第1关:OpenGL点的绘制

// 提示:写完代码请保存之后再进行评测
#include <GL/freeglut.h>
#include<stdio.h>

// 评测代码所用头文件-开始
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
// 评测代码所用头文件-结束

void myDisplay(void)
{
   // 请在此添加你的代码
   /********** Begin ********/
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glClear(GL_COLOR_BUFFER_BIT);

    glPointSize(3);
    glBegin(GL_POINTS);
    glColor3f(1.0f, 0.0f, 0.0f);  glVertex2f(-0.4f, -0.4f);
    glColor3f(0.0f, 1.0f, 0.0f);  glVertex2f(0.0f, 0.0f);
    glColor3f(0.0f, 0.0f, 1.0f);  glVertex2f(0.4f, 0.4f);
    glEnd();
   /********** End **********/

     glFlush();
}

int main(int argc, char *argv[])
{

    glutInit(&argc, argv);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(400, 400);
    glutCreateWindow("Hello Point!");
    glutDisplayFunc(&myDisplay);
    glutMainLoopEvent();     
     
     
    /*************以下为评测代码,与本次实验内容无关,请勿修改**************/
    GLubyte* pPixelData = (GLubyte*)malloc(400 * 400 * 3);//分配内存
    GLint viewport[4] = {0};    
    glReadBuffer(GL_FRONT);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
    glGetIntegerv(GL_VIEWPORT, viewport);
    glReadPixels(viewport[0], viewport[1], viewport[2], viewport[3], GL_RGB, GL_UNSIGNED_BYTE, pPixelData);

     cv::Mat img;
    std::vector<cv::Mat> imgPlanes;
    img.create(400, 400, CV_8UC3);
    cv::split(img, imgPlanes);
 
        for(int i = 0; i < 400; i ++) {
            unsigned char* plane0Ptr = imgPlanes[0].ptr<unsigned char>(i);
            unsigned char* plane1Ptr = imgPlanes[1].ptr<unsigned char>(i);
            unsigned char* plane2Ptr = imgPlanes[2].ptr<unsigned char>(i);
            for(int j = 0; j < 400; j ++) {
                int k = 3 * (i * 400 + j);
                plane2Ptr[j] = pPixelData[k];
                plane1Ptr[j] = pPixelData[k+1];
                plane0Ptr[j] = pPixelData[k+2];
            }
        }
        cv::merge(imgPlanes, img);
        cv::flip(img, img ,0); 
        cv::namedWindow("openglGrab");
        cv::imshow("openglGrab", img);
        //cv::waitKey();
        cv::imwrite("../img_step1/test.jpg", img);
    return 0;
}

第2关:OpenGL简单图形绘制

// 提示:写完代码请保存之后再进行评测
#include <GL/freeglut.h>
#include<stdio.h>

// 评测代码所用头文件-开始
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
// 评测代码所用头文件-结束

void myDisplay(void)
{
   // 请在此添加你的代码
   /********** Begin ********/
   glClearColor(0.0, 0.0, 0.0, 0.0);
    glClear(GL_COLOR_BUFFER_BIT);

    glColor3f(1.0f, 1.0f, 1.0f);
    glRectf(-0.5f, -0.5f, 0.5f, 0.5f);

    glBegin(GL_TRIANGLES);
    glColor3f(1.0f, 0.0f, 0.0f);  glVertex2f(0.0f, 1.0f);
    glColor3f(0.0f, 1.0f, 0.0f);  glVertex2f(0.8f, -0.5f);
    glColor3f(0.0f, 0.0f, 1.0f);  glVertex2f(-0.8f, -0.5f);
    glEnd();

    glPointSize(3);
    glBegin(GL_POINTS);
    glColor3f(1.0f, 0.0f, 0.0f);  glVertex2f(-0.4f, -0.4f);
    glColor3f(0.0f, 1.0f, 0.0f);  glVertex2f(0.0f, 0.0f);
    glColor3f(0.0f, 0.0f, 1.0f);  glVertex2f(0.4f, 0.4f);
    glEnd();
   /********** End **********/

     glFlush();
}

int main(int argc, char *argv[])
{

    glutInit(&argc, argv);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(400, 400);
    glutCreateWindow("Hello Point!");
    glutDisplayFunc(&myDisplay);
    glutMainLoopEvent();     
     
