Add SDL headers and PhysFS to libretro builds

I don't think I'll be needing SDL. Pretty sure about 100% of the
functionality of SDL that's currently being used here is either trivial
to reimplement or needs to be replaced for the libretro core to work in
the first place. For example, I already know I'm going to need to
completely replace the SDL input handling with libretro's input API.
Also, I'll need to get rid of the use of SDL threads in the audio code
later because libretro cores need to render audio synchronously with the
video rendering.

I'm including the SDL headers, though, to reduce the number of
compilation errors.

meson.build

@@ -98,6 +98,15 @@ if get_option('retro') == true
         'ENABLE_ZSTD': true,
     })
 
+    physfs_options = cmake.subproject_options()
+    physfs_options.add_cmake_defines({
+        'CMAKE_POSITION_INDEPENDENT_CODE': get_option('b_staticpic'),
+        'PHYSFS_BUILD_STATIC': true,
+        'PHYSFS_BUILD_SHARED': false,
+        'PHYSFS_BUILD_TEST': false,
+        'PHYSFS_BUILD_DOCS': false,
+    })
+
     openal_options = cmake.subproject_options()
     openal_options.add_cmake_defines({
         'CMAKE_POSITION_INDEPENDENT_CODE': get_option('b_staticpic'),
@@ -174,6 +183,7 @@ if get_option('retro') == true
             cmake.subproject('liblzma', options: liblzma_options).dependency('liblzma'),
             cmake.subproject('zstd', options: zstd_options).dependency('libzstd_static'),
             cmake.subproject('libzip', options: libzip_options).dependency('zip'),
+            cmake.subproject('physfs', options: physfs_options).dependency('physfs-static'),
             cmake.subproject('openal-soft', options: openal_options).dependency('OpenAL'),
         ],
         c_args: [
@@ -200,6 +210,7 @@ if get_option('retro') == true
             include_directories(retro_phase1),
             include_directories(join_paths(retro_phase1, 'wasm2c')),
             include_directories(join_paths(retro_phase1, 'mkxp-retro-ruby')),
+            include_directories(join_paths(retro_phase1, 'sdl/include')),
         ],
         sources: [
             'src/core.cpp',

retro/Makefile

@@ -6,6 +6,7 @@ LIBYAML_VERSION ?= 0.2.5
 ZLIB_VERSION ?= 1.3.1
 OPENSSL_VERSION ?= 3.2.0
 WASM_RT_VERSION ?= 1.0.36
+SDL_VERSION ?= 2.30.11
 P7ZIP_VERSION ?= 17.06
 TARGET ?= wasm32-wasip1
 WASI_SDK ?= /opt/wasi-sdk
@@ -51,7 +52,7 @@ ruby-dist: $(OUTDIR)/mkxp-retro-dist.zip.c $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-
 
 ruby-bindings: $(OUTDIR)/mkxp-sandbox-bindgen.cpp $(OUTDIR)/mkxp-sandbox-bindgen.h
 
-deps: $(OUTDIR)/libretro.h $(OUTDIR)/wasm2c/wasm-rt.h $(OUTDIR)/wasm2c/wasm-rt-impl.c $(OUTDIR)/wasm2c/wasm-rt-mem-impl.c
+deps: $(OUTDIR)/libretro.h $(OUTDIR)/wasm2c/wasm-rt.h $(OUTDIR)/wasm2c/wasm-rt-impl.c $(OUTDIR)/wasm2c/wasm-rt-mem-impl.c $(OUTDIR)/sdl/include/SDL.h
 
 clean: clean-ruby-dist clean-ruby-bindings clean-deps
 	rm -rf $(LIBDIR)/*
@@ -70,6 +71,7 @@ clean-ruby-bindings:
 clean-deps:
 	rm -f $(OUTDIR)/libretro.h
 	rm -rf $(OUTDIR)/wasm2c
+	rm -rf $(OUTDIR)/sdl
 	rm -rf $(DOWNLOADS)/wabt
 
 $(OUTDIR)/libretro.h:
@@ -77,11 +79,16 @@ $(OUTDIR)/libretro.h:
 	$(CURL) -s -L -o $(OUTDIR)/libretro.h https://raw.githubusercontent.com/libretro/libretro-common/$(LIBRETRO_REF)/include/libretro.h
 
 $(OUTDIR)/wasm2c/wasm-rt.h $(OUTDIR)/wasm2c/wasm-rt-impl.c $(OUTDIR)/wasm2c/wasm-rt-mem-impl.c &:
+	mkdir -p $(DOWNLOADS)
 	mkdir -p $(OUTDIR)
 	$(CLONE) $(GITHUB)/WebAssembly/wabt $(DOWNLOADS)/wabt -b $(WASM_RT_VERSION)
 	$(SED) -i 's/# *define * WASM_RT_C11_AVAILABLE//g' $(DOWNLOADS)/wabt/wasm2c/wasm-rt.h # Stop wasm-rt from trying to use threads because it causes compiler errors on some game console toolchains, and also because OpenAL Soft defines a header file named "threads.h" which conflicts with the C11 threads.h that this file tries to include
 	cp -r $(DOWNLOADS)/wabt/wasm2c $(OUTDIR)
 
+$(OUTDIR)/sdl/include/SDL.h:
+	mkdir -p $(OUTDIR)
+	$(CLONE) $(GITHUB)/libsdl-org/SDL $(OUTDIR)/sdl -b release-$(SDL_VERSION)
+
 # Cross Ruby (targets WASI)
 
 $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-ruby.h $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-ruby-impl.h $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-ruby_0.c $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-ruby_1.c $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-ruby_2.c $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-ruby_3.c $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-ruby_4.c $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-ruby_5.c $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-ruby_6.c $(OUTDIR)/mkxp-retro-ruby/mkxp-retro-ruby_7.c &: $(LIBDIR)/mkxp-retro-dist/bin/ruby

src/etc/etc-internal.h

@@ -24,17 +24,7 @@
 
 #include "util.h"
 
-#ifdef MKXPZ_RETRO
-struct SDL_Rect
-{
-	int x;
-	int y;
-	int w;
-	int h;
-};
-#else
 #include <SDL_rect.h>
-#endif // MKXPZ_RETRO
 
 struct Vec2
 {

subprojects/physfs.wrap

@@ -0,0 +1,4 @@
+[wrap-git]
+url = https://github.com/icculus/physfs
+revision = release-3.2.0
+depth = 1