# 32bpp_base.hpp

Go to the documentation of this file.

    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 Colour LookupColourInPalette(uint index)
    00040   {
    00041     return _cur_palette.palette[index];
    00042   }
    00043
    00047   static inline Colour ComposeColourRGBANoCheck(uint r, uint g, uint b, uint a, Colour current)
    00048   {
    00049     uint cr = current.r;
    00050     uint cg = current.g;
    00051     uint cb = current.b;
    00052
    00053     /* The 256 is wrong, it should be 255, but 256 is much faster... */
    00054     return Colour(
    00055               ((int)(r - cr) * a) / 256 + cr,
    00056               ((int)(g - cg) * a) / 256 + cg,
    00057               ((int)(b - cb) * a) / 256 + cb);
    00058   }
    00059
    00064   static inline Colour ComposeColourRGBA(uint r, uint g, uint b, uint a, Colour current)
    00065   {
    00066     if (a == 0) return current;
    00067     if (a >= 255) return Colour(r, g, b);
    00068
    00069     return ComposeColourRGBANoCheck(r, g, b, a, current);
    00070   }
    00071
    00075   static inline Colour ComposeColourPANoCheck(Colour colour, uint a, Colour current)
    00076   {
    00077     uint r  = colour.r;
    00078     uint g  = colour.g;
    00079     uint b  = colour.b;
    00080
    00081     return ComposeColourRGBANoCheck(r, g, b, a, current);
    00082   }
    00083
    00088   static inline Colour ComposeColourPA(Colour colour, uint a, Colour current)
    00089   {
    00090     if (a == 0) return current;
    00091     if (a >= 255) {
    00092       colour.a = 255;
    00093       return colour;
    00094     }
    00095
    00096     return ComposeColourPANoCheck(colour, a, current);
    00097   }
    00098
    00106   static inline Colour MakeTransparent(Colour colour, uint nom, uint denom = 256)
    00107   {
    00108     uint r = colour.r;
    00109     uint g = colour.g;
    00110     uint b = colour.b;
    00111
    00112     return Colour(r * nom / denom, g * nom / denom, b * nom / denom);
    00113   }
    00114
    00120   static inline Colour MakeGrey(Colour colour)
    00121   {
    00122     uint r = colour.r;
    00123     uint g = colour.g;
    00124     uint b = colour.b;
    00125
    00126     /* To avoid doubles and stuff, multiple it with a total of 65536 (16bits), then
    00127      *  divide by it to normalize the value to a byte again. See heightmap.cpp for
    00128      *  information about the formula. */
    00129     uint grey = ((r * 19595) + (g * 38470) + (b * 7471)) / 65536;
    00130
    00131     return Colour(grey, grey, grey);
    00132   }
    00133
    00134   static const int DEFAULT_BRIGHTNESS = 64;
    00135
    00136   static inline Colour AdjustBrightness(Colour colour, uint8 brightness)
    00137   {
    00138     /* Shortcut for normal brightness */
    00139     if (brightness == DEFAULT_BRIGHTNESS) return colour;
    00140
    00141     uint16 ob = 0;
    00142     uint16 r = colour.r * brightness / DEFAULT_BRIGHTNESS;
    00143     uint16 g = colour.g * brightness / DEFAULT_BRIGHTNESS;
    00144     uint16 b = colour.b * brightness / DEFAULT_BRIGHTNESS;
    00145
    00146     /* Sum overbright */
    00147     if (r > 255) ob += r - 255;
    00148     if (g > 255) ob += g - 255;
    00149     if (b > 255) ob += b - 255;
    00150
    00151     if (ob == 0) return Colour(r, g, b, colour.a);
    00152
    00153     /* Reduce overbright strength */
    00154     ob /= 2;
    00155     return Colour(
    00156                          r >= 255 ? 255 : min(r + ob * (255 - r) / 256, 255),
    00157                          g >= 255 ? 255 : min(g + ob * (255 - g) / 256, 255),
    00158                          b >= 255 ? 255 : min(b + ob * (255 - b) / 256, 255),
    00159                          colour.a);
    00160   }
    00161 };
    00162
    00163 #endif /* BLITTER_32BPP_BASE_HPP */