return (int)t;
}
+static unsigned int mul_Lecuyer[4] = { 0x12e15e35, 0xb500f16e, 0x2e714eb2, 0xb37916a5 };
+
+static void mul128(unsigned int a[], unsigned int b[], unsigned int dest[4])
+{
+ unsigned long long t[4];
+ t[0] = a[0] * b[0];
+ t[1] = a[1] * b[1];
+ t[2] = a[2] * b[2];
+ t[3] = a[3] * b[3];
+
+ // this is complicated because C doesn't have a way to make use of the
+ // cpu status carry flag, so we do it all in reverse order from what
+ // would otherwise make sense, and have to make multiple passes...
+ t[3] += t[2] >> 32; t[2] &= 0xffffffff;
+ t[2] += t[1] >> 32; t[1] &= 0xffffffff;
+ t[1] += t[0] >> 32; t[0] &= 0xffffffff;
+
+ t[3] += t[2] >> 32; t[2] &= 0xffffffff;
+ t[2] += t[1] >> 32; t[1] &= 0xffffffff;
+
+ t[3] += t[2] >> 32; t[2] &= 0xffffffff;
+
+ dest[0] = t[0] & 0xffffffff;
+ dest[1] = t[1] & 0xffffffff;
+ dest[2] = t[2] & 0xffffffff;
+ dest[3] = t[3] & 0xffffffff;
+}
+
+void Math_RandomSeed_Reset(randomseed_t *r)
+{
+ r->s[0] = 1;
+ r->s[1] = 0;
+ r->s[2] = 0;
+ r->s[3] = 0;
+}
+
+void Math_RandomSeed_FromInt(randomseed_t *r, unsigned int n)
+{
+ // if the entire s[] is zero the algorithm would break completely, so make sure it isn't zero by putting a 1 here
+ r->s[0] = 1;
+ r->s[1] = 0;
+ r->s[2] = 0;
+ r->s[3] = n;
+}
+
+unsigned long long Math_rand64(randomseed_t *r)
+{
+ unsigned int o[4];
+ mul128(r->s, mul_Lecuyer, o);
+ r->s[0] = o[0];
+ r->s[1] = o[1];
+ r->s[2] = o[2];
+ r->s[3] = o[3];
+ return ((unsigned long long)o[3] << 32) + o[2];
+}
+
+float Math_randomf(randomseed_t *r)
+{
+ unsigned long long n = Math_rand64(r);
+ return n * (0.25f / 0x80000000 / 0x80000000);
+}
+
+float Math_crandomf(randomseed_t *r)
+{
+ // do this with a signed number and double the result, so we make use of all parts of the cow
+ long long n = (long long)Math_rand64(r);
+ return n * (0.5f / 0x80000000 / 0x80000000);
+}
+
+float Math_randomrangef(randomseed_t *r, float minf, float maxf)
+{
+ return Math_randomf(r) * (maxf - minf) + minf;
+}
+
+int Math_randomrangei(randomseed_t *r, int mini, int maxi)
+{
+ unsigned long long n = Math_rand64(r);
+ return (int)(((n >> 33) * (maxi - mini) + mini) >> 31);
+}
}
#endif
-#define lhcheeserand() (seed = (seed * 987211u) ^ (seed >> 13u) ^ 914867)
-#define lhcheeserandom(MIN,MAX) ((double)(lhcheeserand() + 0.5) / ((double)4096.0*1024.0*1024.0) * ((MAX)-(MIN)) + (MIN))
-#define VectorCheeseRandom(v) do{(v)[0] = lhcheeserandom(-1, 1);(v)[1] = lhcheeserandom(-1, 1);(v)[2] = lhcheeserandom(-1, 1);}while(DotProduct(v, v) > 1)
+#define lhcheeserand(seed) ((seed) = ((seed) * 987211u) ^ ((seed) >> 13u) ^ 914867)
+#define lhcheeserandom(seed,MIN,MAX) ((double)(lhcheeserand(seed) + 0.5) / ((double)4096.0*1024.0*1024.0) * ((MAX)-(MIN)) + (MIN))
+#define VectorCheeseRandom(seed,v) do{(v)[0] = lhcheeserandom(seed,-1, 1);(v)[1] = lhcheeserandom(seed,-1, 1);(v)[2] = lhcheeserandom(seed,-1, 1);}while(DotProduct(v, v) > 1)
+#define VectorLehmerRandom(seed,v) do{(v)[0] = Math_crandomf(seed);(v)[1] = Math_crandomf(seed);(v)[2] = Math_crandomf(seed);}while(DotProduct(v, v) > 1)
/*
// LordHavoc: quaternion math, untested, don't know if these are correct,
int LoopingFrameNumberFromDouble(double t, int loopframes);
+// implementation of 128bit Lehmer Random Number Generator with 2^126 period
+// https://en.wikipedia.org/Lehmer_random_number_generator
+typedef struct randomseed_s
+{
+ unsigned int s[4];
+}
+randomseed_t;
+
+void Math_RandomSeed_Reset(randomseed_t *r);
+void Math_RandomSeed_FromInt(randomseed_t *r, unsigned int n);
+unsigned long long Math_rand64(randomseed_t *r);
+float Math_randomf(randomseed_t *r);
+float Math_crandomf(randomseed_t *r);
+float Math_randomrangef(randomseed_t *r, float minf, float maxf);
+int Math_randomrangei(randomseed_t *r, int mini, int maxi);
+
void Mathlib_Init(void);
#endif
