clipplaneview.cpp

C:Documents and SettingsAdministrator桌面VC++多媒体特效制作百例CHAR09ClipPlane

// ClipPlaneView.cpp : implementation of the CClipPlaneView class
//

#include "stdafx.h"
#include "ClipPlane.h"

#include "ClipPlaneDoc.h"
#include "ClipPlaneView.h"

//add down 
#include "gl\gl.h"
#include "gl\glu.h"
#include "gl\glaux.h"
//add up

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CClipPlaneView

IMPLEMENT_DYNCREATE(CClipPlaneView, CView)

BEGIN_MESSAGE_MAP(CClipPlaneView, CView)
	//{{AFX_MSG_MAP(CClipPlaneView)
	ON_WM_CREATE()
	ON_WM_DESTROY()
	ON_WM_SIZE()
	ON_WM_ERASEBKGND()
	//}}AFX_MSG_MAP
	// Standard printing commands
	ON_COMMAND(ID_FILE_PRINT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_DIRECT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_PREVIEW, CView::OnFilePrintPreview)
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CClipPlaneView construction/destruction

CClipPlaneView::CClipPlaneView()
{
	//add dowm
	m_pDC = NULL;
	//add up
}

CClipPlaneView::~CClipPlaneView()
{
}

BOOL CClipPlaneView::PreCreateWindow(CREATESTRUCT& cs)
{
	// TODO: Modify the Window class or styles here by modifying
	//  the CREATESTRUCT cs
	//add down
	cs.style |= WS_CLIPSIBLINGS | WS_CLIPCHILDREN;
	//add up

	return CView::PreCreateWindow(cs);
}

/////////////////////////////////////////////////////////////////////////////
// CClipPlaneView drawing

void CClipPlaneView::OnDraw(CDC* pDC)
{
	CClipPlaneDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	// TODO: add draw code for native data here
	//add down
	DrawScene();
	//add up
}

/////////////////////////////////////////////////////////////////////////////
// CClipPlaneView printing

BOOL CClipPlaneView::OnPreparePrinting(CPrintInfo* pInfo)
{
	// default preparation
	return DoPreparePrinting(pInfo);
}

void CClipPlaneView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add extra initialization before printing
}

void CClipPlaneView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add cleanup after printing
}

/////////////////////////////////////////////////////////////////////////////
// CClipPlaneView diagnostics

#ifdef _DEBUG
void CClipPlaneView::AssertValid() const
{
	CView::AssertValid();
}

void CClipPlaneView::Dump(CDumpContext& dc) const
{
	CView::Dump(dc);
}

CClipPlaneDoc* CClipPlaneView::GetDocument() // non-debug version is inline
{
	ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CClipPlaneDoc)));
	return (CClipPlaneDoc*)m_pDocument;
}
#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////
// CClipPlaneView message handlers

int CClipPlaneView::OnCreate(LPCREATESTRUCT lpCreateStruct) 
{
	if (CView::OnCreate(lpCreateStruct) == -1)
		return -1;
	
	//add down
	Init(); // initialize OpenGL
	//add up
	
	return 0;
}

void CClipPlaneView::OnDestroy() 
{
	//add down
	HGLRC   hrc;

	hrc = ::wglGetCurrentContext();

	::wglMakeCurrent(NULL,  NULL);

	if (hrc)
		::wglDeleteContext(hrc);

	if (m_pDC)
		delete m_pDC;
	//add up

	CView::OnDestroy();
}

void CClipPlaneView::OnSize(UINT nType, int cx, int cy) 
{
	CView::OnSize(nType, cx, cy);
	
	//add down
	if(cy > 0)
	{
		glViewport(0, 0, cx, cy);

		//客户窗口变化时刷新窗口
		if((m_oldRect.right > cx) || (m_oldRect.bottom > cy))
			RedrawWindow();

		m_oldRect.right = cx;
		m_oldRect.bottom = cy;

		glMatrixMode(GL_PROJECTION);
		glLoadIdentity();
		//定义为透视投影
		gluPerspective(45.0f, (GLdouble)cx/cy, 3.0f, 7.0f);
		glMatrixMode(GL_MODELVIEW);
	}
	//add up
}


