source-engine/bitmap/float_cube.cpp
FluorescentCIAAfricanAmerican 3bf9df6b27 1
2020-04-22 12:56:21 -04:00

120 lines
3.1 KiB
C++

//========= Copyright Valve Corporation, All rights reserved. ============//
#include <tier0/platform.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#include "bitmap/float_bm.h"
#include <filesystem.h>
#include <mathlib/vector.h>
static Vector face_xvector[6]={ // direction of x pixels on face
Vector(-1,0,0), // back
Vector(1,0,0), // down
Vector(1,0,0), // front
Vector(0,1,0), // left
Vector(0,-1,0), // right
Vector(1,0,0) // up
};
static Vector face_yvector[6]={ // direction of y pixels on face
Vector(0,0,-1), // back
Vector(0,1,0), // down
Vector(0,0,-1), // front
Vector(0,0,-1), // left
Vector(0,0,-1), // right
Vector(0,-1,0) // up
};
static Vector face_zvector[6]={
Vector(1,1,1), // back
Vector(-1,-1,-1), // down
Vector(-1,-1,1), // front
Vector(1,-1,1), // left
Vector(-1,1,1), // right
Vector(-1,1,1) // up
};
static char const *namepts[6]={"%sbk.pfm","%sdn.pfm","%sft.pfm","%slf.pfm","%srt.pfm","%sup.pfm"};
FloatCubeMap_t::FloatCubeMap_t(char const *basename)
{
for(int f=0;f<6;f++)
{
char fnamebuf[512];
sprintf(fnamebuf,namepts[f],basename);
face_maps[f].LoadFromPFM(fnamebuf);
}
}
void FloatCubeMap_t::WritePFMs(char const *basename)
{
for(int f=0;f<6;f++)
{
char fnamebuf[512];
sprintf(fnamebuf,namepts[f],basename);
face_maps[f].WritePFM(fnamebuf);
}
}
Vector FloatCubeMap_t::PixelDirection(int face, int x, int y)
{
FloatBitMap_t const &bm=face_maps[face];
float xc=x*1.0/(bm.Width-1);
float yc=y*1.0/(bm.Height-1);
Vector dir=2*xc*face_xvector[face]+
2*yc*face_yvector[face]+face_zvector[face];
VectorNormalize(dir);
return dir;
}
Vector FloatCubeMap_t::FaceNormal(int face)
{
float xc=0.5;
float yc=0.5;
Vector dir=2*xc*face_xvector[face]+
2*yc*face_yvector[face]+face_zvector[face];
VectorNormalize(dir);
return dir;
}
void FloatCubeMap_t::Resample( FloatCubeMap_t &out, float flPhongExponent )
{
// terribly slow brute force algorithm just so I can try it out
for(int dface=0;dface<6;dface++)
{
for(int dy=0;dy<out.face_maps[dface].Height;dy++)
for(int dx=0;dx<out.face_maps[dface].Width;dx++)
{
float sum_weights=0;
float sum_rgb[3]={0,0,0};
for(int sface=0;sface<6;sface++)
{
// easy 15% optimization - check if faces point away from each other
if (DotProduct(FaceNormal(sface),FaceNormal(sface))>-0.9)
{
Vector ddir=out.PixelDirection(dface,dx,dy);
for(int sy=0;sy<face_maps[sface].Height;sy++)
for(int sx=0;sx<face_maps[sface].Width;sx++)
{
float dp=DotProduct(ddir,PixelDirection(sface,sx,sy));
if (dp>0.0)
{
dp=pow( dp, flPhongExponent );
sum_weights += dp;
for(int c=0;c<3;c++)
sum_rgb[c] += dp*face_maps[sface].Pixel( sx, sy, c );
}
}
}
}
for(int c=0;c<3;c++)
out.face_maps[dface].Pixel( dx, dy, c )=sum_rgb[c]*(1.0/sum_weights);
}
}
}