OpenGL - Why are my objects transparent? - opengl

I am trying to make a motorcycle with primitive shapes. For some reason, the shapes that I have made are see-through. I am not specifying any alpha anywhere; here is my code:
#include <GL/glut.h>
#include <math.h>
GLUquadricObj *quadratic;
static int isWire = 0; // Is wireframe?
static int distance = 10;
static float angleH = 0;
static float angleV = 0;
static float R = 2.0; // Radius of hemisphere.
static int p = 4; // Number of longitudinal slices.
static int q = 6; // Number of latitudinal slices.
#define PI 3.14159265358979324
static unsigned int pipe, seat, cover, wheel, wheelCenter, cycles; // parts of the motorcycle to make as display lists.
GLUquadricObj *cylinder;
void drawCoordinates();
void drawMotorcycle();
void drawTrailer();
void drawHemisphere();
void drawCylinder(float x, float y, float z);
void drawHandle(float x, float y, float z);
void drawLight();
void drawBase();
void setup();
void display () {
/* clear window */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(distance*cos(angleH), distance*cos(angleV), distance*sin(angleH), 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
/* future matrix manipulations should affect the modelview matrix */
glMatrixMode(GL_MODELVIEW);
if (isWire) glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); else glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glPushMatrix();
drawCoordinates();
glPushMatrix();
glTranslatef(0.0, 0.0, 0.0); // Move the motorcycle around the world space
drawMotorcycle();
drawTrailer();
glPopMatrix();
glPopMatrix();
/* flush drawing routines to the window */
glFlush();
}
void drawCoordinates()
{
/***************** DRAW AXIS *****************/
glPushMatrix();
GLUquadricObj *xAxis;
xAxis=gluNewQuadric();
glColor3f(1,0,0);
glRotatef(-90, 0, 1, 0);
gluCylinder(xAxis,0.05,0.05,1,5,5);
glPopMatrix();
glPushMatrix();
GLUquadricObj *yAxis;
yAxis=gluNewQuadric();
glColor3f(0,1,0);
glRotatef(-90, 1, 0, 0);
gluCylinder(yAxis,0.05,0.05,1,5,5);
glPopMatrix();
glPushMatrix();
GLUquadricObj *zAxis;
zAxis=gluNewQuadric();
glColor3f(0,0,1);
gluCylinder(zAxis,0.05,0.05,1,5,5);
glPopMatrix();
/***************** END OF DRAW AXIS *****************/
}
void drawMotorcycle()
{
//DRAW ENGINE
glPushMatrix();
//drawCoordinates();
glColor3f(.6, 0, 0);
glScalef(1.4, 0.8, 1.0);
glutSolidSphere(1,8,8);
glPushMatrix();
//drawCoordinates();
glPopMatrix();
glPopMatrix();
//DRAW PIPES UNDER ENGINE
glPushMatrix();
glRotatef(-90, 1, 0, 0);
glRotatef(80, 0, 1, 0);
glTranslatef(0.5, 1.0, -1.5);
glCallList(pipe);
glTranslatef(0.0, -2.0, 0.0);
glCallList(pipe);
glPopMatrix();
//DRAW SEAT
glPushMatrix();
glPushMatrix();
glRotatef(15, 0, 0, 1);
glTranslatef(-2.0, -0.4, 0.0);
glScalef(2.0, 0.2, 1.2);
glCallList(seat);
glPopMatrix();
//DRAW BACK SEAT
glRotatef(-40, 0, 0, 1);
glTranslatef(-2.3, -2.8, 0.0);
glScalef(2.0, 0.2, 1.2);
glCallList(seat);
glPopMatrix();
//DRAW FRONT PLATE
glPushMatrix();
glRotatef(120, 0, 0, 1);
glTranslatef(0.8, -1.3, 0.0);
glScalef(2.0, 0.2, 1.35);
glColor3f(0.5,0.0,0.0);
glutSolidCube(1);
glPushMatrix();
//drawCoordinates();
glPopMatrix();
glPopMatrix();
//DRAW FRONT PIPES
glPushMatrix();
glRotatef(-90, 1, 0, 0);
glRotatef(-30, 0, 1, 0);
glTranslatef(1.3, -0.9, -5.7);
glScalef(1.0, 1.0, 2.5);
glCallList(pipe);
glTranslatef(0.0, 1.7, 0.0);
glCallList(pipe);
glPopMatrix();
//DRAW WHEEL COVERS
glPushMatrix();
glTranslatef(3.5, -3.0, 0.0);
glScalef(1.0, 0.5, 1.0);
glRotatef(45, 0, 0, 1);
glCallList(cover);
glTranslatef(-5.5, 0.0, 0.0);
glRotatef(-100, 0, 0, 1);
glTranslatef(-8.5, 0.2, 0.0);
glCallList(cover);
glPopMatrix();
//DRAW WHEELS
glPushMatrix();
glTranslatef(3.9, -4.1, 0.0);
glCallList(wheel);
glTranslatef(-9.2, 2.0, 0.0);
glCallList(wheel);
glPopMatrix();
//DRAW WHEEL CENTER PIECES
glPushMatrix();
glTranslatef(3.9, -4.1, 0.0);
glCallList(wheelCenter);
glTranslatef(-9.2, 2.0, 0.0);
glCallList(wheelCenter);
glPopMatrix();
//DRAW CYCLES AROUND WHEELS
glPushMatrix();
glTranslatef(3.9, -4.1, 0.0);
glRotatef(-90, 1, 0, 0);
for(int i=0; i<8; i++)
{
glRotatef(45, 0, 1, 0);
glPushMatrix();
glCallList(cycles);
glPopMatrix();
}
glTranslatef(-9.2, 0.0, 2.0);
for(int i=0; i<8; i++)
{
glRotatef(45, 0, 1, 0);
glPushMatrix();
glCallList(cycles);
glPopMatrix();
}
glPopMatrix();
//DRAW HANDLE BARS
glPushMatrix();
glTranslatef(0.2, 2.0, 0.0);
glRotatef(-45, 1, 0, 0);
glScalef(0.7, 0.7, 0.7);
glCallList(pipe);
glRotatef(-90, 1, 0, 0);
glCallList(pipe);
glPopMatrix();
//DRAW LIGHT
glPushMatrix();
glTranslatef(1.0, 1.0, 0.0);
glColor3f(0.5, 0.5, 0.0);
//glScalef(1.0, 0.5, 1.0);
glutSolidSphere(0.5, 5, 5);
glPushMatrix();
//drawCoordinates();
glPopMatrix();
glPopMatrix();
//DRAW BASE
glPushMatrix();
glRotatef(10.0, 0.0, 0.0, 1.0);
glScalef(3.5, 1.5, 1.0);
glTranslatef(-0.4, -1.0, 0.0);
glColor3f(0.3, 0.3, 0.3);
glutSolidCube(1);
glPopMatrix();
//GAS TANK
glPushMatrix();
glScalef(2.5, 1.0, 0.8);
glTranslatef(-0.8, -1.7, -1.4);