     
    /*************以下为评测代码,与本次实验内容无关,请勿修改**************/
    GLubyte* pPixelData = (GLubyte*)malloc(400 * 400 * 3);//分配内存
    GLint viewport[4] = {0};    
    glReadBuffer(GL_FRONT);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
    glGetIntegerv(GL_VIEWPORT, viewport);
    glReadPixels(viewport[0], viewport[1], viewport[2], viewport[3], GL_RGB, GL_UNSIGNED_BYTE, pPixelData);

     cv::Mat img;
    std::vector<cv::Mat> imgPlanes;
    img.create(400, 400, CV_8UC3);
    cv::split(img, imgPlanes);
 
        for(int i = 0; i < 400; i ++) {
            unsigned char* plane0Ptr = imgPlanes[0].ptr<unsigned char>(i);
            unsigned char* plane1Ptr = imgPlanes[1].ptr<unsigned char>(i);
            unsigned char* plane2Ptr = imgPlanes[2].ptr<unsigned char>(i);
            for(int j = 0; j < 400; j ++) {
                int k = 3 * (i * 400 + j);
                plane2Ptr[j] = pPixelData[k];
                plane1Ptr[j] = pPixelData[k+1];
                plane0Ptr[j] = pPixelData[k+2];
            }
        }
        cv::merge(imgPlanes, img);
        cv::flip(img, img ,0); 
        cv::namedWindow("openglGrab");
        cv::imshow("openglGrab", img);
        //cv::waitKey();
        cv::imwrite("../img_step2/test.jpg", img);
    return 0;
}

第3关:OpenGL直线绘制

// 提示:写完代码请保存之后再进行评测
#include <GL/freeglut.h>
#include<stdio.h>

// 评测代码所用头文件-开始
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
// 评测代码所用头文件-结束

void myDisplay(void)
{
   // 请在此添加你的代码
   /********** Begin ********/
    glClear(GL_COLOR_BUFFER_BIT);
    glColor3f(1.0f, 0.0f, 0.0f);
    glRectf(25.0, 25.0, 75.0, 75.0);
    glPointSize(10);
    glBegin(GL_POINTS);
    glColor3f(0.0f, 1.0f, 0.0f); glVertex2f(0.0f, 0.0f);
    glEnd();
    glBegin(GL_LINES);
    glColor3f(0.0f, 1.0f, 0.0f); glVertex2f(100.0f, 0.0f);
    glColor3f(0.0f, 1.0f, 0.0f); glVertex2f(180.0f, 240.0f);
    glEnd();
   /********** End **********/
     glFlush();
}
void Init()
{
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glShadeModel(GL_SMOOTH);
}
void myReshape(int w, int h)
{
    glViewport(0, 0, (GLsizei)w, (GLsizei)h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0, (GLdouble)w, 0.0, (GLdouble)h);
}

int main(int argc, char *argv[])
{

    glutInit(&argc, argv);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(400, 400);
    glutCreateWindow("Hello Point!");
    Init();
    glutDisplayFunc(myDisplay);
    glutReshapeFunc(myReshape);
    glutMainLoopEvent();     
     
     
     
    /*************以下为评测代码,与本次实验内容无关,请勿修改**************/
    GLubyte* pPixelData = (GLubyte*)malloc(400 * 400 * 3);//分配内存
    GLint viewport[4] = {0};    
    glReadBuffer(GL_FRONT);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
    glGetIntegerv(GL_VIEWPORT, viewport);
    glReadPixels(viewport[0], viewport[1], viewport[2], viewport[3], GL_RGB, GL_UNSIGNED_BYTE, pPixelData);

     cv::Mat img;
    std::vector<cv::Mat> imgPlanes;
    img.create(400, 400, CV_8UC3);
    cv::split(img, imgPlanes);
 
