Question

下面是我的代码。我可以通过绘制身体，窗户，门和屋顶来画房子。现在，我想扩展我的代码;这样，如果按'f'，身体就会被移除。

如何修改代码才能执行此操作？

// ============================================= ======

#include <stdlib.h>
#include "GL\glut.h" // Header file for GLUT and OpenGL

void house();
void door();
void window();
void roof();


 //--------------------------------------------------------------
 // DRAWING CALLBACK FUNCTION
 //--------------------------------------------------------------
void draw(){
// background colour: yellow (Now GREEN)
    glClearColor( 100, 100, 0, 0 );
    glClear ( GL_COLOR_BUFFER_BIT );

 // Sets up the DOMAIN (xmin,xmax,ymin,ymax) in R2.
 // Let (xmin,xmax,ymin,ymax)=(0.0,20.0,0.0,20.0)
 glMatrixMode(GL_PROJECTION);
 glLoadIdentity();
 gluOrtho2D(0.0,22.0,0.0,22.0);

 // Let us now define the line segment in red
 // Endpoints: (5.0,1.5) and (9.3,7.2)
 glMatrixMode(GL_MODELVIEW);
 glLoadIdentity();


 //====================================
 //=============House==================
     glTranslatef(5,5,0);   
     house ();
 //=============Door===================
     glTranslatef(3.5,0,0);
     door();
//==============Window=================
     glTranslatef(3.5,6,0);
     window();
     glTranslatef(-6,0,0);
     window();
//=============Roof====================
     glTranslatef(-3,4,0);
     roof();
//===================================== 

 // display line segment
 glutSwapBuffers();
 }

 //---------------------------------------------------------------
 // KEYBOARD CALLBACK FUNCTION
 //---------------------------------------------------------------
 void house (){
 glColor3f( 1, 0, 0 );
 glBegin(GL_QUADS);
 glVertex2f(0.0,0.0);
 glVertex2f(10.0,0.0);
 glVertex2f(10.0,10.0);
 glVertex2f(0.0,10.0);
 glEnd();
}
 //=====================================
 void door (){
 glColor3f( 0, 1, 0 );
 glBegin(GL_QUADS);
 glVertex2f(0.0,0.0);
 glVertex2f(3.0,0.0);
 glVertex2f(3.0,5.0);
 glVertex2f(0.0,5.0);
 glEnd();
 }
 //=====================================
 void window (){
 glColor3f( 0, 0, 1 );
 glBegin(GL_QUADS);
 glVertex2f(0.0,0.0);
 glVertex2f(2.0,0.0);
 glVertex2f(2.0,2.0);
 glVertex2f(0.0,2.0);
 glEnd();
 }
 //=====================================
 void roof (){
 glColor3f( 0, 0, 1 );
 glBegin(GL_TRIANGLES);
 glVertex2f(0.0,0.0);
 glVertex2f(14.0,0.0);
 glVertex2f(7.0,5.0);
 glEnd();
 }
 //=====================================

 void keyboard(unsigned char key,int x,int y)
 {
 // press ESC key to quit
 if(key==27) exit(0);
 }

 //---------------------------------------------------------------
 // MAIN FUNCTION
 //---------------------------------------------------------------

 int main(int argc, char ** argv)
 {
 glutInit(&argc, argv);
 // Double Buffered RGB display
 glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE);
 // Set window size
 glutInitWindowSize( 600,600 );
 glutCreateWindow("Line Segment");
 // Declare callback functions
 glutDisplayFunc(draw);
 glutKeyboardFunc(keyboard);
 // Start the main loop of events
 glutMainLoop();
 return 0;
 }

// ============================================= ============

Answer 1

在keyboard()中添加一个支票，用于切换bool可以看到的house()：

#include <GL/glut.h>

bool showBody = true;
void keyboard(unsigned char key,int x,int y)
{
    // press ESC key to quit
    if(key==27) exit(0);
    if(key=='f') showBody = !showBody;
    glutPostRedisplay();
}

void house ()
{
    if( !showBody ) return;

    glColor3f( 1, 0, 0 );
    glBegin(GL_QUADS);
    glVertex2f(0.0,0.0);
    glVertex2f(10.0,0.0);
    glVertex2f(10.0,10.0);
    glVertex2f(0.0,10.0);
    glEnd();
}

void door ()
{
    glColor3f( 0, 1, 0 );
    glBegin(GL_QUADS);
    glVertex2f(0.0,0.0);
    glVertex2f(3.0,0.0);
    glVertex2f(3.0,5.0);
    glVertex2f(0.0,5.0);
    glEnd();
}

void window ()
{
    glColor3f( 0, 0, 1 );
    glBegin(GL_QUADS);
    glVertex2f(0.0,0.0);
    glVertex2f(2.0,0.0);
    glVertex2f(2.0,2.0);
    glVertex2f(0.0,2.0);
    glEnd();
}

void roof ()
{
    glColor3f( 0, 0, 1 );
    glBegin(GL_TRIANGLES);
    glVertex2f(0.0,0.0);
    glVertex2f(14.0,0.0);
    glVertex2f(7.0,5.0);
    glEnd();
}

void draw()
{
    // background colour: yellow (Now GREEN)
    glClearColor( 100, 100, 0, 0 );
    glClear ( GL_COLOR_BUFFER_BIT );

    // Sets up the DOMAIN (xmin,xmax,ymin,ymax) in R2.
    // Let (xmin,xmax,ymin,ymax)=(0.0,20.0,0.0,20.0)
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0,22.0,0.0,22.0);

    // Let us now define the line segment in red
    // Endpoints: (5.0,1.5) and (9.3,7.2)
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    //=============House==================
    glTranslatef(5,5,0);   
    house ();

    //=============Door===================
    glTranslatef(3.5,0,0);
    door();

    //==============Window=================
    glTranslatef(3.5,6,0);
    window();
    glTranslatef(-6,0,0);
    window();

    //=============Roof====================
    glTranslatef(-3,4,0);
    roof();

    glutSwapBuffers();
}

int main(int argc, char ** argv)
{
    glutInit(&argc, argv);
    // Double Buffered RGB display
    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE);
    // Set window size
    glutInitWindowSize( 600,600 );
    glutCreateWindow("Line Segment");
    // Declare callback functions
    glutDisplayFunc(draw);
    glutKeyboardFunc(keyboard);
    // Start the main loop of events
    glutMainLoop();
    return 0;
}

在获得某个键后按cpp中的图形按[让我们说'f']

1 个答案: