GPC多边形初始化 [英] GPC Polygon Initialization

问题描述

我使用的是GPC 多边形裁剪的lib 并希望编程方式创建一个多边形。我只看到code如何创建一个从文件。我该怎么办初始化在我的code？

解决方案

  gpc_polygon主题;
INT W = 100，H = 100，verticesCnt = 30;//设置一个gpc_polygon容器中，用随机顶点填充...
subject.num_contours = 1;
subject.hole = 0;
subject.contour =新gpc_vertex_list; //此处即只是一个单一的多边形
subject.contour-＆GT;为num_vertices = verticesCnt;
subject.contour-＆GT;顶点=新gpc_vertex [verticesCnt]
对于（i = 0; I＆LT; verticesCnt;我++）{
    subject.contour [0] .vertex [I]的.x =随机（重量）;
    subject.contour [0] .vertex [I] .Y =随机（H）;
}//做的东西用在这里，然后... ...gpc_free_polygon（安培;一级学科）;
 

I am using the GPC Polygon Clipping lib and want to create a polygon programatically. I only see code for how to create one from a file. How can I do the initialization in my code?

解决方案

gpc_polygon subject;
int w = 100, h = 100, verticesCnt = 30;

//setup a gpc_polygon container and fill it with random vertices ...
subject.num_contours = 1;
subject.hole = 0;
subject.contour = new gpc_vertex_list; //ie just a single polygon here
subject.contour->num_vertices = verticesCnt;
subject.contour->vertex = new gpc_vertex [verticesCnt];
for (i = 0; i < verticesCnt; i++){
    subject.contour[0].vertex[i].x = random(w);
    subject.contour[0].vertex[i].y = random(h);
}

//do stuff with it here, then ...

gpc_free_polygon(&subject);

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