FindSDL_gfx

在 3.25 版本中添加。

找到 SDL_gfx 库

此模块定义

SDL::SDL_gfx, the name of the target to use with target_*() commands
SDL_GFX_LIBRARIES, the name of the library to link against
SDL_GFX_INCLUDE_DIRS, where to find the headers
SDL_GFX_FOUND, if false, do not try to link against
SDL_GFX_VERSION_STRING - human-readable string containing the
                           version of SDL_gfx

$SDLDIR 是环境变量，它将对应于用于构建 SDL 的 ./configure --prefix=$SDLDIR。