module.exports = [
    '#define SHADER_NAME SHADOW_FS',
    '',
    'precision mediump float;',
    '',
    'uniform sampler2D uMainSampler;',
    'uniform vec2 lightPosition;',
    'uniform vec4 shadowColor;',
    'uniform float decay;',
    'uniform float power;',
    'uniform float intensity;',
    '',
    'varying vec2 outTexCoord;',
    '',
    'const int SAMPLES = __SAMPLES__;',
    '',
    'void main ()',
    '{',
    '    vec4 texture = texture2D(uMainSampler, outTexCoord);',
    '',
    '    vec2 pc = (lightPosition - outTexCoord) * intensity;',
    '',
    '    float shadow = 0.0;',
    '',
    '    for (int i = 0; i < SAMPLES; ++i)',
    '    {',
    '        shadow += texture2D(uMainSampler, outTexCoord + float(i) * decay / float(SAMPLES) * pc).a * power;',
    '    }',
    '',
    '    float mask = 1.0 - texture.a;',
    '',
    '    gl_FragColor = mix(texture, shadowColor, shadow * mask);',
    '}',
    ''
].join('\n');