alphaview.cpp

C:Documents and SettingsAdministrator桌面VC++多媒体特效制作百例CHAR13Alpha

// AlphaView.cpp : implementation of the CAlphaView class
//

#include "stdafx.h"
#include "Alpha.h"

#include "AlphaDoc.h"
#include "AlphaView.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

/////////////////////////////////////////////////////////////////////////////
// CAlphaView

IMPLEMENT_DYNCREATE(CAlphaView, CView)

BEGIN_MESSAGE_MAP(CAlphaView, CView)
	//{{AFX_MSG_MAP(CAlphaView)
	ON_WM_CREATE()
	ON_WM_DESTROY()
	ON_WM_ERASEBKGND()
	ON_WM_SIZE()
	//}}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()

/////////////////////////////////////////////////////////////////////////////
// CAlphaView construction/destruction

CAlphaView::CAlphaView()
{
	//add down
	m_pDC = NULL;
	//add up
}

CAlphaView::~CAlphaView()
{
}

BOOL CAlphaView::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);
}

/////////////////////////////////////////////////////////////////////////////
// CAlphaView drawing

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

/////////////////////////////////////////////////////////////////////////////
// CAlphaView printing

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

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

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

/////////////////////////////////////////////////////////////////////////////
// CAlphaView diagnostics

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

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

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

/////////////////////////////////////////////////////////////////////////////
// CAlphaView message handlers

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

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

	hrc = ::wglGetCurrentContext();

	::wglMakeCurrent(NULL,  NULL);

	if (hrc)
		::wglDeleteContext(hrc);

	if (m_pDC)
		delete m_pDC;
	//add up

	CView::OnDestroy();
}

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

void CAlphaView::OnSize(UINT nType, int cx, int cy) 
{
	CView::OnSize(nType, cx, cy);
	
	//add down
	int w=cx;
	int h=cy;
	//避免除数为0
	if(h==0) h=1;

	//设置视口与窗口匹配
	glViewport(0,0,w,h);

	//重新设置坐标系统
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	
	//建立正交变换下的剪切体
	if(w<=h)
		gluOrtho2D(0.0,1.0,0.0,1.0*(GLfloat)h/(GLfloat)w);
	else
		gluOrtho2D(0.0,1.0*(GLfloat)w/(GLfloat)h,0.0,1.0);
	
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	//add up
}

//add down
void CAlphaView::Init()
{
	PIXELFORMATDESCRIPTOR pfd;
	int         n;
	HGLRC       hrc;

	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);

	//使混合模式有效
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
	glShadeModel(GL_FLAT);
	glClearColor(0.0,0.0,0.0,0.0);
}

BOOL CAlphaView::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 CAlphaView::DrawScene(void)
{
	//清除颜色缓冲区
	glClear(GL_COLOR_BUFFER_BIT);
	
	glColor4f(1.0,1.0,0.0,0.75);
	glRectf(0.0,0.0,0.5,1.0);
	glColor4f(0.0,1.0,1.0,0.75);
	glRectf(0.0,0.0,1.0,0.5);

	//在右上角以相反次序绘制着色矩形
	glColor4f(0.0,1.0,1.0,0.75);
	glRectf(0.5,0.5,1.0,1.0);
	glColor4f(1.0,1.0,0.0,0.75);
	glRectf(0.5,0.5,1.0,1.0);

	//刷新屏幕，绘制图形
	glFinish();
	SwapBuffers(wglGetCurrentDC());
}