46 lines
1.2 KiB
GLSL
46 lines
1.2 KiB
GLSL
#ifdef GLES
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precision mediump float;
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#endif
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uniform mat4 u_mvp;
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uniform float u_phase;
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uniform float u_scale;
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attribute vec2 a_pos;
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varying vec2 v_tex;
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void main() {
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gl_Position = u_mvp * vec4(a_pos * u_scale * u_phase, 0.0, 1.0);
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v_tex = a_pos;
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}
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$$
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#ifdef GLES
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precision mediump float;
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#endif
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varying vec2 v_tex;
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uniform float u_scale;
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uniform float u_phase;
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uniform vec2 u_dir;
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uniform int u_mode;
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void main() {
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float len = 1.0 - length(v_tex);
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if (u_mode == -1) {
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gl_FragColor = vec4(0.2, 0.2, 0.8, 1.0) * len;
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} else {
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// outer ring
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float a = smoothstep(0.0, 2.0 / u_scale, len);
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// inner ring
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float b = 0.8 * smoothstep(3.0 / u_scale, 4.0 / u_scale, len);
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// center point
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float c = 0.5 * (1.0 - smoothstep(14.0 / u_scale, 16.0 / u_scale, 1.0 - len));
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vec2 dir = normalize(v_tex);
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float d = dot(dir, u_dir);
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// 0.5 width of viewshed
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d = clamp(smoothstep(0.7, 0.7 + 2.0 / u_scale, d) * len, 0.0, 1.0);
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// - subtract inner from outer to create the outline
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// - multiply by viewshed
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// - add center point
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a = max(d, (a - (b + c)) + c) + (u_mode == 2 ? c : 0);
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gl_FragColor = vec4(0.2, 0.2, 0.8, 1.0) * a;
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}
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}
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