bgfx/examples/18-ibl/fs_ibl_skybox.sc

46 lines
1,017 B
Scala

$input v_dir
/*
* Copyright 2014-2016 Dario Manesku. All rights reserved.
* License: https://github.com/bkaradzic/bgfx#license-bsd-2-clause
*/
#include "../common/common.sh"
#include "uniforms.sh"
SAMPLERCUBE(s_texCube, 0);
SAMPLERCUBE(s_texCubeIrr, 1);
// Ref: http://the-witness.net/news/2012/02/seamless-cube-map-filtering/
vec3 fixCubeLookup(vec3 _v, float _lod, float _topLevelCubeSize)
{
float ax = abs(_v.x);
float ay = abs(_v.y);
float az = abs(_v.z);
float vmax = max(max(ax, ay), az);
float scale = 1.0 - exp2(_lod) / _topLevelCubeSize;
if (ax != vmax) { _v.x *= scale; }
if (ay != vmax) { _v.y *= scale; }
if (az != vmax) { _v.z *= scale; }
return _v;
}
void main()
{
vec3 dir = normalize(v_dir);
vec4 color;
if (u_bgType == 7.0)
{
color = toLinear(textureCube(s_texCubeIrr, dir));
}
else
{
float lod = u_bgType;
dir = fixCubeLookup(dir, lod, 256.0);
color = toLinear(textureCubeLod(s_texCube, dir, lod));
}
color *= exp2(u_exposure);
gl_FragColor = toFilmic(color);
}