如何使用鼠標拖動移動三角形

Question

我使用鼠標拖動繪製三角形。 繪製了許多不同的三角形後，我想用鼠標拖動將一些三角形移動到不同的位置，但是我不知道如何將三角形拖到不同的位置。請幫助：=（

Answer 1

彼得是對的，你問的最後時間（link）

下面是一些psudocode闡述了他在說什麼。

 
    on mouse down: 
    for each triangle, in reverse order of their drawing 
     if the pointer is within the triangle's area 
     set the "dragging" state in a member variable 
     add a reference to the triangle to a member variable 
     record the mouse position in a member variable 
     record the initial position of the triangle in a member variable 
     break 
     end if 
    end for 


    on mouse move: 
    if currently in the "dragging" state 
     move the triangle by the same amount the mouse has moved 
    end if 


    on mouse up: 
    if currently in the "dragging" state 
     move the triangle by the same amount as the mouse has moved 
     exit the "dragging" state 
    end if