ref: 3033fafd257e3dff9a8c6621076c6dc15849bafc
dir: /d_alpha.c/
#include "quakedef.h" pixel_t blendalpha(pixel_t ca, pixel_t cb, int alpha, uzint izi) { int a, b, c; alpha = (ca >> 24)*alpha >> 8; if(currententity != nil && currententity->effects & EF_ADDITIVE){ ca = R_BlendFog(ca, izi); a = (alpha*((ca>> 0)&0xff) + 255*((cb>> 0)&0xff))>> 8; b = (alpha*((ca>> 8)&0xff) + 255*((cb>> 8)&0xff))>> 8; c = (alpha*((ca>>16)&0xff) + 255*((cb>>16)&0xff))>> 8; return (cb & 0xff000000) | min(a, 255) | min(b, 255)<<8 | min(c, 255)<<16; } return R_BlendFog( (cb & 0xff000000) | ((alpha*((ca>> 0)&0xff) + (255-alpha)*((cb>> 0)&0xff))>> 8) << 0 | ((alpha*((ca>> 8)&0xff) + (255-alpha)*((cb>> 8)&0xff))>> 8) << 8 | ((alpha*((ca>>16)&0xff) + (255-alpha)*((cb>>16)&0xff))>> 8) << 16, izi ); } float alphafor(int flags) { if(flags & (SURF_TELE|SURF_FENCE)) return 1.0; if(flags & SURF_LAVA) return r_lavaalpha.value; if(flags & SURF_SLIME) return r_slimealpha.value; return r_wateralpha.value; }