我需要编写和算法填充的关闭多行的有水平等距线。

我已经做了类似的事情的矩形和圆的，这里是一个code段为后者的：

  //圆的参数：中心（点（0）.X，点（0）·Y），半径
INT offsetX =点（0）.X +半径;
INT offsetY =点（0）.Y +半径;
对于（INT I = -radius; I＆LT;半径; I + =间距）{
    INT RY =我;
    INT RX =开方（双（半径*半径 -  RY * RY））;
    //参数是一对水平行的坐标的
    fl_line（offsetX  -  RX，offsetY + I，
            offsetX + RX，offsetY + I）;
}
 

在的的封闭折线的情况下的难度的附加度数（我）是水平行的坐标将不被从一个单一等式（圆萃取，矩形的高度，等），而是从线与方程相同的y的的坐标，这将不连续匹配

问：

你能为我提供关于如何着手创建一种算法，填补了封闭聚线与水平线一些见解？ 解决方案

这是扫描线算法的一个特例（设计用于填充面）：的 http://www.tutorialspoint.com/computer_graphics/polygon_filling_algorithm.htm

这是YMIN（您多边形的顶部），以YMAX迭代y随所需的步骤（间隔）。

对于每个Y，找到交叉点与多边形线段，责令他们的x坐标，用线连接每隔一

I need to write and algorithm that fills closed poly-line with horizontal equidistant lines.

I've done similar things with rectangles and circles, here is a code snippet for the latter:

// circle parameters: center(point(0).x, point(0).y), radius
int offsetX = point(0).x + radius;
int offsetY = point(0).y + radius;
for(int i = -radius; i < radius; i += spacing){
    int ry = i;
    int rx = sqrt(double(radius*radius - ry*ry));
    // the parameters are pair of coordinates of the horizontal line
    fl_line(offsetX - rx, offsetY + i, 
            offsetX + rx, offsetY + i);
}

In the case of closed poly-line the additional degree of difficulty (for me) is that the coordinates of the horizontal lines would not be extracted from a single equation (circle, height of rectangle, etc), but rather from the equations of the lines with the same "y" coordinates, which will not match continuously.

Question:

Could you provide me with some insight on how to proceed with creating an algorithm that fills closed poly-lines with horizontal lines?

解决方案

This is just a special case of the scan line algorithm (designed for filling polygons): http://www.tutorialspoint.com/computer_graphics/polygon_filling_algorithm.htm

Iterate y from yMin (top of your polygon) to yMax with the desired step (spacing).

For each y, find intersections with the polygon line segments, order them by their x-coordinate, connect every other pair with a line