三角形光柵化演算法__opencv

原理解釋：http://www.sunshine2k.de/coding/java/TriangleRasterization/TriangleRasterization.html

//// Created by yyy on 12/6/17.//#include <iostream>using namespace std;#include<fstream>#include<opencv2/opencv.hpp>#include<opencv2/core.hpp>#include<opencv/cv.h>#include<vector>void drawLine(cv::Mat& mat,int x1,int y1,int x2,int y2){    for(int i=x1;i<=x2;i++){           mat.at<int>(y1,i)=1;    }}void fillBottomFlatTriangle(cv::Mat& mat,cv::Point& v1,cv::Point& v2,cv::Point& v3){    float invslope1 = float(v2.x - v1.x) / float(v2.y - v1.y);    float invslope2 = float(v3.x - v1.x) / float(v3.y - v1.y);    float curx1 = v1.x;    float curx2 = v1.x;    for (int scanlineY = v1.y; scanlineY <= v2.y; scanlineY++)    {    drawLine(mat,(int)curx1, scanlineY, (int)curx2, scanlineY);      curx1 += invslope1;      curx2 += invslope2;    }}void fillTopFlatTriangle(cv::Mat& mat,cv::Point& v1,cv::Point& v2,cv::Point& v3){  float invslope1 = float(v3.x - v1.x) / float(v3.y - v1.y);  float invslope2 = float(v3.x - v2.x) / float(v3.y - v2.y);  float curx1 = v3.x;  float curx2 = v3.x;  for (int scanlineY = v3.y; scanlineY > v1.y; scanlineY--)  {  drawLine(mat,(int)curx1, scanlineY, (int)curx2, scanlineY);    curx1 -= invslope1;    curx2 -= invslope2;  }}void drawTriangle( cv::Mat& mat,std::vector<cv::Point>& triPts){   /* at first sort the three vertices by y-coordinate ascending so v1 is the topmost vertice */     std::sort(triPts.begin(),triPts.end(),[](cv::Point& p1,cv::Point&p2){return (p1.y==p2.y)?p1.x<p2.x : p1.y<p2.y;});       cv::Point& v1=triPts[0];       cv::Point& v2=triPts[1];       cv::Point& v3=triPts[2];  /* here we know that v1.y <= v2.y <= v3.y */  /* check for trivial case of bottom-flat triangle */  if (v2.y == v3.y)  {    fillBottomFlatTriangle(mat,v1, v2, v3);  }  /* check for trivial case of top-flat triangle */  else if (v1.y == v2.y)  {    fillTopFlatTriangle(mat, v1, v2, v3);  }  else  {    /* general case - split the triangle in a topflat and bottom-flat one */    cv::Point v4(      (int)(v1.x + ((float)(v2.y - v1.y) / (float)(v3.y - v1.y)) * (v3.x - v1.x)), v2.y);    fillBottomFlatTriangle(mat, v1, v2, v4);    fillTopFlatTriangle(mat, v2, v4, v3);  }}int main(){    cv::Mat mm(30,20,CV_32SC1,cv::Scalar(0));    cv::Mat mmm(30,20,CV_32SC1,cv::Scalar(0));    std::vector<cv::Point> triPts2(3);   triPts2[0]=(cv::Point(12,2));   triPts2[1]=(cv::Point(2,9));  triPts2[2]=(cv::Point(17,29));   drawTriangle(mm,triPts2);   cv::fillConvexPoly(mmm,triPts2,cv::Scalar(1));   //opencv 光柵化   std::cout<<"\n";   std::cout<<"\n";   std::cout<<"\n";   for(int i=0;i<mm.rows;i++){       for(int j=0;j<mm.cols;j++){            std::cout<<mm.at<int>(i,j)<<" ";        }    std::cout<<"\n";    }   std::cout<<"\n";   std::cout<<"\n";   std::cout<<"\n";   std::cout<<"\n";   std::cout<<"\n";   for(int i=0;i<mmm.rows;i++){       for(int j=0;j<mmm.cols;j++){            std::cout<<mmm.at<int>(i,j)<<" ";        }    std::cout<<"\n";    }   std::cout<<"\n";   std::cout<<"\n";    return 0;}