void display()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glLoadIdentity();
//gluLookAt(0, 0, 20 + zoomValue, 0, 0, 0, 0, 1, 0);
gluLookAt(0, 0, 0, lx, ly, lz, 0, 1, 0);
// multiply current matrix with arcball matrix
glMultMatrixf( arcball.get() );
GLUquadric *sphere = gluNewQuadric();
glPolygonMode( GL_FRONT_AND_BACK, GL_FILL );
draw_sun();
//draw_coordinate_system(5.0f);
RenderScene();
glutPostRedisplay();
glutSwapBuffers();
}
void drawscene(void){ //draw the whole scene
GLint viewport[4];
glGetIntegerv( GL_VIEWPORT, viewport );
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective( 45, double(viewport[2])/viewport[3], 0.1, 1000 );
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt( 100,25,200,0,0,lookz, 0,1,0 ); //the PRP is at (100,25,200), looking at (0,0,lookz), VUP is (0,1,0)
glMultMatrixf( gsrc_getmo() );
glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH); //initialize the display mode, double buffer
glClear(GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST); //enable depth test
glClear(GL_COLOR_BUFFER_BIT);
//Add a ambient light
GLfloat ambientColor[] = {0.2f, 0.2f, 0.2f, 1.0f}; //the ambient Color is (0.2, 0.2, 0.2)
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambientColor);
//Add directed light
GLfloat lightColor1[] = {0.3f, 0.3f, 0.3f, 1.0f}; //Color (0.5, 0.2, 0.2)
GLfloat lightPos1[] = {-1.0f, 0.5f, 0.5f, 0.0f}; //the light comes from the direction (-1, 0.5, 0.5)
glLightfv(GL_LIGHT1, GL_DIFFUSE, lightColor1);
glLightfv(GL_LIGHT1, GL_POSITION, lightPos1);
//Add a point light source
GLfloat lightColor0[] = {0.5f, 0.5f, 0.5f, 1.0f}; //Color (0.5, 0.5, 0.5)
GLfloat lightPos0[] = {-20.0f, 50.0f, 70.0f, 1.0f}; //Positioned at (-20,50,70)
glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColor0);
glLightfv(GL_LIGHT0, GL_POSITION, lightPos0);
////////draw the cube used for the background/////////////////////////////////////////
glPushMatrix ( );
glTranslatef(100,150,100);
CreateBox();
glPopMatrix ( );
//////////////////////////////////////////////////////////////////
glPushMatrix();
glTranslatef(-20.0f,50.0f,70.0f);
draw_sun(); //draw a sun positioned at the point light source
glPopMatrix ();
GLfloat M[16]= { 1, 0, 0, 0,
0, 1, 0, -1/(50-0.1),
0, 0, 1, 0,
0, 0, 0, 0 }; //perspective projection
draw_object(); //draw the whole object
/////////////////draw the shadow///////////////////////////
//glPushMatrix();
glMatrixMode(GL_MODELVIEW);
glTranslatef(-20,50,70); //M wc<-s
glMultMatrixf(M); //perspective project
glTranslatef(20,-50,-70); //M s<-wc
glColor4f(0.3f,0.3f,0.3f,0.2f); //the color of the shadow
draw_shadow(); //draw the shadows
glutSwapBuffers(); //swap buffers to display
glFlush();
}
