flutter_elinux/shaders/triangleRotation.frag
2024-03-09 14:29:48 +01:00

58 lines
1.5 KiB
GLSL

#version 460 core
#include <flutter/runtime_effect.glsl>
uniform vec2 uSize;
uniform float iTime;
vec2 iResolution;
out vec4 fragColor;
#define PI 3.1415926535897932384626433832795
#define TWO_PI 6.28318530718
#define SCALE_FACTOR 8
#define TIME_SCALE 0.005
mat2 rotate2d(float _angle){
return mat2(cos(_angle),-sin(_angle),
sin(_angle),cos(_angle));
}
void main(void) {
iResolution = uSize;
vec2 fragCoord = gl_FragCoord.xy; // Get the fragment coordinates
vec2 center = 2.0 * vec2(fragCoord.xy - 0.5 * iResolution.xy) / iResolution.y;
// Normalized pixel coordinates (from 0 to 1)
vec2 uv = fragCoord/iResolution.xy;
uv = uv * 2.0 - vec2(1.0);
uv.y *= iResolution.y/iResolution.x;
vec2 pos = vec2(0.) - uv;
//pos += vec2(cos(iTime) - 0.04,sin(iTime)-0.04);
mat2 rotation = rotate2d(PI/2. * float(iTime/2));
pos = rotation * pos;
float len = length(pos);
float angle = atan(pos.x,pos.y);
float r = TWO_PI/float(3);
float d = cos(floor(.5+angle/r)*r-angle)*length(pos);
// Time varying pixel color
vec3 col = vec3(0.0);
col.g += (1.0 - step(0.2,d));
// Output to screen
fragColor = vec4(col,1.0);
// Triangle logic (adjust for size and position)
// if (center.y > -0.1 && // Smaller bound on the bottom
// center.x > -sqrt(1.0) * center.y - 0.001 && // Smaller bound on the left
// center.x < sqrt(1.0) * center.y + 0.1) { // Smaller bound on the right
// fragColor = vec4(1.0, 0.5, 0.2, 1.0);
// }
}