        for(int i = 0; i < 400; i ++) {
            unsigned char* plane0Ptr = imgPlanes[0].ptr<unsigned char>(i);
            unsigned char* plane1Ptr = imgPlanes[1].ptr<unsigned char>(i);
            unsigned char* plane2Ptr = imgPlanes[2].ptr<unsigned char>(i);
            for(int j = 0; j < 400; j ++) {
                int k = 3 * (i * 400 + j);
                plane2Ptr[j] = pPixelData[k];
                plane1Ptr[j] = pPixelData[k+1];
                plane0Ptr[j] = pPixelData[k+2];
            }
        }
        cv::merge(imgPlanes, img);
        cv::flip(img, img ,0); 
        cv::namedWindow("openglGrab");
        cv::imshow("openglGrab", img);
        //cv::waitKey();
        cv::imwrite("../img_step3/test.jpg", img);
    return 0;
}

第4关:0<k<1直线绘制-DDA算法

// 提示:写完代码请保存之后再进行评测
#include <GL/freeglut.h>
#include<stdio.h>

// 评测代码所用头文件-开始
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
// 评测代码所用头文件-结束


void LineDDA(int x0, int y0, int x1, int y1)
{
 // 请在此添加你的代码
   /********** Begin ********/
    int x, dy, dx, y;
    float m;
    dx = x1 - x0;
    dy = y1 - y0;
    m = dy / dx;
    y = y0;
    glColor3f(1.0f, 1.0f, 0.0f);
    glPointSize(1);
    for (x = x0; x <= x1; x++)
    {
        glBegin(GL_POINTS);
        glVertex2i(x, (int)(y + 0.5));
        glEnd();
        y += m;
    }
   /********** End **********/
     glFlush();
}

void myDisplay(void)
{
   // 请在此添加你的代码
   /********** Begin ********/
    LineDDA( 0, 0, 200, 300);
   /********** End **********/
     glFlush();
}
void Init()
{
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glShadeModel(GL_SMOOTH);
}
void myReshape(int w, int h)
{
    glViewport(0, 0, (GLsizei)w, (GLsizei)h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0, (GLdouble)w, 0.0, (GLdouble)h);
}

int main(int argc, char *argv[])
{

    glutInit(&argc, argv);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(400, 400);
    glutCreateWindow("Hello Point!");
    Init();
    glutDisplayFunc(myDisplay);
    glutReshapeFunc(myReshape);
    glutMainLoopEvent();     
     
     
     
    /*************以下为评测代码,与本次实验内容无关,请勿修改**************/
    GLubyte* pPixelData = (GLubyte*)malloc(400 * 400 * 3);//分配内存
    GLint viewport[4] = {0};
    glReadBuffer(GL_FRONT);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
    glGetIntegerv(GL_VIEWPORT, viewport);
    glReadPixels(viewport[0], viewport[1], viewport[2], viewport[3], GL_RGB, GL_UNSIGNED_BYTE, pPixelData);

     cv::Mat img;
    std::vector<cv::Mat> imgPlanes;
    img.create(400, 400, CV_8UC3);
    cv::split(img, imgPlanes);
 
        for(int i = 0; i < 400; i ++) {
            unsigned char* plane0Ptr = imgPlanes[0].ptr<unsigned char>(i);
            unsigned char* plane1Ptr = imgPlanes[1].ptr<unsigned char>(i);
            unsigned char* plane2Ptr = imgPlanes[2].ptr<unsigned char>(i);
            for(int j = 0; j < 400; j ++) {
                int k = 3 * (i * 400 + j);
                plane2Ptr[j] = pPixelData[k];
                plane1Ptr[j] = pPixelData[k+1];
                plane0Ptr[j] = pPixelData[k+2];
            }
        }
        cv::merge(imgPlanes, img);
        cv::flip(img, img ,0); 
        cv::namedWindow("openglGrab");
        cv::imshow("openglGrab", img);
        //cv::waitKey();
        cv::imwrite("../img_step4/test.jpg", img);
    return 0;
}

