OpenGL: 实现立体显示

立体显示原理：设没有立体显示的模型视图矩阵ModelView为Mv,投影矩阵为Mp，则、物体空间的任何一点为P，则变换到屏幕坐标P*=Mp×Mv×P；注意前面已经说过opengl里面坐标列优先，所以矩阵都是右乘。左眼和右眼的变换都是由中间的变换矩阵变换而来，则立体显示中左眼的变换矩阵公式为：P(L)*=Ms(L) × Mp(L) × Mt(L) × Mv(L) × P；右眼的矩阵变换公式为：P(R)*=Ms(R) × Mp(R) × Mt(R) × Mv(R) × P；其中Ms，Mt是立体显示需要而增加的变换。程序里面有几个参数，现实世界眼睛到屏幕的距离Fd，两眼之间的距离Sd，比例尺R，如图：

如上图：没有立体显示，视点位于就是中间的蓝色位置，立体显示就是将左眼(红色)，右眼(绿色)的视图分开绘制。程序中左眼用红色去画，右眼同时用绿色和蓝色绘制。 代码：

#include <windows.h>
#include <GL/glut.h>
#include <math.h>

#pragma comment(lib,"glut32.lib")
#pragma comment(lib,"glu32.lib")
#pragma comment(lib,"opengl32.lib")

void init(void) 
{
    GLfloat mat_diffuse[] = { 1.0, 1.0, 0.0 };
    GLfloat mat_specular[] = {0.8, 0.8, 0.0, 1.0};
    GLfloat mat_shininess[] = { 300. };
    GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
    GLfloat light_diffuse[] = { 1.0, 1.0, 0.0 };
    GLfloat light_ambient[] = {0.7, 0.2, 0.2, 1.0};

    glClearColor (0.0, 0.0, 0.0, 0.0);
    glShadeModel (GL_SMOOTH);

    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
    glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);

    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_DEPTH_TEST);
}
/**//*----------------------------------------------------------------------------
*    初始化参数    
*/
GLfloat PI=3.1415926;
GLfloat Fd=5.0;            //fusion distance
GLfloat RealScreenToEyeDistance=1.0;
GLfloat R = Fd / RealScreenToEyeDistance;    //比例尺 R =  Fd / RealScreenToEyeDistance
GLfloat Sd = 0.05;                        //两眼之间的距离
GLfloat aspect = 1.0;                        //gluLookAt函数里面的参数
GLfloat fovy = 60.0;                        //张角
GLfloat f = 1 / tan( (fovy * PI) / (2 * 180) );    //f=ctg(fovy/2);

//列优先的矩阵模型视图矩阵，投影矩阵
GLfloat LeftModelViewMatrix[16]=
{
    1.0, 0.0, 0.0, 0.0,
    0.0, 1.0, 0.0, 0.0, 
    0.0, 0.0, 1.0, 0.0, 
    Sd * R / 2.0, 0.0, 0.0, 1.0
};

GLfloat LeftProjectMatrix[16]=
{
    1.0, 0.0, 0.0, 0.0,
    0.0, 1.0, 0.0, 0.0, 
    0.0, 0.0, 1.0, 0.0, 
    -(Sd * f) / (2.0 * Fd * aspect), 0.0, 0.0, 1.0    
};

GLfloat RightModelViewMatrix[16]=
{
    1.0, 0.0, 0.0, 0.0,
    0.0, 1.0, 0.0, 0.0, 
    0.0, 0.0, 1.0, 0.0, 
    -Sd * R / 2.0, 0.0, 0.0, 1.0
};

GLfloat RightProjectMatrix[16]=
{
    1.0, 0.0, 0.0, 0.0,
    0.0, 1.0, 0.0, 0.0, 
    0.0, 0.0, 1.0, 0.0, 
    (Sd * f) / (2.0 * Fd * aspect), 0.0, 0.0, 1.0    
};

