glow.frag.glsl.ecr

#version 130

uniform sampler2D source;

in vec2 tex_coords;
out vec4 frag_color;

void main() {
  ivec2 coord = ivec2(vec2(textureSize(source, 0)) * tex_coords);

  vec3 result = vec3(0, 0, 0);
  float a = 0;
  vec4 px;
  float result_malpha = 0;
  float result_max = 0;
  <%- (-glow_resolution..glow_resolution).each do |i| -%>
    <%- m = gauss(i) / gauss(-glow_resolution, glow_resolution) * glow_intensity -%>
    px = texelFetch(source, coord + ivec2(<%= horizontal ? i : 0 %>, <%= horizontal ? 0 : i %>), 0);
    result += px.rgb * px.a * <%= m %>;
    result_malpha += px.a * <%= m %>;
    result_max += <%= m %>;
    a += px.a * <%= m %>;
  <%- end -%>
  frag_color = vec4(result / result_malpha * result_max, a);
}

use.cr

    glow_resolution = (resolution * (GlowTarget.size.x + GlowTarget.size.y) / 3000).to_i
    glow_intensity = intensity
    horizontal = false
    GlowShader::Shader1.load_from_memory({{read_file("base.vert.glsl")}}, ECR.render("glow.frag.glsl.ecr"))
    horizontal = true
    GlowShader::Shader2.load_from_memory({{read_file("base.vert.glsl")}}, ECR.render("glow.frag.glsl.ecr"))