glCallList(pipe);
glPopMatrix();
}
void drawTrailer()
{
//DRAW BODY
glPushMatrix();
glColor3f(0.0, 0.0, 0.3);
glScalef(2.0, 2.5, 1.5);
glTranslatef(-4.5, -0.5, 0.0);
glutSolidCube(1);
glPopMatrix();
//DRAW WHEELS
glPushMatrix();
glPushMatrix();
glScalef(0.8, 0.8, 0.8);
glTranslatef(-12.0, -1.5, 2.0);
glCallList(wheel);
glCallList(wheelCenter);
glRotatef(90, 1, 0, 0);
for(int i=0; i<8; i++)
{
glRotatef(45, 0, 1, 0);
glPushMatrix();
glCallList(cycles);
glPopMatrix();
}
glPopMatrix();
glPushMatrix();
glScalef(0.8, 0.8, 0.8);
glTranslatef(-12.0, -1.5, -2.0);
glCallList(wheel);
glCallList(wheelCenter);
glRotatef(90, 1, 0, 0);
for(int i=0; i<8; i++)
{
glRotatef(45, 0, 1, 0);
glPushMatrix();
glCallList(cycles);
glPopMatrix();
}
glPopMatrix();
glPopMatrix();
//DRAW CONNECTION TO MOTORCYCLE
glPushMatrix();
glRotatef(90, 0, 1, 0);
glTranslatef(0.0, -1.0, -8.0);
glCallList(pipe);
glPopMatrix();
}
void drawHemisphere()
{
for(int j = 0; j < q; j++)
{
// One latitudinal triangle strip.
glBegin(GL_TRIANGLE_STRIP);
for(int i = 0; i <= p; i++)
{
glVertex3f( R * cos( (float)(j+1)/q * PI/2.0 ) * cos( 2.0 * (float)i/p * PI ),
R * sin( (float)(j+1)/q * PI/2.0 ),
R * cos( (float)(j+1)/q * PI/2.0 ) * sin( 2.0 * (float)i/p * PI ) );
glVertex3f( R * cos( (float)j/q * PI/2.0 ) * cos( 2.0 * (float)i/p * PI ),
R * sin( (float)j/q * PI/2.0 ),
R * cos( (float)j/q * PI/2.0 ) * sin( 2.0 * (float)i/p * PI ) );
}
glEnd();
}
}
void reshape (int w, int h)
{
// (Window of width = zero is not possible).
if(h == 0)
h = 1;
float ratio = 1.0* w / h;
// Reset the coordinate system before modifying
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// Set the viewport to be the entire window
glViewport(0, 0, w, h);
// Set the correct perspective.
gluPerspective(90,ratio,-1,1);
}
// Keyboard input processing routine.
void keyInput(unsigned char key, int x, int y)
{
switch(key)
{
case 'c' : distance = 10; angleH=0; angleV=0.0; break;
case 'C' : distance = 10; angleH=0; angleV=0.0; break;
case 'f': distance = (distance == 4)? 4:distance-1; break;
case 'F': distance = (distance == 4)? 4:distance-1; break;
case 'b': distance = (distance == 20)? 20:distance+1; break;
case 'B': distance = (distance == 20)? 20:distance+1; break;
case 'w': if (isWire == 0) isWire = 1; else isWire = 0; break;
case 'W': if (isWire == 0) isWire = 1; else isWire = 0; break;
//case 27: exit(0); break;
default: break;
}
}
void specialKeyboard(int key, int x, int y) {
switch (key)
{
case GLUT_KEY_RIGHT:
angleH -= .2;
break;
case GLUT_KEY_LEFT:
angleH += .2;
break;
case GLUT_KEY_UP:
angleV += .2;
break;
case GLUT_KEY_DOWN:
angleV -= .2;
break;
}
}
void update(void){
glutPostRedisplay();
}
void setup()
{
// PARTS
pipe = glGenLists(1);
seat = glGenLists(1);
cover = glGenLists(1);
wheel = glGenLists(1);
wheelCenter = glGenLists(1);
cycles = glGenLists(1);
glNewList(pipe, GL_COMPILE); // Any cylinder on the motorcycle
GLUquadricObj *cylinder;
cylinder=gluNewQuadric();
glPushMatrix();
glColor3f(.5,.5,.5);
gluCylinder(cylinder,0.2,0.2,3,5,5);
glPushMatrix();
//drawCoordinates();
glPopMatrix();
glPopMatrix();
glEndList();
glNewList(seat, GL_COMPILE);
glPushMatrix();
glColor3f(0.5, 0.35, 0.05);
glutSolidCube(1);
glPushMatrix();
//drawCoordinates();
glPopMatrix();
glPopMatrix();
glEndList();
glNewList(cover, GL_COMPILE);
glPushMatrix();
glColor3f(0.5, 0.0, 0.0);
drawHemisphere();
glPushMatrix();
//drawCoordinates();
glPopMatrix();
glPopMatrix();
glEndList();
glNewList(wheel, GL_COMPILE);
glPushMatrix();
glColor3f(0.1, 0.1, 0.1);
glutSolidTorus(0.2, 1.2, 20, 20);
glPushMatrix();
//drawCoordinates();
glPopMatrix();
glPopMatrix();
glEndList();
glNewList(wheelCenter, GL_COMPILE);
glPushMatrix();
glColor3f(0.4, 0.5, 0.5);
glScalef(1.0, 0.5, 1.0);
glutSolidSphere(0.8, 5, 5);
glPushMatrix();
//drawCoordinates();
glPopMatrix();
glPopMatrix();
glEndList();
glNewList(cycles, GL_COMPILE);
glColor3f(0.5, 0.5, 0.5);
glScalef(0.25, 0.25, 0.25);
cylinder=gluNewQuadric();
gluCylinder(cylinder,0.5,0.5,5,15,5);
glEndList();
}
int main (int argc, char** argv) {
/* initialize GLUT, using any commandline parameters passed to the
program */
glutInit(&argc,argv);
/* setup the size, position, and display mode for new windows */
glutInitWindowSize(500,500);
glutInitWindowPosition(0,0);
glutInitDisplayMode( GLUT_RGB | GLUT_DEPTH );
/* create and set up a window */
glutCreateWindow("Motorcycle");
setup(); // Build all the display lists, ready to use
glutIdleFunc(update);
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutKeyboardFunc(keyInput);
glutSpecialFunc(specialKeyboard);
/* set up depth-buffering */
glEnable(GL_DEPTH_TEST);
/* background color */
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
/* tell GLUT to wait for events */
glutMainLoop();
return 0;
}
You can rotate the camera with the arrow keys to see that the objects are see through. How can I fix this? Is there anything else I can do to improve my code?

