This is based on research from nouveau. Many things are currently unknown and will require hwtests in the future.
This commit also stubs QueryMode::Write2 to do the same as Write. Nouveau code treats them interchangeably, it is currently unknown what the difference is.

The Ryujinx macro interpreter and envydis were used as reference.

Macros are programs that are uploaded by the games during boot and can later be called by writing to their method id in a GPU command buffer.

TODO: A shader may not use all of these textures at the same time, shader analysis should be performed to determine which textures are actually sampled.

Allow unswizzling of DXT1 textures.

This macro simply sets the current CB_ADDRESS to the texture buffer address for the input shader stage.

This macro binds the SSBO Info Buffer as the current ConstBuffer.
This buffer is usually bound to c0 during shader execution.
Games seem to use this macro instead of directly writing the address for some reason.

Writing to this method will cause the written value to be stored in the currently-set ConstBuffer plus CB_POS.

This method is usually used to upload uniforms or other shader-visible data.

It'll now set the CB_SIZE, CB_ADDRESS and CB_BIND registers when it's called.

Presumably this SetShader function is binding the constant shader uniforms to buffer 1 (c1[]).

Register 0xE24 is actually a macro that sets some shader parameters in the register structure.

Macros are uploaded to the GPU at startup and have their own ISA, we'll probably write an interpreter for this in the future.

Accumulate all arguments before calling the desired method.

Note: Maybe we should do the same for the NonIncreasing mode?

Shader address calculation depends on this value to some extent, we do not currently know what it being 0 entails.

This is the register that gets written after a game calls DrawArrays().

We should collect all GPU state and draw using our graphics API here.

Only QueryMode::Write is supported at the moment.

Also moved the GPU MemoryManager class to video_core since it makes more sense for it to be there.

GPU: Added a command processor to decode the GPU pushbuffers and forward the commands to their respective engines.