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//========= Copyright Valve Corporation, All rights reserved. ============//
// $Id$
#include "raytrace.h"
#include <mathlib/halton.h>
static uint32 MapDistanceToPixel(float t){ if (t<0) return 0xffff0000; if (t>100) return 0xff000000; int a=t*1000; a&=0xff; int b=t*10; b &=0xff; int c=t*.01; c &=0xff; return 0xff000000+(a<<16)+(b<<8)+c;}
#define IGAMMA (1.0/2.2)
#define MAGIC_NUMBER (1<<23)
static fltx4 Four_MagicNumbers={ MAGIC_NUMBER, MAGIC_NUMBER, MAGIC_NUMBER, MAGIC_NUMBER };static ALIGN16 int32 Four_255s[4]= {0xff,0xff,0xff,0xff};#define PIXMASK ( * ( reinterpret_cast< fltx4 *>( &Four_255s ) ) )
void MapLinearIntensities(FourVectors const &intens,uint32 *p1, uint32 *p2, uint32 *p3, uint32 *p4){ // convert four pixels worth of sse-style rgb into argb lwords
// NOTE the _mm_empty macro is voodoo. do not mess with this routine casually - simply throwing
// anything that ends up generating a fpu stack references in here would be bad news.
static fltx4 pixscale={255.0,255.0,255.0,255.0}; fltx4 r,g,b; r=MinSIMD(pixscale,MulSIMD(pixscale,PowSIMD(intens.x,IGAMMA))); g=MinSIMD(pixscale,MulSIMD(pixscale,PowSIMD(intens.y,IGAMMA))); b=MinSIMD(pixscale,MulSIMD(pixscale,PowSIMD(intens.z,IGAMMA))); // now, convert to integer
r=AndSIMD( AddSIMD( r, Four_MagicNumbers ), PIXMASK ); g=AndSIMD( AddSIMD( g, Four_MagicNumbers ), PIXMASK ); b=AndSIMD( AddSIMD( b, Four_MagicNumbers ), PIXMASK );
*(p1)=(SubInt(r, 0))|(SubInt(g, 0)<<8)|(SubInt(b, 0)<<16); *(p2)=(SubInt(r, 1))|(SubInt(g, 1)<<8)|(SubInt(b, 1)<<16); *(p3)=(SubInt(r, 2))|(SubInt(g, 2)<<8)|(SubInt(b, 2)<<16); *(p4)=(SubInt(r, 3))|(SubInt(g, 3)<<8)|(SubInt(b, 3)<<16);}
static ALIGN16 uint32 signmask[4]={0x80000000,0x80000000,0x80000000,0x80000000};static ALIGN16 int32 all_ones[4]={-1,-1,-1,-1};static fltx4 all_zeros={0,0,0,0};static fltx4 TraceLimit={1.0e20,1.0e20,1.0e20,1.0e20};
void RayTracingEnvironment::RenderScene( int width, int height, // width and height of desired rendering
int stride, // actual width in pixels of target buffer
uint32 *output_buffer, // pointer to destination
Vector CameraOrigin, // eye position
Vector ULCorner, // word space coordinates of upper left
// monitor corner
Vector URCorner, // top right corner
Vector LLCorner, // lower left
Vector LRCorner, // lower right
RayTraceLightingMode_t lmode){ // first, compute deltas
Vector dxvector=URCorner; dxvector-=ULCorner; dxvector*=(1.0/width); Vector dxvectortimes2=dxvector; dxvectortimes2+=dxvector;
Vector dyvector=LLCorner; dyvector-=ULCorner; dyvector*=(1.0/height);
// block_offsets-relative offsets for eahc of the 4 pixels in the block, in sse format
FourVectors block_offsets; block_offsets.LoadAndSwizzle(Vector(0,0,0),dxvector,dyvector,dxvector+dyvector); FourRays myrays; myrays.origin.DuplicateVector(CameraOrigin); // tmprays is used fo rthe case when we cannot trace 4 rays at once.
