffer(const void *video, void *dst, int width, int height);
    00029   /* virtual */ void CopyImageToBuffer(const void *video, void *dst, int width, int height, int dst_pitch);
    00030   /* virtual */ void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y);
    00031   /* virtual */ int BufferSize(int width, int height);
    00032   /* virtual */ void PaletteAnimate(const Palette &palette);
    00033   /* virtual */ Blitter::PaletteAnimation UsePaletteAnimation();
    00034   /* virtual */ int GetBytesPerPixel() { return 4; }
    00035
    00039   static inline uint32 ComposeColour(uint a, uint r, uint g, uint b)
    00040   {
    00041     return (((a) << 24) & 0xFF000000) | (((r) << 16) & 0x00FF0000) | (((g) << 8) & 0x0000FF00) | ((b) & 0x000000FF);
    00042   }
    00043
    00047   static inline uint32 LookupColourInPalette(uint index)
    00048   {
    00049     return _cur_palette.palette[index].data;
    00050   }
    00051
    00055   static inline uint32 ComposeColourRGBANoCheck(uint r, uint g, uint b, uint a, uint32 current)
    00056   {
    00057     uint cr = GB(current, 16, 8);
    00058     uint cg = GB(current, 8,  8);
    00059     uint cb = GB(current, 0,  8);
    00060
    00061     /* The 256 is wrong, it should be 255, but 256 is much faster... */
    00062     return ComposeColour(0xFF,
    00063               ((int)(r - cr) * a) / 256 + cr,
    00064               ((int)(g - cg) * a) / 256 + cg,
    00065               ((int)(b - cb) * a) / 256 + cb);
    00066   }
    00067
    00072   static inline uint32 ComposeColourRGBA(uint r, uint g, uint b, uint a, uint32 current)
    00073   {
    00074     if (a == 0) return current;
    00075     if (a >= 255) return ComposeColour(0xFF, r, g, b);
    00076
    00077     return ComposeColourRGBANoCheck(r, g, b, a, current);
    00078   }
    00079
    00083   static inline uint32 ComposeColourPANoCheck(uint32 colour, uint a, uint32 current)
    00084   {
    00085     uint r  = GB(colour,  16, 8);
    00086     uint g  = GB(colour,  8,  8);
    00087     uint b  = GB(colour,  0,  8);
    00088
    00089     return ComposeColourRGBANoCheck(r, g, b, a, current);
    00090   }
    00091
    00096   static inline uint32 ComposeColourPA(uint32 colour, uint a, uint32 current)
    00097   {
    00098     if (a == 0) return current;
    00099     if (a >= 255) return (colour | 0xFF000000);
    00100
    00101     return ComposeColourPANoCheck(colour, a, current);
    00102   }
    00103
    00111   static inline uint32 MakeTransparent(uint32 colour, uint nom, uint denom = 256)
    00112   {
    00113     uint r = GB(colour, 16, 8);
    00114     uint g = GB(colour, 8,  8);
    00115     uint b = GB(colour, 0,  8);
    00116
    00117     return ComposeColour(0xFF, r * nom / denom, g * nom / denom, b * nom / denom);
    00118   }
    00119
    00125   static inline uint32 MakeGrey(uint32 colour)
    00126   {
    00127     uint r = GB(colour, 16, 8);
    00128     uint g = GB(colour, 8,  8);
    00129     uint b = GB(colour, 0,  8);
    00130
    00131     /* To avoid doubles and stuff, multiple it with a total of 65536 (16bits), then
    00132      *  divide by it to normalize the value to a byte again. See heightmap.cpp for
    00133      *  information about the formula. */
    00134     colour = ((r * 19595) + (g * 38470) + (b * 7471)) / 65536;
    00135
    00136     return ComposeColour(0xFF, colour, colour, colour);
    00137   }
    00138
    00139   static const int DEFAULT_BRIGHTNESS = 64;
    00140
    00141   static inline uint32 AdjustBrightness(uint32 colour, uint8 brightness)
    00142   {
    00143     /* Shortcut for normal brightness */
    00144     if (brightness == DEFAULT_BRIGHTNESS) return colour;
    00145
    00146     uint16 ob = 0;
    00147     uint16 r = GB(colour, 16, 8) * brightness / DEFAULT_BRIGHTNESS;
    00148     uint16 g = GB(colour, 8,  8) * brightness / DEFAULT_BRIGHTNESS;
    00149     uint16 b = GB(colour, 0,  8) * brightness / DEFAULT_BRIGHTNESS;
    00150
    00151     /* Sum overbright */
    00152     if (r > 255) ob += r - 255;
    00153     if (g > 255) ob += g - 255;
    00154     if (b > 255) ob += b - 255;
    00155
    00156     if (ob == 0) return ComposeColour(GB(colour, 24, 8), r, g, b);
    00157
    00158     /* Reduce overbright strength */
    00159     ob /= 2;
    00160     return ComposeColour(GB(colour, 24, 8),
    00161                          r >= 255 ? 255 : min(r + ob * (255 - r) / 256, 255),
    00162                          g >= 255 ? 255 : min(g + ob * (255 - g) / 256, 255),
    00163                          b >= 255 ? 255 : min(b + ob * (255 - b) / 256, 255));
    00164   }
    00165 };
    00166
    00167 #endif /* BLITTER_32BPP_BASE_HPP */