我错过了什么纹理不工作 OpenGL

Question

我现在正在尝试将纹理应用到面部，直到我让它正常工作，但每次应用程序运行时面部只是默认的白色，但我不知道是什么出问题了。

LoadTexture function:

GLuint LoadTexture( const char* texture )
{
    GLuint textureID = SOIL_load_OGL_texture( texture, SOIL_LOAD_AUTO, SOIL_CREATE_NEW_ID, SOIL_FLAG_MIPMAPS );

    glBindTexture( GL_TEXTURE_2D, textureID );
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
    glBindTexture( GL_TEXTURE_2D, 0 );

    return textureID;
}

Main code:

GLuint tex = LoadTexture("grass.jpg");
int crotate = 0;

void Reshape(int w, int h)
{
    if (h == 0) h = 1;
    float ratio = w * 1.0 / h;
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glViewport(0, 0, w, h);
    gluPerspective(45.0f, ratio, 0.1f, 1000);
    glMatrixMode(GL_MODELVIEW);
}
void Cube()
{
    glTranslatef(0, 0, -5);
    crotate++;
    glRotatef(crotate, 1,1,0);
    glActiveTexture(tex);
    glEnable(GL_TEXTURE_2D);
    glBindTexture( GL_TEXTURE_2D, tex);
    glBegin(GL_POLYGON);
    glTexCoord2f(0.0, 1.0); glVertex3f(-0.5,-0.5,0);
    glTexCoord2f(0.0, 0.0); glVertex3f(-0.5,0.5,0);
    glTexCoord2f(1.0, 0.0); glVertex3f(0.5,0.5,0);
    glTexCoord2f(1.0, 0.0); glVertex3f(0.5,0.5,0);
    glTexCoord2f(1.0, 1.0); glVertex3f(0.5,-0.5,0);
    glTexCoord2f(0.0, 1.0); glVertex3f(-0.5,-0.5,0);
    glEnd();
    glDisable(GL_TEXTURE_2D);
}

void Display()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();
    Cube();
    glutPostRedisplay();
    glutSwapBuffers();
}

void Init()
{

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    //Lighting
    /*
    glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, GL_TRUE);
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    GLfloat qaDiffuseLight[] = {0.8, 0.8, 0.8, 1};
    glLightfv(GL_LIGHT0, GL_DIFFUSE, qaDiffuseLight);
    GLfloat qaLightPos[] = {0.5, 0.5, 0, 1.0};
    glLightfv(GL_LIGHT0, GL_POSITION, qaLightPos); */
    gluPerspective(45.5, 1.0f, 0.1f, 1000);
    glMatrixMode(GL_MODELVIEW);
    glEnable(GL_DEPTH_TEST);

    glClearColor(0, 0.6, 1, 1);
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE);
    glutInitWindowSize(1280,720);
    glutCreateWindow("OpenGL Program");
    Init();
    glutReshapeFunc(Reshape);
    glutDisplayFunc(Display);
    glutMainLoop();
    return 0;

}

我搜索了许多纹理贴图教程，但我尝试过的所有教程仍然不适合我，我正在使用 GLUT 我遵循的最新教程或博客是尝试添加纹理的 https://www.3dgep.com/texturing-and-lighting-in-opengl/

Answer 1

glActiveTexture的参数为纹理单元：

~~`glActiveTexture(tex);~~

glActiveTexture(GL_TEXTURE0);

纹理对象绑定到纹理单元。当前纹理单元可以用 glActiveTexture 设置。默认纹理单元为 0 (GL_TEXTURE0).

在拥有有效的当前 OpenGL 上下文之前，您无法执行 OpenGL 语句。因此，您必须在创建 OpenGL window 和上下文之后创建纹理对象。在创建 window 并且上下文成为当前上下文后调用 GLuint tex = LoadTexture("grass.jpg");。

GLuint tex = 0;

void Init()
{
    tex = LoadTexture("grass.jpg");

    // [...]
}

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

    glutCreateWindow("OpenGL Program");
    Init();

    // [...]
}

我错过了什么纹理不工作 OpenGL

What am i missing that texture isn't working OpenGL

c++

opengl

freeglut