C++ glut中的简单2d动画

我有一项任务要做，但我似乎不能真正理解它。 任务如下：将纹理添加到背景太阳系，将纹理添加到2个绘制形状的对象，并添加动画，其中两个对象必须相互反弹&从屏幕末端的远墙反弹

除了动画片，我什么都做了。 我如何制作这种动画？ p、 那里的美国动画是我能想到的最好的

#include <gl/glut.h>
#include <gl/gl.h >
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>


float x;
float y;



unsigned char *imageData;
int imageRows, imageCols;

extern void loadBMP(char *);
char cotton1[] = "cotton1.bmp";
char cotton2[] = "cotton2.bmp";
char fons[] = "solar.bmp";

GLuint texture[3];
float cube[1], Vcube[1];

/* GLUT callback Handlers */

void init()
{
cube[0]=0;
Vcube[0]=0.01;
cube[1]=0;
Vcube[1]=0.01;


glShadeModel(GL_SMOOTH);

glGenTextures( 3, &texture[0] );

   loadBMP(cotton1);
   glBindTexture( GL_TEXTURE_2D, texture[0] );
   glTexImage2D(GL_TEXTURE_2D, 0, 3, imageCols, imageRows,
         0, GL_RGB, GL_UNSIGNED_BYTE, imageData);

   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

     loadBMP(cotton2);
   glBindTexture( GL_TEXTURE_2D, texture[1] );
   glTexImage2D(GL_TEXTURE_2D, 0, 3, imageCols, imageRows,
         0, GL_RGB, GL_UNSIGNED_BYTE, imageData);

   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

        loadBMP(fons);
   glBindTexture( GL_TEXTURE_2D, texture[2] );
   glTexImage2D(GL_TEXTURE_2D, 0, 3, imageCols, imageRows,
         0, GL_RGB, GL_UNSIGNED_BYTE, imageData);

   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

}

static void 
resize(int width, int height)
{
    const float ar = (float) width / (float) height;

    glViewport(0, 0, width, height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity() ;
}

static void 
idle(void)
{
    glutPostRedisplay();
}

void animation()
{
cube[1]+=Vcube[1];
if (cube[1]<0.1)
{ Vcube[1]+=Vcube[1]; }
if (cube[1]>0.095)
{ Vcube[1]=-0.01; }
if (cube[1]<0)
{ Vcube[1]=+0.01; }

glTranslatef(cube[1],0,0);
       Sleep(100);
       glutPostRedisplay();
}


void animation2()
{
  cube[0]+=Vcube[0];
if (cube[0]<(-0.1))
{ Vcube[0]-=0.01; }
if (cube[0]>0)
{ Vcube[0]-=0.01; }
if (cube[0]<0.1)
{ Vcube[0]+=0.01; }


glTranslatef(cube[0],0,0);
       Sleep(100);
       glutPostRedisplay();
}

void display() {


    glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT);  


//Background
    glLoadIdentity();
    glBindTexture( GL_TEXTURE_2D, texture[2]);
    glEnable( GL_TEXTURE_2D );

    glPushMatrix();
     glBegin( GL_QUADS );
      glTexCoord2f(1.0,1.0); glVertex2f(-1.0,1.0);
      glTexCoord2f(0.0,1.0); glVertex2f(1.0,1.0);
      glTexCoord2f(0.0,0.0); glVertex2f(1.0,-1.0);
      glTexCoord2f(1.0,0.0); glVertex2f(-1.0,-1.0);
      glEnd();
      glPopMatrix();
    glDisable(GL_TEXTURE_2D);

  animation();

//TEXTURE 1
    glBindTexture( GL_TEXTURE_2D, texture[0]);

    glEnable( GL_TEXTURE_2D );

    glPushMatrix();
    glBegin( GL_TRIANGLE_FAN );
glTexCoord2f(0.5f, 0.5f);  glVertex2f(  0.5f,  0.0f);   //center
glTexCoord2f(1.0f, 0.5f);  glVertex2f(  0.8f+x,  0.0f);   //right
glTexCoord2f(0.75f, 1.0f); glVertex2f(  0.55f+x, 0.3f+x);  //top right
glTexCoord2f(0.25f, 1.0f); glVertex2f(  0.35f-x, 0.3f+x);   //Top left
glTexCoord2f(0.0f, 0.5f);  glVertex2f(  0.25f-x, 0.0f);   //left
glTexCoord2f(0.25f, 0.0f); glVertex2f(  0.45f-x,-0.3f-x);   //bottom left
glTexCoord2f(0.75f, 0.0f); glVertex2f(  0.7f+x, -0.2f-x);   //bottom right
glTexCoord2f(1.0f, 0.5f);  glVertex2f(  0.8f+x,  0.0f);   //right
      glEnd();
      glPopMatrix();
    glDisable(GL_TEXTURE_2D);
//TEXTURE 2

