如何使用 Opengl 库从文本文件中显示 3D 点

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【中文标题】如何使用 Opengl 库从文本文件中显示 3D 点【英文标题】：How to display the 3D point from text file by using Opengl library 【发布时间】：2017-03-18 12:28:41 【问题描述】：

我想在文本文件中绘制由 column[0] 中的值指定的 3D 点。例如，column[0] 等于 2，然后显示 3D 点 (xyz) 如下： (1.529, 0.25,-2.038 ), (1.530,0.253,-2.040), (1.530,0.253,-2.044)

test.txt

1 1.529 0.253 -2.038

1 1.529 0.253 -2.038

2 1.529 0.253 -2.038

2 1.530 0.253 -2.040

2 1.530 0.253 -2.044

3 1.532 0.254 -2.038

3 1.533 0.255 -2.036

3 1.533 0.255 -2.036

3 1.534 0.255 -2.036

3 1.534 0.255 -2.036

这是我的代码

#include <Windows.h> 
#include <GL\glew.h> 
#include <GL\freeglut.h> 
#include <stdio.h> 
#include <vector> 
#include <stdlib.h> 
#include <fstream>
#include <iostream>
#include <sstream>
#include <string>

using namespace std;

char title[] = "Point";

void initGL() 
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Set background color to black 
    glClearDepth(1.0f);                   // Set background depth to farthest
    glEnable(GL_DEPTH_TEST);   // Enable depth testing for z-culling
    glDepthFunc(GL_LEQUAL);    // Set the type of depth-test
    glShadeModel(GL_SMOOTH);   // Enable smooth shading
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);  


void display() 

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear color and depth buffers
    glMatrixMode(GL_MODELVIEW);     // To operate on model-view matrix
    glLoadIdentity();                 // Reset the model-view matrix
    glTranslatef(1.5f, 0.0f, -7.0f);  // Move right and into the screen

    vector<vector<double>> tempdouble;
    ifstream in("test.txt");
    string line;

    double Dstage1x = 0.0;  
    double Dstage1y = 0.0;
    double Dstage1z = 0.0;
    double Dstage2x = 0.0;
    double Dstage2y = 0.0;
    double Dstage2z = 0.0;
    double Dstage3x = 0.0;
    double Dstage3y = 0.0;
    double Dstage3z = 0.0;
    int ii = 0;
    int stage1 = 0;
    int stage2 = 0;
    int stage3 = 0;

    while (std::getline(in, line))
    
        tempdouble.push_back(vector<double>());
        stringstream ss(line);
        double num;
        while (ss >> num)
        
            tempdouble.back().push_back(num);
        
    

    for (int i = 0; i < tempdouble.size(); i++)
    
        for (int j = 0; j < tempdouble[i].size(); j++)
        

            int st1_x=0; int st1_y=0; int st1_z=0;
            int st2_x=0; int st2_y=0; int st2_z=0;
            int st3_x=0; int st3_y=0; int st3_z=0;

            if(tempdouble[i][0]==1 )
            

                glPointSize(5);glColor3f(1.0f, 0.5f, 0.0f); 
                glBegin(GL_POINTS); 


                st1_x += Dstage1x*0;  st1_y += Dstage1y*0; st1_z += Dstage1z*0;   //set value 
                Dstage1x = st1_x + tempdouble[i][1];
                Dstage1y = st1_y + tempdouble[i][2];
                Dstage1z = st1_z + tempdouble[i][3];
                stage1++;
                //cout <<"Check tempdouble[i][0] state1 : " << tempdouble[i][0] <<"\t"<<endl;

                cout << "state1(xyz) : " << "( " << Dstage1x << " ," << Dstage1y << "," << Dstage1z << ")"<< endl;
                glVertex3f(Dstage1x, Dstage1y, Dstage1z);
                //glVertex3f(tempdouble[i][1], tempdouble[i][2], tempdouble[i][3]);
                //glVertex3f(tempdouble[i][j], tempdouble[i][j], tempdouble[i][j]);
                glEnd();
                break;

