324 lines
9.8 KiB
Text
324 lines
9.8 KiB
Text
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/* BTW: You can use ANY function as the noise/plasma function
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* It just needs to return a float in the range 0.0 - 17.0
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* But shouldn't return 0.0 or 17.0 (they're exclusive bounds).
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* View this shader on shadertoy: https://www.shadertoy.com/view/t3tSRj#
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*/
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// is highp wasteful for this shader?
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#ifdef GL_ES
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# ifdef GL_FRAGMENT_PRECISION_HIGH
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precision highp float;
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# else
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precision mediump float;
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# endif
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#endif
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uniform float u_time;
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uniform vec2 u_resolution;
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/* ==== Text Colouring ==== */
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#define PHOSPHOR_COL vec4(196./255., 167./255., 231./255., 1.)
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// #define BG_COL vec4(0.2, 0.0, 0.2, 0.5)
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#define BG_COL vec4(14./255., 13./255., 20./255., 1.)
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/* ======= Text Size ======= */
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#define FONT_SIZE vec2(10.,20.)
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#define ROWCOLS vec2(80., 24.)
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// ===================================================================
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// Library Functions
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//
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float rand (in vec2 _st) {
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return fract(sin(dot(_st.xy, vec2(12.9898,78.233))) * 43758.5453123);
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}
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float quantise(float val, float n) {
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return clamp(floor(val * n), 0.0, n) / n;
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}
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float roundSquare(vec2 p, vec2 b, float r) {
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return length(max(abs(p)-b,0.0))-r;
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}
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// ===================================================================
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// VT220 Font Rendering
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// Author/Source : https://www.shadertoy.com/view/llSXDV
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//
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#define l(y,a,b) roundLine(p, vec2(float(a), float(y)), vec2(float(b), float(y)))
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float roundLine(vec2 p, vec2 a, vec2 b) {
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b -= a + vec2(1.0,0.);
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p -= a;
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float f = length(p-clamp(dot(p,b)/dot(b,b),0.0,1.0)*b);
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if (u_resolution.y < 320.) // attempt to get rid of aliasing on small resolution
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return smoothstep(1.0, 0.9, f);
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else if (u_resolution.y < 720.)
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return smoothstep(0.75, 0.5, f);
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else
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return smoothstep(1., 0., f);
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}
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float vt220Font(vec2 p, float c) {
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if (c < 1.) return 0.;
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if (p.y > 16.) {
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if (c > 2.) return 0.0;
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if (c > 1.) return l(17,1,9);
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}
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if (p.y > 14.) {
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if (c > 16.) return l(15,3,8);
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if (c > 15.) return l(15,1,8);
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if (c > 14.) return l(15,1,3)+ l(15,7,9);
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if (c > 13.) return l(15,2,8);
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if (c > 12.) return l(15,1,9);
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if (c > 11.) return l(15,2,8);
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if (c > 10.) return l(15,1,3)+ l(15,6,8);
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if (c > 9.) return l(15,4,6);
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if (c > 8.) return l(15,2,4)+ l(15,5,7);
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if (c > 7.) return l(15,2,8);
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if (c > 6.) return l(15,2,8);
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if (c > 5.) return l(15,2,8);
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if (c > 4.) return l(15,2,9);
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if (c > 3.) return l(15,1,8);
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if (c > 2.) return l(15,2,9);
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}
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if (p.y > 12.) {
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if (c > 16.) return l(13,2,4)+ l(13,7,9);
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if (c > 15.) return l(13,2,4)+ l(13,7,9);
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if (c > 14.) return l(13,1,3)+ l(13,7,9);
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if (c > 13.) return l(13,1,3)+ l(13,7,9);
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if (c > 12.) return l(13,1,3);
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if (c > 11.) return l(13,4,6);
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if (c > 10.) return l(13,2,4)+ l(13,5,9);
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if (c > 9.) return l(13,2,8);
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if (c > 8.) return l(13,2,4)+ l(13,5,7);
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if (c > 7.) return l(13,1,3)+ l(13,7,9);
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if (c > 6.) return l(13,1,3)+ l(13,7,9);
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if (c > 5.) return l(13,1,3)+ l(13,7,9);
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if (c > 4.) return l(13,1,3)+ l(15,2,9);
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if (c > 3.) return l(13,1,4)+ l(13,7,9);
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if (c > 2.) return l(13,1,3)+ l(13,6,9);
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}
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if (p.y > 10.) {
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if (c > 16.) return l(11,1,3);
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if (c > 15.) return l(11,2,4)+ l(11,7,9);
