CauldronGPU.Setup (CauldronGPU v0.3.3)

What building the renderer needs on this machine, and the build configuration mix cauldron_gpu.setup writes.

Each platform module (CauldronGPU.Setup.MacOS, CauldronGPU.Setup.Linux, CauldronGPU.Setup.Windows) implements CauldronGPU.Setup.Platform: it looks for each thing the build needs in that platform's usual places, installs what it can, and turns what it found into configuration.

The configuration is build.config in :filename.basedir(:user_config, "cauldron_gpu"), Erlang terms read with :file.consult/1. mix.exs passes it to make or nmake:

{choice, card | software}: software builds no renderer
{pkg_config, Path}: PKG_CONFIG, the pkg-config program
{pkg_config_path, Path}: added to PKG_CONFIG_PATH
{sdl3_dir, Path}: SDL3_DIR, an SDL3 development folder (Windows)
{vulkan_include, Path}: VULKAN_INCLUDE, the folder holding vulkan/vulkan.hpp
{msvc_env, [{Name, Value}]}: the environment MSVC's vcvars64.bat sets, used when cl is not already on PATH
{nmake, Path}: MSVC's nmake.exe, used when nmake is not on PATH

Other variables already set in the environment take precedence over the file.

Summary

Functions

build_env(config)

The environment variables config sets for the build, as mix.exs passes them; set in this process before rebuilding, so the build that follows uses them.

cache_dir()

The folder downloads and builds go into.

card_status()

Whether games can draw on the graphics card: {:ok, device, backends} when the renderer loads and opens an offscreen device, else {:error, text} saying why. Loads the renderer again first, so a build made since this process started is the one checked.

config_path()

The configuration file's path.

platform()

The platform module for the machine this runs on.

read_config()

The configuration written last, or %{}.

sdl3_version()

The SDL3 release downloaded when SDL3 is fetched rather than installed.

vulkan_headers_version()

The Vulkan-Headers release downloaded when Vulkan's headers are missing.

write_config(config)

Writes config as the configuration, replacing the file.

Types

item()

@type item() :: %{
  key: atom(),
  name: String.t(),
  required?: boolean(),
  found: String.t() | nil,
  install: String.t() | nil,
  manual: String.t()
}

One thing the build needs:

key: the platform's name for it
name: what to call it when talking to a person
required?: whether the renderer can be built without it
found: where it is, or nil
install: what the automatic install does, or nil when it cannot be automated
manual: how a person installs it themselves