Springs.cpp

/*
            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE 
                    Version 2, December 2004 

 Copyright (C) 2016 Darren Mothersele <me@daz.is> 

 Everyone is permitted to copy and distribute verbatim or modified 
 copies of this license document, and changing it is allowed as long 
 as the name is changed. 

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE 
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 

  0. You just DO WHAT THE FUCK YOU WANT TO.
*/


#include "Springs.h"


FFGL_PLUGIN(Springs,"DZSR","Springs",FF_SOURCE,"Sample FFGL Plugin",
            "by Darren Mothersele - www.darrenmothersele.com")


std::string fragmentShaderCode = R"GLSL(

uniform vec3      size;
uniform float     time;

// https://www.shadertoy.com/view/ld23DG
// Crazy Springs by eiffie
// Don't know why there is a seam on the springs.
// Well looking at my code I know why. I just don't know exactly why. :)


//#define SHADOWS
float f1,f2,f3;
float DE(vec3 p)
{
	vec3 g=floor(p+0.5);
	vec3 g1=g+sin(g.yzx*f1+g.zxy*f2+g*f3)*0.25;
	vec4 dlt=vec4(sign(p-g1),0.0);
	vec3 g2=g+dlt.xww;
	vec3 g3=g+dlt.wyw;
	vec3 g4=g+dlt.wwz;
	g1-=p;
	g2+=sin(g2.yzx*f1+g2.zxy*f2+g2*f3)*0.25-p;
	g3+=sin(g3.yzx*f1+g3.zxy*f2+g3*f3)*0.25-p;
	g4+=sin(g4.yzx*f1+g4.zxy*f2+g4*f3)*0.25-p;
	vec3 gD=g2-g1,gDs=gD;
	float t1=clamp(dot(-g1,gD)/dot(gD,gD),0.0,1.0);
	vec3 p1=mix(g1,g2,t1);
	float m1=dot(p1,p1);
	gD=g3-g1;
	float t2=clamp(dot(-g1,gD)/dot(gD,gD),0.0,1.0);
	vec3 p2=mix(g1,g3,t2);
	float m2=dot(p2,p2);
	if(m2<m1){m1=m2;t1=t2;p1=p2;gDs=gD;}
	gD=g4-g1;
	t2=clamp(dot(-g1,gD)/dot(gD,gD),0.0,1.0);
	vec3 p3=mix(g1,g4,t2);
	m2=dot(p3,p3);
	if(m2<m1){m1=m2;t1=t2;p1=p3;gDs=gD;}
	float d1=sqrt(min(dot(g1,g1),min(dot(g2,g2),min(dot(g3,g3),dot(g4,g4)))))-0.15;
	float len=length(gDs);
	float d2=sqrt(m1)-0.07+len*sqrt(d1)*0.02;
	float d=0.25;
	if(d2<d && d2<d1){
		if(d2<0.015){
			gDs/=len;
			gD=normalize(cross(gDs,vec3(1.0,0.0,0.0)));
			float b=dot(p1,gD),c=dot(p1,cross(gDs,gD));
			vec2 v=vec2(d2,(fract( (t1*16.0+atan(b,c)*0.795775))-0.5)*0.05*len);
			d2=length(v)-0.01;
		}
		d=d2;
	}
	if(d1<d){
		d=d1;
	}
	return d;
}
vec3 getColor(vec3 p){
	vec3 g=floor(p+0.5);
	vec3 g1=g+sin(g.yzx*f1+g.zxy*f2+g*f3)*0.25;
	vec4 dlt=vec4(sign(p-g1),0.0);
	vec3 g2=g+dlt.xww;
	vec3 g3=g+dlt.wyw;
	vec3 g4=g+dlt.wwz;
	g1-=p;
	g2+=sin(g2.yzx*f1+g2.zxy*f2+g2*f3)*0.25-p;
	g3+=sin(g3.yzx*f1+g3.zxy*f2+g3*f3)*0.25-p;
	g4+=sin(g4.yzx*f1+g4.zxy*f2+g4*f3)*0.25-p;
	float d1=sqrt(min(dot(g1,g1),min(dot(g2,g2),dot(g3,g3))))-0.15;
	if(d1<0.005)return vec3(0.6,0.2,0.0)+sin(g*2.0)*0.2;
	return vec3(0.5,0.4,0.2)+sin(p*100.0)*0.1;
}
#ifdef SHADOWS
float linstep(float a, float b, float t){return clamp((t-a)/(b-a),0.,1.);}//from knighty
//random seed and generator
float randSeed,GoldenAngle;
float randStep(){//crappy random number generator
	randSeed=fract(randSeed+GoldenAngle);
	return  (0.8+0.2*randSeed);
}
float FuzzyShadow(vec3 ro, vec3 rd, float coneGrad){
	float t=0.01,d,s=1.0,r;
	ro+=rd*t;
	for(int i=0;i<8;i++){
		r=t*coneGrad;
		d=DE(ro+rd*t)+r*0.5;
		s*=linstep(-r,r,d);
		t+=d*randStep();
	}
	return clamp(s,0.3,1.0);
}
#endif
mat3 lookat(vec3 fw,vec3 up){
	fw=normalize(fw);vec3 rt=normalize(cross(fw,up));return mat3(rt,cross(rt,fw),fw);
}

