myneonview.cpp

用VC++与OPENGL研发的粒子系统的模拟程序

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BOOL CMyNeonView::RenderScene() 
{
	glClearColor(0.0f, 0.0f, 0.0f, 0.5);
	glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();												
	RenderToTexture();			// 渲染到纹理
	ProcessHelix();				// 绘制螺旋对象
	DrawBlur(25,0.02f);			// 绘制模糊效果
	glFlush ();				

	::SwapBuffers(m_pDC->GetSafeHdc());		//交互缓冲区
	return TRUE;
}

void CMyNeonView::RenderToTexture()	
{
	glViewport(0,0,128,128);		// 设置视口变换(与纹理尺寸对应)
	ProcessHelix();					// 渲染螺旋对象
	glBindTexture(GL_TEXTURE_2D,BlurTexture);	
	glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, 0, 0, 128, 128, 0);
	glClearColor(0.0f, 0.0f, 0.5f, 0.5);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	
	glViewport(0, 0, 640, 480);		// 设置视口变换
}

void CMyNeonView::ProcessHelix()	// 绘制螺旋对象
{
	GLfloat x;						// 螺旋的X坐标
	GLfloat y;						// 螺旋的Y坐标
	GLfloat z;						// 螺旋的Z坐标
	GLfloat phi;					// 角度
	GLfloat theta;					// 角度
	GLfloat v,u;					// 角度
	GLfloat r;						// 螺旋的半径
	int twists = 5;					// 5个螺旋

	GLfloat glfMaterialColor[]={0.4f,0.2f,0.8f,1.0f};   // 设置材质颜色
	GLfloat specular[]={1.0f,1.0f,1.0f,1.0f};   		// 设置高光
	glLoadIdentity();									
	gluLookAt(0, 5, 50, 0, 0, 0, 0, 1, 0);				
	glPushMatrix();										
	glTranslatef(0,0,-50);								
	glRotatef(angle/2.0f,1,0,0);						
	glRotatef(angle/3.0f,0,1,0);						
    glMaterialfv(GL_FRONT_AND_BACK,GL_AMBIENT_AND_DIFFUSE,glfMaterialColor);
	glMaterialfv(GL_FRONT_AND_BACK,GL_SPECULAR,specular);

	r=1.5f;												// 半径

	glBegin(GL_QUADS);									// 绘制四边形
	for(phi=0; phi <= 360; phi+=20.0)					// 步长为20,总长360
	{
		for(theta=0; theta<=360*twists; theta+=20.0)	
		{
			v=(phi/180.0f*3.142f);						
			u=(theta/180.0f*3.142f);					

			x=float(cos(u)*(2.0f+cos(v) ))*r;			
			y=float(sin(u)*(2.0f+cos(v) ))*r;			
			z=float((( u-(2.0f*3.142f)) + sin(v) ) * r);

			vertexes[0][0]=x;							
			vertexes[0][1]=y;							
			vertexes[0][2]=z;							

			v=(phi/180.0f*3.142f);		
			u=((theta+20)/180.0f*3.142f);		

			x=float(cos(u)*(2.0f+cos(v) ))*r;
			y=float(sin(u)*(2.0f+cos(v) ))*r;	
			z=float((( u-(2.0f*3.142f)) + sin(v) ) * r);

			vertexes[1][0]=x;									
			vertexes[1][1]=y;									
			vertexes[1][2]=z;									

			v=((phi+20)/180.0f*3.142f);						
			u=((theta+20)/180.0f*3.142f);					

			x=float(cos(u)*(2.0f+cos(v) ))*r;			
			y=float(sin(u)*(2.0f+cos(v) ))*r;			
			z=float((( u-(2.0f*3.142f)) + sin(v) ) * r);

			vertexes[2][0]=x;						
			vertexes[2][1]=y;						
			vertexes[2][2]=z;						

			v=((phi+20)/180.0f*3.142f);				
			u=((theta)/180.0f*3.142f);				

			x=float(cos(u)*(2.0f+cos(v) ))*r;			
			y=float(sin(u)*(2.0f+cos(v) ))*r;			
			z=float((( u-(2.0f*3.142f)) + sin(v) ) * r);

			vertexes[3][0]=x;							
			vertexes[3][1]=y;						
			vertexes[3][2]=z;						

			calcNormal(vertexes,normal);						// 计算四边形法线

			glNormal3f(normal[0],normal[1],normal[2]);			// 设置法线

			// 渲染四边形
			glVertex3f(vertexes[0][0],vertexes[0][1],vertexes[0][2]);
			glVertex3f(vertexes[1][0],vertexes[1][1],vertexes[1][2]);
			glVertex3f(vertexes[2][0],vertexes[2][1],vertexes[2][2]);
			glVertex3f(vertexes[3][0],vertexes[3][1],vertexes[3][2]);
		}
	}
	glEnd();											
	
	glPopMatrix();									
}

void CMyNeonView::DrawBlur(int times, float inc)	// 绘制模糊影像
{
	float spost = 0.0f;								// 纹理坐标偏移
	float alphainc = 0.9f / times;					// Alpha混合的淡化速度
	float alpha = 0.2f;								// 初始Alpha值

	glDisable(GL_TEXTURE_GEN_S);
	glDisable(GL_TEXTURE_GEN_T);

