Geometry Shaders:
	emitting, and starting with a whole triangle
	Can we make the cube have extra faces that are further away?
		Of course!
	We can use "if" statements over the whole thing
	Do we want to apply the MVP, or have a different shader do it?
		We probably want to apply it in the geometry shader
		That way we can work in model space instead of world space

Geometry shaders and loss of parallelism:
	Once per primitive, instead of once per vertex
	Easy to contrive a workflow that reduces parallelism
	gl_InvocationID and multiple invocations of the same geometry shader
	Need OpenGL 4.0+ for this

Tesselation Shaders:
	Two pieces:  Tesselation Control Shader, Tesselation Evaluation Shader

TCS -> Primitive Generator -> TES

TCS outputs:
	Tessellation Level
	Vertices (can move stuff, like vertex and geometry shaders)
	Optional, can use glPatchParameterfv to set default values
		Transformation can be applied in the vertex shader instead

Primitive Generation:
	Normalized Coordinates (Barycentric coordinates)
		In triangles vs. in quads
		No awareness of "actual" coordinates!
	Tessellation levels:
		In general, these are the number of segments an edge is tessellated into
		Edge tessellation should match the neighboring patch
		Triangles:  One inner level, three outer levels	
		Can be discareded if level is 0
			That allows the TCS to cull patches
	Picture of how these come together

TES outputs:
	gl_Position
	Anything else we've defined, like color
	Calculate this from:
		gl_TessCoord (vec3, barycentric coordinates)
		gl_in with patch vertices
		
Demo:
	Add a tcs and tes to the cube to make it into a sphere
		using normalize

Compute Shaders:
	3D grid of workgroups
	Placing instances in a 3D grid can help organize image or spacial processing
		Or other stuff, but I think that was the intent
	If you don't really want a 3D grid, just pick one dimension to use

Storage!
	Shader Storage Buffers
	in/out parameter, basically
	We have to explain the layout
	We did that already with the vertex shader and positions
	bound by number
	Cube top/bottom bounce demo

You can use a compute shader for something that has nothing to do with graphics at all