Add galaxy

README.md

@@ -1,9 +1,10 @@
 # Shaders
 
-Shader projects for [SHADERed](https://github.com/dfranx/SHADERed).
+GLSL shaders and projects for [SHADERed](https://github.com/dfranx/SHADERed).
 
 ## Gallery
 
 ![neon_pulse](/render/neon_pulse.gif)
 ![flame](/render/flame.gif)
 ![sun](/render/sun.gif)
+![galaxy](/render/galaxy.gif)

galaxy.sprj

@@ -0,0 +1,44 @@
+<?xml version="1.0"?>
+<project version="2">
+	<pipeline>
+		<pass name="Galaxy" type="shader" active="true" patchverts="1">
+			<shader type="vs" path="shaders/galaxy_GalaxyVS.glsl" entry="main" />
+			<shader type="ps" path="shaders/galaxy_GalaxyPS.glsl" entry="main" />
+			<inputlayout>
+				<item value="Position" semantic="POSITION" />
+			</inputlayout>
+			<rendertexture />
+			<items>
+				<item name="Quad" type="geometry">
+					<type>ScreenQuadNDC</type>
+					<width>1</width>
+					<height>1</height>
+					<depth>1</depth>
+					<topology>TriangleList</topology>
+				</item>
+			</items>
+			<itemvalues />
+			<variables>
+				<variable type="float2" name="uResolution" system="ViewportSize" />
+				<variable type="float" name="uTime" system="Time" />
+			</variables>
+			<macros />
+		</pass>
+	</pipeline>
+	<objects />
+	<cameras />
+	<settings>
+		<entry type="property" name="Galaxy" item="pipe" />
+		<entry type="file" name="Galaxy" shader="vs" />
+		<entry type="file" name="Galaxy" shader="ps" />
+		<entry type="camera" fp="false">
+			<distance>4</distance>
+			<pitch>25</pitch>
+			<yaw>319</yaw>
+			<roll>360</roll>
+		</entry>
+		<entry type="clearcolor" r="0" g="0" b="0" a="0" />
+		<entry type="usealpha" val="false" />
+	</settings>
+	<plugindata />
+</project>

shaders/galaxy_GalaxyPS.glsl

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+#version 330
+
+uniform vec2 uResolution;
+uniform float uTime;
+
+out vec4 outColor;
+
+const float PI = 3.14159;
+const int CIRCLES = 2000;
+const float OUTER_RAD = 1.0;
+const float TILT_X = 0.05;
+const float TILT_Y = 0.1;
+const float CENTER_SPIN_SPEED = 1.0;
+
+float circle(vec2 uv, vec2 center, float r0, float r1)
+{
+    float d = length(center - uv);
+    return 1.0 - smoothstep(r0, r1, d);
+}
+
+float rand(vec2 co)
+{
+    return fract(sin(dot(co, vec2(12.9898, 78.233))) * 43758.5453);
+}
+
+// https://iquilezles.org/articles/palettes/
+// http://dev.thi.ng/gradients/
+vec3 palette(float t)
+{
+    vec3 a = vec3(0.838, 0.838, 0.788);
+    vec3 b = vec3(0.445, 0.390, 0.641);
+    vec3 c = vec3(0.380, 0.584, 0.380);
+    vec3 d = vec3(-0.272, -0.239, 0.075);
+
+    return a + b*cos(6.28318*(c*t+d));
+}
+
+void main()
+{
+    vec2 uv = (gl_FragCoord.xy * 2.0 - uResolution.xy) / uResolution.y;
+    vec3 finalColor = vec3(0.0);
+
+    for (int i = 0; i < CIRCLES; i++)    
+    {
+        float centerDist = rand(vec2(i));
+        float offset = i * PI * 2 / CIRCLES;
+        float distSpeed = 1.0 + (1.0 - centerDist) * CENTER_SPIN_SPEED;
+        float posX = sin(uTime * (TILT_X + distSpeed) + offset);
+        float posY = cos(uTime * (TILT_Y + distSpeed) + offset);
+        
+        vec3 col = palette(centerDist + sin(uTime) * 0.5);
+
+        finalColor += circle(
+            uv,
+            vec2(
+                posX * OUTER_RAD * centerDist,
+                posY * OUTER_RAD * centerDist
+            ),
+            0.0,
+            0.04 * (1.0 - centerDist * 0.5)
+        ) * col;
+    }
+    
+    outColor = vec4(finalColor,1.0);
+}

shaders/galaxy_GalaxyVS.glsl

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+#version 330
+
+layout (location = 0) in vec2 pos;
+
+void main() {
+   gl_Position = vec4(pos, 0.0f, 1);
+}