OpenGL supports the ability to start a new Triangle Strip in an index array by inserting two duplicate indices, (what they call a "degenerate triangle"), like this:
GLuint idxs[] = {0, 1, 2, 3, 3, 4, 4, 5, 6, 7};
And it supports a similar ability to start a new Triangle Fan in an index array by defining and inserting a Primitive Restart index, like this:
GLuint PRIMITIVE_RESTART = 12345; // magic value
glEnable(GL_PRIMITIVE_RESTART);
glPrimitiveRestartIndex(PRIMITIVE_RESTART);
GLuint idxs[] = {0, 1, 2, 3, PRIMITIVE_RESTART, 4, 5, 6, 7};
That’s nice, but I’m using LibGdx.
LibGdx supports the Degenerate Triangle technique for Triangle Strips, but does it support Primitive Restarts for Triangle Fans as well?
I get the benefit of optimizing GPU IO traffic by cramming as much data into as small a mesh as possible by reusing vertices that are referenced by multiple indices and using triangle strips and fans rather than a bunch of single triangles. All of which is better than composing a lot of small meshes rendering one triangle, strip, or fan at a time.
I am tessellating a large region of space with Triangle Fans, and I want to cram a TON of them into a single mesh. Is that possible? Or am I going to have to resort to breaking the fans down into individual triangles? A mesh is composed of only one array of vertices and one array of indices, right? And a mesh can’t reference vertices from a different mesh, right? So it seems like my solution has to be in the indices array.
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