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Why is my canvas not clearing correctly?


The problem lies with your rect function. Specifically, with the usage of the .rect() member of the ctx. The rect member creates a path, which you then fill with ctx.fill() - only problem is, it doesn't close the path, so it remains open and is added to when the second call to poles comes along.

You can either close the path before exiting the rect function, or even more simply, avoid paths altogether by defining and filling the rectangle in a single call, by using ctx.fillRect.

The following change makes the code function as expected:

function rect(w, h, x, y) 
{
//    ctx.rect(x, y, w, h);
//    ctx.fill();
    ctx.fillRect(x,y,w,h);
}

Categories : Javascript

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