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//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
//===========================================================================//
#include "tier0/platform.h"
#include <stdio.h>
#include "bitmap/float_bm.h"
#include "mathlib/mathlib.h"
#include "tier2/tier2.h"
#define BRIGHT_THRESH 0.90 // pixels within this % of average are "bright"
#define GROUND_IMPORTANCE 0.2 // weight for downward pointing skymap pixels
float Importance(Vector const &direction)
{
// this returns a scale factor which can be used to recurd the importance of certain
// directions. in particular, this version makes the ground a lot less important than the sky
if (direction.z>.2)
return 1.0;
if (direction.z>0)
return FLerp(1.0,GROUND_IMPORTANCE,.2,0,direction.z);
else
return GROUND_IMPORTANCE;
}
void main(int argc,char **argv)
{
InitCommandLineProgram(argc, argv);
if (argc!=2)
{
printf("format is %s basename\n",argv[0]);
}
else
{
FloatCubeMap_t cmap(argv[1]);
// find the brightest pixel. We will consider the pixels neat this to be the
// ones contrinbuting to the light source
float max_color=cmap.BrightestColor();
float threshhold=max_color*.90;
// now, find average color of non-bright pixels
float sumweights=0.0;
Vector AverageColor(0,0,0);
for(int f=0;f<6;f++)
for(int y=0;y<cmap.face_maps[f].Height;y++)
for(int x=0;x<cmap.face_maps[f].Width;x++)
{
Vector clr(
cmap.face_maps[f].Pixel(x,y,0),
cmap.face_maps[f].Pixel(x,y,1),
cmap.face_maps[f].Pixel(x,y,2));
float mag=clr.Length();
if (mag<threshhold)
{
float weight=Importance(cmap.PixelDirection(f,x,y));
sumweights+=weight;
AverageColor+=weight*clr;
}
}
AverageColor*=(1.0/sumweights);
Vector avg_light_dir(0,0,0);
Vector AverageHue(0,0,0);
// now, find average direction and color of bright pixels
for(int f=0;f<6;f++)
for(int y=0;y<cmap.face_maps[f].Height;y++)
for(int x=0;x<cmap.face_maps[f].Width;x++)
{
Vector clr(
cmap.face_maps[f].Pixel(x,y,0),
cmap.face_maps[f].Pixel(x,y,1),
cmap.face_maps[f].Pixel(x,y,2));
float mag=clr.Length();
if (mag>threshhold)
{
clr-=AverageColor;
AverageHue+=clr;
Vector pdir=cmap.PixelDirection(f,x,y);
pdir*=clr.Length();
avg_light_dir+=pdir;
}
}
VectorNormalize(AverageHue);
VectorNormalize(avg_light_dir);
printf("Point light dir=%f %f %f\n",avg_light_dir.x,avg_light_dir.y,avg_light_dir.z);
// printf("Point light color=%f %f %f\n",AverageHue.x,AverageHue.y,AverageHue.z);
printf("Point light color=%d %d %d 255\n",
( int )( 255 * pow( AverageHue.x, 1.0f / 2.2f ) ),
( int )( 255 * pow( AverageHue.y, 1.0f / 2.2f ) ),
( int )( 255 * pow( AverageHue.z, 1.0f / 2.2f ) ) );
// now, output ambient cube maps for image-based lighting. During this pass, we will also
// correct the ambient color
FloatCubeMap_t conv(32,32);
Vector AmbientColor(0,0,0);
float sumweights_amb=0;
for(int f=0;f<6;f++)
for(int y=0;y<conv.face_maps[f].Height;y++)
for(int x=0;x<conv.face_maps[f].Width;x++)
{
Vector pdir=conv.PixelDirection(f,x,y);
float dot=pdir.Dot(avg_light_dir);
if (dot<0) dot=0;
float sumdot=0;
Vector sumlight(0,0,0);
for(int f1=0;f1<6;f1++)
for(int y1=0;y1<cmap.face_maps[f].Height;y1+=20)
for(int x1=0;x1<cmap.face_maps[f].Width;x1+=20)
{
Vector sdir=cmap.PixelDirection(f1,x1,y1);
float dot_sphere=sdir.Dot(pdir);
if (dot_sphere>0)
{
sumdot+=dot_sphere;
for(int comp=0;comp<3;comp++)
sumlight[comp]+=
dot_sphere*cmap.face_maps[f1].Pixel(x1,y1,comp);
}
}
sumlight*=1.0/sumdot;
// sumlight is the desired lighting
// use our calculated point light source to find the error
float weight=Importance(pdir);
sumweights_amb+=weight;
for(int comp=0;comp<3;comp++)
{
conv.face_maps[f].Pixel(x,y,comp)=sumlight[comp];
AmbientColor[comp]+=weight*(sumlight[comp]-dot*AverageHue[comp]);
}
}
AmbientColor*=1.0/sumweights_amb;
conv.WritePFMs("ambient_cube_");
// printf("Ambient color=%f %f %f\n",AmbientColor.x,AmbientColor.y,AmbientColor.z);
// convert to gamma space. . .
printf("Ambient color=%d %d %d 255\n",
( int )( 255 * pow( AmbientColor.x, 1.0f/2.2f ) ),
( int )( 255 * pow( AmbientColor.y, 1.0f/2.2f ) ),
( int )( 255 * pow( AmbientColor.z, 1.0f/2.2f ) ) );
for(int f=0;f<6;f++)
for(int y=0;y<cmap.face_maps[f].Height;y++)
for(int x=0;x<cmap.face_maps[f].Width;x++)
{
Vector pdir=cmap.PixelDirection(f,x,y);
float dot=pdir.Dot(avg_light_dir);
if (dot<0) dot=0;
dot=pow(dot,7);
for(int comp=0;comp<3;comp++)
cmap.face_maps[f].Pixel(x,y,comp)=AmbientColor[comp]+dot*AverageHue[comp];
}
cmap.WritePFMs("directional_plus_ambient_");
}
}
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