Use find_package for SDL libraries

CMake already distributes FindSDL*.cmake files for SDL and SDL_mixer,
which support custom prefixes via environment variables, removing the
need for ad-hoc logic in Win9x builds.

Also, according to FindSDL.cmake, #include <SDL.h> is the preferred way
for portability reasons, instead of #include <SDL/SDL.h>, which is the
option that has been used so far.

CMakeLists.txt

@@ -14,11 +14,26 @@ if(CMAKE_TOOLCHAIN_FILE MATCHES "ps1")
     set(PS1_BUILD 1)
 elseif(CMAKE_TOOLCHAIN_FILE MATCHES "win9x")
     set(WIN9X_BUILD 1)
+    set(SDL1_2_BUILD 1)
 else()
     set(HOST_BUILD 1)
+    set(SDL1_2_BUILD 1)
 endif()
 
 add_executable(${PROJECT_NAME} "src/main.c")
+
+if(SDL1_2_BUILD)
+    find_package(SDL 1.2 REQUIRED)
+    find_package(SDL_gfx 2.0 REQUIRED)
+    find_package(SDL_mixer 1.2 REQUIRED)
+    # FindSDL_mixer.cmake does not export any target, so do it here instead.
+    add_library(SDL::SDL_mixer STATIC IMPORTED)
+    set_property(TARGET SDL::SDL_mixer PROPERTY
+        IMPORTED_LOCATION ${SDL_MIXER_LIBRARIES})
+    target_include_directories(SDL::SDL_mixer INTERFACE ${SDL_MIXER_INCLUDE_DIRS})
+    target_link_libraries(SDL::SDL_mixer INTERFACE SDL::SDL)
+endif()
+
 set(cdroot ${CMAKE_BINARY_DIR}/cdimg)
 file(MAKE_DIRECTORY ${cdroot})
 # Avoid C11 since it is not supported by the i386-mingw32 toolchain.

cmake/host.cmake

@@ -1,8 +1,3 @@
-find_package(SDL 1.2 REQUIRED)
-find_package(SDL_mixer 1.2 REQUIRED)
-find_package(SDL_gfx 2.0 REQUIRED)
-set(SDL1_2_BUILD 1)
-
 if(CMAKE_BUILD_TYPE STREQUAL "Debug")
         set(cflags ${cflags} -Og)
 else()

cmake/win9x.cmake

@@ -1,11 +1,3 @@
-if("$ENV{SDL_PATH}" STREQUAL "")
-    message(FATAL_ERROR "please define env variable SDL_PATH")
-elseif("$ENV{SDL_MIXER_PATH}" STREQUAL "")
-    message(FATAL_ERROR "please define env variable SDL_MIXER_PATH")
-elseif("$ENV{SDL_GFX_PATH}" STREQUAL "")
-    message(FATAL_ERROR "please define env variable SDL_GFX_PATH")
-endif()
-
 add_custom_command(OUTPUT ${cdroot}/${PROJECT_NAME}
         COMMAND i386-mingw32-strip ${PROJECT_NAME} -o ${cdroot}/${PROJECT_NAME}
         WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
@@ -13,26 +5,9 @@ add_custom_command(OUTPUT ${cdroot}/${PROJECT_NAME}
         VERBATIM)
 add_custom_target(stripped-exe ALL DEPENDS ${cdroot}/${PROJECT_NAME})
 
-add_library(SDL STATIC IMPORTED)
-set_property(TARGET SDL PROPERTY IMPORTED_LOCATION $ENV{SDL_PATH}/lib/libSDL.a)
-target_include_directories(SDL INTERFACE
-        $ENV{SDL_PATH}/include $ENV{SDL_PATH}/include/SDL)
-target_link_libraries(SDL INTERFACE gdi32 user32 winmm dxguid)
-
-add_library(SDL_mixer STATIC IMPORTED)
-set_property(TARGET SDL_mixer PROPERTY IMPORTED_LOCATION
-    $ENV{SDL_MIXER_PATH}/lib/libSDL_mixer.a)
-target_include_directories(SDL_mixer INTERFACE $ENV{SDL_MIXER_PATH}/include)
-target_link_libraries(SDL_mixer INTERFACE SDL)
-
-add_library(SDL_gfx STATIC IMPORTED)
-set_property(TARGET SDL_gfx PROPERTY IMPORTED_LOCATION
-    $ENV{SDL_GFX_PATH}/lib/libSDL_gfx.a)
-target_include_directories(SDL_gfx INTERFACE $ENV{SDL_GFX_PATH}/include)
-target_link_libraries(SDL_gfx INTERFACE SDL)
+target_link_libraries(SDL::SDL INTERFACE gdi32 user32 winmm dxguid)
 
 add_compile_options(-march=i386)
-set(SDL1_2_BUILD 1)
 
 if(CMAKE_BUILD_TYPE STREQUAL "Debug")
     # i386-mingw32-gcc 3.4.5 does not support -Og.

