diff --git a/src/r_data.c b/src/r_data.c index 87212c175..3d80bbda3 100644 --- a/src/r_data.c +++ b/src/r_data.c @@ -230,25 +230,30 @@ static inline void R_DrawFlippedColumnInCache(column_t *patch, UINT8 *cache, tex UINT32 ASTBlendPixel(RGBA_t background, RGBA_t foreground, int style, UINT8 alpha) { RGBA_t output; + INT16 fullalpha = (alpha - (0xFF - foreground.s.alpha)); if (style == AST_TRANSLUCENT) { - if (alpha == 0) + if (fullalpha <= 0) output.rgba = background.rgba; - else if (alpha == 0xFF) - output.rgba = foreground.rgba; - else if (alpha < 0xFF) - { - UINT8 beta = (0xFF - alpha); - output.s.red = ((background.s.red * beta) + (foreground.s.red * alpha)) / 0xFF; - output.s.green = ((background.s.green * beta) + (foreground.s.green * alpha)) / 0xFF; - output.s.blue = ((background.s.blue * beta) + (foreground.s.blue * alpha)) / 0xFF; - } - // write foreground pixel alpha - // if there's no pixel in here - if (!background.rgba) - output.s.alpha = foreground.s.alpha; else - output.s.alpha = 0xFF; + { + // don't go too high + if (fullalpha >= 0xFF) + fullalpha = 0xFF; + alpha = (UINT8)fullalpha; + + // if the background pixel is empty, match software and don't blend anything + if (!background.s.alpha) + output.rgba = 0; + else + { + UINT8 beta = (0xFF - alpha); + output.s.red = ((background.s.red * beta) + (foreground.s.red * alpha)) / 0xFF; + output.s.green = ((background.s.green * beta) + (foreground.s.green * alpha)) / 0xFF; + output.s.blue = ((background.s.blue * beta) + (foreground.s.blue * alpha)) / 0xFF; + output.s.alpha = 0xFF; + } + } return output.rgba; } #define clamp(c) max(min(c, 0xFF), 0x00);