replaced r_shadow_bouncegrid_particlespacing with

r_shadow_bouncegrid_photons which makes the number of photons traced per
frame completely uniform, fixing performance issues in some maps

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@10883 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/r_shadow.c b/r_shadow.c
index 4288fe163ee2bb444df32f503f7852631ac99132..626c9f96264a6facd5a0f6b32cf54cac7f874ac9 100644 (file)
--- a/r_shadow.c
+++ b/r_shadow.c
@@ -328,7 +328,7 @@ cvar_t r_shadow_bouncegrid_lightradiusscale = {CVAR_SAVE, "r_shadow_bouncegrid_l
 cvar_t r_shadow_bouncegrid_maxbounce = {CVAR_SAVE, "r_shadow_bouncegrid_maxbounce", "3", "maximum number of bounces for a particle (minimum is 1)"};
 cvar_t r_shadow_bouncegrid_particlebounceintensity = {CVAR_SAVE, "r_shadow_bouncegrid_particlebounceintensity", "4", "amount of energy carried over after each bounce, this is a multiplier of texture color and the result is clamped to 1 or less, to prevent adding energy on each bounce"};
 cvar_t r_shadow_bouncegrid_particleintensity = {CVAR_SAVE, "r_shadow_bouncegrid_particleintensity", "2", "brightness of particles contributing to bouncegrid texture"};
-cvar_t r_shadow_bouncegrid_particlespacing = {CVAR_SAVE, "r_shadow_bouncegrid_particlespacing", "32", "emit one particle per this many units (squared) of radius (squared)"};
+cvar_t r_shadow_bouncegrid_photons = {CVAR_SAVE, "r_shadow_bouncegrid_photons", "2000", "total photons to shoot per update, divided proportionately between lights"};
 cvar_t r_shadow_bouncegrid_spacingx = {CVAR_SAVE, "r_shadow_bouncegrid_spacingx", "64", "unit size of bouncegrid pixel on X axis"};
 cvar_t r_shadow_bouncegrid_spacingy = {CVAR_SAVE, "r_shadow_bouncegrid_spacingy", "64", "unit size of bouncegrid pixel on Y axis"};
 cvar_t r_shadow_bouncegrid_spacingz = {CVAR_SAVE, "r_shadow_bouncegrid_spacingz", "64", "unit size of bouncegrid pixel on Z axis"};
@@ -721,7 +721,7 @@ void R_Shadow_Init(void)
        Cvar_RegisterVariable(&r_shadow_bouncegrid_maxbounce);
        Cvar_RegisterVariable(&r_shadow_bouncegrid_particlebounceintensity);
        Cvar_RegisterVariable(&r_shadow_bouncegrid_particleintensity);
-       Cvar_RegisterVariable(&r_shadow_bouncegrid_particlespacing);
+       Cvar_RegisterVariable(&r_shadow_bouncegrid_photons);
        Cvar_RegisterVariable(&r_shadow_bouncegrid_spacingx);
        Cvar_RegisterVariable(&r_shadow_bouncegrid_spacingy);
        Cvar_RegisterVariable(&r_shadow_bouncegrid_spacingz);
@@ -2291,6 +2291,7 @@ static void R_Shadow_UpdateBounceGridTexture(void)
        int resolution[3];
        int shootparticles;
        int shotparticles;
+       int photoncount;
        int tex[3];
        trace_t cliptrace;
        //trace_t cliptrace2;
@@ -2319,6 +2320,8 @@ static void R_Shadow_UpdateBounceGridTexture(void)
        vec_t radius;
        vec_t s;
        vec_t lightintensity;
+       vec_t photonscaling;
+       vec_t photonresidual;
        float m[16];
        qboolean isstatic = r_shadow_bouncegrid_updateinterval.value > 1.0f;
        rtlight_t *rtlight;
@@ -2405,6 +2408,7 @@ static void R_Shadow_UpdateBounceGridTexture(void)
        range = Mem_ExpandableArray_IndexRange(&r_shadow_worldlightsarray); // checked
        range1 = isstatic ? 0 : r_refdef.scene.numlights;
        range2 = range + range1;
+       photoncount = 0;
        for (lightindex = 0;lightindex < range2;lightindex++)
        {
                if (isstatic)
@@ -2440,13 +2444,58 @@ static void R_Shadow_UpdateBounceGridTexture(void)
                // distribution, the seeded random is only consistent for a
                // consistent number of particles on this light...
