1.源码实现

#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>
#include <cmath>

using namespace std;

float angleX = 0;
float angleY = 0;

void drawTriangle()
{
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();

    float cameraPos[] = {0.0, 0.0, 0.0};
    float lookat[] = {0.0, 0.0, 0.0};
    float dist = 0.0;

    lookat[0] = -1.0 * sin(angleY * M_PI / 180) * cos(angleX * M_PI / 180);
    lookat[1] = 1.0 * sin(angleX * M_PI / 180);
    lookat[2] = -1.0 * cos(angleY * M_PI / 180) * cos(angleX * M_PI / 180);

    dist = sqrt(lookat[0]*lookat[0]+lookat[1]*lookat[1]+lookat[2]*lookat[2]);

    gluLookAt(0.0, 0.0, 0.0, lookat[0]/dist, lookat[1]/dist, lookat[2]/dist, 0, 0.0, 1.0);
    //gluLookAt(0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0, 1.0, 0);

    glBegin(GL_TRIANGLES);
    glColor3f(1.0, 0.0, 0.0);
    glVertex3f(0.0, 0.0, 0.0);
    glColor3f(0.0, 1.0, 0.0);
    glVertex3f(0.0, 0.8, 0.0);
    glColor3f(0.0, 0.0, 1.0);
    glVertex3f(0.0, 0.8, 0.8);
    glEnd();

    glutSwapBuffers();
}

void keyboardFunc(unsigned char key, int x, int y)
{
    switch(key)
    {
        case 'q':
        case 27:
            exit(0);
            break;

        case 'w':
            angleY += 5;
            break;

        case 's':
            angleY -= 5;
            break;

        case 'a':
            angleX += 5;
            break;

        case 'd':
            angleX -= 5;
            break;

    }

    glutPostRedisplay();
}

int main(int argc, char **argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGBA);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(400, 400);
    glutCreateWindow("hello");

    glutKeyboardFunc(keyboardFunc);
    glutDisplayFunc(&drawTriangle);
    glutMainLoop();

    return 0;
}

2.编译源码

$ g++ -o example example.cpp -std=c++11 -lGL -lglut -lGLU

3.运行结果

3.png