Opengl教程之 读取obj并绘制在picturecontrol控件内

Opengl教程之读取obj并绘制在picturecontrol控件内

By Cracent

注：本文将简单图文表述基于MFC对话框的OpenGL三维显示(picture control 类版)以及obj文件读取绘制


目录
一、 配置相应环境
二、 建立CMyStatic类
2.1 添加类
2.2 类向导
2.2.1添加消息处理函数OnTimer()
2.2.2 重写虚函数PreSubclassWindow()
2.3 添加其他函数与变量
三、 OpenGl使用
3.1函数内容
3.2插入picture control控件， 并为其添加控制变量
3.3绘制简单函数
四、 obj文件读取并绘制
4.1 添加并配置glm.h glm.c
4.2添加函数：ObjRead();和LightShine()


一、 配置相应环境
 


二、 建立CMyStatic类
2.1 添加类
 
建立C++类；
 
2.2 类向导
2.2.1添加消息处理函数OnTimer()
 
2.2.2 重写虚函数PreSubclassWindow()
 


2.3 添加其他函数与变量
void GLDraw();//Opengl绘制
bool InitGL();//Opengl初始化
HGLRC hglrc;
HDC hdc;


三、 OpenGl使用
3.1函数内容
#include <GL\glu.h>
bool CMyStatic::InitGL(void)
{
static PIXELFORMATDESCRIPTOR pfd = 
{
sizeof(PIXELFORMATDESCRIPTOR),
1,
PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,
PFD_TYPE_RGBA,
24 ,
0, 0, 0, 0, 0, 0,
0,
0,
0,
0, 0, 0, 0,
32 ,
0,
0,
PFD_MAIN_PLANE,
0,
0, 0, 0
};


int pixelformat;
hdc = ::GetDC(this->GetSafeHwnd());
if (!(pixelformat = ChoosePixelFormat(hdc , &pfd)))
{
MessageBox("ChoosePixelFormat failed!");
return false;
}


if (!SetPixelFormat(hdc , pixelformat , &pfd))
{
MessageBox("SetPixelFormat failed!");
return false;
}


if (!(hglrc = wglCreateContext(hdc)))
{
MessageBox("CreateContext failed!");
return false;
}


if (!wglMakeCurrent(hdc , hglrc))
{
MessageBox("MakeCurrent failed!");
return false;
}


CRect rect; //在这个矩形中画图
GetClientRect(rect);


glViewport(0 , 0 , rect.Width() , rect.Height());
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
/*gluPerspective(45.0f , rect.Width()/rect.Height() , 0.1f , 100.0f);// 计算窗口的外观比例*/
gluPerspective(45.0f , 640/480 , 0.1f , 100.0f);// 计算窗口的外观比例
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();


glClearColor(0.0f , 0.0f , 0.0f , 1.0f);
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);


SetTimer(1 , 50 , NULL); 
return true;
}




void CMyStatic::OnTimer(UINT nIDEvent) 
{
// TODO: Add your message handler code here and/or call default
DrawFunc();   //定时器中调用这个函数
CStatic::OnTimer(nIDEvent);
}




void CMyStatic::PreSubclassWindow() 
{
// TODO: Add your specialized code here and/or call the base class
InitGL();
CStatic::PreSubclassWindow();
}


若出现此种情况：
 
如此设置：
 


3.2插入picture control控件， 并为其添加控制变量
 

 

3.3绘制简单函数
void CMyStatic::GLDraw(void)
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();

glTranslatef(-0.0f , 0.0f , -10.0f);

static int RotateDegTriangle =1;
glRotatef(RotateDegTriangle++ , 0.0f , 1.0f , 0.0f);
glBegin(GL_TRIANGLES);
glColor3f(1.0f , 0.0f , 0.0f);
glVertex3f(0.0f , 2.0f , 0.0f);
glColor3f(0.0f , 1.0f , 0.0f);
glVertex3f(-1.0f , 0.0f , 1.0f);
glColor3f(0.0f , 0.0f , 1.0f);
glVertex3f(1.0f , 0.0f , 1.0f );

glColor3f(1.0f , 0.0f , 0.0f);
glVertex3f(0.0f , 2.0f , 0.0f);
glColor3f(0.0f , 0.0f , 1.0f);
glVertex3f(1.0f , 0.0f , 1.0f);
glColor3f(0.0f , 1.0f , 0.0f);
glVertex3f(1.0f , 0.0f , -1.0f );