In reshape():
// Set the correct perspective.
gluPerspective(90,ratio,-1,1);
I'm guessing you transliterated parameters from a glOrtho() call, where a negative zNear is perfectly legitimate.
From the gluPerspective() docs:
zNear: Specifies the distance from the viewer to the near clipping plane (always positive).
Try this:
gluPerspective(90,ratio,1,100);

You need to add glEnable(GL_DEPTH_TEST); to your initialization function.

Related

Rotate object like a real wind turbine

#include <stdio.h>
#include <math.h>
#include "glut.h"
void init() {
glClearColor(0.0, 0.0, 0.0, 0.0);
glMatrixMode(GL_PROJECTION);
gluOrtho2D(0.0, 400, 0.0, 300.0);
}
void drawTurbine() {
// draw the tower
glBegin(GL_LINES);
glColor3f(1.0, 1.0, 1.0);
glVertex2f(160, 40);
glVertex2f(163, 180);
glVertex2f(160, 40);
glVertex2f(175, 40);
glVertex2f(175, 40);
glVertex2f(172, 180);
glEnd();
// Rotate object
glPushMatrix();
glRotatef(100, 0, 1, 0);
// draw first rotor blade
glBegin(GL_TRIANGLES);
glColor3f(1.0, 1.0, 1.0);
glVertex2f(173, 180);
glVertex2f(163, 180);
glVertex2f(168, 270);
glEnd();
// draw second rotor blade
glBegin(GL_TRIANGLES);
glColor3f(1.0, 1.0, 1.0);
glVertex2f(170, 174);
glVertex2f(175, 180);
glVertex2f(247, 140);
glEnd();
// draw third rotor blade
glBegin(GL_TRIANGLES);
glColor3f(1.0, 1.0, 1.0);
glVertex2f(162, 180);
glVertex2f(167, 174);
glVertex2f(88, 140);
glEnd();
// circle in the middle
float theta;
glBegin(GL_POLYGON);
glColor3f(1.0, 1.0, 1.0);
for (int i = 0; i <= 360; i++) {
theta = i * 3.142 / 180;
glVertex2f(168 + 7 * cos(theta), 180 + 6.5 * sin(theta));
}
glEnd();
glPopMatrix();
}
void display() {
glClear(GL_COLOR_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
drawTurbine();
glFlush();
glutSwapBuffers();
glutPostRedisplay();
}
void idle() {
display();
}
int main(int argc, char** argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(700, 600);
glutInitWindowPosition(10, 10);
glutCreateWindow("Wind Turbine");
init();
glutIdleFunc(idle);
glutDisplayFunc(display);
glutMainLoop();
return 0;
}
I have created a wind turbine and I am trying to rotate the rotor blades, but the code just makes it disappear. I want it to rotate clockwise. I just need an idea on how I can make it rotate like a real wind turbine. I am new to using glRotatef, and this will be my first time rotating an object with OpenGL.
You need a variable for the current angle of the wind turbine (current_angle) and the rotation angle per frame (step_angle). Further you have to know the center of the wind turbine (center_x, center_y):
float current_angle = 0.0f;
float step_angle = 0.2f;
float center_x = 168.0f;
float center_y = 180.0f;
To rotate around a pivot you have to define a model matrix, which displace by the inverted pivot, then rotates and final transforms back by to the pivot. The rotation axis is the z axis (0, 0, 1) because your geometry is drawn in the xy-plane:
glTranslatef( center_x, center_y, 0.0f );
glRotatef(current_angle, 0, 0, 1);
current_angle += step_angle;
glTranslatef(-center_x, -center_y, 0.0f );
Preview:
Complete code of the function drawTurbine:
void drawTurbine() {
// draw the tower
glBegin(GL_LINES);
glColor3f(1.0, 1.0, 1.0);
glVertex2f(160, 40);
glVertex2f(163, 180);
glVertex2f(160, 40);
glVertex2f(175, 40);
glVertex2f(175, 40);
glVertex2f(172, 180);
glEnd();
// Rotate object
glPushMatrix();
glTranslatef( center_x, center_y, 0.0f );
glRotatef(current_angle, 0, 0, 1);
current_angle += step_angle;
glTranslatef(-center_x, -center_y, 0.0f );
// draw first rotor blade
glBegin(GL_TRIANGLES);
glColor3f(1.0, 1.0, 1.0);
glVertex2f(173, 180);
glVertex2f(163, 180);
glVertex2f(168, 270);
glEnd();
// draw second rotor blade
glBegin(GL_TRIANGLES);
glColor3f(1.0, 1.0, 1.0);
glVertex2f(170, 174);
glVertex2f(175, 180);
glVertex2f(247, 140);
glEnd();
// draw third rotor blade
glBegin(GL_TRIANGLES);
glColor3f(1.0, 1.0, 1.0);
glVertex2f(162, 180);
glVertex2f(167, 174);
glVertex2f(88, 140);
glEnd();
// circle in the middle
float theta;
glBegin(GL_POLYGON);
glColor3f(1.0, 1.0, 1.0);
for (int i = 0; i <= 360; i++) {
theta = i * 3.142 / 180;
glVertex2f(168 + 7 * cos(theta), 180 + 6.5 * sin(theta));
}
glEnd();
glPopMatrix();
}

Black screen on OpenGL

I have an openGL program that drawn 3 houses and another things but, when I compile with gcc, just appears a black screen - and this is happening with all my openGL programs
What can I do?
