C++ OpenGL 立方体未显示在屏幕上

Question

I have been attempting to use OpenGL with C++ lately and I have come a cross a problem when trying to render a cube with lighting, but it doesn't appear I believe this is due to some kinda of clipping error.

Here is my code. The initialization function:

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glEnable(GL_DEPTH_TEST);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_LIGHTING); //Enable lighting
glEnable(GL_LIGHT0); //Enable light #0
glEnable(GL_LIGHT1); //Enable light #1
glEnable(GL_NORMALIZE); //Automatically normalize normals

and here is the draw code

 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glTranslatef(0.0f, 0.0f, -8.0f);

//Add ambient light
GLfloat ambientColor[] = {0.2f, 0.2f, 0.2f, 1.0f}; //Color (0.2, 0.2, 0.2)
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambientColor);

//Add positioned light
GLfloat lightColor0[] = {0.5f, 0.5f, 0.5f, 1.0f}; //Color (0.5, 0.5, 0.5)
GLfloat lightPos0[] = {4.0f, 0.0f, 8.0f, 1.0f}; //Positioned at (4, 0, 8)
glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColor0);
glLightfv(GL_LIGHT0, GL_POSITION, lightPos0);

//Add directed light
GLfloat lightColor1[] = {0.5f, 0.2f, 0.2f, 1.0f}; //Color (0.5, 0.2, 0.2)
//Coming from the direction (-1, 0.5, 0.5)
GLfloat lightPos1[] = {-1.0f, 0.5f, 0.5f, 0.0f};
glLightfv(GL_LIGHT1, GL_DIFFUSE, lightColor1);
glLightfv(GL_LIGHT1, GL_POSITION, lightPos1);

glRotatef(Rotation, 0.0f, 1.0f, 0.0f);
glColor3f(1.0f, 1.0f, 0.0f);
glBegin(GL_QUADS);

//Front
glNormal3f(0.0f, 0.0f, 1.0f);
//glNormal3f(-1.0f, 0.0f, 1.0f);
glVertex3f(-1.5f, -1.0f, 1.5f);
//glNormal3f(1.0f, 0.0f, 1.0f);
glVertex3f(1.5f, -1.0f, 1.5f);
//glNormal3f(1.0f, 0.0f, 1.0f);
glVertex3f(1.5f, 1.0f, 1.5f);
//glNormal3f(-1.0f, 0.0f, 1.0f);
glVertex3f(-1.5f, 1.0f, 1.5f);

//Right
glNormal3f(1.0f, 0.0f, 0.0f);
//glNormal3f(1.0f, 0.0f, -1.0f);
glVertex3f(1.5f, -1.0f, -1.5f);
//glNormal3f(1.0f, 0.0f, -1.0f);
glVertex3f(1.5f, 1.0f, -1.5f);
//glNormal3f(1.0f, 0.0f, 1.0f);
glVertex3f(1.5f, 1.0f, 1.5f);
//glNormal3f(1.0f, 0.0f, 1.0f);
glVertex3f(1.5f, -1.0f, 1.5f);

//Back
glNormal3f(0.0f, 0.0f, -1.0f);
//glNormal3f(-1.0f, 0.0f, -1.0f);
glVertex3f(-1.5f, -1.0f, -1.5f);
//glNormal3f(-1.0f, 0.0f, -1.0f);
glVertex3f(-1.5f, 1.0f, -1.5f);
//glNormal3f(1.0f, 0.0f, -1.0f);
glVertex3f(1.5f, 1.0f, -1.5f);
//glNormal3f(1.0f, 0.0f, -1.0f);
glVertex3f(1.5f, -1.0f, -1.5f);

//Left
glNormal3f(-1.0f, 0.0f, 0.0f);
//glNormal3f(-1.0f, 0.0f, -1.0f);
glVertex3f(-1.5f, -1.0f, -1.5f);
//glNormal3f(-1.0f, 0.0f, 1.0f);
glVertex3f(-1.5f, -1.0f, 1.5f);
//glNormal3f(-1.0f, 0.0f, 1.0f);
glVertex3f(-1.5f, 1.0f, 1.5f);
//glNormal3f(-1.0f, 0.0f, -1.0f);
glVertex3f(-1.5f, 1.0f, -1.5f);

glEnd();

        SwapBuffers(hDC);

        Sleep (1);

---

after following the advice of Keith i attempted to use the gluLookAt like this:

void gluLookAt  (   10.0 , 10.0 , 10.0 , 1.5, -1.0, 1.5, 0.0, 0.0, 1.0 );

but I get an error

|74|error: variable or field `gluLookAt' declared void|

Answer 1

You may need to define the projection matrix .

This can be done with, for example, gluLookAt()

Answer 2

After your edit: gluLookAt is a function just like glVertex3f and such. Therefore invoke it by just calling:

gluLookAt(10.0 , 10.0 , 10.0 , 1.5, -1.0, 1.5, 0.0, 0.0, 1.0 );

Note that there is no void involved in this line of code!

What the compiler sees if there is a void in front of this line is a variable declaration named gluLookAt of type void initialized (constructed) with a bunch of doubles.