Allow for interpolating colors from center to edge of ellipses

shader/ellipseInterpolate.vert

@@ -0,0 +1,16 @@
+#version 430 core
+layout (location = 0) in vec3 position;
+layout (location = 1) in vec4 col;
+out vec4 vCol;
+
+uniform vec2 winSize;
+uniform float zoom;
+uniform vec2 translation;
+uniform float rotation;
+uniform mat4 worldMat;
+
+void main()
+{
+  gl_Position = worldMat * vec4(position,1);
+  vCol = col;
+}