Implement th06::AnmManager::DrawEndingRect

[sere3925sere]

Interesting, those two produce exactly the same code:

    RECT rect;
    POINT point;
    rect.left = rectLeft;
    rect.top = rectTop;
    rect.right = rectLeft + width;
    rect.bottom = rectTop + height;
    point.x = rectX;
    point.y = rectY;

    RECT rect = {rectLeft, rectTop, rectLeft + width, rectTop + height};
    POINT point = {rectX, rectY};

Direct3D9 GetBackBuffer reference https://learn.microsoft.com/en-us/windows/win32/api/d3d9/nf-d3d9-idirect3ddevice9-getbackbuffer