void mainImage( out vec4 fragColor, in vec2 fragCoord ) {
#ifdef SHADOWS
	GoldenAngle=2.0-0.5*(1.0+sqrt(5.0));
	randSeed=fract(sin(dot(fragCoord.xy,vec2(13.434,77.2378))+time*0.1)*41323.34526);
#endif
	f1=fract(time*0.01)*6.2832;f2=6.2832*(1.0-fract(time*0.013));f3=6.2832*(fract(time*0.017));
	vec3 ro = vec3(0.5,0.5,time);
	mat3 rotCam=lookat(vec3(sin(time*0.9)*0.5,sin(time*1.4)*0.3,1.0),vec3(sin(time*0.3),cos(time*0.3)*vec2(cos(time*0.5),sin(time*0.5))));
	vec3 rd = rotCam*normalize(vec3((size.xy-2.0*fragCoord.xy)/size.y,1.75));
	float t=0.0,d=1.0,dm=100.0,tm;
	for(int i=0;i<32;i++){
		t+=d=DE(ro+rd*t);
		if(d<dm){dm=d;tm=t;}
	}
	vec3 L=normalize(vec3(0.3,0.7,-0.4));
	vec3 col=vec3(0.5,0.6,0.7)*pow(0.75+0.25*dot(rd,L),2.0)+rd*0.1;
	if(dm<0.01){
		vec3 p=ro+rd*tm;
		vec2 v=vec2(0.001,0.0);
		vec3 N=normalize(vec3(DE(p+v.xyy)-DE(p-v.xyy),DE(p+v.yxy)-DE(p-v.yxy),DE(p+v.yyx)-DE(p-v.yyx)));
		vec3 scol=getColor(p)*(1.0+dot(N,L));
		scol+=vec3(0.5,0.2,0.75)*pow(max(0.0,dot(reflect(rd,N),L)),8.0);
#ifdef SHADOWS
		scol*=FuzzyShadow(p,L,0.5);
#else
		scol*=clamp((DE(p+N*0.75)+DE(p+N*0.25))*4.0,0.25,1.0);//cheat from mu6k
#endif

		scol=mix(col,scol,exp(-t*0.4));
		col=mix(scol,col,smoothstep(0.0,0.01,dm));
	}
	fragColor = vec4(clamp(col*1.5,0.0,1.0),1.0);

}




void main(void) {
mainImage(gl_FragColor, gl_FragCoord.xy);
}

)GLSL";


PluginConfig Springs::getConfig() {
    PluginConfig pluginConfig;
    pluginConfig.shaderCode = fragmentShaderCode;
    pluginConfig.params.push_back({"Speed", FF_TYPE_STANDARD, 0.5f});
    return pluginConfig;
}

void Springs::init(FFGLShader &shader) {
    timeLocation = shader.FindUniform("time");
    resolutionLocation = shader.FindUniform("size");
    start = std::chrono::steady_clock::now();
}

void Springs::process(std::vector<float> &paramValues, FFGLExtensions &extensions)
{
    float vpdim[4];
    glGetFloatv(GL_VIEWPORT, vpdim);
    extensions.glUniform3fARB(resolutionLocation, vpdim[2], vpdim[3], 1.0);

    double lastTime = elapsedTime;
    elapsedTime = GetCounter()/1000.0;
    globalTime = globalTime + (float)(elapsedTime-lastTime) * (paramValues[0] - 0.5f) * 8.0f;
    extensions.glUniform1fARB(timeLocation, globalTime);

}


double Springs::GetCounter()
{
    end = std::chrono::steady_clock::now();
    return std::chrono::duration_cast<std::chrono::microseconds>(end - start).count()/1000.;
}