diff options
Diffstat (limited to 'src/blitter/32bpp_base.hpp')
-rw-r--r-- | src/blitter/32bpp_base.hpp | 90 |
1 files changed, 86 insertions, 4 deletions
diff --git a/src/blitter/32bpp_base.hpp b/src/blitter/32bpp_base.hpp index 66d7e7529..5eeb8b902 100644 --- a/src/blitter/32bpp_base.hpp +++ b/src/blitter/32bpp_base.hpp @@ -26,10 +26,92 @@ public: /* virtual */ void PaletteAnimate(uint start, uint count); /* virtual */ Blitter::PaletteAnimation UsePaletteAnimation(); - static inline uint32 LookupColourInPalette(uint8 index) { - #define ARGB(a, r, g, b) ((((a) << 24) & 0xFF000000) | (((r) << 16) & 0x00FF0000) | (((g) << 8) & 0x0000FF00) | ((b) & 0x000000FF)) - if (index == 0) return 0x00000000; - return ARGB(0xFF, _cur_palette[index].r, _cur_palette[index].g, _cur_palette[index].b); + /** + * Compose a colour based on RGB values. + */ + static inline uint ComposeColour(uint a, uint r, uint g, uint b) + { + return (((a) << 24) & 0xFF000000) | (((r) << 16) & 0x00FF0000) | (((g) << 8) & 0x0000FF00) | ((b) & 0x000000FF); + } + + /** + * Look up the colour in the current palette. + **/ + static inline uint32 LookupColourInPalette(uint8 index) + { + if (index == 0) return 0x00000000; // Full transparent pixel */ + return ComposeColour(0xFF, _cur_palette[index].r, _cur_palette[index].g, _cur_palette[index].b); + } + + /** + * Compose a colour based on RGBA values and the current pixel value. + */ + static inline uint ComposeColourRGBA(uint r, uint g, uint b, uint a, uint current) + { + uint cr, cg, cb; + cr = GB(current, 16, 8); + cg = GB(current, 8, 8); + cb = GB(current, 0, 8); + + return ComposeColour(0xFF, + (r * a + cr * (255 - a)) / 255, + (g * a + cg * (255 - a)) / 255, + (b * a + cb * (255 - a)) / 255); + } + + /** + * Compose a colour based on Pixel value, alpha value, and the current pixel value. + */ + static inline uint ComposeColourPA(uint colour, uint a, uint current) + { + uint r, g, b, cr, cg, cb; + r = GB(colour, 16, 8); + g = GB(colour, 8, 8); + b = GB(colour, 0, 8); + cr = GB(current, 16, 8); + cg = GB(current, 8, 8); + cb = GB(current, 0, 8); + + return ComposeColour(0xFF, + (r * a + cr * (255 - a)) / 255, + (g * a + cg * (255 - a)) / 255, + (b * a + cb * (255 - a)) / 255); + } + + /** + * Make a pixel looks like it is transparent. + * @param colour the colour already on the screen. + * @param amount the amount of transparency, times 100. + * @return the new colour for the screen. + */ + static inline uint MakeTransparent(uint colour, uint amount) + { + uint r, g, b; + r = GB(colour, 16, 8); + g = GB(colour, 8, 8); + b = GB(colour, 0, 8); + + return ComposeColour(0xFF, r * amount / 100, g * amount / 100, b * amount / 100); + } + + /** + * Make a colour grey-based. + * @param colour the colour to make grey. + * @return the new colour, now grey. + */ + static inline uint MakeGrey(uint colour) + { + uint r, g, b; + r = GB(colour, 16, 8); + g = GB(colour, 8, 8); + b = GB(colour, 0, 8); + + /* To avoid doubles and stuff, multiple it with a total of 65536 (16bits), then + * divide by it to normalize the value to a byte again. See heightmap.cpp for + * information about the formula. */ + colour = ((r * 19595) + (g * 38470) + (b * 7471)) / 65536; + + return ComposeColour(0xFF, colour, colour, colour); } }; |