ref: 67e63b7e1b4b799192b3e9c8a9702e54c83b67d1
dir: /r_fog.c/
#include "quakedef.h" static cvar_t r_fog = {"r_fog", "1", true}; static cvar_t r_skyfog = {"r_skyfog", "0.5"}; static struct { float density; pixel_t color; }r_fog_data; static void fog(void) { int i, j, n; float x; i = 1; n = Cmd_Argc(); switch(n){ case 5: case 2: x = atof(Cmd_Argv(i++)); r_fog_data.density = max(0.0, x) * 0.016; r_fog_data.density *= r_fog_data.density; if(n == 2) break; case 4: r_fog_data.color = 0; for(j = 0; j < 3; j++, i++){ x = atof(Cmd_Argv(i)); r_fog_data.color = r_fog_data.color << 8 | (int)(0xff * clamp(x, 0.0, 1.0)); } break; } } void R_ResetFog(void) { r_fog_data.density = 0; r_fog_data.color = 0x808080; setcvar("r_skyfog", "0"); } void R_DrawFog(void) { byte ca0, ca1, ca2, skyfogalpha, a; pixel_t *pix; int i, x, y; uzint *z; float d; if(r_fog.value <= 0 || r_fog_data.density <= 0.0) return; ca0 = r_fog_data.color>> 0; ca1 = r_fog_data.color>> 8; ca2 = r_fog_data.color>>16; skyfogalpha = 255 * clamp(r_skyfog.value, 0, 1.0); /* FIXME(sigrid): this is super slow */ for(y = r_refdef.vrect.y; y < r_refdef.vrectbottom; y++){ i = y * vid.width + r_refdef.vrect.x; pix = vid.buffer + i; z = d_pzbuffer + i; for(x = r_refdef.vrect.x; x < r_refdef.vrectright; x++, i++, pix++, z++){ if(*z > 65536){ d = 65536.0 / (float)(*z >> 16); d = 1.0 - exp2(-r_fog_data.density * d*d); a = 255*clamp(d, 0.0, 1.0); }else if(*z < 0){ a = skyfogalpha; }else continue; if(a > 0){ *pix = ((a*ca0 + (255-a)*((*pix>> 0)&0xff)) >> 8) << 0 | ((a*ca1 + (255-a)*((*pix>> 8)&0xff)) >> 8) << 8 | ((a*ca2 + (255-a)*((*pix>>16)&0xff)) >> 8) << 16; } } } } void R_InitFog(void) { Cmd_AddCommand("fog", fog); Cvar_RegisterVariable(&r_fog); Cvar_RegisterVariable(&r_skyfog); }