	glEnable(GL_TEXTURE_2D);				
	glDisable(GL_DEPTH_TEST);			
	glBlendFunc(GL_SRC_ALPHA,GL_ONE);
	glEnable(GL_BLEND);					
	glBindTexture(GL_TEXTURE_2D,BlurTexture);
	ViewOrtho();							

	alphainc = alpha / times;								

	glBegin(GL_QUADS);									
		for (int num = 0;num < times;num++)				
		{
			glColor4f(1.0f, 1.0f, 1.0f, alpha);		
			glTexCoord2f(0+spost,1-spost);			
			glVertex2f(0,0);					

			glTexCoord2f(0+spost,0+spost);		
			glVertex2f(0,480);					

			glTexCoord2f(1-spost,0+spost);		
			glVertex2f(640,480);				

			glTexCoord2f(1-spost,1-spost);	
			glVertex2f(640,0);					

			spost += inc;						
			alpha = alpha - alphainc;			
		}
	glEnd();									

	ViewPerspective();							

	glEnable(GL_DEPTH_TEST);				
	glDisable(GL_TEXTURE_2D);					
	glDisable(GL_BLEND);					
	glBindTexture(GL_TEXTURE_2D,0);				
}

void CMyNeonView::ViewOrtho()						
{
	glMatrixMode(GL_PROJECTION);				
	glPushMatrix();								
	glLoadIdentity();							
	glOrtho( 0, 640 , 480 , 0, -1, 1 );		
	glMatrixMode(GL_MODELVIEW);					
	glPushMatrix();								
	glLoadIdentity();								
}

void CMyNeonView::ViewPerspective()						
{
	glMatrixMode( GL_PROJECTION );					
	glPopMatrix();									
	glMatrixMode( GL_MODELVIEW );				
	glPopMatrix();							
}

GLuint CMyNeonView::EmptyTexture()	// 生成空纹理
{
	GLuint txtnumber;		
	unsigned int* data;		

	data = (unsigned int*)new GLuint[((128 * 128)* 4 * sizeof(unsigned int))];
	ZeroMemory(data,((128 * 128)* 4 * sizeof(unsigned int)));	// 清除内存

	glGenTextures(1, &txtnumber);								// 生成纹理
	glBindTexture(GL_TEXTURE_2D, txtnumber);				
	glTexImage2D(GL_TEXTURE_2D, 0, 4, 128, 128, 0,
		GL_RGBA, GL_UNSIGNED_BYTE, data);			
	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);

	delete [] data;												// 释放内存

	return txtnumber;										
}

void CMyNeonView::ReduceToUnit(float vector[3])		// 矢量单位化
{													
	float length;								
	// 计算矢量的长度
	length = (float)sqrt((vector[0]*vector[0]) + (vector[1]*vector[1]) + (vector[2]*vector[2]));

	if(length == 0.0f)								
		length = 1.0f;								

	vector[0] /= length;									
	vector[1] /= length;									
	vector[2] /= length;							
}

void CMyNeonView::calcNormal(float v[3][3], float out[3])	
{
	float v1[3],v2[3];									
	static const int x = 0;						
	static const int y = 1;							
	static const int z = 2;						

	v1[x] = v[0][x] - v[1][x];						
	v1[y] = v[0][y] - v[1][y];							
	v1[z] = v[0][z] - v[1][z];							
	v2[x] = v[1][x] - v[2][x];							
	v2[y] = v[1][y] - v[2][y];							
	v2[z] = v[1][z] - v[2][z];							
	out[x] = v1[y]*v2[z] - v1[z]*v2[y];				
	out[y] = v1[z]*v2[x] - v1[x]*v2[z];					
	out[z] = v1[x]*v2[y] - v1[y]*v2[x];				

	ReduceToUnit(out);										
}

BOOL CMyNeonView::Init(void)
{
	angle		= 0.0f;											// 开始角度
	BlurTexture = EmptyTexture();								// 生成空纹理
	glEnable(GL_DEPTH_TEST);									
	GLfloat global_ambient[4]={0.2f, 0.2f,  0.2f, 1.0f};		
	GLfloat light0pos[4]=     {0.0f, 5.0f, 10.0f, 1.0f};		
	GLfloat light0ambient[4]= {0.2f, 0.2f,  0.2f, 1.0f};		
	GLfloat light0diffuse[4]= {0.3f, 0.3f,  0.3f, 1.0f};		
	GLfloat light0specular[4]={0.8f, 0.8f,  0.8f, 1.0f};		
	GLfloat lmodel_ambient[]= {0.2f,0.2f,0.2f,1.0f};			
	glLightModelfv(GL_LIGHT_MODEL_AMBIENT,lmodel_ambient);		
	glLightModelfv(GL_LIGHT_MODEL_AMBIENT, global_ambient);	
	glLightfv(GL_LIGHT0, GL_POSITION, light0pos);			
	glLightfv(GL_LIGHT0, GL_AMBIENT, light0ambient);		
	glLightfv(GL_LIGHT0, GL_DIFFUSE, light0diffuse);		
	glLightfv(GL_LIGHT0, GL_SPECULAR, light0specular);		
	glEnable(GL_LIGHTING);								
	glEnable(GL_LIGHT0);								
	glShadeModel(GL_SMOOTH);							
	glMateriali(GL_FRONT, GL_SHININESS, 128);
	glClearColor(0.0f, 0.0f, 0.0f, 0.5);			

	return TRUE;										

}