c++ - 调整屏幕大小时消失的对象(OpenGl)

Question

我正在尝试从 .obj 格式加载 3D 模型，它在屏幕上绘制对象没有任何问题，但是当我调整屏幕大小时，一切都消失了。这是代码:

Obj* object = new Obj();
GLuint  texture[1]; 

void handleResize(int w, int h) {
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0,(double)w / (double)h,1.0,200.0);
}
void initRendering() {
object->GetObj("cube.obj");
glShadeModel(GL_LINEAR);                            
glClearColor(0.0f, 0.0f, 0.0f,     0.5f);                           
glEnable(GL_DEPTH_TEST);
}
void handleKeypress(unsigned char key, int x, int y) {
switch (key) {
    case 27:
        {
        exit(0);
        break;
        }
}
}

void drawScene()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glMatrixMode(GL_MODELVIEW); 
glLoadIdentity();
glPushMatrix();
glRotatef(45.0,0.0,1.0,0.0);
object->DrawObj();
glPopMatrix();
glutSwapBuffers();
glFlush();

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


glutCreateWindow("3D");
initRendering();

glutReshapeFunc(handleResize);
glutDisplayFunc(drawScene);
glutKeyboardFunc(handleKeypress);
glutMainLoop();
return 0;
}

这是 Obj.DrawObj() 的代码:

glBegin(GL_TRIANGLES);
for(int i = 0;i < faces.capacity()-1;i++)
{
        glVertex3f(vertices[faces[i].vertex1].cordinate1,vertices[faces[i].vertex1].cordinate2,vertices[faces[i].vertex1].cordinate3);
    glVertex3f(vertices[faces[i].vertex2].cordinate1,vertices[faces[i].vertex2].cordinate2,vertices[faces[i].vertex2].cordinate3);
      glVertex3f(vertices[faces[i].vertex3].cordinate1,vertices[faces[i].vertex3].cordinate2,vertices[faces[i].vertex3].cordinate3);  
}
glEnd;

Answer 1

在您的绘图代码中，您设置了投影矩阵，这很好。但是，您将其设置为身份。在调整大小处理程序中，您也设置了投影矩阵，但您不应该在那里设置；是的，我知道教程里都有，但这是非常糟糕的风格。您应该将当前在 reshape 处理程序中的所有代码移动到绘图处理程序中，替换投影矩阵的当前设置。