【转】 《基于MFC的OpenGL编程》Part 14 Quadrics

本文在第11篇文章的基础上，为其加入显示各种二次曲面的代码；

Quadrics

Every quadric has a few settings associated with it. We have to create a quadric first and then customize its settings to render the shape we want. The gluNewQuadric function creates a state variable that describes the current drawing style, orientation, lighting mode, texturing mode and the callback functions. Once we use this function to create a new quadric, we can customize the drawing of shapes by changing its state using functions such as

gluQuadricDrawStyle - which selects the type of OpenGL drawing primitives that are used to drw the shape.

gluQuadricOrientation - which controls the direction of the lighting normals.

gluQuadricNormals - which controls the generation of lighting normals.

gluQuadricTexture - which generates texture coordinates automatically for the quadric.

1,在CCY457OpenGLView类中加入下列变量，用来表示二次曲面类型：

//Quadric

GLuint m_Quadric;

2，加入五个控制二次曲面类型的菜单项及其事件处理函数

void CCY457OpenGLView::OnQuadricSphere()

{//球体

m_Quadric = 0;

InvalidateRect(NULL,FALSE);

}

void CCY457OpenGLView::OnUpdateQuadricSphere(CCmdUI* pCmdUI)

{

if(m_Quadric == 0)

pCmdUI->SetRadio(TRUE);

else

pCmdUI->SetRadio(FALSE);

}

void CCY457OpenGLView::OnQuadricCone()

{//圆锥

m_Quadric = 2;

InvalidateRect(NULL,FALSE);

}

void CCY457OpenGLView::OnUpdateQuadricCone(CCmdUI* pCmdUI)

{

if(m_Quadric == 2)

pCmdUI->SetRadio(TRUE);

else

pCmdUI->SetRadio(FALSE);

}

void CCY457OpenGLView::OnQuadricCylinder()

{//柱体

m_Quadric = 1;

InvalidateRect(NULL,FALSE);

}

void CCY457OpenGLView::OnUpdateQuadricCylinder(CCmdUI* pCmdUI)

{

if(m_Quadric == 1)

pCmdUI->SetRadio(TRUE);

else

pCmdUI->SetRadio(FALSE);

}

void CCY457OpenGLView::OnQuadricDisk()

{//圆盘

m_Quadric = 3;

InvalidateRect(NULL,FALSE);

}

void CCY457OpenGLView::OnUpdateQuadricDisk(CCmdUI* pCmdUI)

{

if(m_Quadric == 3)

pCmdUI->SetRadio(TRUE);

else

pCmdUI->SetRadio(FALSE);

}

void CCY457OpenGLView::OnQuadricPartialdisk()

{////半圆盘

m_Quadric = 4;

InvalidateRect(NULL,FALSE);

}

void CCY457OpenGLView::OnUpdateQuadricPartialdisk(CCmdUI* pCmdUI)

{

if(m_Quadric == 4)

pCmdUI->SetRadio(TRUE);

else

pCmdUI->SetRadio(FALSE);

}

3,绘制函数修改如下：

void CCY457OpenGLView::RenderScene ()

{//绘制函数

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);

glEnable(GL_TEXTURE_2D);

glBindTexture(GL_TEXTURE_2D,m_Texture[0]);

GLUquadricObj* obj;

obj = gluNewQuadric();

gluQuadricNormals(obj, GLU_SMOOTH);

gluQuadricTexture(obj, GL_TRUE);

switch(m_Quadric)

{

case 0: gluSphere(obj, 1, 20, 20);

break;

case 1: gluCylinder(obj, 1, 1, 3, 20, 20);

break;

case 2: gluCylinder(obj, 0.1, 1, 3, 20, 20);

break;

case 3: gluDisk(obj, 0.5, 1, 20, 20);

break;

case 4: gluPartialDisk(obj, 0.5, 1, 20, 20, 10, 180);

break;

}

glDisable(GL_TEXTURE_2D);

}