Resolves#1879.
- Add an 'indirectdraw' boolean field to the graphics feature support table returned by love.graphics.getSupported. This is almost always supported when compute shaders are supported, except on a few older phones.
- Add an 'indirectarguments' boolean field to the settings table in love.graphics.newBuffer.
- Add love.graphics.dispatchIndirect(shader, argumentsbuffer [, argumentsindex = 1]).
The compute dispatch's threadgroup width, height, and depth values are fetched from the buffer (as 3 uints) instead of coming from function parameters.
- Add love.graphics.drawIndirect(mesh, argumentsbuffer, argumentsindex, x, y, ....).
Vertex or index count, instance count, and other related parameters for drawing the mesh are fetched from the buffer (as 4 or 5 uints depending on whether the mesh has an index buffer) instead of coming from function parameters. It's usually a good idea to keep parameters other than the instance count in sync with what the mesh should be using.
- Add love.graphics.drawFromShaderIndirect(drawmode, argumentsbuffer [, argumentsindex = 1] [, maintexture = nil]) and drawFromShaderIndirect(indexbuffer, argumentsbuffer [, argumentsindex] [, maintexture = nil]).
Vertex or index count, instance count, and other related parameters are fetched from the buffer as 4 or 5 uints, as above.
For the dispatch indirect arguments buffer, it has to have 3 uint32 elements: { uint threadgroupsX, uint threadgroupsY, uint threadgroupsZ }.
For non-indexed draws, the arguments buffer has to have 4 uint32 elements: { uint vertexCount, uint instanceCount, uint baseVertex, uint baseInstance }. Note that baseInstance should always be set to 0 as many drivers don't support non-zero values.
For draws which use an index buffer, the arguments buffer has to have 5 uint32 elements: { uint indexCount, uint instanceCount, uint firstIndex, uint baseVertex, uint baseInstance }. As above, the baseInstance value should always be 0.
A buffer can be created to have an array of those structures, which can be used with the argumentsindex parameter of the Indirect dispatch/draw functions.
Allows buffers created with love.graphics.newBuffer to only allocate VRAM data. Previously they had a copy of their contents in RAM.
Also makes it easier to implement Buffers in other graphics APIs and to implement more types of Buffers in the future.
All enum errors have (hopefully) been changed to a luax_enumerror, which has a
fixed error message. If additionally a list of valid options is passed, it
lists that in the error message. For every enum error with few options I've
implemented this using a getConstants call.
This solution has been designed specifically to reduce the number of template
instantiations (as I've been told that was a concern). All new template code
happens in places where there already was an instantiation of the relevant
StringMap. Of course there is still std::vector<std::string>...
--HG--
branch : minor
Sasha Szpakowski
Bart van Strien