点对点矩形测试 [英] Point-in-rectangle testing
本文介绍了点对点矩形测试的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有这个矩阵
/// as if the create a rectangle
int [][] loc = {
{5, 15},//(x1, y1)
{5, 30}, // (x1, y2)
{20, 15},// (x2, y1)
{20, 30}, // (x2, y2)
}
// this are the point that i want to check if they are in the rectangular range or not
int [] [] point = {
{6, 16}, //(x, y)
{3, 17}, //(x, y)
}
我想要的方法可以取点并搜索是否在loc范围内或不使用
x1< x< x2
和 y1< y< y2
I want i method that can take the point and search if it in the loc range or not by using
x1<x<x2
and y1<y<y2
推荐答案
点(x,y)位于矩形(x1,y1) - (x2,y2)内,如果
A point (x, y) is inside a rectangle (x1,y1) - (x2, y2) if
(x1< = x< = x2)和(y1< = y< = y2)
(x1 <= x <= x2) and (y1 <= y <= y2)
您的代码应如下所示(这实际上是C代码,但JavaScript不应该有太大差异):
Your code should look like this (this actually is C code, but JavaScript shouldn't be much different):
x1 = loc[0][0];
x2 = loc[2][0];
y1 = loc[0][1];
y2 = loc[2][1];
for (int i = 0; i < num_points; i++) {
if ((x1 <= point[i][0]) && (point[i][0] <= x2) &&
(y1 <= point[i][1]) && (point[i][1] <= y2)) {
// This point is inside the rectangle - insert code here
} else {
// This point is not inside the rectangle - insert code here
}
}
请注意,这只适用于(x1< = x2)和(y1< = y2),所以你可能会这样做也许通过使用它来确保上面的前四行:
Note that this will only work if (x1 <= x2) and (y1 <= y2), so you might perhaps make sure by using this instead the first four lines above:
x1 = Math.Min(loc[0][0], loc[2][0]);
x2 = Math.Max(loc[0][0], loc[2][0]);
y1 = Math.Min(loc[0][1], loc[2][1]);
y2 = Math.Max(loc[0][1], loc[2][1]);
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