    animation2();   
    glBindTexture( GL_TEXTURE_2D, texture[1]);

    glEnable( GL_TEXTURE_2D );
    glPushMatrix();
    glBegin( GL_TRIANGLE_FAN );
glTexCoord2f(0.5f, 0.5f);  glVertex2f( -0.5f,  0.0f);  //center
glTexCoord2f(1.0f, 0.5f);  glVertex2f( -0.2f+y,  0.0f);  //right
glTexCoord2f(0.75f, 1.0f); glVertex2f( -0.4f+y,  0.2f+y);  //top right
glTexCoord2f(0.25f, 1.0f); glVertex2f( -0.7f-y,  0.1f+y);  //Top left
glTexCoord2f(0.0f, 0.5f);  glVertex2f( -0.8f-y,  0.0f);  //left
glTexCoord2f(0.25f, 0.0f); glVertex2f( -0.7f-y, -0.1f-y);  //bottom left
glTexCoord2f(0.75f, 0.0f); glVertex2f( -0.3f+y, -0.2f-y);  //bottom right
glTexCoord2f(1.0f, 0.5f);  glVertex2f( -0.2f+y,  0.0f);  //right
      glEnd();
      glPopMatrix();
    glDisable(GL_TEXTURE_2D);
glutSwapBuffers();
glFlush();
}


static void 
key(unsigned char key, int a, int b)
{
    switch (key) 
    {
        case 27 : 
        case 'q':
            exit(0);
            break;

        case '+':
             if ((x+0.01)<0.98)
             x=x+0.01;
             if ((y+0.01)<0.98)
             y=y+0.01;         
            break;

        case '-':
             if ((x-0.1)>(-0.15))
                x=x-0.01;
             if ((y-0.1)>(-0.10))
                y=y-0.01;
           break;

        case 'o':
             if ((x+0.01)<0.98)
             x=x+0.01;
             break;
        case 'p':
             if ((x-0.1)>(-0.15))
             x=x-0.01;
             break;


        case '[':
             if ((y+0.01)<0.98)
             y=y+0.01;
             break;
        case ']':
             if ((y-0.1)>(-0.10))
             y=y-0.01;
             break;



    }
    glutPostRedisplay();
}

int main(int argc, char *argv[]) {
   glutInit(&argc, argv);   

   glutInitWindowSize(640, 640);   
   glutInitWindowPosition(50, 50); 
   glutCreateWindow("Assignment number 3"); 
   glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH);



   glutReshapeFunc(resize);
   glutDisplayFunc(display);      
   glutKeyboardFunc(key);         
   glutIdleFunc(idle);

   glClearColor(1.0, 1.0, 1.0, 1.0);

   init();

   glutMainLoop();               
   return EXIT_SUCCESS;
}

---

问题1：将OpenGL误认为是场景图。以animation1函数为例：

void animation2(
     )
{
    cube[0] += Vcube[0];
    if( cube[0] < ( -0.1 ) ) {
        Vcube[0] -= 0.01;
    }
    if( cube[0] > 0 ) {
        Vcube[0] -= 0.01;
    }
    if( cube[0] < 0.1 ) {
        Vcube[0] += 0.01;
    }


    glTranslatef( cube[0], 0, 0 );
    Sleep( 100 );
    glutPostRedisplay(  );
}

---

问题1：将OpenGL误认为是场景图。以animation1函数为例：

void animation2(
     )
{
    cube[0] += Vcube[0];
    if( cube[0] < ( -0.1 ) ) {
        Vcube[0] -= 0.01;
    }
    if( cube[0] > 0 ) {
        Vcube[0] -= 0.01;
    }
    if( cube[0] < 0.1 ) {
        Vcube[0] += 0.01;
    }


    glTranslatef( cube[0], 0, 0 );
    Sleep( 100 );
    glutPostRedisplay(  );
}

---

@user1462023:FYI：我冒昧地向您的代码添加了所有提到的修复和更改。所以，如果你被卡住了，我可以给你一个工作版本。@user1462023:顺便说一句，你的动画代码本身也有一些问题，比如测试错误的边界条件。如果你能做到这一点，我将不胜荣幸。似乎我对这些对象的动画制作毫无用处。@user1462023:好的，让我对其进行彻底的注释，以便您理解。@user1462023:FYI:我冒昧地向您的代码中添加了所有提到的修复和更改。所以，如果你被卡住了，我可以给你一个工作版本。@user1462023:顺便说一句，你的动画代码本身也有一些问题，比如测试错误的边界条件。如果你能做到这一点，我将不胜荣幸。似乎我对这些对象的动画制作毫无用处。@user1462023:好的，让我彻底地评论一下，这样你就明白了。