想用shader画一些曲线图，网上搜了下画曲线图有些算法的，谁能说下大致有哪些算法？和参考书
比如画出如下图这种效果的曲线图，用的是什么算法？
主要代码：
`mat2 rotate2d(float angle){
return mat2(cos(angle),-sin(angle),
sin(angle),cos(angle));
}
float variation(vec2 v1, vec2 v2, float strength, float speed) {
return sin(
dot(normalize(v1), normalize(v2)) * strength + time * speed
) / 100.0;
}
vec3 paintCircle (vec2 uv, vec2 center, float rad, float width) {
vec2 diff = center-uv;
float len = length(diff);
len += variation(diff, vec2(0.0, 1.0), 5.0, 2.0);
len -= variation(diff, vec2(1.0, 0.0), 5.0, 2.0);
float circle = smoothstep(rad-width, rad, len) - smoothstep(rad, rad+width, len);
return vec3(circle);
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
vec4 myC = texture2D(CC_Texture0, v_texCoord);
// 移植需要转换坐标 v_texCoord.xy
// vec2 uv = fragCoord.xy / iResolution.xy;
vec2 uv = v_texCoord.xy;
uv.x *= 1.5;
uv.x -= 0.25;
vec3 color;
float radius = 0.35;
vec2 center = vec2(0.5);
//paint color circle
color = paintCircle(uv, center, radius, 0.1);
//color with gradient
vec2 v = rotate2d(time) * uv;
color *= vec3(v.x, v.y, 0.7-v.y*v.x);
//paint white circle
color += paintCircle(uv, center, radius, 0.01);
float al = 1.;
// if(color.r + color.g + color.b == 0.){
// al = 0.;
// }
fragColor = vec4(color, al);
}
void main()
{
mainImage(gl_FragColor, gl_FragCoord.xy);
}`