：静的面を維持して平面上に物体（キューブ）を移動する方法？

Question

#include<gl/glut.h> 
#include<stdio.h> 

GLfloat vertices[][3]={ 
{0.0,0.0,0.0},{0.0,0.4,0.0},{0.4,0.4,0.0},{0.4,0.0,0.0} }; 

GLfloat color[2][3]={ {1.0,0.0,0.0},{0.0,1.0,0.0}}; 

void board() 
{ 
    glColor3f(0.0,0.0,1.0); 
    glBegin(GL_LINE_LOOP); 
     glVertex3f(-0.8,-0.8,0.0); 
     glVertex3f(-0.8,0.80,0.0); 
     glVertex3f(0.80,0.80,0.0); 
     glVertex3f(0.8,-0.80,0.0); 
    glEnd(); 
} 

void cube() 
{ 
    glBegin(GL_LINE_LOOP); 
     glColor3f(1.0,0.0,0.0); 
     glVertex3fv(vertices[0]); 
     glVertex3fv(vertices[1]); 
     glVertex3fv(vertices[2]); 
     glVertex3fv(vertices[3]); 
    glEnd();  
} 

void display() 
{ 
    glClearColor(1.0,1.0,1.0,1.0); 
    glViewport(0,0,600,600); 
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); 

    cube(); 
    board(); 

    glFlush(); 
} 

void mykey(int key,int x,int y) 
{ 
    switch(key){ 
     case GLUT_KEY_LEFT: glTranslatef(-0.4,0.0,0.0); break;   
     case GLUT_KEY_RIGHT: glTranslatef(0.4,0.0,0.0); break; 
     case GLUT_KEY_UP: glTranslatef(0.0,0.4,0.0); break; 
     case GLUT_KEY_DOWN: glTranslatef(0.0,-0.3,0.0); break; 
    } 

    glutPostRedisplay(); 
} 


void myinit() 
{ 
    glMatrixMode(GL_PROJECTION); 
    glLoadIdentity(); 
    glOrtho(0,200,0,400,-1,1); 
    glMatrixMode(GL_MODELVIEW); 
} 

int main(int argc,char **argv) 
{ 
    glutInit(&argc,argv); 
    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB|GLUT_DEPTH); 
    glutInitWindowSize(600,600); 
    glutCreateWindow("hello"); 
    glutDisplayFunc(display); 
    glutSpecialFunc(mykey); 
    glutMainLoop(); 

    return 0; 
} 

Answer 1

OpenGLは、描画API、ないシーンレンダラです。あなたは何かを変えたいですか？それから、全体を再描画する必要があります。