BOOL CClipPlaneView::OnEraseBkgnd(CDC* pDC) 
{
	return TRUE;
}

//add down
void CClipPlaneView::Init()
{
	PIXELFORMATDESCRIPTOR pfd;
	int         n;
	HGLRC       hrc;
	GLfloat     fMaxObjSize, fAspect;
	GLfloat     fNearPlane, fFarPlane;

	m_pDC = new CClientDC(this);

	ASSERT(m_pDC != NULL);

	if (!bSetupPixelFormat())
		return;

	n = ::GetPixelFormat(m_pDC->GetSafeHdc());
	::DescribePixelFormat(m_pDC->GetSafeHdc(), n, sizeof(pfd), &pfd);

	hrc = wglCreateContext(m_pDC->GetSafeHdc());
	wglMakeCurrent(m_pDC->GetSafeHdc(), hrc);

	//得到客户区的尺寸
	GetClientRect(&m_oldRect);
	glClearDepth(1.0f);
	glEnable(GL_DEPTH_TEST);

	//给透视投影参数赋值
	if (m_oldRect.bottom)
		fAspect = (GLfloat)m_oldRect.right/m_oldRect.bottom;
	else    // 如果m_oldRect.bottom为0
		fAspect = 1.0f;
	fNearPlane = 3.0f;
	fFarPlane = 7.0f;
	fMaxObjSize = 3.0f;
	m_fRadius = fNearPlane + fMaxObjSize / 2.0f;

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	//根据客户区的初始值定透视投影
	gluPerspective(45.0f, fAspect, fNearPlane, fFarPlane);
	glMatrixMode(GL_MODELVIEW);
}

BOOL CClipPlaneView::bSetupPixelFormat()
{
	static PIXELFORMATDESCRIPTOR pfd =
	{
		sizeof(PIXELFORMATDESCRIPTOR),  // size of this pfd
		1,                              // version number
		PFD_DRAW_TO_WINDOW |            // support window
		  PFD_SUPPORT_OPENGL |          // support OpenGL
		  PFD_DOUBLEBUFFER,             // double buffered
		PFD_TYPE_RGBA,                  // RGBA type
		24,                             // 24-bit color depth
		0, 0, 0, 0, 0, 0,               // color bits ignored
		0,                              // no alpha buffer
		0,                              // shift bit ignored
		0,                              // no accumulation buffer
		0, 0, 0, 0,                     // accum bits ignored
		32,                             // 32-bit z-buffer
		0,                              // no stencil buffer
		0,                              // no auxiliary buffer
		PFD_MAIN_PLANE,                 // main layer
		0,                              // reserved
		0, 0, 0                         // layer masks ignored
	};
	int pixelformat;

	if ( (pixelformat = ChoosePixelFormat(m_pDC->GetSafeHdc(), &pfd)) == 0 )
	{
		MessageBox("ChoosePixelFormat failed");
		return FALSE;
	}

	if (SetPixelFormat(m_pDC->GetSafeHdc(), pixelformat, &pfd) == FALSE)
	{
		MessageBox("SetPixelFormat failed");
		return FALSE;
	}

	return TRUE;
}

void CClipPlaneView::DrawScene(void)
{
	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glPushMatrix();

	glTranslatef(0.0f, 0.0f, -m_fRadius);
	
	//定义数组，定义了一个裁减平面：x+y<0 
	double equation[4]={1.0,1.0,0.0,0.0};

	//指定图形的裁剪平面
	glClipPlane(GL_CLIP_PLANE0,equation);
	//使裁剪平面生效
	glEnable(GL_CLIP_PLANE0);

	//绘制茶壶，但是该图形被上面定义的裁减平面给裁减去了下面的部分
	glColor3f(1.0f, 0.0f, 1.0f);
	auxWireTeapot(0.5f);

	glPopMatrix();

	glFinish();
	SwapBuffers(wglGetCurrentDC());
}
//add up