PS: If I resize my screen, the drawn appears.
OS: macOS Mojave
PC: MacBook Air 2017
Development in Visual Studio Code
gcc version: 10.0.0
#include <stdlib.h>
#include <stdio.h>
#include <glut/glut.h>
#include <math.h>
#define PI 3.14159265358979324
//teto
bool teto = true;
bool base = true;
bool janela = true;
bool porta = true;
void Teto(void)
{
glBegin(GL_TRIANGLES);
glColor3f(1, 0, 0);
glVertex3f(0.0, 0.0, 0.0);
glVertex3f(20.0, 10.0, 0.0);
glVertex3f(40.0, 0.0, 0.0);
glEnd();
}
void Base(void)
{
glBegin(GL_QUADS);
glColor3f(0, 1, 0);
glVertex3f(0.0, 0.0, 0.0);
glVertex3f(0.0, 30.0, 0.0);
glVertex3f(35.0, 30.0, 0.0);
glVertex3f(35.0, 0.0, 0.0);
glEnd();
}
void Porta(void)
{
glBegin(GL_QUADS);
glColor3f(0, 0, 1);
glVertex3f(0, 0.0, 0.0);
glVertex3f(0, 10.0, 0.0);
glVertex3f(5.0, 10.0, 0.0);
glVertex3f(5.0, 0.0, 0.0);
glEnd();
}
void Janela()
{
glBegin(GL_QUADS);
glColor3f(0, 0, 0);
glVertex3f(0.0, 0.0, 0.0);
glVertex3f(0.0, 5.0, 0.0);
glVertex3f(5.0, 5.0, 0.0);
glVertex3f(5.0, 0.0, 0.0);
glEnd();
}
void Sun()
{
static float R = 10.0; // Radius of circle.
static float X = 20.0; // X-coordinate of center of circle.
static float Y = 70.0; // Y-coordinate of center of circle.
static int numVertices = 30; // Number of vertices on circle.
float t = 0; // Angle parameter.
int i;
glClear(GL_COLOR_BUFFER_BIT);
glColor3f(1.0, 1.0, 0.0);
// Draw a line loop with vertices at equal angles apart on a circle
// with center at (X, Y) and radius R, The vertices are colored randomly.
glBegin(GL_LINE_LOOP);
for(i = 0; i < numVertices; ++i)
{
glColor3f(1.0, 1.0, 0.0);
glVertex3f(X + R * cos(t), Y + R * sin(t), 0.0);
t += 2 * PI / numVertices;
}
glEnd();
}
// Drawing routine.
void drawHouse(void)
{
glPopMatrix();
glPushMatrix();
//glPopMatrix();
glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
//Sun();
glTranslatef(30.0f,30.0f,0.0f);
if(teto)
Teto();
glTranslatef(3.0f,-30.0f,0.0f);
if(base)
Base();
glTranslatef(15.0f,0.0f,0.0f);
if(porta)
Porta();
glTranslatef(-10.0f,20.0f,0.0f);
if(janela)
Janela();
glTranslatef(20.0f,0.0f,0.0f);
if(janela)
Janela();
glPopMatrix();
glScalef(0.75f, 0.75f, 0.0f);
glTranslatef(3.0f,30.0f,0.0f);
if(teto)
Teto();
glTranslatef(3.0f,-30.0f,0.0f);
if(base)
Base();
glTranslatef(15.0f,0.0f,0.0f);
if(porta)
Porta();
glTranslatef(-10.0f,20.0f,0.0f);
if(janela)
Janela();
glTranslatef(20.0f,0.0f,0.0f);
if(janela)
Janela();
glPopMatrix();
glScalef(1.75f, 1.75f, 0.0f);
glScalef(1.25f, 1.25f, 0.0f);
//glScalef(0.75f, 0.75f, 0.0f);
glTranslatef(25.0f,20.0f,0.0f);
if(teto)
Teto();
glTranslatef(3.0f,-30.0f,0.0f);
if(base)
Base();
glTranslatef(15.0f,0.0f,0.0f);
if(porta)
Porta();
glTranslatef(-10.0f,20.0f,0.0f);
if(janela)
Janela();
glTranslatef(20.0f,0.0f,0.0f);
if(janela)
Janela();
glFlush();
}
// Initialization routine.
void setup(void)
{
glClearColor(1.0, 1.0, 1.0, 0.0);
}
// OpenGL window reshape routine.
void resize(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0, 130.0, 0.0, 100.0, -1.0, 1.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
// Keyboard input processing routine.
void keyInput(unsigned char key, int x, int y)
{
switch(key)
{
case 27:
exit(0);
break;
case 'c':
base = !base;
break;
case 't':
teto = !teto;
break;
case 'j':
janela = !janela;
break;
case 'p':
porta = !porta;
break;
case 's':
Sun();
//glRotatef(10.0, 0.0f, 0.0f, 1.0f);
break;
default:
break;
}
glutPostRedisplay();
}
// Main routine.
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA);
glutInitWindowSize(900, 700);
glutInitWindowPosition(100, 100);
glutCreateWindow("House.cpp");
glutDisplayFunc(drawHouse);
glutReshapeFunc(resize);
glutKeyboardFunc(keyInput);
setup();
glutMainLoop();
}

glColor3f not coding in List background openGL

Currently creating a small animation of Neptune and its moon's revolving around the sun. With some help I managed to get a background of stars but instead of being white, they're now black. I've tried putting glColor3f(1.0, 1.0, 1.0) inside and outside of the matrix consisting the background and none of it seems to be working. Any solutions?
