c++ opengl绘制地球

1.源码实现

#define GL_GLEXT_PROTOTYPES

#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

//void glGenerateMipmap (GLenum target);

float angle = 0.0;

GLuint textureID;

void init()
{
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_MULTISAMPLE);
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    //glEnable(GL_TEXTURE_2D);

    glDepthFunc(GL_LEQUAL);
    glClearDepth(1.0f);

    GLfloat light_position[] = {1.0, -1.0, -0.5, 0.0};
    GLfloat light_ambient[] = {0.2, 0.2, 0.2, 1.0};
    GLfloat light_diffuse[] = {0.8, 0.8, 0.8, 1.0};

    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);

    glEnable(GL_COLOR_MATERIAL);

    glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);

    //生成纹理对象
    glGenTextures(1, &textureID);

    glBindTexture(GL_TEXTURE_2D, textureID);

    //加载图片并设置纹理参数
    int width, height, channels;
    unsigned char *image = stbi_load("earth.jpg", &width, &height, &channels, STBI_rgb);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);

    glGenerateMipmapEXT(GL_TEXTURE_2D);

    stbi_image_free(image);
}

void update(int value)
{
    angle += 2.0f;

    if(angle > 360)
    {
        angle -= 360;
    }

    glutPostRedisplay();

    glutTimerFunc(32, update, 0);
}

void drawSphere()
{
    GLUquadric *quadric = gluNewQuadric();
    gluQuadricTexture(quadric, GL_TRUE);
    gluQuadricDrawStyle(quadric, GLU_FILL);
    gluQuadricOrientation(quadric, GLU_OUTSIDE);
    gluQuadricNormals(quadric, GLU_SMOOTH);

    gluSphere(quadric, 0.8, 50, 50);

    gluDeleteQuadric(quadric);
}

void display()
{
    glClearColor(0.0, 0.0, 0.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT);

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glLoadIdentity();
    glRotatef(angle, 0.0f, 1.0f, 0.0f);
    glRotatef(angle, 0.0f, 0.0f, 1.0f);

    glEnable(GL_TEXTURE_2D);

    //glTranslatef(0.0f, 0.0f, -0.3f);

        glBindTexture(GL_TEXTURE_2D, textureID);

    //glutSolidCube(0.8);
    //glutSolidSphere(0.8, 50, 50);

    glBegin(GL_TRIANGLES);

    drawSphere();

    glEnd();

    glDisable(GL_TEXTURE_2D);

    glFlush();

    glutSwapBuffers();
}

int main(int argc, char **argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE|GLUT_DEPTH|GLUT_MULTISAMPLE);
    glutInitWindowSize(400, 400);

    glutCreateWindow("OpenGL Sphere with Lighting");

    init();
    glutDisplayFunc(display);
    glutTimerFunc(16, update, 0);

    glutMainLoop();

    return 0;
}

2.素材图片

3.编译源码

$ g++ -o example example.cpp -std=c++11 -I/opt/apps/wxwidget/include -L/opt/apps/wxwidget/lib -lGL -lglut -Wl,-rpath=/opt/apps/wxwidget/lib

4.运行结果

屏幕截图 2024-08-10 202538.png