            

            if (tempdouble[i][0] == 2) 

                glPointSize(5);glColor3f(0.0f, 0.0f, 1.0f);  
                glBegin(GL_POINTS); 

                st2_x += Dstage2x * 0;  st2_y += Dstage2y*0; st2_z += Dstage2z*0;   //set value 

                Dstage2x = st2_x + tempdouble[i][1];
                Dstage2y = st2_y + tempdouble[i][2];
                Dstage2z = st2_z + tempdouble[i][3];
                stage2++;
                cout << "state2(xyz) : " << "( " << Dstage2x << " ," << Dstage2y << "," << Dstage2z << ")"<< endl;

                glVertex3f(Dstage2x,Dstage2y,Dstage2z);
                //glVertex3f(tempdouble[i][1], tempdouble[i][2], tempdouble[i][3]);
                //glVertex3f(tempdouble[i][j], tempdouble[i][j], tempdouble[i][j]);
                glEnd();    
                break;
            

            if (tempdouble[i][0] == 3) 
                glPointSize(5); glColor3f(1.0f, 0.0f, 0.0f);   
                glBegin(GL_POINTS); 


                st3_x += Dstage3x*0;  st3_y += Dstage3y*0; st3_z += Dstage3z*0;   //set value 

                Dstage3x = st3_x + tempdouble[i][1];
                Dstage3y = st3_y + tempdouble[i][2];
                Dstage3z = st3_z + tempdouble[i][3];
                stage3++;
                cout << "state3(xyz) : " << "( " << Dstage3x << " ," << Dstage3y << "," << Dstage3z << ")"<< endl;

                glVertex3f(Dstage3x,Dstage3y,Dstage3z);
                //glVertex3f(tempdouble[i][0],tempdouble[i][1],tempdouble[i][2]);
                //glVertex3f(tempdouble[i][j], tempdouble[i][j], tempdouble[i][j]);
                glEnd();
                break;
            

        

    
    cout << "stage 1: "<< stage1 << endl;
    cout << "stage 2: "<<stage2 << endl;
    cout << "stage 3: "<<stage3 << endl;
    glutSwapBuffers();  // Swap the front and back frame buffers (double buffering)


void reshape(GLsizei width, GLsizei height)   // GLsizei for non-negative integer
    // Compute aspect ratio of the new window
    if (height == 0) height = 1;                // To prevent divide by 0
    GLfloat aspect = (GLfloat)width / (GLfloat)height;

    // Set the viewport to cover the new window
    glViewport(0, 0, width, height);

    // Set the aspect ratio of the clipping volume to match the viewport
    glMatrixMode(GL_PROJECTION);  // To operate on the Projection matrix
    glLoadIdentity();             // Reset
    // Enable perspective projection with fovy, aspect, zNear and zFar
    gluPerspective(45.0f, aspect, 0.1f, 100.0f);

void changeViewPort(int w, int h)

    glViewport(0, 0, w, h);


void render()

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glutSwapBuffers();

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

    void display();

    glutInit(&argc, argv);            // Initialize GLUT
    glutInitDisplayMode(GLUT_DOUBLE); // Enable double buffered mode
    glutInitWindowSize(640, 480);   // Set the window's initial width & height
    glutInitWindowPosition(50, 50); // Position the window's initial top-left corner
    glutCreateWindow(title);          // Create window with the given title
    glutDisplayFunc(display);       // Register callback handler for window re-paint event
    glutReshapeFunc(reshape);       // Register callback handler for window re-size event
    initGL();                       // Our own OpenGL initialization
    glutMainLoop();       

    return 0;

我的问题是点显示在错误的位置。列 [0]（等于 1,2,3）不可能有所有相同的点。有人可以帮我解决这个问题

【问题讨论】：

【参考方案1】： 
setlocale( LC_NUMERIC, "C");

.

【讨论】：

如果您能改进您的答案以便 OP 可以对它做任何事情，那就太好了。【参考方案2】：

https://rocketgit.com/user/bowler17/gl/source/tree/branch/wrench/blob/t.c

大号do while之前的一行

【讨论】：

你在大做之前说过那句话。你指的是哪一行？

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