xxx

xxx

/***************************************************
** Draw a cone                                    **
***************************************************/
void DrawCone()
{
    float angle;
    float weight;
    float red_component;
    float blue_component;

    // Draw conical part, including 40+ triangles
    glBegin( GL_TRIANGLE_FAN );
      // The tip of the cone is green
      glColor3f( 0.0, 1.0, 0.0 );
      
      // The tip of the cone at (0,0,2) 
      glVertex3f( 0.0, 0.0, 2.0 );

      for ( int i = 0; i < 40; i++ ) {
          angle = i*2*PI / 39;

          if ( i < 21 ) {
              weight = i / 20.0;
          }
          else {
              weight = 1.0 - ( i - 20 ) / 20.0;
          }

          red_component = 1.0 * weight;
          blue_component = 1.0 * ( 1.0 - weight );
          glColor3f( red_component, 0.0, blue_component );
          glVertex3f( cos( angle ), sin( angle ), 0.0 );
      }
    glEnd();


    // Draw base part, including 40+ triangles
    glBegin( GL_TRIANGLE_FAN );
      // The tip of the cone is green
      //glColor3f( 0.0, 1.0, 0.0 );
      
      // The tip of the cone at (0,0,0) 
      glVertex3f( 0.0, 0.0, 0.0 );

      for ( int i = 0; i < 40; i++ ) {
          angle = i*2*PI / 39;

          if ( i < 21 ) {
              weight = i / 20.0;
          }
          else {
              weight = 1.0 - ( i - 20 ) / 20.0;
          }

          red_component = 1.0 * weight;
          blue_component = 1.0 * ( 1.0 - weight );
          glColor3f( red_component, 0.0, blue_component );
          glVertex3f( cos( angle ), sin( angle ), 0.0 );
      }
    glEnd();
}