glColor3f(1.0f , 0.0f , 0.0f);
glVertex3f(0.0f , 2.0f , 0.0f);
glColor3f(0.0f , 1.0f , 0.0f);
glVertex3f(1.0f , 0.0f , -1.0f);
glColor3f(0.0f , 0.0f , 1.0f);
glVertex3f(-1.0f , 0.0f , -1.0f );

glColor3f(1.0f , 0.0f , 0.0f);
glVertex3f(0.0f , 2.0f , 0.0f);
glColor3f(0.0f , 0.0f , 1.0f);
glVertex3f(-1.0f , 0.0f , -1.0f);
glColor3f(0.0f , 1.0f , 0.0f);
glVertex3f(-1.0f , 0.0f , 1.0f );

glEnd();
#ifdef TWO_OBJS
glLoadIdentity();
glTranslatef(5.0f , 0.0f , -15.0f);

RotateDegQuad += 3.0f;
glRotatef(RotateDegQuad , 1.0f , 1.0f , 0.0f) ;
glBegin(GL_QUADS);
glColor3f(1.0f , 1.0f , 0.0f);
glVertex3f(-1.0f , 1.0f , 0.0f);
glVertex3f(-1.0f , -1.0f , 0.0f);
glVertex3f(1.0f , -1.0f , 0.0f);
glVertex3f(1.0f , 1.0f , 0.0f);
glEnd();
#endif
SwapBuffers(hdc); //利用双缓冲
}




F5后，可以看到如下画面
一个旋转的彩色立体正四面体
 


四、 obj文件读取并绘制
4.1 添加并配置glm.h glm.c
 
 


若glm.cpp没有#include "stdafx.h"，必须在最开头加上


CMyStatic.cpp添加库头
#include "glm.h"
4.2添加函数：ObjRead();和LightShine()
void CMyStatic::ObjRead(void)
{
GLfloat scalefactor = 0.0;
float modelCenter[] = {0.0f, 0.0f, 0.0f};
//GLMmodel *object1;
object1 = glmReadOBJ("Model/moto.obj");
if(!scalefactor)
{


scalefactor = glmUnitize(object1,modelCenter);
}
else
{


glmScale(object1,scalefactor);
}


glmScale(object1,1.5);
glmFacetNormals(object1);
glmVertexNormals(object1,90.0);
}


void CMyStatic::LightShine(void)
{
GLfloat mat_diffuse[4]={1,0.5,0.5,1.0};
GLfloat mat_specular[4]={1.0,1.0,1.0,1.0};
GLfloat mat_shininess[1]={100.0};


//光源 1
GLfloat light_position0[4]={0,500,500,0};
glMaterialfv(GL_FRONT,GL_DIFFUSE,mat_diffuse);
glMaterialfv(GL_FRONT,GL_SPECULAR,mat_specular);
glMaterialfv(GL_FRONT,GL_SHININESS,mat_shininess);
glLightfv(GL_LIGHT0,GL_POSITION,light_position0);
glEnable(GL_LIGHT0);


//光源 2   
GLfloat light_position1[4]={1000,-1000,1000,0};
GLfloat mat_diffuse1[4]={0.5,0.5,1.0,1.0};
glLightfv(GL_LIGHT1,GL_DIFFUSE,mat_diffuse1);
glLightfv(GL_LIGHT1,GL_SPECULAR,mat_specular);
glLightfv(GL_LIGHT1,GL_SHININESS,mat_shininess);
glLightfv(GL_LIGHT1,GL_POSITION,light_position1);
glEnable(GL_LIGHT1);


//使模型能接受光照
glEnable(GL_LIGHTING); 
glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE);
glDepthFunc(GL_LESS);
glEnable(GL_DEPTH_TEST);


//计算定点法线
glEnable(GL_AUTO_NORMAL);
glEnable(GL_NORMALIZE);
}


修改GLDraw()
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glEnable(GL_POINT_SMOOTH);
glEnable(GL_DEPTH_TEST);
LightShine(); 






glTranslatef(0.0f,0.0f,-5.0f);
static float step = 0.0;
step = step + 1.0;
if (step > 360.0)
step = step - 360.0;
glPushMatrix();
glRotatef(-45,1.0,0.0,0.0);
//glRotatef(step,0.0,1.0,0.0);
glRotatef(step,0.0,0.0,1.0);

if ( object1 )
{
glmDraw(object1, GLM_SMOOTH | GLM_MATERIAL | GLM_TEXTURE );
}
glPopMatrix();
SwapBuffers(hdc);




添加OBJ文件：
 




F5运行程序
如出现此种情况：
 
如此处理即可：


处理后F5可看到如下：
 

OK，我们的第一个Obj模型成功读入

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