关于范围内面积公式, 有谁知这些几何形状范围 - Project1

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# Simple Event Sensor
# Version: 1.10
# Author : LiTTleDRAgo
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#
# Instruction : 
#  
# Set the event name to : <Sensor(RANGE)>
# example :
#            <Sensor4>
#
# If player is in event sensor range, Self switch D (default) will turned ON
#
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class Game_Event < Game_Character
 #-----------------------------------------------------------------------
  SENSOR_SELF_SWITCH = 'D'
 #-----------------------------------------------------------------------
  alias drago64c_update update
  def update
    sensor_updating unless @unsensor
    drago64c_update  
  end
 
  def sensor_updating 
    @event.name =~ /<Sensor(\d+)>/i
    s = [$1.to_i,[$game_map.map_id,@id,SENSOR_SELF_SWITCH],[]]
    s[2] = [(($game_player.x-self.x).abs + ($game_player.y-self.y).abs <=  s[0] ##这里是范圍
 ), $game_self_switches[s[1]]] if s[0] > 0   
    return unless s[0] > 0 && s[2][0] != s[2][1]
    $game_self_switches[s[1]], $game_map.need_refresh = s[2][0], true 
  end
end

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# Simple Event Sensor


# Version: 1.10


# Author : LiTTleDRAgo


#:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=:=


#


# Instruction : 


#  


# Set the event name to : <Sensor(RANGE)>


# example :


#            <Sensor4>


#


# If player is in event sensor range, Self switch D (default) will turned ON


#


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class Game_Event < Game_Character


 #-----------------------------------------------------------------------


  SENSOR_SELF_SWITCH = 'D'


 #-----------------------------------------------------------------------


  alias drago64c_update update


  def update


    sensor_updating unless @unsensor


    drago64c_update  


  end


 


  def sensor_updating 


    @event.name =~ /<Sensor(\d+)>/i


    s = [$1.to_i,[$game_map.map_id,@id,SENSOR_SELF_SWITCH],[]]


    s[2] = [(($game_player.x-self.x).abs + ($game_player.y-self.y).abs <=  s[0] ##这里是范圍


 ), $game_self_switches[s[1]]] if s[0] > 0   


    return unless s[0] > 0 && s[2][0] != s[2][1]


    $game_self_switches[s[1]], $game_map.need_refresh = s[2][0], true 


  end


end

# 三角
def TriangleArea(x1,y1, x2,y2, x3,y3)
return ((x1 * y2 + x2 * y3 + x3 * y1 - x2 * y1 - x3 * y2 - x1 * y3) / 2.0).abs
end
x1,y1,x2,y2,x3,y3 = 100,100,50,200,150,200
x,y = 100,150
t = TriangleArea(x1, y1, x2, y2, x3, y3)
a = TriangleArea(x1, y1, x2, y2, x, y) +
TriangleArea(x1, y1, x, y, x3, y3) +
TriangleArea(x, y, x2, y2, x3, y3)
if (t - a).abs <= 0.01
p 'in_triangle'
end
# 矩形
rect = Rect.new(100,100,100,100)
x,y = 150,150
if x.between?(rect.x, rect.x+rect.width) and
y.between?(rect.y, rect.y+rect.height)
p 'in_rect'
end
# 圆
rx,ry,rd = 100,100,50
x,y = 120,120
if ((x-rx).abs ** 2 + (y-ry).abs ** 2) ** 0.5 <= rd
p 'in_circle'
end

复制代码

张咚咚发表于 2018-10-11 08:41

作者：周智
链接：https://www.zhihu.com/question/31763307/answer/53243067
来源：知乎
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

问题二：线段与线段的关系线段与线段也只有两种关系：两线段相交两线段无关联这种判断稍微复杂一些，为了更方便计算，涉及到了“平移”、“旋转”等操作。给定线段AB和CD，先将两线段整体平移（注意是整体），让线段AB的A端点与原点（0,0）重合，接着将两线段整体旋转（注意是整体），让线段AB与X轴的正方向重合。

如上图，将任意两线段AB和CD按照“先整体平移，再整体旋转”的顺序操作一遍，最终让线段AB的A端点与原点（0,0）重合，并让线段AB与X轴正方向重合。很显然，任意线段均可以进行以上操作。接下来，再在此基础上进行判断就比较简单了，如果线段CD的两个端点C和D的Y坐标均大于零（分布在第一、二象限）或者均小于零（分布在第三、四象限），那么AB与CD肯定不相交，换句话说，CD的两个端点必须一个在X轴上方另一个在X轴下方时，两条线段才有可能相交。如果线段CD的端点确实是一个在X轴上方一个在X轴下方，接下来再计算直线AB和直线CD（注意这里说的是直线）的交点（这时候两条直线一定有交点，并且交点在X轴上），这里暂定交点为P，如果P在X轴的负方向上（P.X<0），那么说明线段AB和CD不相交，如果P在X轴正方向但是P的X坐标大于线段AB的长度，那么说明线段AB和CD也不相交，其他情况下，线段AB和CD才属于“相交”关系。