From 9834a95f0e98efa02da019df902291a6cdd8ffbf Mon Sep 17 00:00:00 2001
From: MatthewBeshay <92357869+MatthewBeshay@users.noreply.github.com>
Date: Wed, 8 Apr 2026 20:09:03 +1000
Subject: [PATCH] build: break platform_sdl2 up into per-subsystem libraries

---
 targets/app/meson.build               |  1 +
 targets/minecraft/meson.build         |  1 +
 targets/platform/fs/meson.build       | 12 ++++++
 targets/platform/input/meson.build    | 13 +++++++
 targets/platform/meson.build          | 55 +++++++++------------------
 targets/platform/profile/meson.build  | 12 ++++++
 targets/platform/renderer/meson.build | 13 +++++++
 targets/platform/storage/meson.build  | 12 ++++++
 8 files changed, 82 insertions(+), 37 deletions(-)
 create mode 100644 targets/platform/fs/meson.build
 create mode 100644 targets/platform/input/meson.build
 create mode 100644 targets/platform/profile/meson.build
 create mode 100644 targets/platform/renderer/meson.build
 create mode 100644 targets/platform/storage/meson.build

diff --git a/targets/app/meson.build b/targets/app/meson.build
index 7fd687740..6641edc3f 100644
--- a/targets/app/meson.build
+++ b/targets/app/meson.build
@@ -15,6 +15,7 @@ client_dependencies = [
   input_dep,
   profile_dep,
   storage_dep,
+  fs_dep,
   assets_localisation_dep,
   platform_dep,
   minecraft_dep,
diff --git a/targets/minecraft/meson.build b/targets/minecraft/meson.build
index 76e7f3fc6..2de8cc71a 100644
--- a/targets/minecraft/meson.build
+++ b/targets/minecraft/meson.build
@@ -28,6 +28,7 @@ lib_minecraft = static_library('minecraft',
     input_dep,
     profile_dep,
     storage_dep,
+    fs_dep,
     glm_dep,
     nbt_dep,
     java_dep,
diff --git a/targets/platform/fs/meson.build b/targets/platform/fs/meson.build
new file mode 100644
index 000000000..bb91f51fb
--- /dev/null
+++ b/targets/platform/fs/meson.build
@@ -0,0 +1,12 @@
+lib_platform_fs_std = static_library(
+  'platform_fs_std',
+  files('std/StdFilesystem.cpp'),
+  include_directories: [platform_inc, include_directories('../..')],
+  dependencies: [_threads],
+  cpp_args: global_cpp_args + global_cpp_defs,
+)
+
+fs_dep = declare_dependency(
+  link_with: lib_platform_fs_std,
+  include_directories: [platform_inc],
+)
diff --git a/targets/platform/input/meson.build b/targets/platform/input/meson.build
new file mode 100644
index 000000000..3ae17a68e
--- /dev/null
+++ b/targets/platform/input/meson.build
@@ -0,0 +1,13 @@
+lib_platform_input_sdl2 = static_library(
+  'platform_input_sdl2',
+  files('sdl2/SDL2Input.cpp'),
+  include_directories: [platform_inc, include_directories('../..')],
+  dependencies: [_sdl2, _threads],
+  cpp_args: global_cpp_args + global_cpp_defs,
+)
+
+input_dep = declare_dependency(
+  link_with: lib_platform_input_sdl2,
+  include_directories: [platform_inc],
+  dependencies: [_sdl2],
+)
diff --git a/targets/platform/meson.build b/targets/platform/meson.build
index 7aed1816f..a52dc8255 100644
--- a/targets/platform/meson.build
+++ b/targets/platform/meson.build
@@ -1,6 +1,16 @@
 platform_inc = include_directories('.')
 _threads = dependency('threads')
+_sdl2 = dependency('sdl2')
 
+if get_option('renderer') == 'gles'
+  _gl = dependency('glesv2', required: true)
+  _defs = ['-DGLES']
+else
+  _gl = dependency('gl', required: true)
+  _defs = []
+endif
+
+# Core: thread + shutdown plumbing, no backend.
 lib_platform_core = static_library('platform_core',
   files('C4JThread.cpp', 'ShutdownManager.cpp'),
   include_directories: [platform_inc, include_directories('..')],
@@ -13,40 +23,11 @@ platform_dep = declare_dependency(
   include_directories: platform_inc,
 )
 
-# SDL2-based platform implementations (formerly 4J.* modules)
-_sdl2 = dependency('sdl2')
-_defs = []
-
-if get_option('renderer') == 'gles'
-  _gl = dependency('glesv2', required: true)
-  _defs += ['-DGLES']
-else
-  _gl = dependency('gl', required: true)
-endif
-
-sdl2_sources = files(
-  'input/sdl2/SDL2Input.cpp',
-  'profile/stub/StubProfile.cpp',
-  'storage/stub/StubStorage.cpp',
-  'renderer/gl/GLRenderer.cpp',
-  'renderer/gl/render_stubs.cpp',
-  'fs/std/StdFilesystem.cpp',
-)
-
-lib_platform_sdl2 = static_library('platform_sdl2',
-  sdl2_sources,
-  include_directories: [platform_inc],
-  dependencies: [_sdl2, _gl, _threads, glm_dep, stb_dep, java_dep],
-  cpp_args: _defs + global_cpp_args + global_cpp_defs,
-)
-
-# Combined dependency: interfaces + SDL2 implementations
-# Replaces the old render_dep, input_dep, profile_dep, storage_dep
-render_dep = declare_dependency(
-  link_with: lib_platform_sdl2,
-  include_directories: [platform_inc],
-  dependencies: [_sdl2, _gl, _threads, glm_dep],
-)
-input_dep = render_dep
-profile_dep = render_dep
-storage_dep = render_dep
+# Per-subsystem backends. Each lives in its own subdir and produces its
+# own library + dep so consumers can ask for the subsystem they need
+# without dragging the others in.
+subdir('input')
+subdir('profile')
+subdir('storage')
+subdir('fs')
+subdir('renderer')
diff --git a/targets/platform/profile/meson.build b/targets/platform/profile/meson.build
new file mode 100644
index 000000000..8990e76d4
--- /dev/null
+++ b/targets/platform/profile/meson.build
@@ -0,0 +1,12 @@
+lib_platform_profile_stub = static_library(
+  'platform_profile_stub',
+  files('stub/StubProfile.cpp'),
+  include_directories: [platform_inc, include_directories('../..')],
+  dependencies: [_threads],
+  cpp_args: global_cpp_args + global_cpp_defs,
+)
+
+profile_dep = declare_dependency(
+  link_with: lib_platform_profile_stub,
+  include_directories: [platform_inc],
+)
diff --git a/targets/platform/renderer/meson.build b/targets/platform/renderer/meson.build
new file mode 100644
index 000000000..ee1bfa419
--- /dev/null
+++ b/targets/platform/renderer/meson.build
@@ -0,0 +1,13 @@
+lib_platform_renderer_gl = static_library(
+  'platform_renderer_gl',
+  files('gl/GLRenderer.cpp', 'gl/render_stubs.cpp'),
+  include_directories: [platform_inc, include_directories('../..')],
+  dependencies: [_sdl2, _gl, _threads, glm_dep, stb_dep, java_dep],
+  cpp_args: _defs + global_cpp_args + global_cpp_defs,
+)
+
+render_dep = declare_dependency(
+  link_with: lib_platform_renderer_gl,
+  include_directories: [platform_inc],
+  dependencies: [_sdl2, _gl, _threads, glm_dep],
+)
diff --git a/targets/platform/storage/meson.build b/targets/platform/storage/meson.build
new file mode 100644
index 000000000..a4b5d57ec
--- /dev/null
+++ b/targets/platform/storage/meson.build
@@ -0,0 +1,12 @@
+lib_platform_storage_stub = static_library(
+  'platform_storage_stub',
+  files('stub/StubStorage.cpp'),
+  include_directories: [platform_inc, include_directories('../..')],
+  dependencies: [_threads],
+  cpp_args: global_cpp_args + global_cpp_defs,
+)
+
+storage_dep = declare_dependency(
+  link_with: lib_platform_storage_stub,
+  include_directories: [platform_inc],
+)