//for the use of rotating
static GLfloat spin = 0.0;

void display(void)
{
    GLfloat matrix[16]={0.};

    glColorMask(1.0, 1.0, 1.0, 1.0);
    glClearColor(0.0, 0.0, 0.0, 1.0);
    glClearDepth(1.0);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glColor3f(1.0, 1.0, 1.0);

    //---------------------------------------------------------------------------------------------
    //Left View port
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
	{
		glGetFloatv(GL_PROJECTION_MATRIX, matrix);
		glLoadIdentity();
		glMultMatrixf(LeftProjectMatrix);
		glMultMatrixf(matrix);
		{
			glMatrixMode(GL_MODELVIEW);
			glLoadIdentity();
			glTranslated(0.0, 0.0, -Fd);
			glPushMatrix();    
			{
				glGetFloatv(GL_MODELVIEW_MATRIX, matrix);
				glLoadIdentity();
				glMultMatrixf(LeftModelViewMatrix);        
				glMultMatrixf(matrix);                    
				glColorMask(1.0, 0.0, 0.0, 1.0);
				/**//*
				*  物体的坐标Vp
				*  变换到屏幕坐标：Vp'= LeftProjectMatrix×Mp × LeftModelViewMatrix×Mv × Mr×Vp
				*/
				glPushMatrix();
				{
					glRotatef(spin, 0.0, 1.0, 0.0);
					glutSolidTeapot(1.0);
				}
				glPopMatrix();
			}
		}
		glPopMatrix();
		glMatrixMode(GL_PROJECTION);
	}
    glPopMatrix();
    glFlush();    

    //---------------------------------------------------------------------------------------------
    //Right View port
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
	{
		glGetFloatv(GL_PROJECTION_MATRIX, matrix);
		glLoadIdentity();
		glMultMatrixf(RightProjectMatrix);
		glMultMatrixf(matrix);

		glMatrixMode(GL_MODELVIEW);    
		glPushMatrix();
		{
			glGetFloatv(GL_MODELVIEW_MATRIX, matrix);
			glLoadIdentity();
			glMultMatrixf(RightModelViewMatrix);
			glMultMatrixf(matrix);
	            
			glColorMask(0.0, 1.0, 1.0, 1.0);
			glClearDepth(1.0);
			glClear(GL_DEPTH_BUFFER_BIT);
			/**//*
			*  物体的坐标Vp
			*    变换到屏幕坐标：Vp'= RightProjectMatrix×Mp× RightModelViewMatrix×Mv × Mr×Vp
			*/
			glPushMatrix();
			{
				glRotatef(spin, 0.0, 1.0, 0.0);
				glutSolidTeapot(1.0);
				//glutSolidSphere(1.0, 20, 5);
			}
		}
		glPopMatrix();

		glMatrixMode(GL_PROJECTION);
	}
    glPopMatrix();
    glFlush ();

    glutSwapBuffers();
}

void reshape (int w, int h)
{
	if (h == 0)
	{
		h == 1;
	}
    glViewport (0, 0, (GLsizei) w, (GLsizei) h);
    glMatrixMode (GL_PROJECTION);
    glLoadIdentity();
    //投影矩阵：Mp
     gluPerspective(fovy, (GLfloat)w / (GLfloat)h, 1.0, 20.0);    
}
void spinDisplay(void)
{
    spin = spin + 1.0;
    if (spin > 360.0)
	{
		spin = spin - 360.0;
	}
    glutPostRedisplay();
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize (500, 500); 
    glutInitWindowPosition (100, 100);
    glutCreateWindow (argv[0]);
    init ();
    glutDisplayFunc(display); 
    glutReshapeFunc(reshape);
    glutIdleFunc(spinDisplay);
    glutMainLoop();
    return 0;
}

相关立体显示链接：http://local.wasp.uwa.edu.au/~pbourke/projection/stereorender//article/1342267.html