Background declaration: Display()
Background call: End of Display()
int triton = 0;
int proteus = 0;
int neptune = 0;
int sun = 0;
GLint buf, sbuf;
void init(void)
{
glClearColor(0.0, 0.0, 0.0, 0.0);
// Kind of Useless rn
glGetIntegerv(GL_SAMPLE_BUFFERS, &buf);
printf("Number of sample Buffers: %d\n", buf);
glGetIntegerv(GL_SAMPLES, &sbuf);
printf("Number of samples: %d\n", sbuf);
printf("Controls: \n A = Orbit Left. \n D = Orbit Right. \n S = Stop. \n (,) = Move Left. \n (.) = Move right.");
glShadeModel(GL_SMOOTH);
// Material Specs
GLfloat mat_specular[] = { 0.8, 0.8, 0.9, 0.1 };
GLfloat mat_shininess[] = { 40.0 };
GLfloat lightDiffuse[] = { 1.0, 1.0, 1.0, 0.8 };
GLfloat lmodel_ambient[] = { 0.1, 0.2, 0.7, 0.0 };
// Light 0 Initialized.
GLfloat light0[] = { 1.0, 1.0, 1.0, 0.9 };
GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
// Spotlight (Sun)
// Mat Specs Implmentations.
glMaterialfv(GL_FRONT, GL_DIFFUSE, lightDiffuse);
glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
// Light 0 implementation
glLightfv(GL_LIGHT0, GL_POSITION, light_position);
glLightfv(GL_LIGHT0, GL_DIFFUSE, light0);
glLightfv(GL_LIGHT0, GL_SPECULAR, light0);
// Ambient surrounding light on object.
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
// Antialias 3D Shape (In Progress)
/*glEnable(GL_BLEND);
glEnable(GL_POLYGON_SMOOTH);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glHint(GL_POLYGON_SMOOTH_HINT, GL_NICEST);*/
// Enable Lighting and Depth
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_DEPTH_TEST);
}
void orbit(void)
{
triton = (triton - 2) % 360;
proteus = (proteus - 5) % 360;
neptune = (neptune - 1) % 360;
glutPostRedisplay();
}
void backorbit(void)
{
triton = (triton + 2) % 360;
proteus = (proteus + 5) % 360;
neptune = (neptune + 1) % 360;
glutPostRedisplay();
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_COLOR_MATERIAL);
glPushMatrix();
glNewList(1, GL_COMPILE);
glBegin(GL_POINTS);
glColor3f(1.0, 1.0, 1.0);
for (int i = 0; i < 300; i++)
{
for (int j = 0; j < 300; j++)
{
if (((i + j) % 2) == 0)
{
glVertex2f(30 * i, 30 * j);
}
}
}
glEnd();
glEndList();
// Sun
glPushMatrix();
glColor3f(1.0, 0.35, 0.1);
glTranslatef(0.0, 0.0, 0.0);
glutSolidSphere(2.0, 100, 100);
// Neptune
glPushMatrix();
glRotatef((GLfloat)neptune, 0.0, 1.0, 0.0);
glTranslatef(3.0, 0.0, 0.0);
glColor3f(0.1, 0.1, 0.3);
glutSolidSphere(0.3, 100, 100);
// Triton
glPushMatrix();
glColor3f(0.85, 0.7, 0.8);
glRotatef((GLfloat)triton, 1.0, 1.0, 1.0);
glTranslatef(1.0, 0.0, 0.0);
glutSolidSphere(0.05, 100, 100);
glPopMatrix(); // Ends Triton
// Proteus
glPushMatrix();
glColor3f(1.0, 1.0, 1.0);
glRotatef((GLfloat)proteus, 0.0, 1.0, 0.0);
glTranslatef(1.0, 0.0, 0.0);
glutSolidSphere(0.02, 100, 100);
glPopMatrix(); // Ends Proteus
glPopMatrix(); // Ends Neptune
glPopMatrix(); // Ends Sun
glEnable(GL_MULTISAMPLE);
// Stars
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
glPushMatrix();
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
gluOrtho2D(0, 1000, 0, 1000);
glColor3f(1.0, 1.0, 1.0);
glCallList(1);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glPopMatrix();
glDisable(GL_COLOR_MATERIAL);
glPopMatrix(); // Ends Solar System
glFlush();
glutSwapBuffers();
}
void reshape(int w, int h)
{
glViewport(0, 0, (GLsizei)w, (GLsizei)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(90.0, (GLfloat)w / (GLfloat)h, 1.0, 20.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -5.0);
}
void keyboard(unsigned char key, int x, int y)
{
switch (key) {
// Triton + Proteus Orbit.
case 'a':
glutIdleFunc(orbit);
break;
case 'd':
glutIdleFunc(backorbit);
break;
case 's':
glutIdleFunc(NULL);
break;
case ',':
glTranslatef(-0.3, 0.0, 0.0);
glutPostRedisplay();
break;
case '.':
glTranslatef(0.3, 0.0, 0.0);
glutPostRedisplay();
break;
case 27:
exit(0);
break;
default:
break;
}
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH | GLUT_RGB | GLUT_MULTISAMPLE);
glutInitWindowSize(1000, 1000);
glutInitWindowPosition(100, 100);
glutCreateWindow("Neptune and Space");
init();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutKeyboardFunc(keyboard);
glutMainLoop();
return 0;
}

OpenGL analog clock doesn't show correctly?

I've a problem with my clock. In the first 10 minutes the hour hand doesn't show the correct hour and it changes when the minute hand's change but after 10 minutes it shows correctly. Could you please help me to fix it?