static void R_Shadow_BounceGrid_TracePhotons(r_shadow_bouncegrid_settings_t settings, unsigned int range, unsigned int range1, unsigned int range2, float photonscaling, int flag)
{
+ vec3_t bouncerandom[10];
dlight_t *light;
int bouncecount;
int hitsupercontentsmask;
//trace_t cliptrace3;
unsigned int lightindex;
unsigned int seed = (unsigned int)(realtime * 1000.0f);
+ randomseed_t randomseed;
vec3_t shotcolor;
vec3_t baseshotcolor;
vec3_t surfcolor;
vec_t s;
rtlight_t *rtlight;
- // we'll need somewhere to store these
+ Math_RandomSeed_FromInt(&randomseed, seed);
+
r_shadow_bouncegrid_state.numsplatpaths = 0;
r_shadow_bouncegrid_state.splatpaths = (r_shadow_bouncegrid_splatpath_t *)R_FrameData_Alloc(sizeof(r_shadow_bouncegrid_splatpath_t) * r_shadow_bouncegrid_state.maxsplatpaths);
VectorScale(rtlight->photoncolor, s, baseshotcolor);
r_refdef.stats[r_stat_bouncegrid_lights]++;
r_refdef.stats[r_stat_bouncegrid_particles] += shootparticles;
+ switch (settings.stablerandom)
+ {
+ default:
+ break;
+ case 1:
+ Math_RandomSeed_FromInt(&randomseed, lightindex * 11937);
+ // prime the random number generator a bit
+ Math_crandomf(&randomseed);
+ break;
+ case 2:
+ seed = lightindex * 11937;
+ // prime the random number generator a bit
+ lhcheeserand(seed);
+ break;
+ }
for (shotparticles = 0;shotparticles < shootparticles;shotparticles++)
{
- if (settings.stablerandom > 0)
- seed = lightindex * 11937 + shotparticles;
VectorCopy(baseshotcolor, shotcolor);
VectorCopy(rtlight->shadoworigin, clipstart);
- if (settings.stablerandom < 0)
+ switch (settings.stablerandom)
+ {
+ default:
+ case 0:
VectorRandom(clipend);
- else
- VectorCheeseRandom(clipend);
+ if (settings.bounceanglediffuse)
+ {
+ // we want random to be stable, so we still have to do all the random we would have done
+ for (bouncecount = 0; bouncecount < maxbounce; bouncecount++)
+ VectorRandom(bouncerandom[bouncecount]);
+ }
+ break;
+ case -1:
+ case 1:
+ VectorLehmerRandom(&randomseed, clipend);
+ if (settings.bounceanglediffuse)
+ {
+ // we want random to be stable, so we still have to do all the random we would have done
+ for (bouncecount = 0; bouncecount < maxbounce; bouncecount++)
+ VectorLehmerRandom(&randomseed, bouncerandom[bouncecount]);
+ }
+ break;
+ case -2:
+ case 2:
+ VectorCheeseRandom(seed, clipend);
+ if (settings.bounceanglediffuse)
+ {
+ // we want random to be stable, so we still have to do all the random we would have done
+ for (bouncecount = 0; bouncecount < maxbounce; bouncecount++)
+ VectorCheeseRandom(seed, bouncerandom[bouncecount]);
+ }
+ break;
+ }
VectorMA(clipstart, radius, clipend, clipend);
for (bouncecount = 0;;bouncecount++)
{
r_refdef.stats[r_stat_bouncegrid_traces]++;
//r_refdef.scene.worldmodel->TraceLineAgainstSurfaces(r_refdef.scene.worldmodel, NULL, NULL, &cliptrace, clipstart, clipend, hitsupercontentsmask);
//r_refdef.scene.worldmodel->TraceLine(r_refdef.scene.worldmodel, NULL, NULL, &cliptrace2, clipstart, clipend, hitsupercontentsmask);
- if (settings.staticmode)
+ if (settings.staticmode || settings.stablerandom <= 0)
{
// static mode fires a LOT of rays but none of them are identical, so they are not cached
+ // non-stable random in dynamic mode also never reuses a direction, so there's no reason to cache it
cliptrace = CL_TraceLine(clipstart, clipend, settings.staticmode ? MOVE_WORLDONLY : (settings.hitmodels ? MOVE_HITMODEL : MOVE_NOMONSTERS), NULL, hitsupercontentsmask, skipsupercontentsmask, collision_extendmovelength.value, true, false, NULL, true, true);
}
else
{
// random direction, primarily along plane normal
s = VectorDistance(cliptrace.endpos, clipend);
- if (settings.stablerandom < 0)
- VectorRandom(clipend);
- else
- VectorCheeseRandom(clipend);
- VectorMA(cliptrace.plane.normal, 0.95f, clipend, clipend);
+ VectorMA(cliptrace.plane.normal, 0.95f, bouncerandom[bouncecount], clipend);
VectorNormalize(clipend);
VectorScale(clipend, s, clipend);
}
projects / xonotic / darkplaces.git / commitdiff