From 61cd8d99e6a3475eaf2bd28bc24892cf1aae0398 Mon Sep 17 00:00:00 2001
From: Matthew Kosarek <matthew@matthewkosarek.xyz>
Date: Tue, 15 Aug 2023 07:29:58 -0400
Subject: WIP on the summer theme

---
 themes/src/_shaders/sun.frag | 48 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 themes/src/_shaders/sun.frag

(limited to 'themes/src/_shaders/sun.frag')

diff --git a/themes/src/_shaders/sun.frag b/themes/src/_shaders/sun.frag
new file mode 100644
index 0000000..dabd7ea
--- /dev/null
+++ b/themes/src/_shaders/sun.frag
@@ -0,0 +1,48 @@
+varying lowp vec4 VertexColor;
+
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+uniform vec2 u_resolution;
+
+vec2 skew (vec2 st) {
+    vec2 r = vec2(0.0);
+    r.x = 1.1547*st.x;
+    r.y = st.y+0.5*r.x;
+    return r;
+}
+
+vec3 simplexGrid (vec2 st) {
+    vec3 xyz = vec3(0.0);
+
+    vec2 p = fract(skew(st));
+    if (p.x > p.y) {
+        xyz.xy = 1.0-vec2(p.x,p.y-p.x);
+        xyz.z = p.y;
+    } else {
+        xyz.yz = 1.0-vec2(p.x-p.y,p.y);
+        xyz.x = p.x;
+    }
+
+    return fract(xyz);
+}
+
+void main() {
+    vec2 st = gl_FragCoord.xy/u_resolution.xy;
+    vec3 color = VertexColor.xyz
+
+    // Scale the space to see the grid
+    st *= 10.;
+
+    // Show the 2D grid
+    color.rg = fract(st);
+
+    // Skew the 2D grid
+    // color.rg = fract(skew(st));
+
+    // Subdivide the grid into to equilateral triangles
+    // color = simplexGrid(st);
+
+    gl_FragColor = vec4(color,1.0);
+}
-- 
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