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if (c > 14.) return l(11,1,9);
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if (c > 13.) return l(11,7,9);
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if (c > 12.) return l(11,2,5);
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if (c > 11.) return l(11,4,6);
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if (c > 10.) return l(11,3,5)+ l(11,6,8);
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if (c > 9.) return l(11,4,6)+ l(11,7,9);
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if (c > 8.) return l(11,1,8);
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if (c > 7.) return l(11,1,3)+ l(11,7,9);
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if (c > 6.) return l(11,1,3)+ l(11,7,9);
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if (c > 5.) return l(11,1,3)+ l(11,7,9);
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if (c > 4.) return l(11,1,3);
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if (c > 3.) return l(11,1,3)+ l(11,7,9);
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if (c > 2.) return l(11,2,9);
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}
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if (p.y > 8.) {
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if (c > 16.) return l(9,1,3);
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if (c > 15.) return l(9,2,8);
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if (c > 14.) return l(9,1,3)+ l(9,7,9);
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if (c > 13.) return l(9,4,8);
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if (c > 12.) return l(9,4,8);
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if (c > 11.) return l(9,4,6);
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if (c > 10.) return l(9,4,6);
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if (c > 9.) return l(9,2,8);
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if (c > 8.) return l(9,2,4)+ l(9,5,7);
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if (c > 7.) return l(9,1,3)+ l(9,7,9);
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if (c > 6.) return l(9,1,3)+ l(9,7,9);
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if (c > 5.) return l(9,1,3)+ l(9,7,9);
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if (c > 4.) return l(9,1,3)+ l(9,7,9);
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if (c > 3.) return l(9,1,4)+ l(9,7,9);
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if (c > 2.) return l(9,7,9);
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}
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if (p.y > 6.) {
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if (c > 16.) return l(7,1,3);
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if (c > 15.) return l(7,2,4)+ l(7,7,9);
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if (c > 14.) return l(7,2,4)+ l(7,6,8);
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if (c > 13.) return l(7,5,7);
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if (c > 12.) return l(7,7,9);
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if (c > 11.) return l(7,2,6);
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if (c > 10.) return l(7,2,4)+ l(7,5,7);
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if (c > 9.) return l(7,1,3)+ l(7,4,6);
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if (c > 8.) return l(7,1,8);
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if (c > 7.) return l(7,2,8);
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if (c > 6.) return l(7,2,8);
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if (c > 5.) return l(7,2,8);
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if (c > 4.) return l(7,2,8);
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if (c > 3.) return l(7,1,8);
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if (c > 2.) return l(7,2,8);
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}
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if (p.y > 4.) {
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if (c > 16.) return l(5,2,4)+ l(5,7,9);
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if (c > 15.) return l(5,2,4)+ l(5,7,9);
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if (c > 14.) return l(5,3,7);
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if (c > 13.) return l(5,6,8);
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if (c > 12.) return l(5,1,3)+ l(5,7,9);
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if (c > 11.) return l(5,3,6);
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if (c > 10.) return l(5,1,5)+ l(5,6,8);
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if (c > 9.) return l(5,2,8);
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if (c > 8.) return l(5,2,4)+ l(5,5,7);
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if (c > 7.) return 0.;
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if (c > 6.) return 0.;
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if (c > 5.) return 0.;
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if (c > 4.) return 0.;
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if (c > 3.) return l(5,1,3);
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if (c > 2.) return 0.;
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}
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if (p.y > 2.) {
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if (c > 16.) return l(3,3,8);
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if (c > 15.) return l(3,1,8);
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if (c > 14.) return l(3,4,6);
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if (c > 13.) return l(3,1,9);
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if (c > 12.) return l(3,2,8);
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if (c > 11.) return l(3,4,6);
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if (c > 10.) return l(3,2,4)+ l(3,7,9);
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if (c > 9.) return l(3,4,6);
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if (c > 8.) return l(3,2,4)+ l(3,5,7);
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if (c > 7.) return l(3,2,4)+ l(3,6,8);
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if (c > 6.) return l(3,1,3)+ l(3,4,7);
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if (c > 5.) return l(3,2,4)+ l(3,6,8);
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if (c > 4.) return 0.;
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if (c > 3.) return l(3,1,3);
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if (c > 2.) return 0.;
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}
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else {
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if (c > 7.) return 0.;
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if (c > 6.) return l(1,2,5)+ l(1,6,8);
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}
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return 0.0;
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}
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// ===================================================================
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// Text Effects
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// textLines(...) is for simulating the writing of random characters in line formats
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// https://www.shadertoy.com/view/llSXDV (same author as VT220 font rendering)
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//
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float textLines(vec2 uvG) {
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float wt = 5. * (u_time + 0.5*sin(u_time*1.4) + 0.2*sin(u_time*2.9)); // wobbly time
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vec2 uvGt = uvG + vec2(0., floor(wt));
