export default /* glsl */`
uniform sampler2D shadow_pass;
uniform vec2 resolution;
uniform float radius;
#include
void main() {
float mean = 0.0;
float squared_mean = 0.0;
// This seems totally useless but it's a crazy work around for a Adreno compiler bug
float depth = unpackRGBAToDepth( texture2D( shadow_pass, ( gl_FragCoord.xy ) / resolution ) );
for ( float i = -1.0; i < 1.0 ; i += SAMPLE_RATE) {
#ifdef HORIZONAL_PASS
vec2 distribution = unpackRGBATo2Half( texture2D( shadow_pass, ( gl_FragCoord.xy + vec2( i, 0.0 ) * radius ) / resolution ) );
mean += distribution.x;
squared_mean += distribution.y * distribution.y + distribution.x * distribution.x;
#else
float depth = unpackRGBAToDepth( texture2D( shadow_pass, ( gl_FragCoord.xy + vec2( 0.0, i ) * radius ) / resolution ) );
mean += depth;
squared_mean += depth * depth;
#endif
}
mean = mean * HALF_SAMPLE_RATE;
squared_mean = squared_mean * HALF_SAMPLE_RATE;
float std_dev = sqrt( squared_mean - mean * mean );
gl_FragColor = pack2HalfToRGBA( vec2( mean, std_dev ) );
}
`;