From 681b4ca820e2201e2a8bb56db1689ba2c1402356 Mon Sep 17 00:00:00 2001
From: polyfloyd <floyd@polyfloyd.net>
Date: Sat, 19 May 2018 16:34:47 +0200
Subject: [PATCH] Add space.glsl

---
 space.glsl | 164 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 164 insertions(+)
 create mode 100644 space.glsl

diff --git a/space.glsl b/space.glsl
new file mode 100644
index 0000000..2b82e84
--- /dev/null
+++ b/space.glsl
@@ -0,0 +1,164 @@
+uniform float time;
+uniform vec2 resolution;
+
+#define mouse vec2(sin(time)/48., cos(time)/48.)
+#define iterations 14
+#define formuparam2 0.79
+
+#define volsteps 5
+#define stepsize 0.390
+
+#define zoom 0.900
+#define tile   0.850
+#define brightness 0.003
+#define darkmatter 0.400
+#define distfading 0.560
+#define saturation 0.800
+
+
+#define transverseSpeed zoom*2.0
+#define cloud 0.11
+
+
+float triangle(float x, float a) {
+	float output2 = 2.0*abs(  2.0*  ( (x/a) - floor( (x/a) + 0.5) ) ) - 1.0;
+	return output2;
+}
+
+float field(in vec3 p) {
+	float strength = 7. + .03 * log(1.e-6 + fract(sin(time) * 4373.11));
+	float accum = 0.;
+	float prev = 0.;
+	float tw = 0.;
+
+	for (int i = 0; i < 6; ++i) {
+		float mag = dot(p, p);
+		p = abs(p) / mag + vec3(-.5, -.8 + 0.1*sin(time*0.7 + 2.0), -1.1+0.3*cos(time*0.3));
+		float w = exp(-float(i) / 7.);
+		accum += w * exp(-strength * pow(abs(mag - prev), 2.3));
+		tw += w;
+		prev = mag;
+	}
+	return max(0., 5. * accum / tw - .7);
+}
+
+
+
+void main() {
+	vec2 uv2 = 2. * gl_FragCoord.xy / vec2(512) - 1.;
+	vec2 uvs = uv2 * vec2(512)  / 512.;
+
+	float time2 = time / 15.0;
+	float speed = .01 * cos(time2*0.02 + 3.1415926/4.0);
+
+	float formuparam = formuparam2;
+
+
+	vec2 uv = uvs;
+
+	float a_xz = 0.9;
+	float a_yz = -.6;
+	float a_xy = 0.9 + time*0.04;
+
+	mat2 rot_xz = mat2(cos(a_xz),sin(a_xz),-sin(a_xz),cos(a_xz));
+	mat2 rot_yz = mat2(cos(a_yz),sin(a_yz),-sin(a_yz),cos(a_yz));
+	mat2 rot_xy = mat2(cos(a_xy),sin(a_xy),-sin(a_xy),cos(a_xy));
+
+
+	float v2 =1.0;
+	vec3 dir=vec3(uv*zoom,1.);
+	vec3 from=vec3(0.0, 0.0,0.0);
+	from.x -= 5.0*(mouse.x-0.5);
+	from.y -= 5.0*(mouse.y-0.5);
+
+
+	vec3 forward = vec3(0.,0.,1.);
+	from.x += transverseSpeed*(1.0)*cos(0.01*time) + 0.001*time;
+	from.y += transverseSpeed*(1.0)*sin(0.01*time) +0.001*time;
+	from.z += 0.003*time;
+
+	dir.xy*=rot_xy;
+	forward.xy *= rot_xy;
+	dir.xz*=rot_xz;
+	forward.xz *= rot_xz;
+	dir.yz*= rot_yz;
+	forward.yz *= rot_yz;
+
+	from.xy*=-rot_xy;
+	from.xz*=rot_xz;
+	from.yz*= rot_yz;
+
+	float zooom = (time2-3311.)*speed;
+	from += forward* zooom;
+	float sampleShift = mod( zooom, stepsize );
+
+	float zoffset = -sampleShift;
+	sampleShift /= stepsize;
+
+
+	float s=0.24;
+	float s3 = s + stepsize/2.0;
+	vec3 v=vec3(0.);
+	float t3 = 0.0;
+
+	vec3 backCol2 = vec3(0.);
+	for (int r=0; r<volsteps; r++) {
+		vec3 p2=from+(s+zoffset)*dir;
+		vec3 p3=from+(s3+zoffset)*dir;
+
+		p2 = abs(vec3(tile)-mod(p2,vec3(tile*2.)));
+		p3 = abs(vec3(tile)-mod(p3,vec3(tile*2.)));
+#ifdef cloud
+		t3 = field(p3);
+#endif
+
+		float pa,a=pa=0.;
+		for (int i=0; i<iterations; i++) {
+			p2=abs(p2)/dot(p2,p2)-formuparam;
+
+			float D = abs(length(p2)-pa);
+			a += i > 7 ? min( 12., D) : D;
+			pa=length(p2);
+		}
+
+
+
+		a*=a*a;
+
+		float s1 = s+zoffset;
+
+		float fade = pow(distfading,max(0.,float(r)-sampleShift));
+
+		v+=fade;
+
+
+
+		if( r == 0 )
+			fade *= (1. - (sampleShift));
+
+		if( r == volsteps-1 )
+			fade *= sampleShift;
+		v+=vec3(s1,s1*s1,s1*s1*s1*s1)*a*brightness*fade;
+
+		backCol2 += mix(.4, 1., v2) * vec3(1.8 * t3 * t3 * t3, 1.4 * t3 * t3, t3) * fade;
+
+
+		s+=stepsize;
+		s3 += stepsize;
+	}
+
+	v=mix(vec3(length(v)),v,saturation);
+
+	vec4 forCol2 = vec4(v*.01,1.);
+#ifdef cloud
+	backCol2 *= cloud;
+#endif
+	backCol2.b *= 1.8;
+	backCol2.r *= 0.05;
+
+	backCol2.b = 0.5*mix(backCol2.g, backCol2.b, 0.8);
+	backCol2.g = 0.0;
+	backCol2.bg = mix(backCol2.gb, backCol2.bg, 0.5*(cos(time*0.01) + 1.0));
+	gl_FragColor = forCol2 + vec4(backCol2, 1.0);
+}
+