Question

我需要在游戏中摆脱物理因素，因此我需要实现自定义碰撞检测功能（每帧都会调用碰撞检测功能）。我想检查矩形是否与圆相交。我从here（e.James的答案）中获取了代码：

bool intersects(CircleType circle, RectType rect)
{
    circleDistance.x = abs(circle.x - rect.x - rect.width/2);
    circleDistance.y = abs(circle.y - rect.y - rect.height/2);

    if (circleDistance.x > (rect.width/2 + circle.r)) { return false; }
    if (circleDistance.y > (rect.height/2 + circle.r)) { return false; }

    if (circleDistance.x <= (rect.width/2)) { return true; } 
    if (circleDistance.y <= (rect.height/2)) { return true; }

    cornerDistance_sq = (circleDistance.x - rect.width/2)^2 +
                         (circleDistance.y - rect.height/2)^2;

    return (cornerDistance_sq <= (circle.r^2));
}

并改为：

--Collision detection between circle and rect
local function intersects(circle, rect)
    if circle ~= nil then
        local circleDistance_x = math.abs(circle.x - rect.x - rect.width/2);
        local circleDistance_y = math.abs(circle.y - rect.y - rect.height/2);

        if (circleDistance_x > (rect.width/2 + circle.r)) then 
            return false
        end
        if (circleDistance_y > (rect.height/2 + circle.r)) then  
            return false
        end

        if (circleDistance_x <= (rect.width/2)) then
            return true
        end

        if (circleDistance_y <= (rect.height/2)) then
            return true
        end

        cornerDistance_sq = (circleDistance_x - rect.width/2)^2 +
                             (circleDistance_y - rect.height/2)^2;

        return (cornerDistance_sq <= (circle.r^2));
        else
            return false
    end
end

我确保给圈子一个r属性并将其设为20.我没有收到任何错误。当矩形靠近圆圈时，矩形被移除（当矩形击中圆的中心时，似乎函数返回true，但我可能错了）。我在转换中做错了吗？

Answer 1

更改这两行：

    local circleDistance_x = math.abs(circle.x - rect.x - rect.width/2);
    local circleDistance_y = math.abs(circle.y - rect.y - rect.height/2);

要：

    local circleDistance_x = math.abs(circle.x+circle.r - rect.x - rect.width/2)
    local circleDistance_y = math.abs(circle.y+circle.r - rect.y - rect.height/2)

似乎要做的伎俩。 Hurray随机猜测！

圆形直接碰撞检测在Corona SDK中不起作用

1 个答案: