74 lines
2.2 KiB
GLSL
74 lines
2.2 KiB
GLSL
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#ifdef GL_ES
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precision mediump float;
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#endif
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#ifdef GLSLVIEWER
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uniform float u_time;
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uniform vec2 u_resolution;
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#endif
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#ifndef GLSLVIEWER
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uniform float time;
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uniform vec2 resolution;
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#endif
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// Control variables
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const float scale_factor = 0.55;
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const float squish_factor = 3.0;
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const float time_factor = -0.025;
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const float dim_factor = 0.2;
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vec4 simpleAlphaCompositing (vec4 source, vec4 backdrop) {
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float final_alpha = source.a + backdrop.a * (1.0 - source.a);
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return vec4(
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(source.rgb * source.a + backdrop.rgb * backdrop.a * (1.0 - source.a)) / final_alpha,
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final_alpha
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);
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}
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vec4 getColor(vec4 input_color, float speed, float freq, float amp, vec2 uv, float phase_offset) {
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#ifdef GLSLVIEWER
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float time = u_time;
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#endif
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float y = uv.y + (time * time_factor * speed);
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float d = uv.x - amp * scale_factor * sin(phase_offset + y * squish_factor * freq);
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float value = clamp((0.01 / (d * d)) * dim_factor, 0.0, 1.0);
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input_color.a = value;
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return input_color;
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}
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void main( void ) {
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#ifdef GLSLVIEWER
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float time = u_time;
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vec2 resolution = u_resolution;
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#endif
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vec2 uv = (gl_FragCoord.xy * 2. - resolution) / resolution.y;
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float tmp_x = uv.x;
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float tmp_y = uv.y;
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uv.x = tmp_y;
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uv.y = tmp_x;
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vec4 background = vec4((24.0/255.0), (73.0/255.0), (86.0/255.0), 0.0);
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vec4 colors[3];
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colors[0] = vec4((250.0/255.0), (87.0/255.0), (80.0/255.0), 0.0);
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colors[1] = vec4((117.0/255.0),(185.0/255.0),(56.0/255.0), 0.0);
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colors[2] = vec4((70.0/255.0),(149.0/255.0),(247.0/255.0),0.0);
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// Relative travel speeds
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vec3 speeds = vec3(1.0, 1.2, 0.8);
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// Relative frequency
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vec3 freqs = vec3(1.0, 1.2, 0.8);
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// Relative amplitude
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vec3 amps = vec3(1.0, 1.5, 0.5);
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// Generate the color maps
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for (int i = 0; i < 3; i++) {
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colors[i] = getColor(colors[i], speeds[i], freqs[i], amps[i], uv, 0.0);
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background.a += colors[i].a;
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}
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// Mix the colors
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background.a = 1.0 - clamp(background.a, 0.0, 1.0);
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vec4 color = simpleAlphaCompositing(colors[0], vec4(0.0, 0.0, 0.0, 1.0));
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color = simpleAlphaCompositing(colors[1], color);
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color = simpleAlphaCompositing(colors[2], color);
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vec4 result = simpleAlphaCompositing(background, color);
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gl_FragColor = result;
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}
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