I think there is a problem in these lines but I am not sure:
static void TimeEvent(int te)
{
rx = 30 * cos( angle );
ry = 30 * sin( angle );
rz = 30 * cos( angle );
angle += 0.01;
if (angle > M_TWOPI) angle = 0;
glutPostRedisplay();
glutTimerFunc( 100, TimeEvent, 1);
}
Here is my whole code:
#include <GL/glut.h>
#include <gl/gl.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
GLUquadricObj *Cylinder;
struct tm *newtime;
time_t l_time;
int M_TWOPI=0;
GLfloat rx, ry, rz, angle;
GLfloat LightAmbient[]= { 0.5f, 0.5f, 0.5f, 1.0f };
GLfloat LightDiffuse[]= { 0.5f, 0.5f, 0.5f, 1.0f };
GLfloat LightPosition[]= { 5.0f, 25.0f, 15.0f, 1.0f };
GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
static int view_state = 1; // Ortho view = 1, Perspective = 0
void newLine(float Start, float End, float angle){
float c = cos(angle), s = sin(angle);
glVertex2f( -8.0f*Start*c, -8.0f*Start*s);
glVertex2f( -8.0f*End*c, -8.0f*End*s);
}
void Sprint( float x, float y, char *st)
{
int l,i;
l=strlen( st );
glRasterPos3f( x, y, -1);
for( i=0; i < l; i++)
{
glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24, st[i]);
}
}
static void TimeEvent(int te)
{
rx = 30 * cos( angle );
ry = 30 * sin( angle );
rz = 30 * cos( angle );
angle += 0.01;
if (angle > M_TWOPI) angle = 0;
glutPostRedisplay();
glutTimerFunc( 100, TimeEvent, 1);
}
void Draw_clock( GLfloat cx, GLfloat cy, GLfloat cz )
{
int hour_ticks , sec_ticks;
glPushMatrix();
glTranslatef(cx,cy,cz);
glRotatef(180, 1.0, 0.0, 0.0);
glPushMatrix();
glColor3f(1.0, 0.5, 0.0);
glTranslatef( 0, 0, 0.0);
glRotatef((360/12) * newtime->tm_hour + (360/60) * (60 / (newtime->tm_min+1)), 0.0, 0.0, 1.0);
glPushMatrix();
glTranslatef(0.0, 0.0, 2.0);
glPopMatrix();
glRotatef(90, 1.0, 0.0, 0.0);
gluCylinder(Cylinder, 0.75, 0, 4, 16, 16);
glPopMatrix();
glPushMatrix();
glColor3f(1.0, 0.0, 1.0);
glTranslatef( 0, 0, 0.0);
glRotatef( (360/60) * newtime->tm_min, 0.0, 0.0, 1.0);
glPushMatrix();
glTranslatef(0.0, 0.0, 3.0);
glScalef(0.5, 0.5, 1.0);
glPopMatrix();
glRotatef( 90, 1.0, 0.0, 0.0);
glutSolidCone (0.5, 6, 6, 16);
glPopMatrix();
glPushMatrix();
glColor3f(1.0, 0.0, 0.0);
glTranslatef( 0, 0, -0.0);
glRotatef( (360/60) * newtime->tm_sec, 0.0, 0.0, 1.0);
glPushMatrix();
glTranslatef(0.0, 0.0, 4.0);
glScalef(0.25, 0.25, 1.0);
glPopMatrix();
glRotatef( 90, 1.0, 0.0, 0.0);
gluCylinder(Cylinder, 0.25, 0, 6, 16, 16);
glPopMatrix();
for(hour_ticks = 0; hour_ticks < 12; hour_ticks++)
{
glPushMatrix();// Draw next arm axis.
glColor3f(0.0, 1.0, 1.0); // give it a color
glTranslatef(0.0, 0.0, 0.0);
glRotatef( (360/12) * hour_ticks, 0.0, 0.0, 1.0);
glTranslatef( 6.0, 0.0, 0.0);
glEnable(GL_LINE_SMOOTH);
glBegin(GL_LINES);
newLine(0.08f, 0.2f, 0.0f);
glEnd();
glPopMatrix();
}
for(sec_ticks = 0; sec_ticks < 60; sec_ticks++)
{
glPushMatrix();
glTranslatef(0.0, 0.0, 0.0);
glRotatef( (360/60) * sec_ticks, 0.0, 0.0, 1.0);
glTranslatef(6.0, 0.0, 0.0);
glutSolidCone(1.0, 2.0, 3, 4);
glPopMatrix();
}
glPopMatrix();
}
void num()
{
glColor3f( 0.0, 0.0, 1.0);
Sprint(-6.2,-0.2,"9"); //counting from center
Sprint(-0.2,-6.2,"6");
Sprint(2.8,-5.5,"5");
Sprint(5.0,-3.2,"4");
Sprint(5.0,+2.8,"2");
Sprint(2.8,+5.0,"1");
Sprint(-3.33,+4.95,"11");
Sprint(-0.2,-6.2,"6");
Sprint(-3.2,-5.45,"7");
Sprint(-0.4,5.7,"12");
Sprint(-5.35,-3.25,"8");
Sprint(-5.55,+2.8,"10");
Sprint(5.8,-0.2,"3");
}
void display_clock()
{
time(&l_time); // Get time
newtime = localtime(&l_time); // Convert to local time
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// easy way to put text on the screen.
glMatrixMode (GL_PROJECTION);
glLoadIdentity();
glOrtho(-8.0, 8.0, -8.0, 8.0, 1.0, 60.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glDisable(GL_LIGHTING);
glDisable(GL_COLOR_MATERIAL);
glColor3f( 1.0, 1.0, 1.0);
Sprint(-2, 3, " Clock");
Draw_clock( 0.0, 0.0, -14.0);
num();
glutSwapBuffers();
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
display_clock();
glFlush();
}
void reshape (int w, int h)
{
glViewport (0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize (500, 500);
glutInitWindowPosition (50, 50);
glutCreateWindow (argv[0]);
glutSetWindowTitle("Clock");
Cylinder = gluNewQuadric();
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutTimerFunc( 10, TimeEvent, 1);
glutMainLoop();
return 0;
}
You are doing integer arithmetic:
glRotatef((360/12) * newtime->tm_hour + (360/60) * (60 / (newtime->tm_min+1)), 0.0, 0.0, 1.0);
should be:
glRotatef(30.0 * newtime->tm_hour + 6.0) * (60.0 / (newtime->tm_min+1)), 0.0, 0.0, 1.0);
and so on.
Though, as 360/12 and 360/60 are constants you might as well replace them with the calculated values.
I believe your problem is here:
glRotatef((360/12) * newtime->tm_hour + (360/60) * (60 / (newtime->tm_min+1)), 0.0, 0.0, 1.0);
It must be:
glRotatef((360/12) * newtime->tm_hour + (360.0/12 / 60 ) * (newtime->tm_min+1), 0.0, 0.0, 1.0);

OpenGL _ Front objects are covered with Back objects. so can't see it

The problem is, 'Objects on the table is covered with table board, so can't see it.'