FourRays tmprays; tmprays.origin.DuplicateVector(CameraOrigin);
// now, we will ray trace pixels. we will do the rays in a 2x2 pattern
for(int y=0;y<height;y+=2) { Vector SLoc=dyvector; SLoc*=((float) y); SLoc+=ULCorner; uint32 *dest=output_buffer+y*stride; for(int x=0;x<width;x+=2) { myrays.direction.DuplicateVector(SLoc); myrays.direction+=block_offsets; myrays.direction.VectorNormalize(); RayTracingResult rslt; Trace4Rays(myrays,all_zeros,TraceLimit, &rslt); if ((rslt.HitIds[0]==-1) && (rslt.HitIds[1]==-1) && (rslt.HitIds[2]==-1) && (rslt.HitIds[3]==-1)) MapLinearIntensities(BackgroundColor,dest,dest+1,dest+stride,dest+stride+1); else { // make sure normal points back towards ray origin
fltx4 ndoti=rslt.surface_normal*myrays.direction; fltx4 bad_dirs=AndSIMD(CmpGtSIMD(ndoti,Four_Zeros), LoadAlignedSIMD((float *) signmask));
// flip signs of all "wrong" normals
rslt.surface_normal.x=XorSIMD(bad_dirs,rslt.surface_normal.x); rslt.surface_normal.y=XorSIMD(bad_dirs,rslt.surface_normal.y); rslt.surface_normal.z=XorSIMD(bad_dirs,rslt.surface_normal.z);
FourVectors intens; intens.DuplicateVector(Vector(0,0,0)); // set up colors
FourVectors surf_colors; surf_colors.DuplicateVector(Vector(0,0,0)); for(int i=0;i<4;i++) { if (rslt.HitIds[i]>=0) { surf_colors.X(i)=TriangleColors[rslt.HitIds[i]].x; surf_colors.Y(i)=TriangleColors[rslt.HitIds[i]].y; surf_colors.Z(i)=TriangleColors[rslt.HitIds[i]].z; }
} FourVectors surface_pos=myrays.direction; surface_pos*=rslt.HitDistance; surface_pos+=myrays.origin; switch(lmode) { case DIRECT_LIGHTING: { // light all points
for(int l=0;l<LightList.Count();l++) { LightList[l].ComputeLightAtPoints(surface_pos,rslt.surface_normal, intens); } } break;
case DIRECT_LIGHTING_WITH_SHADOWS: { // light all points
for(int l=0;l<LightList.Count();l++) { FourVectors ldir; ldir.DuplicateVector(LightList[l].m_Position); ldir-=surface_pos; fltx4 MaxT=ldir.length(); ldir.VectorNormalizeFast(); // now, compute shadow flag
//FourRays myrays;
myrays.origin=surface_pos; FourVectors epsilon=ldir; epsilon*=0.01; myrays.origin+=epsilon; myrays.direction=ldir; RayTracingResult shadowtest; Trace4Rays(myrays,Four_Zeros,MaxT, &shadowtest); fltx4 unshadowed=CmpGtSIMD(shadowtest.HitDistance,MaxT); if (! (IsAllZeros(unshadowed))) { FourVectors tmp; tmp.DuplicateVector(Vector(0,0,0)); LightList[l].ComputeLightAtPoints(surface_pos,rslt.surface_normal, tmp); intens.x=AddSIMD(intens.x,AndSIMD(tmp.x,unshadowed)); intens.y=AddSIMD(intens.y,AndSIMD(tmp.y,unshadowed)); intens.z=AddSIMD(intens.z,AndSIMD(tmp.z,unshadowed)); } } } break; } // now, mask off non-hitting pixels
intens.VProduct(surf_colors); fltx4 no_hit_mask=CmpGtSIMD(rslt.HitDistance,TraceLimit); intens.x=OrSIMD(AndSIMD(BackgroundColor.x,no_hit_mask), AndNotSIMD(no_hit_mask,intens.x)); intens.y=OrSIMD(AndSIMD(BackgroundColor.y,no_hit_mask), AndNotSIMD(no_hit_mask,intens.y)); intens.z=OrSIMD(AndSIMD(BackgroundColor.z,no_hit_mask), AndNotSIMD(no_hit_mask,intens.z));
MapLinearIntensities(intens,dest,dest+1,dest+stride,dest+stride+1); } dest+=2; SLoc+=dxvectortimes2; } }}
#define SQ(x) ((x)*(x))
void RayTracingEnvironment::ComputeVirtualLightSources(void){ int start_pos=0; for(int b=0;b<3;b++) { int nl=LightList.Count(); int where_to_start=start_pos; start_pos=nl; for(int l=where_to_start;l<nl;l++) { DirectionalSampler_t sample_generator; int n_desired=1*LightList[l].m_Color.Length(); if (LightList[l].m_Type==MATERIAL_LIGHT_SPOT) n_desired*=LightList[l].m_Phi/2; for(int try1=0;try1<n_desired;try1++) { LightDesc_t const &li=LightList[l]; FourRays myrays; myrays.origin.DuplicateVector(li.m_Position); RayTracingResult rslt; Vector trial_dir=sample_generator.NextValue(); if (li.IsDirectionWithinLightCone(trial_dir)) { myrays.direction.DuplicateVector(trial_dir); Trace4Rays(myrays,all_zeros,ReplicateX4(1000.0), &rslt); if ((rslt.HitIds[0]!=-1)) { // make sure normal points back towards ray origin
fltx4 ndoti=rslt.surface_normal*myrays.direction; fltx4 bad_dirs=AndSIMD(CmpGtSIMD(ndoti,Four_Zeros), LoadAlignedSIMD((float *) signmask)); // flip signs of all "wrong" normals
rslt.surface_normal.x=XorSIMD(bad_dirs,rslt.surface_normal.x); rslt.surface_normal.y=XorSIMD(bad_dirs,rslt.surface_normal.y); rslt.surface_normal.z=XorSIMD(bad_dirs,rslt.surface_normal.z);
// a hit! let's make a virtual light source
// treat the virtual light as a disk with its center at the hit position
// and its radius scaled by the amount of the solid angle this probe
// represents.
