问题是，“桌子上的东西被桌板盖住了，所以看不见。”
（我使用openGL 3.7 beta。我安装的文件是：http: //ihoo1836.dothome.co.kr/opengl_vs2010+glutdlls37beta.zip ）
所有代码如下。
#include<glut.h>
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
float TableX = 5.0; //Table's X size
float TableY = 8.0; //Table's Y size
float TableHeight = 2.0;//Table's Height
int width=400, height=400; //Window Size
int ViewX = width/2; //for Change Viewpoint by Mouse position
int ViewY = height/2;
int ViewZ = 9;
GLUquadricObj* cyl;
void InitLight( ){
glEnable(GL_DEPTH_TEST); //for opaque
glEnable(GL_NORMALIZE); //normalize
glEnable(GL_SMOOTH); //for smooth color
glEnable(GL_LIGHTING); //light setting
glDepthMask(GL_TRUE);
GLfloat ambientLight[] = {0.3f, 0.3f, 0.3f, 1.0f};
GLfloat diffuseLight[] = {0.7f, 0.7f, 0.7f, 1.0f};
GLfloat specular[] = {1.0f, 1.0f, 1.0f, 1.0f};
GLfloat specref[] = {1.0f, 1.0f, 1.0f, 1.0f};
GLfloat position[]={400.0, 300.0, -700.0, 1.0};
glLightfv(GL_LIGHT0, GL_AMBIENT, ambientLight);
glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuseLight);
glLightfv(GL_LIGHT0, GL_SPECULAR, specular);
glLightfv(GL_LIGHT0, GL_POSITION, position);
glEnable(GL_LIGHT0);
glEnable(GL_COLOR_MATERIAL);
glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
glMateriali(GL_FRONT, GL_SHININESS, 128);
}
//Get Mouse Position to Change ViewPoint
void MyMouseMove(int button, int state, GLint X, GLint Y)
{
//Get Mouse Position X, Y
ViewX = X;
ViewY = Y;
glutPostRedisplay();
}
//Get Mouse Position to Change ViewPoint
void MyMotion(GLint X, GLint Y)
{
//Get Mouse Position X, Y
ViewX = X;
ViewY = Y;
glutPostRedisplay();
}
//Draw Table
void DrawTable(){
glPushMatrix();
glTranslatef(0.0,0.0,1.0);
glColor3f(0.5, 0.25, 0.0);
cyl = gluNewQuadric();
glRotatef(-90,1.0,0.0,0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 1
glPushMatrix();
cyl = gluNewQuadric();
glTranslatef(TableX,0.0,0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 2
glPushMatrix();
cyl = gluNewQuadric();
glTranslatef(0.0, TableY, 0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 3
glPushMatrix();
cyl = gluNewQuadric();
glTranslatef(-TableX,0.0,0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 4
glPushMatrix();
glTranslatef(TableX/2.0, -TableY/2, TableHeight);
glScalef(TableX+0.5, TableY+0.5, 0.5);
glutSolidCube(1); //Board of Table
glPopMatrix();
glPushMatrix(); //triangular1 (Beside of Net)
glTranslatef(0, -TableY/2, TableHeight);
glBegin(GL_TRIANGLES);
glVertex3f(TableY/16.0, 0, TableY/8.0);//1
glVertex3f(0, TableY/8.0, 0);
glVertex3f(0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//2
glVertex3f(0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//3
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, TableY/8.0, 0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//4
glVertex3f(TableY/16.0, TableY/8.0, 0);
glVertex3f(0, TableY/8.0, 0);
glEnd();
glPushMatrix(); //triangular2 (Beside of Net)
glTranslatef(TableX - TableY/8.0, 0 , 0);
glBegin(GL_TRIANGLES);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//1
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/16.0, TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//2
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/8.0, -TableY/8.0, 0);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//3
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/8.0, -TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/8.0, TableY/8.0, 0);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//4
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/8.0, TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/16.0, TableY/8.0, 0);
glEnd();
glPopMatrix();
glPushMatrix(); //Net
glBegin(GL_POLYGON);
glColor3f(1.0, 1.0, 1.0);
glVertex3f(TableY/16.0, 0.0, TableY/8.0);
glVertex3f((TableX - TableY/16.0), 0, TableY/8.0);
glVertex3f((TableX - TableY/16.0), 0, 0);
glVertex3f(TableY/16.0, 0.0, 0.0);
glEnd();
glPopMatrix();
glPopMatrix();
glPopMatrix();
glPopMatrix();
glPopMatrix();
glPopMatrix();
}
//Display Callback Function
void MyDisplay( ){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity( );
gluPerspective(60.0, (GLfloat)width/height, 0.0, 10.0);
//Change Viewpoint by Mouse Position
gluLookAt((float)(ViewX - width/2)/width*20 + 2.5, (float)(height/2 - ViewY)/height*20 + 2.5, ViewZ, TableX/2, TableY/2, TableHeight, 0.0, 1.0, 0.0);
printf("eyex = %f , eyey = %f , eyez = %f \n",(float)(ViewX - width/2.0)/width*10, (float)(height/2 - ViewY)/height*10, (float)ViewZ);
DrawTable(); //Draw Table
glutSwapBuffers(); //for 'Double Buffering'
}
//for Reshape Window
void MyReshape (int w, int h){
width = w;
height = h;
printf("width = %d, height = %d \n", width, height);
glViewport (0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode (GL_PROJECTION);
glLoadIdentity( );
glOrtho (-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
}
//Main Function
int main(int argc, char** argv){
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
glutInitWindowSize(width, height);
glutInitWindowPosition(200, 200);
glutCreateWindow("OpenGL Sample Drawing");
glClearColor(0.4, 0.4, 0.4, 1.0);
InitLight(); //set Light Setting
glutDisplayFunc(MyDisplay);
glutMouseFunc(MyMouseMove); //get Mouse Position, to Change Viewpoint
glutMotionFunc(MyMotion); //get Mouse Position, to Change Viewpoint
glutReshapeFunc(MyReshape);
glutMainLoop( );
}