                radius = rtlight->radius * bound(0.0001f, r_shadow_bouncegrid_lightradiusscale.value, 1024.0f);
-               s = rtlight->radius / bound(1.0f, r_shadow_bouncegrid_particlespacing.value, 1048576.0f);
-               lightintensity = VectorLength(rtlight->color) * rtlight->ambientscale + rtlight->diffusescale + rtlight->specularscale;
+               s = rtlight->radius;
+               lightintensity = VectorLength(rtlight->color) * (rtlight->ambientscale + rtlight->diffusescale + rtlight->specularscale);
                if (lightindex >= range)
                        lightintensity *= r_shadow_bouncegrid_dlightparticlemultiplier.value;
-               shootparticles = (int)bound(0, lightintensity * s *s, MAXBOUNCEGRIDPARTICLESPERLIGHT);
+               photoncount += max(0.0f, lightintensity * s * s);
+       }
+       photonscaling = bound(1, r_shadow_bouncegrid_photons.value, 1048576) / max(1, photoncount);
+       photonresidual = 0.0f;
+       for (lightindex = 0;lightindex < range2;lightindex++)
+       {
+               if (isstatic)
+               {
+                       light = (dlight_t *) Mem_ExpandableArray_RecordAtIndex(&r_shadow_worldlightsarray, lightindex);
+                       if (!light || !(light->flags & flag))
+                               continue;
+                       rtlight = &light->rtlight;
+                       // when static, we skip styled lights because they tend to change...
+                       if (rtlight->style > 0)
+                               continue;
+                       VectorScale(rtlight->color, (rtlight->ambientscale + rtlight->diffusescale + rtlight->specularscale) * (rtlight->style >= 0 ? r_refdef.scene.rtlightstylevalue[rtlight->style] : 1), lightcolor);
+               }
+               else
+               {
+                       if (lightindex < range)
+                       {
+                               light = (dlight_t *) Mem_ExpandableArray_RecordAtIndex(&r_shadow_worldlightsarray, lightindex);
+                               rtlight = &light->rtlight;
+                       }
+                       else
+                               rtlight = r_refdef.scene.lights[lightindex - range];
+                       // draw only visible lights (major speedup)
+                       if (!rtlight->draw)
+                               continue;
+                       VectorScale(rtlight->currentcolor, rtlight->ambientscale + rtlight->diffusescale + rtlight->specularscale, lightcolor);
+               }
+               if (!VectorLength2(lightcolor))
+                       continue;
+               // shoot particles from this light
+               // use a calculation for the number of particles that will not
+               // vary with lightstyle, otherwise we get randomized particle
+               // distribution, the seeded random is only consistent for a
+               // consistent number of particles on this light...
+               radius = rtlight->radius * bound(0.0001f, r_shadow_bouncegrid_lightradiusscale.value, 1024.0f);
+               s = rtlight->radius;
+               lightintensity = VectorLength(rtlight->color) * (rtlight->ambientscale + rtlight->diffusescale + rtlight->specularscale);
+               if (lightindex >= range)
+                       lightintensity *= r_shadow_bouncegrid_dlightparticlemultiplier.value;
+               photonresidual += lightintensity * s * s * photonscaling;
+               shootparticles = (int)bound(0, photonresidual, MAXBOUNCEGRIDPARTICLESPERLIGHT);
                if (!shootparticles)
                        continue;
+               photonresidual -= shootparticles;
                s = 65535.0f * r_shadow_bouncegrid_particleintensity.value / shootparticles;
                VectorScale(lightcolor, s, baseshotcolor);
                if (VectorLength2(baseshotcolor) < 3.0f)