[mappu]

> because those instruction sets are somewhat secret, I think

The GPU ISAs are known (e.g. the PTX compiler for NVidia is open source and has a backend in LLVM). The main problem is that the GPU ISA changes with every GPU hardware generation and manufacturer, so if you want to support Nvidia 3xxx + 4xxx + AMD VLIW + AMD GCN + ... you have to use the common demoninator GLSL/HLSL/SPIR-V/whatever.

> why they didn’t emulate Flipper at a low enough level to use the precompiled shaders directly.

They did. Originally the GPU emulator was done in the CPU, and in 2017, the GPU emulator itself was moved into a shader ("ubershader").

The console game itself does not include shaders in text format like many PC games do.

[mandarax8]

> The GPU ISAs are known (e.g. the PTX compiler for NVidia is open source and has a backend in LLVM)

PTX is only and IR afaik, kinda like SPIRV. It also goes through another compiler in the driver so doesn't really help here