static void
display(void) {
glClear(GL_COLOR_BUFFER_BIT);
loadtiles();
if (texture) {
drawtexture();
} else {
drawmesh(64,64);
if (grid) showgrid();
}
glutSwapBuffers();
}
void display(void)
{
// clear all pixels
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) ;
// draw white polygon (square) of unit length centered at the origin
// Note that vertices must generally go counterclockwise
// Change from the first program, in that I just made it white.
// The old OpenGL code of using glBegin... glEnd no longer appears.
// The new version uses vertex buffer objects from init.
// Does the order of drawing matter? What happens if I draw the ground
// after the pillars? I will show this in class
glUniform1i(islight,0) ; // Turn off lighting (except on teapot, later)
glUniform1i(istex,texturing) ;
drawtexture(FLOOR,texNames[0]) ; // Texturing floor
// drawobject(FLOOR) ;
glUniform1i(istex,0) ; // Other items aren't textured
// Now draw several cubes with different transforms, colors
// I continue to use the deprecated push-pop and matrix mode
// Since it is convenient (or you have to write your own stack).
glMatrixMode(GL_MODELVIEW) ;
// 1st pillar
glPushMatrix() ;
glTranslatef(-0.4,-0.4,0.0) ;
drawcolor(CUBE, 0) ;
glPopMatrix() ;
// 2nd pillar
glPushMatrix() ;
glTranslatef(0.4,-0.4,0.0) ;
drawcolor(CUBE, 1) ;
glPopMatrix() ;
// 3rd pillar
glPushMatrix() ;
glTranslatef(0.4,0.4,0.0) ;
drawcolor(CUBE, 2) ;
glPopMatrix() ;
// 4th pillar
glPushMatrix() ;
glTranslatef(-0.4,0.4,0.0) ;
drawcolor(CUBE, 3) ;
glPopMatrix() ;
// Draw the glut teapot
// This is using deprecated old-style OpenGL certainly
/* New for Demo 3; add lighting effects */
{
const GLfloat one[] = {1,1,1,1};
const GLfloat medium[] = {0.5, 0.5, 0.5, 1};
const GLfloat small[] = {0.2, 0.2, 0.2, 1};
const GLfloat high[] = {100} ;
const GLfloat zero[] = {0.0, 0.0, 0.0, 1.0} ;
const GLfloat light_specular[] = {1, 1, 0, 1};
const GLfloat light_specular1[] = {0, 0.5, 1, 1};
const GLfloat light_direction[] = {0.5, 0, 0, 0}; // Dir light 0 in w
const GLfloat light_position1[] = {0, -0.5, 0, 1};
GLfloat light0[4], light1[4] ;
// Set Light and Material properties for the teapot
// Lights are transformed by current modelview matrix.
// The shader can't do this globally.
// So we need to do so manually.
transformvec(light_direction, light0) ;
transformvec(light_position1, light1) ;
glUniform3fv(light0dirn, 1, light0) ;
glUniform4fv(light0color, 1, light_specular) ;
glUniform4fv(light1posn, 1, light1) ;
glUniform4fv(light1color, 1, light_specular1) ;
// glUniform4fv(light1color, 1, zero) ;
glUniform4fv(ambient,1,small) ;
glUniform4fv(diffuse,1,medium) ;
glUniform4fv(specular,1,one) ;
glUniform1fv(shininess,1,high) ;
// Enable and Disable everything around the teapot
// Generally, we would also need to define normals etc.
// But glut already does this for us
if (DEMO > 4)
glUniform1i(islight,lighting) ; // turn on lighting only for teapot.
}
// ** NEW ** Put a teapot in the middle that animates
glColor3f(0.0,1.0,1.0) ; // Deprecated command to set the color
glPushMatrix() ;
// I now transform by the teapot translation for animation
glTranslatef(teapotloc, 0.0, 0.0) ;
// The following two transforms set up and center the teapot
// Remember that transforms right-multiply the stack
glTranslatef(0.0,0.0,0.1) ;
glRotatef(rotamount, 0.0, 0.0, 1.0);
glRotatef(90.0,1.0,0.0,0.0) ;
glutSolidTeapot(0.15) ;
glUniform1i(islight,0) ; // turn off lighting
glPopMatrix() ;
// Does order of drawing matter?
// What happens if I draw the ground after the pillars?
// I will show this in class.
// drawobject(FLOOR) ;
// don't wait!
// start processing buffered OpenGL routines
glutSwapBuffers() ;
glFlush ();
}