( I using openGL 3.7 beta. Files that I installed is : http://ihoo1836.dothome.co.kr/opengl_vs2010+glutdlls37beta.zip )
All Codes are following.
#include<glut.h>
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
float TableX = 5.0; //Table's X size
float TableY = 8.0; //Table's Y size
float TableHeight = 2.0;//Table's Height
int width=400, height=400; //Window Size
int ViewX = width/2; //for Change Viewpoint by Mouse position
int ViewY = height/2;
int ViewZ = 9;
GLUquadricObj* cyl;
void InitLight( ){
glEnable(GL_DEPTH_TEST); //for opaque
glEnable(GL_NORMALIZE); //normalize
glEnable(GL_SMOOTH); //for smooth color
glEnable(GL_LIGHTING); //light setting
glDepthMask(GL_TRUE);
GLfloat ambientLight[] = {0.3f, 0.3f, 0.3f, 1.0f};
GLfloat diffuseLight[] = {0.7f, 0.7f, 0.7f, 1.0f};
GLfloat specular[] = {1.0f, 1.0f, 1.0f, 1.0f};
GLfloat specref[] = {1.0f, 1.0f, 1.0f, 1.0f};
GLfloat position[]={400.0, 300.0, -700.0, 1.0};
glLightfv(GL_LIGHT0, GL_AMBIENT, ambientLight);
glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuseLight);
glLightfv(GL_LIGHT0, GL_SPECULAR, specular);
glLightfv(GL_LIGHT0, GL_POSITION, position);
glEnable(GL_LIGHT0);
glEnable(GL_COLOR_MATERIAL);
glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
glMateriali(GL_FRONT, GL_SHININESS, 128);
}
//Get Mouse Position to Change ViewPoint
void MyMouseMove(int button, int state, GLint X, GLint Y)
{
//Get Mouse Position X, Y
ViewX = X;
ViewY = Y;
glutPostRedisplay();
}
//Get Mouse Position to Change ViewPoint
void MyMotion(GLint X, GLint Y)
{
//Get Mouse Position X, Y
ViewX = X;
ViewY = Y;
glutPostRedisplay();
}
//Draw Table
void DrawTable(){
glPushMatrix();
glTranslatef(0.0,0.0,1.0);
glColor3f(0.5, 0.25, 0.0);
cyl = gluNewQuadric();
glRotatef(-90,1.0,0.0,0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 1
glPushMatrix();
cyl = gluNewQuadric();
glTranslatef(TableX,0.0,0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 2
glPushMatrix();
cyl = gluNewQuadric();
glTranslatef(0.0, TableY, 0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 3
glPushMatrix();
cyl = gluNewQuadric();
glTranslatef(-TableX,0.0,0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 4
glPushMatrix();
glTranslatef(TableX/2.0, -TableY/2, TableHeight);
glScalef(TableX+0.5, TableY+0.5, 0.5);
glutSolidCube(1); //Board of Table
glPopMatrix();
glPushMatrix(); //triangular1 (Beside of Net)
glTranslatef(0, -TableY/2, TableHeight);
glBegin(GL_TRIANGLES);
glVertex3f(TableY/16.0, 0, TableY/8.0);//1
glVertex3f(0, TableY/8.0, 0);
glVertex3f(0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//2
glVertex3f(0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//3
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, TableY/8.0, 0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//4
glVertex3f(TableY/16.0, TableY/8.0, 0);
glVertex3f(0, TableY/8.0, 0);
glEnd();
glPushMatrix(); //triangular2 (Beside of Net)
glTranslatef(TableX - TableY/8.0, 0 , 0);
glBegin(GL_TRIANGLES);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//1
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/16.0, TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//2
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/8.0, -TableY/8.0, 0);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//3
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/8.0, -TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/8.0, TableY/8.0, 0);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//4
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/8.0, TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/16.0, TableY/8.0, 0);
glEnd();
glPopMatrix();
glPushMatrix(); //Net
glBegin(GL_POLYGON);
glColor3f(1.0, 1.0, 1.0);
glVertex3f(TableY/16.0, 0.0, TableY/8.0);
glVertex3f((TableX - TableY/16.0), 0, TableY/8.0);
glVertex3f((TableX - TableY/16.0), 0, 0);
glVertex3f(TableY/16.0, 0.0, 0.0);
glEnd();
glPopMatrix();
glPopMatrix();
glPopMatrix();
glPopMatrix();
glPopMatrix();
glPopMatrix();
}
//Display Callback Function
void MyDisplay( ){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity( );
gluPerspective(60.0, (GLfloat)width/height, 0.0, 10.0);
//Change Viewpoint by Mouse Position
gluLookAt((float)(ViewX - width/2)/width*20 + 2.5, (float)(height/2 - ViewY)/height*20 + 2.5, ViewZ, TableX/2, TableY/2, TableHeight, 0.0, 1.0, 0.0);
printf("eyex = %f , eyey = %f , eyez = %f \n",(float)(ViewX - width/2.0)/width*10, (float)(height/2 - ViewY)/height*10, (float)ViewZ);
DrawTable(); //Draw Table
glutSwapBuffers(); //for 'Double Buffering'
}
//for Reshape Window
void MyReshape (int w, int h){
width = w;
height = h;
printf("width = %d, height = %d \n", width, height);
glViewport (0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode (GL_PROJECTION);
glLoadIdentity( );
glOrtho (-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
}
//Main Function
int main(int argc, char** argv){
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
glutInitWindowSize(width, height);
glutInitWindowPosition(200, 200);
glutCreateWindow("OpenGL Sample Drawing");
glClearColor(0.4, 0.4, 0.4, 1.0);
InitLight(); //set Light Setting
glutDisplayFunc(MyDisplay);
glutMouseFunc(MyMouseMove); //get Mouse Position, to Change Viewpoint
glutMotionFunc(MyMotion); //get Mouse Position, to Change Viewpoint
