opencv：图形绘制与填充

#include <opencv2/opencv.hpp>
#include <iostream>
using namespace cv;
using namespace std;
int main(int argc, char** argv)
{
    Mat canvas = Mat::zeros(Size(512, 512), CV_8UC3);
    // 相关绘制的API
    /* line 参数说明：
        1. 在哪个图像上绘制
        2. 起点
        3. 终点
        4. 颜色
        5. 线宽
        6. type：绘制模式,LINE_AA反锯齿，LINE_8就是8
        7. 水平位移，默认0，一般用不到
    */
    line(canvas, Point(0, 0), Point(200, 200), Scalar(0,0,255), 5, LINE_8);
    Rect rect(100, 100, 200, 200);
    rectangle(canvas, rect, Scalar(255, 0, 0), 4, LINE_8);
    circle(canvas, Point(256, 256), 100, Scalar(0, 255, 0), 1, 8);
    RotatedRect rrt;
    rrt.center = Point2f(256, 256);
    rrt.angle = 45; // 这里是角度
    rrt.size = Size(100, 200);
    ellipse(canvas, rrt, Scalar(0, 255, 255), 1, 8);
    //线宽如果为-1，则会变成填充模式
    namedWindow("canvas", WINDOW_AUTOSIZE);
    imshow("canvas", canvas);
    // 绘制随机形状
    Mat image = Mat::zeros(Size(512, 512), CV_8UC3);
    int x1 = 0, y1 = 0;
    int x2 = 0, y2 = 0;
    RNG rng(12345);
    while (true) {
        x1 = (int)rng.uniform(0, 512);
        x2 = (int)rng.uniform(0, 512);
        y1 = (int)rng.uniform(0, 512);
        y2 = (int)rng.uniform(0, 512);
        int w = abs(x2 - x1);
        int h = abs(y2 - y1);
        rect.x = x1;
        rect.y = y1;
        rect.width = w;
        rect.height = h;
        image = Scalar(0, 0, 0);
        Scalar color(rng.uniform(0, 256), rng.uniform(0, 256), rng.uniform(0, 256));
        rectangle(image, rect, color, 1, 8);
        //line(image, Point(x1, y1), Point(x2, y2), Scalar(rng.uniform(0, 256), rng.uniform(0, 256), rng.uniform(0, 256)), 1, 8);
        imshow("image", image);
        char c = waitKey(10);
        if (c == 27) {
            break;
        }
    }
    waitKey(0);
    destroyAllWindows();
    return 0;
}