src/gfx/CMakeLists.txt

@@ -24,8 +24,8 @@ elseif(SDL1_2_BUILD)
         "sdl-1.2/src/rect.c"
         "sdl-1.2/src/sprite.c"
         "sdl-1.2/src/quad.c")
-    set(deps ${deps} SDL)
-    set(privdeps ${privdeps} header SDL_gfx)
+    set(deps ${deps} SDL::SDL)
+    set(privdeps ${privdeps} header SDL::SDL_gfx)
 endif()
 
 add_library(gfx ${src})

src/gfx/sdl-1.2/inc/gfx/port.h

@@ -1,7 +1,7 @@
 #ifndef GFX_SDL_H
 #define GFX_SDL_H
 
-#include <SDL/SDL.h>
+#include <SDL.h>
 #include <stdbool.h>
 
 #ifdef __cplusplus

src/gfx/sdl-1.2/privinc/sdl-1.2/gfx_private.h

@@ -2,7 +2,7 @@
 #define GFX_SDL_12_PRIVATE_H
 
 #include <gfx.h>
-#include <SDL/SDL.h>
+#include <SDL.h>
 
 #ifdef __cplusplus
 extern "C"

src/gfx/sdl-1.2/src/env.c

@@ -1,7 +1,7 @@
 #include <gfx.h>
 #include <gfx_private.h>
 #include <sdl-1.2/gfx_private.h>
-#include <SDL/SDL.h>
+#include <SDL.h>
 #include <inttypes.h>
 #include <stdbool.h>
 #include <stdio.h>

src/gfx/sdl-1.2/src/rect.c

@@ -1,7 +1,7 @@
 #include <gfx.h>
 #include <gfx/port.h>
 #include <sdl-1.2/gfx_private.h>
-#include <SDL/SDL.h>
+#include <SDL.h>
 
 void rect_sort(struct rect *const r)
 {

src/gfx/sdl-1.2/src/sprite.c

@@ -2,8 +2,8 @@
 #include <gfx/port.h>
 #include <header.h>
 #include <sdl-1.2/gfx_private.h>
-#include <SDL/SDL.h>
-#include <SDL/SDL_rotozoom.h>
+#include <SDL.h>
+#include <SDL_rotozoom.h>
 #include <errno.h>
 #include <stddef.h>
 #include <stdlib.h>

src/keyboard/CMakeLists.txt

@@ -6,7 +6,7 @@ if(PS1_BUILD)
     set(privdeps ${privdeps} PSXSDK::PSXSDK)
 elseif(SDL1_2_BUILD)
     set(src ${src} "sdl-1.2/src/keyboard.c")
-    set(deps ${deps} SDL)
+    set(privdeps ${privdeps} SDL::SDL)
 endif()
 
 add_library(keyboard ${src})

src/keyboard/sdl-1.2/src/keyboard.c

@@ -1,6 +1,6 @@
 #include <keyboard.h>
 #include <keyboard_key.h>
-#include <SDL/SDL.h>
+#include <SDL.h>
 #include <stdio.h>
 
 static void append_key(const enum keyboard_key key, struct keyboard *const k)

src/mouse/CMakeLists.txt

@@ -6,7 +6,7 @@ if(PS1_BUILD)
     set(privdeps ${privdeps} PSXSDK::PSXSDK)
 elseif(SDL1_2_BUILD)
     set(src ${src} "sdl-1.2/src/mouse.c")
-    set(deps ${deps} SDL)
+    set(privdeps ${privdeps} SDL::SDL)
 endif()
 
 add_library(mouse ${src})

src/mouse/sdl-1.2/src/mouse.c

@@ -1,5 +1,5 @@
 #include <mouse.h>
-#include <SDL/SDL.h>
+#include <SDL.h>
 #include <stdint.h>
 #include <inttypes.h>
 #include <stdio.h>

src/pad/CMakeLists.txt

@@ -9,7 +9,7 @@ if(PS1_BUILD)
 elseif(SDL1_2_BUILD)
     set(src ${src} "sdl-1.2/src/pad.c")
     set(inc ${inc} "sdl-1.2/inc")
-    set(deps ${deps} SDL)
+    set(deps ${deps} SDL::SDL)
 endif()
 
 add_library(pad ${src})

src/pad/sdl-1.2/src/pad.c

@@ -1,5 +1,5 @@
 #include <pad.h>
-#include <SDL/SDL.h>
+#include <SDL.h>
 #include <stdio.h>
 
 void pad_port_update(struct pad *const p)

src/sfx/CMakeLists.txt

@@ -9,8 +9,8 @@ elseif(SDL1_2_BUILD)
     set(src
         "sdl-1.2/src/sound.c")
     set(inc ${inc} "sdl-1.2/inc")
-    set(deps ${deps} SDL_mixer)
-    set(privdeps ${privdeps} SDL header)
+    set(deps ${deps} SDL::SDL_mixer)
+    set(privdeps ${privdeps} SDL::SDL header)
 endif()
 
 add_library(sfx ${src})

src/sfx/sdl-1.2/inc/sfx/port.h

@@ -1,7 +1,7 @@
 #ifndef SFX_SDL1_2_H
 #define SFX_SDL1_2_H
 
-#include <SDL/SDL_mixer.h>
+#include <SDL_mixer.h>
 #include <stdbool.h>
 
 #ifdef __cplusplus

src/sfx/sdl-1.2/src/sound.c

@@ -1,8 +1,8 @@
 #include <sfx.h>
 #include <sfx/port.h>
 #include <header.h>
-#include <SDL/SDL.h>
-#include <SDL/SDL_mixer.h>
+#include <SDL.h>
+#include <SDL_mixer.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>

src/system/CMakeLists.txt

@@ -8,6 +8,7 @@ if(PS1_BUILD)
 elseif(SDL1_2_BUILD)
     set(src "sdl-1.2/src/system.c")
     set(inc ${inc} "sdl-1.2/inc")
+    set(privdeps ${privdeps} SDL::SDL)
 endif()
 
 add_library(system ${src})

src/system/sdl-1.2/src/system.c

@@ -1,7 +1,7 @@
 #include <gfx.h>
 #include <sfx.h>
 #include <system.h>
-#include <SDL/SDL.h>
+#include <SDL.h>
 #include <stdio.h>
 #include <stdlib.h>