From 7514345d8f731affc1fe0f2b1f38822103fdaac5 Mon Sep 17 00:00:00 2001
From: hellerve <veit@veitheller.de>
Date: Tue, 6 Jun 2017 09:16:18 -0400
Subject: [PATCH] utils: added translation and box shape

---
 utilities/shapes.glsl      | 8 ++++++++
 utilities/translation.glsl | 8 ++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 utilities/translation.glsl

diff --git a/utilities/shapes.glsl b/utilities/shapes.glsl
index dd4d343..6cc6ffa 100644
--- a/utilities/shapes.glsl
+++ b/utilities/shapes.glsl
@@ -5,6 +5,14 @@ vec3 circle(in vec2 _st, in float _radius, vec3 color){
                          dot(dist,dist)*4.0);
 }
 
+vec3 box(vec2 width, vec2 height) {
+    height = vec2(0.5) - height*0.5;
+    vec2 he = height+0.001;
+    vec2 uv = smoothstep(height, he, width);
+    uv *= smoothstep(height, he, vec2(1.0)-width);
+    return vec3(uv.x*uv.y);
+}
+
 // Inspired by (but modified)
 // http://thndl.com/square-shaped-shaders.html
 #define TAU 6.28318530718
diff --git a/utilities/translation.glsl b/utilities/translation.glsl
new file mode 100644
index 0000000..63d2c71
--- /dev/null
+++ b/utilities/translation.glsl
@@ -0,0 +1,8 @@
+mat2 rotate2d(float a) {
+    float c = cos(a);
+    return mat2(c, -sin(a), sin(a), c);
+}
+
+mat2 scale(vec2 s) {
+    return mat2(s.x, 0., 0., s.y);
+}