float area_of_virtual_light= 4.0*M_PI*SQ( SubFloat( rslt.HitDistance, 0 ) )*(1.0/n_desired);
FourVectors intens; intens.DuplicateVector(Vector(0,0,0));
FourVectors surface_pos=myrays.direction; surface_pos*=rslt.HitDistance; surface_pos+=myrays.origin; FourVectors delta=rslt.surface_normal; delta*=0.1; surface_pos+=delta; LightList[l].ComputeLightAtPoints(surface_pos,rslt.surface_normal, intens); FourVectors surf_colors; surf_colors.DuplicateVector(TriangleColors[rslt.HitIds[0]]); intens*=surf_colors; // see if significant
LightDesc_t l1; l1.m_Type=MATERIAL_LIGHT_SPOT; l1.m_Position=Vector(surface_pos.X(0),surface_pos.Y(0),surface_pos.Z(0)); l1.m_Direction=Vector(rslt.surface_normal.X(0),rslt.surface_normal.Y(0), rslt.surface_normal.Z(0)); l1.m_Color=Vector(intens.X(0),intens.Y(0),intens.Z(0)); if (l1.m_Color.Length()>0) { l1.m_Color*=area_of_virtual_light/M_PI; l1.m_Range=0.0; l1.m_Falloff=1.0; l1.m_Attenuation0=1.0; l1.m_Attenuation1=0.0; l1.m_Attenuation2=1.0; // intens falls off as 1/r^2
l1.m_Theta=0; l1.m_Phi=M_PI; l1.RecalculateDerivedValues(); LightList.AddToTail(l1); } } } } } }}
static unsigned int GetSignMask(Vector const &v){ unsigned int ret=0; if (v.x<0.0) ret++; if (v.y<0) ret+=2; if (v.z<0) ret+=4; return ret;}
inline void RayTracingEnvironment::FlushStreamEntry(RayStream &s,int msk){ assert(msk>=0); assert(msk<8); fltx4 tmax=s.PendingRays[msk].direction.length(); fltx4 scl=ReciprocalSaturateSIMD(tmax); s.PendingRays[msk].direction*=scl; // normalize
RayTracingResult tmpresult; Trace4Rays(s.PendingRays[msk],Four_Zeros,tmax,msk,&tmpresult); // now, write out results
for(int r=0;r<4;r++) { RayTracingSingleResult *out=s.PendingStreamOutputs[msk][r]; out->ray_length=SubFloat( tmax, r ); out->surface_normal.x=tmpresult.surface_normal.X(r); out->surface_normal.y=tmpresult.surface_normal.Y(r); out->surface_normal.z=tmpresult.surface_normal.Z(r); out->HitID=tmpresult.HitIds[r]; out->HitDistance=SubFloat( tmpresult.HitDistance, r ); } s.n_in_stream[msk]=0;}
void RayTracingEnvironment::AddToRayStream(RayStream &s, Vector const &start,Vector const &end, RayTracingSingleResult *rslt_out){ Vector delta=end; delta-=start; int msk=GetSignMask(delta); assert(msk>=0); assert(msk<8); int pos=s.n_in_stream[msk]; assert(pos<4); s.PendingRays[msk].origin.X(pos)=start.x; s.PendingRays[msk].origin.Y(pos)=start.y; s.PendingRays[msk].origin.Z(pos)=start.z; s.PendingRays[msk].direction.X(pos)=delta.x; s.PendingRays[msk].direction.Y(pos)=delta.y; s.PendingRays[msk].direction.Z(pos)=delta.z; s.PendingStreamOutputs[msk][pos]=rslt_out; if (pos==3) { FlushStreamEntry(s,msk); } else s.n_in_stream[msk]++;}
void RayTracingEnvironment::FinishRayStream(RayStream &s){ for(int msk=0;msk<8;msk++) { int cnt=s.n_in_stream[msk]; if (cnt) { // fill in unfilled entries with dups of first
for(int c=cnt;c<4;c++) { s.PendingRays[msk].origin.X(c) = s.PendingRays[msk].origin.X(0); s.PendingRays[msk].origin.Y(c) = s.PendingRays[msk].origin.Y(0); s.PendingRays[msk].origin.Z(c) = s.PendingRays[msk].origin.Z(0); s.PendingRays[msk].direction.X(c) = s.PendingRays[msk].direction.X(0); s.PendingRays[msk].direction.Y(c) = s.PendingRays[msk].direction.Y(0); s.PendingRays[msk].direction.Z(c) = s.PendingRays[msk].direction.Z(0); s.PendingStreamOutputs[msk][c]=s.PendingStreamOutputs[msk][0]; } FlushStreamEntry(s,msk); } }}
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