Do angle addition

1 files changed, 4 insertions, 2 deletions

diff --git a/data/angle_addition.vert b/data/angle_addition.vert
index f410305..72d745e 100644
--- a/data/angle_addition.vert
+++ b/data/angle_addition.vert
@@ -5,8 +5,10 @@ uniform float rotation_angle;
 
 void main()
 {
-  gl_Position.x = z.x;
-  gl_Position.y = z.y;
+  float x = z.x * cos(z.y);
+  float y = z.x * sin(z.y);
+  gl_Position.x = x * cos(rotation_angle) - y * sin(rotation_angle);
+  gl_Position.y = x * sin(rotation_angle) + y * cos(rotation_angle);
   gl_Position.z = 0.;
   gl_Position.w = 1.;
   gl_PointSize = 32.;