NeHe 系列教程之五： 绘制3D几何对象

英文教程地址：lesson05

本课在第四课的基础上， 绘制真实的3D 对象， 具体如下：

void MyGLWidget::paintGL()
{glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);  // Clear The Screen And The Depth BufferglLoadIdentity();       // Reset The Current Modelview MatrixglTranslatef(-1.5f,0.0f,-6.0f);     // Move Left 1.5 Units And Into The Screen 6.0glRotatef(rtri,0.0f,1.0f,0.0f);                // Rotate The Pyramid On It's Y AxisglBegin(GL_TRIANGLES);                 // Start Drawing The PyramidglColor3f(1.0f,0.0f,0.0f);          // RedglVertex3f( 0.0f, 1.0f, 0.0f);            // Top Of Triangle (Front)glColor3f(0.0f,1.0f,0.0f);            // GreenglVertex3f(-1.0f,-1.0f, 1.0f);          // Left Of Triangle (Front)glColor3f(0.0f,0.0f,1.0f);           // BlueglVertex3f( 1.0f,-1.0f, 1.0f);           // Right Of Triangle (Front)glColor3f(1.0f,0.0f,0.0f);          // RedglVertex3f( 0.0f, 1.0f, 0.0f);            // Top Of Triangle (Right)glColor3f(0.0f,0.0f,1.0f);            // BlueglVertex3f( 1.0f,-1.0f, 1.0f);           // Left Of Triangle (Right)glColor3f(0.0f,1.0f,0.0f);           // GreenglVertex3f( 1.0f,-1.0f, -1.0f);         // Right Of Triangle (Right)glColor3f(1.0f,0.0f,0.0f);          // RedglVertex3f( 0.0f, 1.0f, 0.0f);            // Top Of Triangle (Back)glColor3f(0.0f,1.0f,0.0f);         // GreenglVertex3f( 1.0f,-1.0f, -1.0f);         // Left Of Triangle (Back)glColor3f(0.0f,0.0f,1.0f);            // BlueglVertex3f(-1.0f,-1.0f, -1.0f);          // Right Of Triangle (Back)glColor3f(1.0f,0.0f,0.0f);           // RedglVertex3f( 0.0f, 1.0f, 0.0f);            // Top Of Triangle (Left)glColor3f(0.0f,0.0f,1.0f);         // BlueglVertex3f(-1.0f,-1.0f,-1.0f);           // Left Of Triangle (Left)glColor3f(0.0f,1.0f,0.0f);            // GreenglVertex3f(-1.0f,-1.0f, 1.0f);          // Right Of Triangle (Left)glEnd();                        // Done Drawing The PyramidglLoadIdentity();glTranslatef(1.5f,0.0f,-7.0f);              // Move Right And Into The ScreenglRotatef(rquad,1.0f,1.0f,1.0f);            // Rotate The Cube On X, Y & ZglBegin(GL_QUADS);                  // Start Drawing The CubeglColor3f(0.0f,1.0f,0.0f);          // Set The Color To GreenglVertex3f( 1.0f, 1.0f,-1.0f);          // Top Right Of The Quad (Top)glVertex3f(-1.0f, 1.0f,-1.0f);          // Top Left Of The Quad (Top)glVertex3f(-1.0f, 1.0f, 1.0f);          // Bottom Left Of The Quad (Top)glVertex3f( 1.0f, 1.0f, 1.0f);          // Bottom Right Of The Quad (Top)glColor3f(1.0f,0.5f,0.0f);          // Set The Color To OrangeglVertex3f( 1.0f,-1.0f, 1.0f);          // Top Right Of The Quad (Bottom)glVertex3f(-1.0f,-1.0f, 1.0f);          // Top Left Of The Quad (Bottom)glVertex3f(-1.0f,-1.0f,-1.0f);          // Bottom Left Of The Quad (Bottom)glVertex3f( 1.0f,-1.0f,-1.0f);          // Bottom Right Of The Quad (Bottom)glColor3f(1.0f,0.0f,0.0f);          // Set The Color To RedglVertex3f( 1.0f, 1.0f, 1.0f);          // Top Right Of The Quad (Front)glVertex3f(-1.0f, 1.0f, 1.0f);          // Top Left Of The Quad (Front)glVertex3f(-1.0f,-1.0f, 1.0f);          // Bottom Left Of The Quad (Front)glVertex3f( 1.0f,-1.0f, 1.0f);          // Bottom Right Of The Quad (Front)glColor3f(1.0f,1.0f,0.0f);          // Set The Color To YellowglVertex3f( 1.0f,-1.0f,-1.0f);          // Bottom Left Of The Quad (Back)glVertex3f(-1.0f,-1.0f,-1.0f);          // Bottom Right Of The Quad (Back)glVertex3f(-1.0f, 1.0f,-1.0f);          // Top Right Of The Quad (Back)glVertex3f( 1.0f, 1.0f,-1.0f);          // Top Left Of The Quad (Back)glColor3f(0.0f,0.0f,1.0f);          // Set The Color To BlueglVertex3f(-1.0f, 1.0f, 1.0f);          // Top Right Of The Quad (Left)glVertex3f(-1.0f, 1.0f,-1.0f);          // Top Left Of The Quad (Left)glVertex3f(-1.0f,-1.0f,-1.0f);          // Bottom Left Of The Quad (Left)glVertex3f(-1.0f,-1.0f, 1.0f);          // Bottom Right Of The Quad (Left)glColor3f(1.0f,0.0f,1.0f);          // Set The Color To VioletglVertex3f( 1.0f, 1.0f,-1.0f);          // Top Right Of The Quad (Right)glVertex3f( 1.0f, 1.0f, 1.0f);          // Top Left Of The Quad (Right)glVertex3f( 1.0f,-1.0f, 1.0f);          // Bottom Left Of The Quad (Right)glVertex3f( 1.0f,-1.0f,-1.0f);          // Bottom Right Of The Quad (Right)glEnd();                     // Done Drawing The Quadrtri += 0.2f;                    // Increase The Rotation Variable For The Triangle ( NEW )rquad -= 0.15f;                  // Decrease The Rotation Variable For The Quad     ( NEW )
}

运行效果如下所示：