C语言中的OpenGL添加另一个对象

Posted 2023-02-16

【中文标题】C语言中的OpenGL添加另一个对象

【英文标题】：OpenGL in C language add another object

【发布时间】：2020-03-01 10:20:49

【问题描述】：

我需要帮助将另一个对象添加到我的“绘图”中。 在我的大学教师代码的帮助下，我能够创建一个脸型。

我想给脸上添加笑容 在绘图中添加什么形状？

我尝试在 void face() 后面添加类似：

glVertex2f(100, 125);
glVertex2f(400, 125);

这是C语言的代码：

#include <GL/glut.h>
#include <math.h>
#include<Windows.h>
#include <GL/gl.h>
#include <GL/GLU.h>
#include <stdlib.h>
float  counter = 200;
static GLfloat spin = 0.0;
static GLfloat R = 0.2;
static GLfloat G = 0.9;
static GLfloat B = 0.8;
float carx = 500, cary = 50, fr = 0, fl = 0, fo = 0, fu = 0, mx = 0, my = 0;
void initOpenGl()

    glClearColor(0.0, 0.0, 1.8, 0); //Background Color
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0, 1500, 0, 500);
    glMatrixMode(GL_MODELVIEW);


void eye(int x, int y)

    float th;
    glBegin(GL_POLYGON);
    glColor3f(0, 0, 0);
    for (int i = 0; i < 360; i++)
    

        th = i * (3.1416 / 180);
        glVertex2f(x + 25 * cos(th), y + 20 * sin(th));
    
    glEnd();



void face()

    glLoadIdentity();//Bottom Par
    counter = counter - 0.03;
    if (fr > 0)
        carx += fr;
    if (fl > 0)
        carx -= fl;
    if (fu > 0)
        cary += fu;
    if (fo > 0)
        cary -= fo;
    if (mx > 0)
        carx += mx;
    if (my > 0)
        carx -= my;

    glTranslated(carx, cary, 0.0);
    glBegin(GL_POLYGON);   //Top Part
    glVertex2f(100, 125);
    glVertex2f(400, 125);
    glVertex2f(400, 300);
    glVertex2f(100, 300);


    glEnd();
    eye(165, 230);
    eye(315, 230);







void display()

    glClear(GL_COLOR_BUFFER_BIT);
    glColor3f(0.5, 0.9, 0.33); //Push and pop matrix for separating circle object from Background
    face();
    pa();
    glutSwapBuffers();
    glFlush();

void mouse(int button)

    switch (button) 
    case GLUT_LEFT_BUTTON: mx = 0.3;
        break;
    case GLUT_RIGHT_BUTTON:my = 0.2;
        break;
    default:
        break;
    

void keyFunc(unsigned char key, int x, int y)

    switch (key) 

    case 'w': fu = 0.3, fo = 0, fr = 0, fl = 0;
        break;

    case 's': fu = 0, fo = 0.2, fr = 0, fl = 0;
        break;
    case 'a': fu = 0.01, fo = 0, fr = 0, fl = 0.2;
        break;
    case 'd': fu = 0.01, fo = 0, fr = 0.2, fl = 0;
        break;
    case 'z': fu = 0, fo = 0.2, fr = 0, fl = 0.2;
        break;
    case 'c': fu = 0, fo = 0.2, fr = 0.2, fl = 0;
        break;
    default:
        break;

    
    glutPostOverlayRedisplay();




int main(int argc, char **argv)

    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH);
    glutInitWindowSize(1500, 700);
    glutInitWindowPosition(0, 0);
    glutCreateWindow("Shai Goldenebrg");
    initOpenGl();
    glutDisplayFunc(display);
    glutMouseFunc(mouse);
    glutKeyboardFunc(keyFunc);
    glutIdleFunc(display);
    glutMainLoop();
    return 0;

【参考方案1】：

微笑的嘴是Concave polygon。我建议使用GL_TRIANGLE_STRIP primitive 来生成嘴巴。例如：

void mouth(int x, int y)

    float th, s, c;
    glBegin(GL_TRIANGLE_STRIP);
    glColor3f(0, 0, 0);
    for (int i = 240; i < 300; i++)
    
        th = i * (3.1416 / 180);
        c = cos(th);
        s = sin(th);
        glVertex2f(x +  90 * cos(th), y + 100 +  90 * sin(th));
        glVertex2f(x + 110 * cos(th), y + 100 + 110 * sin(th));
    
    glEnd();

void face()

    // [...]

    eye(165, 230);
    eye(315, 230);
    mouth(240, 150);