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float ll = rand(vec2(uvGt.y, - 1.)) * ROWCOLS.x; // line length
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if (uvG.y > ROWCOLS.y - 2.){
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if (ceil(uvG.x) == floor(min(ll, fract(wt)*ROWCOLS.x)))
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return 2.;
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if (ceil(uvG.x) > floor(min(ll, fract(wt)*ROWCOLS.x)))
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return 0.;
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}
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if (uvGt.x > 5. && rand(uvGt) < .075)
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return 0.;
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if (max(5., uvGt.x) > ll)
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return 0.;
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return rand(uvGt)*15. + 2.;
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}
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// ===================================================================
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// Noise Generation Algorithms
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// noise(...) is for the main noise generation algorithm (very tunable)
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// https://www.shadertoy.com/view/MsdGWn
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//
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// Based on Morgan McGuire @morgan3d
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// https://www.shadertoy.com/view/4dS3Wd
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float noise (in vec2 _st) {
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vec2 i = floor(_st);
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vec2 f = fract(_st);
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// Four corners in 2D of a tile
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float a = rand(i);
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float b = rand(i + vec2(1.0, 0.0));
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float c = rand(i + vec2(0.0, 1.0));
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float d = rand(i + vec2(1.0, 1.0));
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vec2 u = f * f * (3.0 - 2.0 * f);
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return mix(a, b, u.x) +
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(c - a)* u.y * (1.0 - u.x) +
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(d - b) * u.x * u.y;
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}
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#define NUM_OCTAVES 100
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// Brightness (0.0 - 1.0)
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#define BRIGHTNESS 0.55
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#define LACUNARITY 2.0
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#define GAIN 0.5
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#define SHIFT 100.0
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// VAR_THETA defines whether to compute
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// sin/cos values at runtime or
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#define VAR_THETA 0
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#define THETA 0.5
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#if (VAR_THETA == 1)
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#endif
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float fbm( in vec2 _st) {
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float v = 0.0;
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float a = BRIGHTNESS;
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// Rotate to reduce axial bias
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mat2 T = LACUNARITY * mat2(cos(THETA), sin(THETA),
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-sin(THETA), cos(THETA));
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for (int i = 0; i < NUM_OCTAVES; ++i) {
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_st = T * _st + SHIFT;
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v += noise(_st) * a;
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a *= GAIN;
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}
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return v;
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}
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#define SCALE_UV 3.
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#define SCALE_TIME 1.
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// XXX: TODO: use two shaders, the first on a MUCH lower resolution (one pixel for each text character)
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// XXX: TODO: then the second should map those pixel values to higher resolution text characters
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void main() {
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vec2 uv = gl_FragCoord.xy / u_resolution;
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vec2 st = uv * SCALE;
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// // uvNoise = ceil(uvNoise * ROWCOLS) / ROWCOLS;
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// float val = noise(st);
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// // Noise is fed through a sigmoid function, then quantised to integer range 0-17
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// val = (exp(val) / 2.71828); // increase contrast (normalised 0.0 - 1.0)
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// val = 1.0 / val;
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// val *= 1.0 / (1.0 + exp(-val)) - 0.5; // subtraction value is tunable (range 0.0 - 0.5)
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// val *= quantise(val, 17.0); // quantise by 17 then normalise back to 0.0 - 1.0
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// val = pow(18.0, val) - 1.0; // TODO: try changing 18.0 to 200.0 and you'll notice some pretty changes :)
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// // VT220 Font Rendering
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// vec2 base = uv;
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// base.y = 1 - base.y;
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// vec2 uvT = ROWCOLS * FONT_SIZE * base;
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// vec2 uvG = floor(ROWCOLS * base;
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// gl_FragColor = vt220Font(uvT - uvG * FONT_SIZE, val) * PHOSPHOR_COL + BG_COL;
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vec2 q = vec2(
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fbm( st + 0.*u_time),
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fbm( st + vec2(1.0))
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);
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vec2 r = vec2(
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fbm( st + 1.0*q + vec2(1.7,9.2)+ 0.15*u_time ),
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fbm( st + 1.0*q + vec2(8.3,2.8)+ 0.126*u_time)
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);
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float f = fbm(st+r);
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vec3 color = mix(vec3(0.101961,0.619608,0.666667),
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vec3(0.666667,0.666667,0.498039),
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|
|
clamp((f*f)*4.0,0.0,1.0));
|
||
|
|
|
||
|
|
color = mix(color,
|
||
|
|
vec3(0,0,0.164706),
|
||
|
|
clamp(length(q),0.0,1.0));
|
||
|
|
|
||
|
|
color = mix(color,
|
||
|
|
vec3(0.666667,1,1),
|
||
|
|
clamp(length(r.x),0.0,1.0));
|
||
|
|
|
||
|
|
gl_FragColor = vec4((f*f*f+.6*f*f+.5*f)*color,1.);
|
||
|
|
}
|
||
|
|
|