Below is the computer graphics program to display sun rise and fall. First try to run the program. Below are the details for terminologies and functions used in program. Try to understand importance of each function.
glColor3f(colR,colG,colB);
//set ball colour
void glTranslatef(GLfloat x, GLfloat y, GLfloat z);
// moving it toward the screen a bit on creation
void glutSolidSphere(GLdouble radius,GLint slices, GLint stacks);
// render sphere objects
void glClearColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha);
// It specifies value to clear color buffer.
void glEnable(GLenum cap);
// enable / disable server side GL capabilities
void glViewport(GLint x, GLint y, GLsizei width, GLsizei height);
// initialize the viewport
void glMatrixMode(GLenum mode);
void glMatrixMode(GLenum mode);
// transforms current matrix to identity matrix
void gluPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar);
// set up value for perspective projection matrix
void glClear(GLbitfield mask);
// clear preset values of buffer
void glLightModelf(GLenum pname, GLfloat param);
// set the lighting model parameters
void glLightf(GLenum light, GLenum pname, GLfloat param);
// initialize light source parameters
void glPushMatrix( void);
// it does pop and push current matrix stack.
void glutPostRedisplay(void);
// it marks current window to re-display.
void glutInit(int *argcp, char **argv);
// it initialize GLUT library.
void glutInitDisplayMode(unsigned int mode);
// Used to set initial display mode.
void glutInitWindowSize(int width, int height);
//it sets the size of window and position of window.
int glutCreateWindow(char *name);
// It creates Top Level window.
void glutDisplayFunc(void (*func)(void));
// it sets display callback for current window
void glutFullScreen(void);
// call the current window be made full screen.
void glutSpecialFunc(void (*func)(int key, int x, int y));
// it sets the keyboard callback for current window.
void glutTimerFunc(unsigned int msecs,void (*func)(int value), value);
// it registers timer callback to get triggered in a specified milliseconds.
void glutMainLoop(void);
// enters to GLUT event processing loop
Program:
#include
#include
#ifdef __APPLE__
#include
#include
#else
#include
#endif
using namespace std;
float ballX = -0.8f;
float ballY = -0.3f;
float ballZ = -1.2f;
float colR=3.0;
float colG=1.5;
float colB=1.0;
float bgColR=0.0;
float bgColG=0.0;
float bgColB=0.0;
static int flag=1;
void drawBall(void) {
glColor3f(colR,colG,colB); //set ball colour
glTranslatef(ballX,ballY,ballZ); //moving it toward the screen a bit on creation
glutSolidSphere (0.05, 30, 30); //create ball.
}
void drawAv(void) {
glBegin(GL_POLYGON);
glColor3f(1.0,1.0,1.0);
glVertex3f(-0.9,-0.7,-1.0);
glVertex3f(-0.5,-0.1,-1.0);
glVertex3f(-0.2,-1.0,-1.0);
glVertex3f(0.5,0.0,-1.0);
glVertex3f(0.6,-0.2,-1.0);
glVertex3f(0.9,-0.7,-1.0);
glEnd();
}
void drawClouds(){}
void keyPress(int key, int x, int y)
{
if(key==GLUT_KEY_RIGHT)
ballX -= 0.05f;
if(key==GLUT_KEY_LEFT)
ballX += 0.05f;
glutPostRedisplay();
}
void initRendering() {
glEnable(GL_DEPTH_TEST);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_LIGHTING); //Enable lighting
glEnable(GL_LIGHT0); //Enable light #0
glEnable(GL_LIGHT1); //Enable light #1
glEnable(GL_NORMALIZE); //Automatically normalize normals
//glShadeModel(GL_SMOOTH); //Enable smooth shading
}
//Called when the window is resized
void handleResize(int w, int h) {
//Tell OpenGL how to convert from coordinates to pixel values
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION); //Switch to setting the camera perspective
//Set the camera perspective
glLoadIdentity(); //Reset the camera
gluPerspective(45.0, //The camera angle
(double)w / (double)h, //The width-to-height ratio
1.0, //The near z clipping coordinate
200.0); //The far z clipping coordinate
}
void drawScene()
{
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glClearColor(bgColR,bgColG,bgColB,0.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
//Add ambient light
GLfloat ambientColor[] = {0.2f, 0.2f, 0.2f, 1.0f}; //Color (0.2, 0.2, 0.2)
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambientColor);
//Add positioned light
GLfloat lightColor0[] = {0.5f, 0.5f, 0.5f, 1.0f}; //Color (0.5, 0.5, 0.5)
GLfloat lightPos0[] = {4.0f, 0.0f, 8.0f, 1.0f}; //Positioned at (4, 0, 8)
glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColor0);
glLightfv(GL_LIGHT0, GL_POSITION, lightPos0);
//Add directed light
GLfloat lightColor1[] = {0.5f, 0.2f, 0.2f, 1.0f}; //Color (0.5, 0.2, 0.2)
//Coming from the direction (-1, 0.5, 0.5)
GLfloat lightPos1[] = {-1.0f, 0.5f, 0.5f, 0.0f};
glLightfv(GL_LIGHT1, GL_DIFFUSE, lightColor1);
glLightfv(GL_LIGHT1, GL_POSITION, lightPos1);
//drawing the SUN
glPushMatrix();
drawBall();
glPopMatrix();
//drawing the Mount Avarest
glPushMatrix();
drawAv();
glPopMatrix();
//drawing the Clouds
glPushMatrix();
drawClouds();
glPopMatrix();
glutSwapBuffers();
}
//float _angle = 30.0f;
void update(int value) {
if(ballX>0.9f)
{
ballX = -0.8f;
ballY = -0.3f;
flag=1;
colR=2.0;
colG=1.50;
colB=1.0;
bgColB=0.0;
}
if(flag)
{
ballX += 0.001f;
ballY +=0.0007f;
colR-=0.001;
//colG+=0.002;
colB+=0.005;
bgColB+=0.001;
if(ballX>0.01)
{
flag=0;
}
}
if (!flag)
{
ballX += 0.001f;
ballY -=0.0007f;
colR+=0.001;
colB-=0.01;
bgColB-=0.001;
if(ballX {
flag=1;
}
}
glutPostRedisplay(); //Tell GLUT that the display has changed
//Tell GLUT to call update again in 25 milliseconds
glutTimerFunc(25, update, 0);
}
int main(int argc,char** argv)
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);
glutInitWindowSize(400,400);
glutCreateWindow("Sun");
initRendering();
glutDisplayFunc(drawScene);
glutFullScreen();
glutSpecialFunc(keyPress);
glutReshapeFunc(handleResize);
glutTimerFunc(25, update, 0);
glutMainLoop();
return(0);
}
#include
#ifdef __APPLE__
#include
#include
#else
#include
#endif
using namespace std;
float ballX = -0.8f;
float ballY = -0.3f;
float ballZ = -1.2f;
float colR=3.0;
float colG=1.5;
float colB=1.0;
float bgColR=0.0;
float bgColG=0.0;
float bgColB=0.0;
static int flag=1;
void drawBall(void) {
glColor3f(colR,colG,colB); //set ball colour
glTranslatef(ballX,ballY,ballZ); //moving it toward the screen a bit on creation
glutSolidSphere (0.05, 30, 30); //create ball.