第5关:0<k<1直线绘制-中点算法

// 提示:写完代码请保存之后再进行评测
#include <GL/freeglut.h>
#include<stdio.h>

// 评测代码所用头文件-开始
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
// 评测代码所用头文件-结束


void MidPLine(int x0, int y0, int x1, int y1)
{
 // 请在此添加你的代码
   /********** Begin ********/
    int dx, dy, dt, db, d, x, y;
    dx = x1 - x0;
    dy = y1 - y0;
    d = dx - 2*dy;           //即原初值d1
    dt = 2*dx - 2*dy;         //原1-k
    db = -2*dy;             //原-k
    x = x0; y = y0;
    glColor3f(0.0f, 1.0f, 0.0f);
    glPointSize(1);
    glBegin(GL_POINTS);
    glVertex2i(x, y);
    glEnd();
    while (x < x1)
    {
        if (d < 0)
        {
            x++;
            y++;
            d += dt;
        }
        else
        {
            x++;
            d += db;
        }
        glColor3f(0.0f, 1.0f, 0.0f);
        glPointSize(1);
        glBegin(GL_POINTS);
        glVertex2i(x, y);
        glEnd();
    }
   /********** End **********/
     glFlush();
}

void myDisplay(void)
{
   // 请在此添加你的代码
   /********** Begin ********/
    MidPLine( 10, 50,300 ,260 );
    //glColor3f(0.0f, 1.0f, 0.0f);
    //glLineWidth(1);
   /********** End **********/
     glFlush();
}
void Init()
{
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glShadeModel(GL_SMOOTH);
}
void myReshape(int w, int h)
{
    glViewport(0, 0, (GLsizei)w, (GLsizei)h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0, (GLdouble)w, 0.0, (GLdouble)h);
}

int main(int argc, char *argv[])
{

    glutInit(&argc, argv);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(400, 400);
    glutCreateWindow("Hello Point!");
    Init();
    glutDisplayFunc(myDisplay);
    glutReshapeFunc(myReshape);
    glutMainLoopEvent();     
     
     
     
    /*************以下为评测代码,与本次实验内容无关,请勿修改**************/
    GLubyte* pPixelData = (GLubyte*)malloc(400 * 400 * 3);//分配内存
    GLint viewport[4] = {0};
    glReadBuffer(GL_FRONT);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
    glGetIntegerv(GL_VIEWPORT, viewport);
    glReadPixels(viewport[0], viewport[1], viewport[2], viewport[3], GL_RGB, GL_UNSIGNED_BYTE, pPixelData);

     cv::Mat img;
    std::vector<cv::Mat> imgPlanes;
    img.create(400, 400, CV_8UC3);
    cv::split(img, imgPlanes);
 
        for(int i = 0; i < 400; i ++) {
            unsigned char* plane0Ptr = imgPlanes[0].ptr<unsigned char>(i);
            unsigned char* plane1Ptr = imgPlanes[1].ptr<unsigned char>(i);
            unsigned char* plane2Ptr = imgPlanes[2].ptr<unsigned char>(i);
            for(int j = 0; j < 400; j ++) {
                int k = 3 * (i * 400 + j);
                plane2Ptr[j] = pPixelData[k];
                plane1Ptr[j] = pPixelData[k+1];
                plane0Ptr[j] = pPixelData[k+2];
            }
        }
        cv::merge(imgPlanes, img);
        cv::flip(img, img ,0); 
        cv::namedWindow("openglGrab");
        cv::imshow("openglGrab", img);
        //cv::waitKey();//
        cv::imwrite("../img_step5/test.jpg", img);
    return 0;
}

第6关:一般直线绘制

// 提示:写完代码请保存之后再进行评测
#include <GL/freeglut.h>
#include <algorithm>
#include <stdio.h>
using namespace std;

