minglview.cpp

visual c++数字图像与图形处理中的光盘内容

// MinGlView.cpp : implementation of the CMinGlView class
//

#include "stdafx.h"
#include "MinGl.h"

#include "MinGlDoc.h"
#include "MinGlView.h"

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


#pragma comment(lib,  "OpenGL32.lib")
#pragma comment(lib,  "glu32.lib")

#include "GL\gl.h"
#include "GL\glu.h"


/////////////////////////////////////////////////////////////////////////////
// CMinGlView

IMPLEMENT_DYNCREATE(CMinGlView,  CView)

BEGIN_MESSAGE_MAP(CMinGlView,  CView)
	//{{AFX_MSG_MAP(CMinGlView)
	ON_WM_CREATE()
	ON_WM_DESTROY()
	ON_WM_SIZE()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMinGlView construction/destruction

CMinGlView::CMinGlView()
{
	// TODO: add construction code here
	m_pDC = NULL;
}

CMinGlView::~CMinGlView()
{
}

BOOL CMinGlView::PreCreateWindow(CREATESTRUCT& cs)
{
	// TODO: Modify the Window class or styles here by modifying
	//  the CREATESTRUCT cs

	//设置 OpenGL 窗口风格,  windows NT 下是必须的
	cs.style |= WS_CLIPCHILDREN | WS_CLIPSIBLINGS;

	return CView::PreCreateWindow(cs);
}

/////////////////////////////////////////////////////////////////////////////
// CMinGlView drawing

void CMinGlView::OnDraw(CDC* pDC)
{

	DrawScene();
}

/////////////////////////////////////////////////////////////////////////////
// CMinGlView diagnostics

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

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

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

/////////////////////////////////////////////////////////////////////////////
// CMinGlView message handlers

//设置像素格式
BOOL CMinGlView::SetupPixelFormat()
{
	static PIXELFORMATDESCRIPTOR pfd = 
	{
        sizeof(PIXELFORMATDESCRIPTOR),		   // size of this pfd
        1,									   // version number
        PFD_DRAW_TO_WINDOW |				   // support window
          PFD_SUPPORT_OPENGL, 				   // support OpenGL
        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
    };

	//选择硬件所支持的像素格式与 pfd 最接近的一个
    int nPixelformat;
    if ( (nPixelformat = ChoosePixelFormat(m_pDC->GetSafeHdc(),  &pfd)) == 0 )
    {
        MessageBox("ChoosePixelFormat failed");
        return FALSE;
    }

	//设置已经匹配的像素格式
    if (SetPixelFormat(m_pDC->GetSafeHdc(),  nPixelformat,  &pfd) == FALSE)
    {
        MessageBox("SetPixelFormat failed");
        return FALSE;
    }
    return TRUE;
}

//初始化OpenGL
void CMinGlView::Init()
{
	PIXELFORMATDESCRIPTOR pfd;
 
	m_pDC = new CClientDC(this);
	ASSERT(m_pDC != NULL);

	//设置像素格式
    if(!SetupPixelFormat())return;

	//测试并描述像素格式
    int nIndex = GetPixelFormat(m_pDC->GetSafeHdc());
    DescribePixelFormat(m_pDC->GetSafeHdc(),  nIndex,  sizeof(pfd),  &pfd);

	//创建着色描述表
	HGLRC hrc = wglCreateContext(m_pDC->GetSafeHdc());

	//当前化着色描述表
	wglMakeCurrent(m_pDC->GetSafeHdc(),  hrc);

	//允许深度测试, 深度初始值为远剪切面深度(规格化坐标系中)
    glClearDepth(1.0f);
    glEnable(GL_DEPTH_TEST);

}

int CMinGlView::OnCreate(LPCREATESTRUCT lpCreateStruct) 
{
	if (CView::OnCreate(lpCreateStruct) == -1)
		return -1;
	
	// TODO: Add your specialized creation code here
	
	//初始化
	Init();

	return 0;
}

void CMinGlView::OnDestroy() 
{
	CView::OnDestroy();
	
	// TODO: Add your message handler code here

	//获取当前着色描述表句柄
	HGLRC hrc = wglGetCurrentContext();

	//撤消与着色描述表关联的着色任务
	wglMakeCurrent(NULL,  NULL);

	//释放
	if(hrc)wglDeleteContext(hrc);
	if(m_pDC) delete m_pDC;
}

void CMinGlView::OnSize(UINT nType,  int cx,  int cy) 
{
	CView::OnSize(nType,  cx,  cy);
	
	// TODO: Add your message handler code here

	//启动透视变换矩阵
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	
	//设置视景体
	glFrustum(-1.0,  1.0,  -1.0,  1.0,  3.0,  7.0);

	//设置视口
	glViewport(0,  0,  (GLsizei)cx,  (GLsizei)cy);
}

void CMinGlView::DrawScene()
{
	//启动模型变换矩阵, 并单位化
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

	//将景物移至视景体之中
	glTranslatef(0.0f,  0.0f,  -4.5f);

	//颜色缓冲区清除颜色为白色
	glClearColor(1.0f,  1.0f,  1.0f,  1.0f);
	//同时清除颜色缓冲区和深度缓冲区
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);


	//绘制一条直线
	glBegin(GL_LINES);
		
		//颜色
		glColor3f(1.0f,  0.0f,  0.0f);
		
		//直线两端点坐标
		glVertex3f(-0.8f,  0.8f,  0.5f);
		glVertex3f(0.8f,  -0.8f,  0.5f);

	glEnd();


	//完成绘制指令后交换缓冲区
	glFinish();	
 
}