glutReshapeFunc(MyReshape);
glutMainLoop( );
}
The third argument to gluPerspective() should be non-zero, positive, and less than the forth argument:
#include <GL/glut.h>
#include <stdio.h>
float TableX = 5.0; //Table's X size
float TableY = 8.0; //Table's Y size
float TableHeight = 2.0;//Table's Height
int ViewX = 400/2; //for Change Viewpoint by Mouse position
int ViewY = 400/2;
int ViewZ = 9;
GLUquadricObj* cyl;
void InitLight( ){
glEnable(GL_DEPTH_TEST); //for opaque
glEnable(GL_NORMALIZE); //normalize
glEnable(GL_SMOOTH); //for smooth color
glEnable(GL_LIGHTING); //light setting
glDepthMask(GL_TRUE);
GLfloat ambientLight[] = {0.3f, 0.3f, 0.3f, 1.0f};
GLfloat diffuseLight[] = {0.7f, 0.7f, 0.7f, 1.0f};
GLfloat specular[] = {1.0f, 1.0f, 1.0f, 1.0f};
GLfloat specref[] = {1.0f, 1.0f, 1.0f, 1.0f};
GLfloat position[]={400.0, 300.0, -700.0, 1.0};
glLightfv(GL_LIGHT0, GL_AMBIENT, ambientLight);
glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuseLight);
glLightfv(GL_LIGHT0, GL_SPECULAR, specular);
glLightfv(GL_LIGHT0, GL_POSITION, position);
glEnable(GL_LIGHT0);
glEnable(GL_COLOR_MATERIAL);
glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
glMateriali(GL_FRONT, GL_SHININESS, 128);
}
//Get Mouse Position to Change ViewPoint
void MyMouseMove(int button, int state, GLint X, GLint Y)
{
//Get Mouse Position X, Y
ViewX = X;
ViewY = Y;
glutPostRedisplay();
}
//Get Mouse Position to Change ViewPoint
void MyMotion(GLint X, GLint Y)
{
//Get Mouse Position X, Y
ViewX = X;
ViewY = Y;
glutPostRedisplay();
}
//Draw Table
void DrawTable(){
glPushMatrix();
glTranslatef(0.0,0.0,1.0);
glColor3f(0.5, 0.25, 0.0);
cyl = gluNewQuadric();
glRotatef(-90,1.0,0.0,0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 1
glPushMatrix();
cyl = gluNewQuadric();
glTranslatef(TableX,0.0,0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 2
glPushMatrix();
cyl = gluNewQuadric();
glTranslatef(0.0, TableY, 0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 3
glPushMatrix();
cyl = gluNewQuadric();
glTranslatef(-TableX,0.0,0.0);
gluCylinder(cyl, 0.2, 0.2, TableHeight, 10, 20); //Leg of Table 4
glPushMatrix();
glTranslatef(TableX/2.0, -TableY/2, TableHeight);
glScalef(TableX+0.5, TableY+0.5, 0.5);
glutSolidCube(1); //Board of Table
glPopMatrix();
glPushMatrix(); //triangular1 (Beside of Net)
glTranslatef(0, -TableY/2, TableHeight);
glBegin(GL_TRIANGLES);
glVertex3f(TableY/16.0, 0, TableY/8.0);//1
glVertex3f(0, TableY/8.0, 0);
glVertex3f(0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//2
glVertex3f(0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//3
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glVertex3f(TableY/16.0, TableY/8.0, 0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//4
glVertex3f(TableY/16.0, TableY/8.0, 0);
glVertex3f(0, TableY/8.0, 0);
glEnd();
glPushMatrix(); //triangular2 (Beside of Net)
glTranslatef(TableX - TableY/8.0, 0 , 0);
glBegin(GL_TRIANGLES);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//1
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/16.0, TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//2
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/16.0, -TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/8.0, -TableY/8.0, 0);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//3
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/8.0, -TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/8.0, TableY/8.0, 0);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(TableY/16.0, 0, TableY/8.0);//4
glColor3f(0.0, 1.0, 0.0);
glVertex3f(TableY/8.0, TableY/8.0, 0);
glColor3f(0.0, 0.0, 1.0);
glVertex3f(TableY/16.0, TableY/8.0, 0);
glEnd();
glPopMatrix();
glPushMatrix(); //Net
glBegin(GL_POLYGON);
glColor3f(1.0, 1.0, 1.0);
glVertex3f(TableY/16.0, 0.0, TableY/8.0);
glVertex3f((TableX - TableY/16.0), 0, TableY/8.0);
glVertex3f((TableX - TableY/16.0), 0, 0);
glVertex3f(TableY/16.0, 0.0, 0.0);
glEnd();
glPopMatrix();
glPopMatrix();
glPopMatrix();
glPopMatrix();
glPopMatrix();
glPopMatrix();
}
//Display Callback Function
void MyDisplay( ){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode (GL_PROJECTION);
glLoadIdentity( );
double width = glutGet( GLUT_WINDOW_WIDTH );
double height = glutGet( GLUT_WINDOW_HEIGHT );
gluPerspective(60.0, (GLfloat)width/height, 0.01, 100.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity( );
//Change Viewpoint by Mouse Position
gluLookAt((float)(ViewX - width/2)/width*20 + 2.5, (float)(height/2 - ViewY)/height*20 + 2.5, ViewZ, TableX/2, TableY/2, TableHeight, 0.0, 1.0, 0.0);
printf("eyex = %f , eyey = %f , eyez = %f \n",(float)(ViewX - width/2.0)/width*10, (float)(height/2 - ViewY)/height*10, (float)ViewZ);
DrawTable(); //Draw Table
glutSwapBuffers(); //for 'Double Buffering'
}
//Main Function
int main(int argc, char** argv){
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
glutInitWindowSize(400, 400);
glutInitWindowPosition(200, 200);
glutCreateWindow("OpenGL Sample Drawing");
glClearColor(0.4, 0.4, 0.4, 1.0);
InitLight(); //set Light Setting
glEnable( GL_DEPTH_TEST );
glutDisplayFunc(MyDisplay);
glutMouseFunc(MyMouseMove); //get Mouse Position, to Change Viewpoint
glutMotionFunc(MyMotion); //get Mouse Position, to Change Viewpoint
glutMainLoop( );
}