Deprecate <TARGET>_BUILD in favor of CMAKE_TOOLCHAIN_FILE

CMakeLists.txt

@@ -1,22 +1,5 @@
 cmake_minimum_required(VERSION 3.13)
 
-option(PS1_BUILD "Build for the original Sony Playstation" OFF)
-option(HOST_BUILD "Build for host platform using SDL-1.2" OFF)
-option(WIN9X_BUILD "Build for Win9x using SDL-1.2" OFF)
-
-if(NOT PS1_BUILD AND NOT HOST_BUILD AND NOT WIN9X_BUILD)
-    message(STATUS "Assuming native build. "
-"Please use one of the available options in CMakeLists.txt to "
-"cross-compile for a specific target.")
-    set(HOST_BUILD ON)
-endif()
-
-if(PS1_BUILD)
-    include("cmake/ps1-toolchain.cmake")
-elseif(WIN9X_BUILD)
-    include("cmake/win9x-toolchain.cmake")
-endif()
-
 set(TOOLS_PREFIX ${CMAKE_BINARY_DIR}/tools)
 include(ExternalProject)
 ExternalProject_Add(tools
@@ -26,6 +9,14 @@ ExternalProject_Add(tools
 
 project(rts)
 
+if(CMAKE_TOOLCHAIN_FILE MATCHES "ps1")
+    set(PS1_BUILD 1)
+elseif(CMAKE_TOOLCHAIN_FILE MATCHES "win9x")
+    set(WIN9X_BUILD 1)
+else()
+    set(HOST_BUILD 1)
+endif()
+
 add_executable(${PROJECT_NAME} "src/main.c")
 set(cdroot ${CMAKE_BINARY_DIR}/cdimg)
 # Avoid C11 since it is not supported by the i386-mingw32 toolchain.

README.md

@@ -34,6 +34,8 @@ hardware.
 
 ## Building from source
 
+### Native build
+
 A native version of **RTS** can be built using the typical CMake build
 process:
 
@@ -41,21 +43,25 @@ process:
 mkdir build
 cd build
 cmake ..
+make -j$(nproc --all)
 ```
 
-The following options can be otherwise defined:
+### Cross-compilation
 
-- `PS1_BUILD`: builds for Sony Playstation 1
-- `HOST_BUILD`: builds for the host operating system using SDL-1.2
-- `WIN9X_BUILD`: builds for Microsoft Win9x operating systems using
-SDL-1.2. A `i386-mingw32` cross-toolchain must be available.
+[`CMAKE_TOOLCHAIN_FILE`](https://cmake.org/cmake/help/latest/variable/CMAKE_TOOLCHAIN_FILE.html)
+can be used to set up the cross-toolchain. Files labeled as
+`cmake/*-toolchain.cmake` can be used as values.
+
+#### Sony PlayStation 1
 
 For example, the Sony PlayStation 1 version can be built using:
 
 ```sh
 mkdir build
 cd build
-cmake .. -DPS1_BUILD=1 -DVIDEO_MODE=VMODE_PAL
+cmake .. \
+    -DCMAKE_TOOLCHAIN_FILE=../cmake/ps1-toolchain.cmake \
+    -DVIDEO_MODE=VMODE_PAL # VMODE_NTSC can be otherwise used
 make -j$(nproc --all)
 ```
 
@@ -63,6 +69,18 @@ This will generate a `.bin`/`.cue` file pair in `build` that can be
 played on an emulator or burnt into a CD-r in order to play the game
 on real hardware.
 
+#### Microsoft Win9x
+
+```sh
+mkdir build
+cd build
+cmake .. -DCMAKE_TOOLCHAIN_FILE=../cmake/win9x-toolchain.cmake
+make -j$(nproc --all)
+```
+
+A stripped version of the executable, as well as game assets, will be
+located in `build/cdimg`.
+
 ## License
 
 Unless stated otherwise, **RTS** follows the license described by the