}
void drawAv(void) {
glBegin(GL_POLYGON);
glColor3f(1.0,1.0,1.0);
glVertex3f(-0.9,-0.7,-1.0);
glVertex3f(-0.5,-0.1,-1.0);
glVertex3f(-0.2,-1.0,-1.0);
glVertex3f(0.5,0.0,-1.0);
glVertex3f(0.6,-0.2,-1.0);
glVertex3f(0.9,-0.7,-1.0);
glEnd();
}
void drawClouds(){}
void keyPress(int key, int x, int y)
{
if(key==GLUT_KEY_RIGHT)
ballX -= 0.05f;
if(key==GLUT_KEY_LEFT)
ballX += 0.05f;
glutPostRedisplay();
}
void initRendering() {
glEnable(GL_DEPTH_TEST);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_LIGHTING); //Enable lighting
glEnable(GL_LIGHT0); //Enable light #0
glEnable(GL_LIGHT1); //Enable light #1
glEnable(GL_NORMALIZE); //Automatically normalize normals
//glShadeModel(GL_SMOOTH); //Enable smooth shading
}
//Called when the window is resized
void handleResize(int w, int h) {
//Tell OpenGL how to convert from coordinates to pixel values
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION); //Switch to setting the camera perspective
//Set the camera perspective
glLoadIdentity(); //Reset the camera
gluPerspective(45.0, //The camera angle
(double)w / (double)h, //The width-to-height ratio
1.0, //The near z clipping coordinate
200.0); //The far z clipping coordinate
}
void drawScene()
{
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glClearColor(bgColR,bgColG,bgColB,0.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
//Add ambient light
GLfloat ambientColor[] = {0.2f, 0.2f, 0.2f, 1.0f}; //Color (0.2, 0.2, 0.2)
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambientColor);
//Add positioned light
GLfloat lightColor0[] = {0.5f, 0.5f, 0.5f, 1.0f}; //Color (0.5, 0.5, 0.5)
GLfloat lightPos0[] = {4.0f, 0.0f, 8.0f, 1.0f}; //Positioned at (4, 0, 8)
glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColor0);
glLightfv(GL_LIGHT0, GL_POSITION, lightPos0);
//Add directed light
GLfloat lightColor1[] = {0.5f, 0.2f, 0.2f, 1.0f}; //Color (0.5, 0.2, 0.2)
//Coming from the direction (-1, 0.5, 0.5)
GLfloat lightPos1[] = {-1.0f, 0.5f, 0.5f, 0.0f};
glLightfv(GL_LIGHT1, GL_DIFFUSE, lightColor1);
glLightfv(GL_LIGHT1, GL_POSITION, lightPos1);
//drawing the SUN
glPushMatrix();
drawBall();
glPopMatrix();
//drawing the Mount Avarest
glPushMatrix();
drawAv();
glPopMatrix();
//drawing the Clouds
glPushMatrix();
drawClouds();
glPopMatrix();
glutSwapBuffers();
}
//float _angle = 30.0f;
void update(int value) {
if(ballX>0.9f)
{
ballX = -0.8f;
ballY = -0.3f;
flag=1;
colR=2.0;
colG=1.50;
colB=1.0;
bgColB=0.0;
}
if(flag)
{
ballX += 0.001f;
ballY +=0.0007f;
colR-=0.001;
//colG+=0.002;
colB+=0.005;
bgColB+=0.001;
if(ballX>0.01)
{
flag=0;
}
}
if (!flag)
{
ballX += 0.001f;
ballY -=0.0007f;
colR+=0.001;
colB-=0.01;
bgColB-=0.001;
if(ballX {
flag=1;
}
}
glutPostRedisplay(); //Tell GLUT that the display has changed
//Tell GLUT to call update again in 25 milliseconds
glutTimerFunc(25, update, 0);
}
int main(int argc,char** argv)
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);
glutInitWindowSize(400,400);
glutCreateWindow("Sun");
initRendering();
glutDisplayFunc(drawScene);
glutFullScreen();
glutSpecialFunc(keyPress);
glutReshapeFunc(handleResize);
glutTimerFunc(25, update, 0);
glutMainLoop();
return(0);
}
