GLSLで魔法陣
glsl#ifdef GL_ES
precision mediump float;
#endif
#extension GL_OES_standard_derivatives : enable
uniform float time;
uniform vec2 mouse;
uniform vec2 resolution;
float circle(float r, float radius, float stroke_width) {
return (abs(r - radius) <= stroke_width) ? 1. : 0.;
}
float line(vec2 p, float y, float stroke_width){
return abs(p.y - y) <= stroke_width ? 1. : 0.;
}
vec2 rotate(vec2 v, float th) {
return vec2(cos(th) * v.x - sin(th) * v.y, sin(th) * v.x + cos(th) * v.y);
}
void main( void ) {
vec2 from_center_x2 = (gl_FragCoord.xy * 2. - resolution);
vec2 p_ = from_center_x2 / min(resolution.y, resolution.x);
vec2 p = rotate(p_, time);
float r = length(p);
float f_inside = 1. - step(1., r);
float f_circle = circle(r, 1.0, 0.02);
float f_lines = 0.;
for(int i = 0; i <3; i++){
f_lines += line(rotate(p, 2. * 3.1415 / 3. * float(i)), 0.5, 0.01);
}
for(int i = 0; i <3; i++){
f_lines += line(rotate(p, 2. * 3.1415 / 3. * (float(i) + .5)), 0.5, 0.01);
}
float addition = f_lines + f_circle;
float multiplication = addition * f_inside;
gl_FragColor=vec4(multiplication);
}
glsl#ifdef GL_ES
precision mediump float;
#endif
#extension GL_OES_standard_derivatives : enable
uniform float time;
uniform vec2 mouse;
uniform vec2 resolution;
float circle(float r, float radius, float stroke_width) {
return (abs(r - radius) <= stroke_width) ? 1. : 0.;
}
float line(vec2 p, float y, float stroke_width){
return abs(p.y - y) <= stroke_width ? 1. : 0.;
}
vec2 rotate(vec2 v, float th) {
return vec2(cos(th) * v.x - sin(th) * v.y, sin(th) * v.x + cos(th) * v.y);
}
float hexagram(vec2 p, vec2 center, float radius, float stroke_width) {
float r = length(p - center);
float f_inside = 1. - step(radius, r);
float f_circle = circle(r, radius, stroke_width * 2.);
float f_lines = 0.;
for(int i = 0; i <3; i++){
f_lines += line(rotate(p, 2. * 3.1415 / 3. * float(i)), radius / 2., stroke_width);
}
for(int i = 0; i <3; i++){
f_lines += line(rotate(p, 2. * 3.1415 / 3. * (float(i) + .5)), radius / 2., stroke_width);
}
float addition = f_lines + f_circle;
float multiplication = addition * f_inside;
return multiplication;
}
void main( void ) {
vec2 from_center_x2 = (gl_FragCoord.xy * 2. - resolution);
vec2 p = from_center_x2 / min(resolution.y, resolution.x);
//vec2 p = rotate(p_, time);
float addition = 0.;
float radius = .8;
float stroke_width = 0.01;
for(int i = 0; i <10; i++){
addition += hexagram(rotate(p, .5 * time * float(i + 1)), vec2(0., 0.), radius, stroke_width);
radius /= 2.;
stroke_width /= 2.;
}
float multiplication = addition * 1.;
gl_FragColor=vec4(multiplication);
}
"Engineer's way of creating knowledge" the English version of my book is now available on [Engineer's way of creating knowledge]
(C)NISHIO Hirokazu / Converted from [Scrapbox] at [Edit]