SDL_SetWindowMouseRect — the set area is one pixel too small

[furious-programming]

On the Windows platform, the cursor boundary area is one pixel too small — pixel is missing on the right and bottom of the selected area. To avoid this error, currently I have to increase Rect.W and Rect.H by one pixel first, and then pass it to SDL_SetWindowMouseRect.

This problem does not occur when null is passed as a pointer to a rect. Apparently, the SDL_SetWindowMouseRect function miscalculates the coordinates of the right and bottom sides of the rectangle by subtracting one pixel unnecessarily.

[flibitijibibo]

I think this is the relevant block:

https://github.com/libsdl-org/SDL/blob/main/src/video/windows/SDL_windowswindow.c#L1291-L1307

[furious-programming]

Thank you @flibitijibibo.

Note that the functions from the Win32 API take care of the correctness of right and bottom coordinates, not including these values in the handling of rects. So, wherever rect must be passed, right and bottom should be computed as X + W and Y + H respectively, without subtracting anything.

[flibitijibibo]

Makes sense to me! But, it looks like @slouken wrote this, so will defer to him since I don't know the Windows side very well:

7d21322

[slouken]

Fixed, thanks!