Rotating glScissor for layer clipping

OpenGL OpenGL: Basic Coding
1

Dear All,

I am looking forward for implementing layer Clipping for OpenGL ES 2.0 based UI system where in all childern are
clipped inside parent region. Imagine like a Message box as parent with buttons as childern in it. This UI Tree has more than 5 levels of depth ( parent->parent->…parent->leaf child).

The idea is to make sure child is clipped with in Parent bounds
even during rotation. Let me know the right appoarch

  1. stencil buffers. ( need to know performance hit)
  2. re-generate the verticies of childern (in this case rect may not stay rect).
  3. glScissor ( is not helping us during rotation of parent or child)
  4. Clipping planes ( not directly supported in OpenGL ES )

Regards,
Kumar.k

2

“even during rotation” : what is your UI use case for this ?
Scissor is probably the fastest, but GL ES hardware is special, you have to benchmark each way to very the performance impact.

3

Find the attached images explaining where childern goes out of parent, and needs clipping, Images are only in XY Plane they can be any any orientation( both parent and child).