Hi guys!
I am learning something about the shader. I try to convert the code from shadertoy to processing, but it seems that everything is ok but it runs without any effect. Can anyone give some suggestions?
This is processing code!
PShader Shrtoy;
void setup() {
size(640,360,P3D);
//noStroke();
Shrtoy = loadShader("ShrtoyFrag.glsl");
Shrtoy.set("iResolution", float(width), float(height));
}
void draw() {
background(0);
Shrtoy.set("iMouse", float(mouseX), float(mouseY));
Shrtoy.set("iTime", millis() / 1000.0);
println(millis() / 1000.0);
shader(Shrtoy);
rect(0, 0, width, height);
//resetShader();
}
Shadertoy code!
“ShrtoyFrag.glsl”
#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif
uniform vec2 iResolution;
#define PROCESSING_COLOR_SHADER
uniform float iTime; // image/sound/buffer Current time in seconds
uniform vec4 iMouse; // image/buffer xy = current pixel coords (if LMB is down). zw = click pixel
vec4 fragColor;
vec2 fragCoord = gl_FragCoord.xy;
#define manhattan 0
#define neat 1
#define PI 3.1415926535
void mainImage( out vec4 fragColor, in vec2 fragCoord );
void main() {
mainImage(gl_FragColor,gl_FragCoord.xy);
}
vec3 hsv2rgb(vec3 c)
{
vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
}
float VoroLen(vec2 a, vec2 b) {
#if manhattan
vec2 c = abs(a - b);
return c.x + c.y;
#else
return length(a-b);
#endif
}
float EdgeDistance(vec2 a, vec2 b, vec2 c) {
#if manhattan
float halfLen = VoroLen(a, b) * 0.5;
float a2c = VoroLen(a, c);
float b2c = VoroLen(b, c);
return max(halfLen - a2c, b2c - halfLen);
#else
vec2 halfJoin = (a - b) * 0.5;
vec2 edgeOrigin = b + halfJoin;
vec2 edgeNormal = normalize(halfJoin);
return dot(edgeNormal, c - edgeOrigin);
#endif
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
float scale = 10.;
vec2 suv = (fragCoord-0.5*iResolution.xy)/iResolution.y;
suv *= scale;
vec2 mousePos = (iMouse.xy -0.5 * iResolution.xy)/iResolution.y;
mousePos *= scale;
float t = iTime * 0.25;
float r = 4.5;
float rsqrt = r * 0.707;
vec2[9] point;
point[0] = mousePos;
point[1] = vec2(sin(t)*rsqrt, sin(t)*rsqrt);
point[2] = vec2(-sin(t+PI*0.5)*rsqrt, sin(t+PI*0.5)*rsqrt);
point[3] = vec2(0., sin(t*2.-0.5)*r);
point[4] = vec2(sin(t*2.+0.7)*r, 0.);
point[5] = vec2(r, r);
point[6] = vec2(-r, r);
point[7] = vec2(r, -r);
point[8] = vec2(-r, -r);
// Determine some cool colors.
vec3[point.length()] color;
float pi2 = PI * 2.;
float theta = 0.;
float increment = pi2 / float(point.length());
for(int i = 0; i < color.length(); i++) {
color[i] = hsv2rgb(vec3(theta/pi2, 1., 1.));
theta += increment;
}
// Get nearest voronoi point.
int nearest = 0;
float dnearest = VoroLen(suv, point[0]);
for (int i = 1; i < point.length(); i++) {
float dcurrent = VoroLen(suv, point[i]);
if (dcurrent < dnearest) {
dnearest = dcurrent;
nearest = i;
}
}
// Get the nearest edge.
// Note: nearest edge can't be inferred from the second-nearest voronoi point.
// i.e.: For a point in Red, the second nearest point may be Blue, but the nearest edge could be Red-Green.
float edgeDistance = 1000.;
for (int i = 0; i < point.length(); i++) {
if (i == nearest) continue;
float edgeDistCurrent = EdgeDistance(point[nearest], point[i], suv);
if (edgeDistCurrent < edgeDistance) {
edgeDistance = edgeDistCurrent;
}
}
float pointcolor = clamp(0., 1., 1. - smoothstep(0.04, 0.08, dnearest));
#if neat
vec3 edgeColor = vec3(smoothstep(0.01, 0.02, 0.04-edgeDistance));
vec3 backgroundColor = color[nearest] * (1. - pow(edgeDistance / scale, 0.125));
fragColor = vec4(max(max(edgeColor, backgroundColor), vec3(pointcolor)), 1.0);
#else
fragColor = vec4(1.0,1.0,0.0, 1.0);
#endif
}
Hope to get your help！
If you visualize the color stored in 
Thank you so much for trying!