// 评测代码所用头文件-开始
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
// 评测代码所用头文件-结束


void Line(int x0, int y0, int x1, int y1)
{
 // 请在此添加你的代码
   /********** Begin ********/
    glColor3f(1.0f, 0.0f, 0.0f);
    glBegin(GL_POINTS);
    glPointSize(1);

    int dx = abs(x1 - x0);
    int dy = abs(y1 - y0);
    if (dx > dy) // x方向为步进方向
    {
        if (x0 > x1) //确保x0<x1,这样循环中x=x+1
        {
            swap(x0, x1);
            swap(y0, y1);
        }

        int d = dx - 2 * dy;
        int d1 = 2 * dx - 2 * dy;
        int d2 = -2 * dy;
        int x = x0;
        int y = y0;
        int yIncr = (y1 > y0) ? 1 : -1; // 比较两端点y值大小决定y的增量值
        glVertex2i(x, y);
        for (int x = x0 + 1; x <= x1; x++)
        {
            if (d < 0)
            {
                y = y + yIncr;
                d = d + d1;
            }
            else
                d = d + d2;

            glVertex2i(x, y);
        }
    }
    else
    {
        if (y0 > y1)
        {
            swap(x0, x1);
            swap(y0, y1);
        }

        int d = dy - 2 * dx;
        int d1 = 2 * dy - 2 * dx;
        int d2 = -2 * dx;
        int x = x0;
        int y = y0;
        int xIncr = (x1 > x0) ? 1 : -1;
        glVertex2i(x, y);
        for (int y = y0 + 1; y <= y1; y++)
        {
            if (d < 0)
            {
                x = x + xIncr;
                d = d + d1;
            }
            else
                d = d + d2;

            glVertex2i(x, y);
        }
    }
    glEnd();
   /********** End **********/
}

void myDisplay(void)
{
    glClear(GL_COLOR_BUFFER_BIT);
   // 请在此添加你的代码用来测试直线绘制代码
   /********** Begin ********/
    Line(261, 215, 344, 275);
    Line(344, 275, 429, 213);
    Line(429, 213, 398, 319);
    Line(398, 319, 477, 384);
    Line(477, 384, 378, 385);
    Line(378, 385, 344, 491);
    Line(344, 491, 310, 384);
    Line(310, 384, 209, 382);
    Line(209, 382, 292, 319);
    Line(292, 319, 261, 215);
   /********** End **********/
     glFlush();
}
void Init()
{
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glShadeModel(GL_SMOOTH);
}
void myReshape(int w, int h)
{
    glViewport(0, 0, (GLsizei)w, (GLsizei)h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0, (GLdouble)w, 0.0, (GLdouble)h);
}

int main(int argc, char *argv[])
{
    int width = 800;
    int height = 600;
    
    glutInit(&argc, argv);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(width, height);
    glutCreateWindow("Hello Line!");
    Init();
    glutDisplayFunc(myDisplay);
    glutReshapeFunc(myReshape);
    glutMainLoopEvent();    
   
     
    /*************以下为评测代码,与本次实验内容无关,请勿修改**************/
    GLubyte* pPixelData = (GLubyte*)malloc(width * height * 3);//分配内存
    GLint viewport[4] = {0};
    glReadBuffer(GL_FRONT);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
    glGetIntegerv(GL_VIEWPORT, viewport);
    glReadPixels(viewport[0], viewport[1], viewport[2], viewport[3], GL_RGB, GL_UNSIGNED_BYTE, pPixelData);

    cv::Mat img;
    std::vector<cv::Mat> imgPlanes;
    img.create(height, width, CV_8UC3);
    cv::split(img, imgPlanes);
 
    for(int i = 0; i < height; i ++) {
        unsigned char* plane0Ptr = imgPlanes[0].ptr<unsigned char>(i);
        unsigned char* plane1Ptr = imgPlanes[1].ptr<unsigned char>(i);
        unsigned char* plane2Ptr = imgPlanes[2].ptr<unsigned char>(i);
        for(int j = 0; j < width; j ++) {
            int k = 3 * (i * width + j);
            plane2Ptr[j] = pPixelData[k];
            plane1Ptr[j] = pPixelData[k+1];
            plane0Ptr[j] = pPixelData[k+2];
        }
    }
    cv::merge(imgPlanes, img);
    cv::flip(img, img ,0); 
    cv::namedWindow("openglGrab");
    cv::imshow("openglGrab", img);
    //cv::waitKey();//
    cv::imwrite("../img_step6/test.jpg", img);
    return 0;
}