From c76455fab051d3d4ed0bcc0d4f0d554d3edde3a3 Mon Sep 17 00:00:00 2001
From: polyfloyd <floyd@polyfloyd.net>
Date: Sat, 19 May 2018 15:11:49 +0200
Subject: [PATCH] Add galaxy.glsl

---
 galaxy.glsl | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 galaxy.glsl

diff --git a/galaxy.glsl b/galaxy.glsl
new file mode 100644
index 0000000..d34e8b8
--- /dev/null
+++ b/galaxy.glsl
@@ -0,0 +1,55 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+uniform float time;
+uniform vec2 resolution;
+
+#define FORMUPARAM 0.589
+#define ITERATIONS 100
+#define INNER_ITERS 11
+#define ZOOM -1.2
+
+void main()
+{
+
+	vec2 uv = vec2(gl_FragCoord.x - resolution.x * 0.5, gl_FragCoord.y - resolution.y * 0.5) / max(resolution.x, resolution.y);
+	uv *= ZOOM;
+	//	uv += vec2(.15 * sin(time * .2), .1 * cos(time * .1));
+
+
+	float t = time * .15 + ((.25+.05*sin(time*.1))/(length(uv.xy)+.07))* 2.2;
+	float si = sin(t);
+	float co = cos(t);
+	mat2 ma = mat2(co, si, -si, co);
+
+	float c = 0.0;
+	float v1 = 0.0;
+	float v2 = 0.0;
+
+	for (int i = 0; i < ITERATIONS; i++)
+	{
+		float s = float(i) * .035;
+		vec3 p = s * vec3(uv, 1.0 + sin(time * .015));
+		p.xy *= ma;
+		p += vec3(.22,.3, s-1.5-sin(t*.13)*.1);
+		for (int i = 0; i < INNER_ITERS; i++)
+		{
+			p = abs(p) / dot(p,p) - FORMUPARAM;
+		}
+		v1 += dot(p,p)*.0015 * (2.8+sin(length(uv.xy*18.0)+.5-t*.7));
+		v2 += dot(p,p)*.0025 * (1.5+sin(length(uv.xy*13.5)+1.21-t*.3));
+		c = length(p.xy*.3) * .85;
+	}
+
+	float len = length(uv);
+	v1 *= smoothstep(.7, .0, len);
+	v2 *= smoothstep(.6, .0, len);
+
+	float re = clamp(c, 0.0, 1.0);
+	float gr = clamp((v1+c)*.25, 0.0, 1.0);
+	float bl = clamp(v2, 0.0, 1.0);
+	vec3 col = vec3(re, gr, bl) + smoothstep(0.15, .0, len) * .9;
+
+	gl_FragColor=vec4(col, 1.0);
+}