feat: 假如 USE_SDL_FROM_SRC 选项用于强制使用源码中的 SDL2，并更新 README

CMakeLists.txt

@@ -14,11 +14,15 @@ add_compile_options("$<$<CXX_COMPILER_ID:MSVC>:/utf-8>")
 add_subdirectory(dependencies/lvgl)
 
 find_package(SDL2 CONFIG COMPONENTS SDL2 SDL2main SDL2-static)
-if(NOT SDL2_FOUND)
-  message(WARNING "SDL2 notfound in your system! SDL2 in source code will be used.")
+
+if(USE_SDL_FROM_SRC)
+  message(STATUS "Using the SDL2 from the source code.")
+  add_subdirectory(dependencies/sdl2)
+elseif(NOT SDL2_FOUND)
+  message(WARNING "SDL2 notfound in your system! Using the SDL2 from the source code.")
   add_subdirectory(dependencies/sdl2)
 else()
-  message(STATUS "SDL2 found in your system.")
+  message(STATUS "Installed SDL2 has been found in your system. Using the SDL2 from your system.")
 endif()
 
 add_subdirectory(src)

README.md

@@ -2,7 +2,7 @@
 
 Other Languages: [简体中文](README_zh_CN.md)
 
-A Cross-Platform Simulator for LVGL using SDL2.
+A Cross-Platform Simulator Library for LVGL using SDL2. Supports Multi-Window.
 
 ## Contents
 
@@ -19,7 +19,7 @@ You need to install this library first, and then create a new project or use the
 
 The purpose is to **avoid repeated compilation** and **make the compiled product distributable** at will.
 
-1. **Clone this repository:**
+1. **Clone this repository**: **Be sure to add** `--recursive` **flag !!!**
    ```shell
    git clone --recursive https://github.com/Augtons/lvglsim.git
    ```
@@ -43,6 +43,18 @@ The purpose is to **avoid repeated compilation** and **make the compiled product
 > 
 > The benefit of this is to avoid cumbersome dependency management
 >
+> **Using the System SDL2 Library:**
+> 
+> If CMake successfully locates the SDL2 library using `find_package` during the project build,
+> it will **directly use it instead of compiling from source**.
+> 
+> If you want to use an already installed SDL2 library or if you are cross-compiling this project,
+> you can specify `-DCMAKE_PREFIX_PATH=<path>` when loading the project,
+> for adding the **parent path** containing `SDL2/SDL2Config.cmake`.
+> 
+> To **force compilation of the SDL library from the source code**,
+> specify `-DUSE_SDL_FROM_SRC=ON` when loading the project
+> 
 > **Uninstall:**
 >
 > If you want to uninstall this library, only requires deleting the export file and deleting the cmake compilation intermediate folder

README_zh_CN.md

@@ -2,7 +2,7 @@
 
 其他语言：[English](README.md)
 
-基于 SDL2 的跨平台 LVGL 模拟器。
+基于 SDL2 的跨平台 LVGL 模拟器。支持多窗口。
 
 ## 目录
 
@@ -19,7 +19,7 @@
 
 目的是为了**避免重复编译**和**使编译的产品可以随意分发**。
 
-1. **克隆本仓库：**
+1. **克隆本仓库：** **务必添加** `--recursive` **标志！！！**
    ```shell
    git clone --recursive https://github.com/Augtons/lvglsim.git
    ```
@@ -42,6 +42,15 @@
 >
 > 这样做的好处是避免了繁琐的依赖管理
 >
+> **使用系统 SDL2 库:**
+> 
+> 若构建此项目时，CMake 成功使用 `find_package` 找到 SDL2 库，那么就会**直接使用而不是从源码编译**。
+> 
+> 如果你想使用已被安装到的 SDL2 库，或者你正在交叉编译本项目。
+> 你可以在加载项目时指定 `-DCMAKE_PREFIX_PATH=<路径>`，将包含 `SDL2/SDL2Config.cmake` 的**父路径**添加进去
+>
+> 如果想**强制编译源码中的 SDL 库**，您可在加载项目时指定 `-DUSE_SDL_FROM_SRC=ON`
+> 
 > **卸载:**
 > 
 > 如果你想卸载这个库，只需要删除导出文件 (export file) 以及删除cmake编译中间文件夹