如何制作带有圆角的SDL2窗口？

Question

我正在使用函数

SDL_WINDOW_BORDERLESS

中的选项

SDL_CreateWindow()

来删除窗口顶部菜单。它可以工作，但是我怎样才能圆化窗口的边框角呢？

顺便说一句，我正在使用 Mac

Answer 1

SDL_shape.h

中有形状窗口创建/操作功能：

/**
 *  \brief Create a window that can be shaped with the specified position, dimensions, and flags.
 *
 *  \param title The title of the window, in UTF-8 encoding.
 *  \param x     The x position of the window, ::SDL_WINDOWPOS_CENTERED, or
 *               ::SDL_WINDOWPOS_UNDEFINED.
 *  \param y     The y position of the window, ::SDL_WINDOWPOS_CENTERED, or
 *               ::SDL_WINDOWPOS_UNDEFINED.
 *  \param w     The width of the window.
 *  \param h     The height of the window.
 *  \param flags The flags for the window, a mask of SDL_WINDOW_BORDERLESS with any of the following:
 *               ::SDL_WINDOW_OPENGL,     ::SDL_WINDOW_INPUT_GRABBED,
 *               ::SDL_WINDOW_HIDDEN,     ::SDL_WINDOW_RESIZABLE,
 *               ::SDL_WINDOW_MAXIMIZED,  ::SDL_WINDOW_MINIMIZED,
 *       ::SDL_WINDOW_BORDERLESS is always set, and ::SDL_WINDOW_FULLSCREEN is always unset.
 *
 *  \return The window created, or NULL if window creation failed.
 *
 *  \sa SDL_DestroyWindow()
 */
extern DECLSPEC SDL_Window * SDLCALL SDL_CreateShapedWindow(const char *title,unsigned int x,unsigned int y,unsigned int w,unsigned int h,Uint32 flags);

/**
 * \brief Set the shape and parameters of a shaped window.
 *
 * \param window The shaped window whose parameters should be set.
 * \param shape A surface encoding the desired shape for the window.
 * \param shape_mode The parameters to set for the shaped window.
 *
 * \return 0 on success, SDL_INVALID_SHAPE_ARGUMENT on an invalid shape argument, or SDL_NONSHAPEABLE_WINDOW
 *           if the SDL_Window given does not reference a valid shaped window.
 *
 * \sa SDL_WindowShapeMode
 * \sa SDL_GetShapedWindowMode.
 */
extern DECLSPEC int SDLCALL SDL_SetWindowShape(SDL_Window *window,SDL_Surface *shape,SDL_WindowShapeMode *shape_mode);

test/testshape.c

中的使用示例