18 lines
467 B
GLSL
18 lines
467 B
GLSL
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precision mediump float;
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varying vec2 v_texcoord;
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uniform vec2 half_size;
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uniform vec2 position;
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uniform float radius;
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void main() {
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vec2 q = abs(gl_FragCoord.xy - position - half_size) - half_size + radius;
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float dist = min(max(q.x,q.y), 0.0) + length(max(q, 0.0)) - radius;
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float smoothedAlpha = 1.0 - smoothstep(-1.0, 0.5, dist);
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gl_FragColor = mix(vec4(0.0), vec4(1.0), smoothedAlpha);
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if (gl_FragColor.a == 0.0) {
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discard;
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}
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}
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