OpenGL支持兩種顏色模式：RGBA和顏色索引模式，本文關注于前者。
Smooth Shading and Flat Shading
When Smooth Shading is specified, the color values are interpolated between vertices. If Flat Shading is specified, one vertex is selected as being representative of all the vertices, thus the entire primitive is displayed using one single color.
一個簡單Demo
1,在CCY457OpenGLView.h中加入如下旋轉控制變量：
GLfloat m_xRot, m_yRot;//繞x,y軸旋轉的角度，隨時間不斷變化
并在構造函數中初始化：
CCY457OpenGLView::CCY457OpenGLView()
{
m_xRot = 0.0f;
m_yRot = 0.0f;
}
2，在OnTimer函數中，修改繞x,y軸旋轉的角度值
void CCY457OpenGLView::OnTimer(UINT nIDEvent)
{
m_xRot = m_xRot + 0.5f;
m_yRot = m_yRot + 0.5f;
InvalidateRect(NULL, FALSE);
CView::OnTimer(nIDEvent);
}
3,加入兩個菜單項，控制OpenGL的渲染模式
void CCY457OpenGLView::OnShadingmodelSmooth()
{
glShadeModel(GL_SMOOTH);
InvalidateRect(NULL,FALSE);
}
void CCY457OpenGLView::OnShadingmodelFlat()
{
glShadeModel(GL_FLAT);
InvalidateRect(NULL,FALSE);
}
4，在RenderScene中加入繪制代碼：
void CCY457OpenGLView::RenderScene ()
{//繪制函數
glTranslatef(0.0f,0.0f,-5.0f);
glRotatef(m_xRot,1.0f,0.0f,0.0f);
glRotatef(m_yRot,0.0f,1.0f,0.0f);
//Front Face
glBegin(GL_POLYGON);
glColor3f(1.0f,0.0f,0.0f);
glVertex3f(-1.0f,-1.0f,0.0f);
glColor3f(1.0f,1.0f,0.0f);
glVertex3f( 1.0f,-1.0f,0.0f);
glColor3f(1.0f,0.0f,1.0f);
glVertex3f( 1.0f, 1.0f,0.0f);
glColor3f(1.0f,1.0f,1.0f);
glVertex3f(-1.0f, 1.0f,0.0f);
glEnd();
glColor3f(1.0f,1.0f,0.0f);
//Back Face
glBegin(GL_POLYGON);
glVertex3f(-1.0f,-1.0f,-1.0f);
glVertex3f(-1.0f, 1.0f,-1.0f);
glVertex3f( 1.0f, 1.0f,-1.0f);
glVertex3f( 1.0f,-1.0f,-1.0f);
glEnd();
glColor3f(1.0f,0.0f,1.0f);
//Left Face
glBegin(GL_POLYGON);
glVertex3f(-1.0f,-1.0f, 0.0f);
glVertex3f(-1.0f, 1.0f, 0.0f);
glVertex3f(-1.0f, 1.0f,-1.0f);
glVertex3f(-1.0f,-1.0f,-1.0f);
glEnd();
glColor3f(0.0f,1.0f,0.0f);
//Right Face
glBegin(GL_POLYGON);
glVertex3f(1.0f,-1.0f, 0.0f);
glVertex3f(1.0f,-1.0f,-1.0f);
glVertex3f(1.0f, 1.0f,-1.0f);
glVertex3f(1.0f, 1.0f, 0.0f);
glEnd();
glColor3f(0.0f,1.0f,1.0f);
//Top Face
glBegin(GL_POLYGON);
glVertex3f(-1.0f, 1.0f, 0.0f);
glVertex3f( 1.0f, 1.0f, 0.0f);
glVertex3f( 1.0f, 1.0f, -1.0f);
glVertex3f(-1.0f, 1.0f, -1.0f);
glEnd();
glColor3f(0.0f,0.0f,1.0f);
//Botton Face
glBegin(GL_POLYGON);
glVertex3f(-1.0f, -1.0f, 0.0f);
glVertex3f(-1.0f, -1.0f, -1.0f);
glVertex3f( 1.0f, -1.0f, -1.0f);
glVertex3f( 1.0f, -1.0f, 0.0f);
glEnd();
}
原文鏈接：
http://www.cnblogs.com/phinecos/archive/2008/11/05/1327571.html