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View Full Version : Problems with glFrustum(view set and light set)



michellex
09-27-2016, 06:13 PM
I am trying to implement a subwindow with three torus, but failed to display anything on my window..


main function for subwindow:
instrument_window = glutCreateSubWindow(main_window, GAP, view_height + 3*GAP, 2*(view_width+GAP), INSTRUMENT_HEIGHT);
glutDisplayFunc(display);
//lighting
const GLfloat light_ambient[] = { 0.0f, 0.0f, 0.0f, 1.0f };
const GLfloat light_diffuse[] = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_position[] = { INSTRUMENT_HEIGHT*5, INSTRUMENT_HEIGHT*10, INSTRUMENT_HEIGHT*10, 0.0f };

const GLfloat mat_ambient[] = { 0.7f, 0.7f, 0.7f, 1.0f };
const GLfloat mat_diffuse[] = { 0.8f, 0.8f, 0.8f, 1.0f };
const GLfloat mat_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat high_shininess[] = { 100.0f };

//glClearColor(0.33,0.33,0.33,0.33);
glEnable(GL_CULL_FACE);
glCullFace(GL_BACK);

glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);

glEnable(GL_LIGHT0);
glEnable(GL_NORMALIZE);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_LIGHTING);

glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
glLightfv(GL_LIGHT0, GL_POSITION, light_position);

glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
glMaterialfv(GL_FRONT, GL_SHININESS, high_shininess);
//end of lighting


glutMainLoop();

-------------------------------------------end of main part for sub window

for display function:
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

float width = 2*(GAP+view_width);
float height = INSTRUMENT_HEIGHT;
const float ar = (float) width / (float) height;

//glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(width/4.0, width*3.0/4.0, height*3.0/4.0, height/4.0, 2.0, 100.0);
//gluPerspective (160.0, 2*view_width/INSTRUMENT_HEIGHT, 0.1, 1000.0);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity() ;

// Draw first
draw (view_width+GAP-400, INSTRUMENT_HEIGHT/2);

// Draw second
draw (view_width+GAP-150, INSTRUMENT_HEIGHT/2);

// Draw third
draw (view_width+GAP+100, INSTRUMENT_HEIGHT/2);

----------------------------------------------end of display function----------------

for draw function:
void draw(double cx,double cf)
glColor3f(0.34f,0.34f,0.34f);
glPushMatrix();
glTranslated(0.0, cx, cy);
glRotated(-10, 1.0, 0.0, 0.0);
glutSolidTorus(OUTER_DIAL_RADIUS, OUTER_DIAL_RADIUS+30, 100, 200);
glPopMatrix();
end

----------------------------------------------end of draw function------------------

really find frustrating since it just display nothing and don't know how to debug. Any hints are highly appreciate!!!!