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https://github.com/3b1b/manim.git
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115 lines
No EOL
2.7 KiB
GLSL
115 lines
No EOL
2.7 KiB
GLSL
#version 330
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uniform vec3 light_source_position;
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uniform float gloss;
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uniform float shadow;
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uniform float focal_distance;
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uniform vec4 color0;
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uniform vec4 color1;
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uniform vec4 color2;
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uniform vec2 root0;
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uniform vec2 root1;
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// uniform vec2 coef0;
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// uniform vec2 coef1;
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// uniform vec2 coef2;
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// uniform vec2 coef3;
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uniform vec2 z0;
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uniform float n_roots;
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uniform float n_steps;
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uniform float julia_highlight;
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uniform float color_mult;
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uniform vec2 frame_shape;
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in vec3 xyz_coords;
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out vec4 frag_color;
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#INSERT finalize_color.glsl
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#INSERT complex_functions.glsl
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const int MAX_DEGREE = 3;
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vec2 poly(vec2 z, vec2[MAX_DEGREE + 1] coefs){
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vec2 result = vec2(0.0);
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for(int n = 0; n < int(n_roots) + 1; n++){
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result += complex_mult(coefs[n], complex_pow(z, n));
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}
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return result;
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}
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vec2 dpoly(vec2 z, vec2[MAX_DEGREE + 1] coefs){
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vec2 result = vec2(0.0);
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for(int n = 1; n < int(n_roots) + 1; n++){
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result += n * complex_mult(coefs[n], complex_pow(z, n - 1));
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}
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return result;
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}
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vec2 seek_root(vec2 z, vec2[MAX_DEGREE + 1] coefs, int max_steps, out float n_iters){
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float last_len;
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float curr_len;
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float threshold = 1e-3;
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for(int i = 0; i < max_steps; i++){
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last_len = curr_len;
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n_iters = float(i);
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vec2 step = complex_div(poly(z, coefs), dpoly(z, coefs));
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curr_len = length(step);
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if(curr_len < threshold){
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break;
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}
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z = z - step;
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}
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n_iters -= clamp((threshold - curr_len) / (last_len - curr_len), 0.0, 1.0);
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return z;
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}
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void main() {
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vec2 root2 = xyz_coords.xy;
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vec2 coef0 = -complex_mult(complex_mult(root0, root1), root2);
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vec2 coef1 = complex_mult(root0, root1) + complex_mult(root0, root2) + complex_mult(root1, root2);
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vec2 coef2 = -(root0 + root1 + root2);
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vec2 coef3 = vec2(1.0, 0.0);
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vec2[MAX_DEGREE + 1] coefs = vec2[MAX_DEGREE + 1](coef0, coef1, coef2, coef3);
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vec2[MAX_DEGREE] roots = vec2[MAX_DEGREE](root0, root1, root2);
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vec4[MAX_DEGREE] colors = vec4[MAX_DEGREE](color0, color1, color2);
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// vec2 z = z0;
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vec2 z = -coef2 / 3.0;
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float n_iters;
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vec2 found_root = seek_root(z, coefs, int(n_steps), n_iters);
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vec4 color = vec4(0.0);
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float min_dist = 1e10;
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float dist;
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for(int i = 0; i < int(n_roots); i++){
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dist = distance(roots[i], found_root);
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if(dist < min_dist){
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min_dist = dist;
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color = colors[i];
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}
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}
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// color *= (1.0 + (color_mult - 1) * (n_iters - 5));
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if (min_dist > 1e-2){
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color = vec4(0.0, 0.0, 0.0, 1.0);
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}
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frag_color = finalize_color(
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color,
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xyz_coords,
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vec3(0.0, 0.0, 1.0),
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light_source_position,
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gloss,
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shadow
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);
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} |