text: #include <GL/gl.h>
  #include <GL/glu.h>
  #include <GL/glut.h>
  #include <stdlib.h>
  #include <stdio.h>
  
  #define stripeImageWidth 32
  GLubyte stripeImage[4*stripeImageWidth];
  
  static GLuint texName;
  
  void makeStripeImage(void)
  {
      int j;
  
      for (j = 0; j < stripeImageWidth; j++) {
          stripeImage[4*j] = (GLubyte) ((j<=4) ? 255 : 0);
          stripeImage[4*j+1] = (GLubyte) ((j>4) ? 255 : 0);
          stripeImage[4*j+2] = (GLubyte) 0;
          stripeImage[4*j+3] = (GLubyte) 255;
      }
  }
  
  /*  planes for texture coordinate generation  */
  static GLfloat xequalzero[] = {1.0, 0.0, 0.0, 0.0};
  static GLfloat slanted[] = {1.0, 1.0, 1.0, 0.0};
  static GLfloat *currentCoeff;
  static GLenum currentPlane;
  static GLint currentGenMode;
  
  void init(void)
  {
      glClearColor (0.0, 0.0, 0.0, 0.0);
      glEnable(GL_DEPTH_TEST);
      glShadeModel(GL_SMOOTH);
  
      makeStripeImage();
      glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  
      glGenTextures(1, &texName);
      glBindTexture(GL_TEXTURE_1D, texName);
      glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_REPEAT);
      glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER,
                      GL_LINEAR);
      glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER,
                      GL_LINEAR);
      glTexImage1D(GL_TEXTURE_1D, 0, GL_RGBA, stripeImageWidth, 0,
                   GL_RGBA, GL_UNSIGNED_BYTE, stripeImage);
  
      glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
      currentCoeff = xequalzero;
      currentGenMode = GL_OBJECT_LINEAR;
      currentPlane = GL_OBJECT_PLANE;
      glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, currentGenMode);
      glTexGenfv(GL_S, currentPlane, currentCoeff);
  
      glEnable(GL_TEXTURE_GEN_S);
      glEnable(GL_TEXTURE_1D);
      glEnable(GL_CULL_FACE);
      glEnable(GL_LIGHTING);
      glEnable(GL_LIGHT0);
      glEnable(GL_AUTO_NORMAL);
      glEnable(GL_NORMALIZE);
      glFrontFace(GL_CW);
      glCullFace(GL_BACK);
      glMaterialf (GL_FRONT, GL_SHININESS, 64.0);
  }
  
  void display(void)
  {
      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  
      glPushMatrix ();
      glRotatef(45.0, 0.0, 0.0, 1.0);
      glBindTexture(GL_TEXTURE_1D, texName);
      glutSolidTeapot(2.0);
      glPopMatrix ();
      glFlush();
  }
  
  void reshape(int w, int h)
  {
      glViewport(0, 0, (GLsizei) w, (GLsizei) h);
      glMatrixMode(GL_PROJECTION);
      glLoadIdentity();
      if (w <= h)
          glOrtho (-3.5, 3.5, -3.5*(GLfloat)h/(GLfloat)w, 
                   3.5*(GLfloat)h/(GLfloat)w, -3.5, 3.5);
      else
          glOrtho (-3.5*(GLfloat)w/(GLfloat)h, 
                   3.5*(GLfloat)w/(GLfloat)h, -3.5, 3.5, -3.5, 3.5);
      glMatrixMode(GL_MODELVIEW);
      glLoadIdentity();
  }
  
  void keyboard (unsigned char key, int x, int y)
  {
      switch (key) {
          case 'e':
          case 'E':
              currentGenMode = GL_EYE_LINEAR;
              currentPlane = GL_EYE_PLANE;
              glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, currentGenMode);
              glTexGenfv(GL_S, currentPlane, currentCoeff);
              glutPostRedisplay();
              break;
          case 'o':
          case 'O':
              currentGenMode = GL_OBJECT_LINEAR;
              currentPlane = GL_OBJECT_PLANE;
              glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, currentGenMode);
              glTexGenfv(GL_S, currentPlane, currentCoeff);
              glutPostRedisplay();
              break;
          case 's':
          case 'S':
              currentCoeff = slanted;
              glTexGenfv(GL_S, currentPlane, currentCoeff);
              glutPostRedisplay();
              break;
          case 'x':
          case 'X':
              currentCoeff = xequalzero;
              glTexGenfv(GL_S, currentPlane, currentCoeff);
              glutPostRedisplay();
              break;
          case 27:
              exit(0);
              break;
          default:
              break;
      }
  }
  
  int main(int argc, char** argv)
  {
      glutInit(&argc, argv);
      glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
      glutInitWindowSize(256, 256);
      glutInitWindowPosition(100, 100);
      glutCreateWindow (argv[0]);
      init ();
      glutDisplayFunc(display);
      glutReshapeFunc(reshape);
      glutKeyboardFunc(keyboard);
      glutMainLoop();
      return 0;
  }
  
  