demotool/shaders/bloom-highpass.glsl

#version 450 core

layout( location = 0 ) uniform sampler2D u_Input;
layout( location = 1 ) uniform int u_LOD;
layout( location = 2 ) uniform vec2 u_InputSize;
layout( location = 3 ) uniform vec3 u_FilterParams;

layout( location = 0 ) out vec3 color;


void main( void )
{
	vec3 c = textureLod( u_Input , gl_FragCoord.xy / u_InputSize.xy , u_LOD ).xyz;
	color = max( vec3(0) , ( pow( c , vec3( u_FilterParams.x ) ) * u_FilterParams.y - c ) / u_FilterParams.z );
}