drawLines = reglLines(regl, {
vert: `
precision highp float;
#pragma lines: attribute vec4 xyt;
#pragma lines: position = getPosition(xyt);
#pragma lines: varying vec2 phase = getPhase(xyt);
uniform float dt0, time;
uniform mat4 viewInverse, view;
${cylinderFlow}
const int n = 10;
vec4 getPosition(vec4 xyt) {
if (xyt.z < -5.0) return vec4(0);
vec2 state = (viewInverse * vec4(xyt.xy, 0, 1)).xy;
if (dot(state, state) < 1.0) return vec4(0);
float dt = dt0 * xyt.z / float(n - 1);
float t0 = 0.0;
for (int i = 0; i < n; i++) {
vec2 deriv = derivative(state.xy, t0);
vec2 xyHalf = state + (dt * 0.5) * normalize(deriv);
deriv = derivative(xyHalf.xy, t0 + dt * 0.5);
state += dt * normalize(deriv);
}
return view * vec4(state, 0, 1);
}
vec2 getPhase(vec4 xyt) {
return vec2(
xyt.z,
xyt.w
);
}
#pragma lines: varying vec3 s = getS(xyt);
vec3 getS(vec4 xyt) {
vec3 state = vec3((viewInverse * vec4(xyt.xy, 0, 1)).xy, 0);
float dt = dt0 * xyt.z / float(n - 1);
float t0 = 0.0;
float v0 = length(derivative(state.xy, t0));
for (int i = 0; i < n; i++) {
vec2 deriv = derivative(state.xy, t0);
vec3 xyHalf = state + (dt * 0.5) * vec3(normalize(deriv), 1.0 / length(deriv));
deriv = derivative(xyHalf.xy, t0 + dt * 0.5);
state += dt * vec3(normalize(deriv), 1.0 / length(deriv));
}
return vec3(state.z, v0, length(derivative(state.xy, t0)));
}
#pragma lines: width = getWidth();
uniform float width;
float getWidth() {
return width;
}`,
frag: `
precision highp float;
uniform float time, fade, speed, position, freq, texture, stripes;
uniform sampler2D colorscale;
varying vec2 phase;
varying vec3 s;
#define PI ${Math.PI}
void main () {
float alpha = 1.0 - fade * phase.x * phase.x;
float norm = ${~opts.indexOf("normalize") ? "s.y" : "1.0"};
float stripe = 0.15 * stripes * sin((2.0 * PI) * (phase.y + freq * (norm * (s.x * 7.0 - position))));
float colorBase = (0.3 + 0.07 * s.z) + (phase.y - 0.5) * texture;
//float colorBase = (0.3 + 0.07 * s.z) + (sin(2.0 * PI * phase.y + 32.0 * time)) * texture;
gl_FragColor = texture2D(colorscale, vec2(colorBase + stripe, 0.5));
gl_FragColor.a *= alpha;
}`,
uniforms: {
alpha: regl.prop("alpha"),
beta: regl.prop("beta"),
gamma: regl.prop("gamma"),
delta: regl.prop("delta"),
colorscale: regl.prop("colorscale.texture"),
width: ({ pixelRatio }, { lineWidth }) => pixelRatio * lineWidth,
time: ({ time }, { animate }) => (animate ? time : 0),
dt0: regl.prop("dt"),
fade: regl.prop("fade"),
texture: regl.prop("texture"),
stripes: regl.prop("stripes"),
speed: regl.prop("speed"),
position: regl.prop("position"),
freq: regl.prop("freq")
},
blend: {
enable: true,
func: {
srcRGB: "src alpha",
srcAlpha: 1,
dstRGB: "one minus src alpha",
dstAlpha: 1
},
equation: {
rgb: "add",
alpha: "add"
}
},
depth: { enable: false }
})
One platform to build and deploy the best data apps
Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.