#include <glut.h>
#include <glaux.h>
#include <stdio.h>

typedef struct
{
int r,g,b;
GLfloat dist, angle;
} stars;

GLuint texture[1];
GLuint loop;
const int num = 50;
stars star[num];

GLuint spini;
GLfloat title = 90.0f;
GLfloat zoom = -15.0f;

bool twinkle; // be twink
bool tp;   // "t" key Pressed

//load bmp file
AUX_RGBImageRec *LoadBMP(char* fileName)
{
FILE *file = NULL;

if (!fileName)
{
   return NULL;
}

file = fopen(fileName, "r");
if (!file)
{
   return NULL;
}

fclose(file);
return auxDIBImageLoad(fileName);
}

//set textures
int LoadGLTextures()
{
int Status = FALSE;

AUX_RGBImageRec* TextureImage[1];
memset(TextureImage, 0, sizeof(void *)*1);

if (TextureImage[0] = LoadBMP("Star.bmp"))
{
   Status = TRUE;

glGenTextures(1, &texture[0]);
   glBindTexture(GL_TEXTURE_2D, texture[0]);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
   glTexImage2D(GL_TEXTURE_2D, 0, 3, TextureImage[0]->sizeX,
    TextureImage[0]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE,
    TextureImage[0]->data );

if (TextureImage[0])
   {
    if (TextureImage[0]->data)
    {
     free(TextureImage[0]->data);
    }
    free(TextureImage[0]);
   }
}

return Status;
}

int init()
{

if (!LoadGLTextures())
{
   return FALSE;
}

glClearColor(0.0,0.0,0.0,0.5);
glClearDepth(1.0f);
glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);
glBlendFunc(GL_SRC_ALPHA, GL_ONE);

glEnable(GL_SMOOTH);
glEnable(GL_BLEND);
glEnable(GL_TEXTURE_2D);

for (loop=0; loop<num; loop++)
{
   star[loop].angle = 0.0f;
   star[loop].dist = (float(loop)/num)*5.0f;
   star[loop].r = rand()%256;
   star[loop].g = rand()%256;
   star[loop].r = rand()%256;
}
return TRUE;
}

void reshape(int w, int h)
{
if (h == 0)
{
   h = 1;
}

glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();

gluPerspective(45.0f,(GLfloat)w/(GLfloat)h, 0.1f, 100.0f);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}

void display()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glBindTexture(GL_TEXTURE_2D, texture[0]);

for (loop=0; loop<num; loop++)
{
   glLoadIdentity();
   glTranslatef(0.0f, 0.0f, zoom);
   glRotatef(title, 1.0, 0.0f, 0.0f);
  
   glRotatef(star[loop].angle, 0.0f, 1.0f, 0.0f);
   glTranslatef(star[loop].dist, 0.0f, 0.0f);
   glRotatef(-star[loop].angle, 0.0f, 1.0f, 0.0f);
   glRotatef(-title, 1.0f, 0.0f, 0.0f);

if (!twinkle)
   {
    glColor4ub(star[num-loop-1].r, star[num-loop-1].g,
     star[num-loop-1].b, 255);
    glBegin(GL_QUADS);
     glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 0.0f);
     glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, -1.0f, 0.0f);
     glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, 0.0f);
     glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 0.0);
    glEnd();
   }

glRotatef(spini, 0.0f, 0.0f, 1.0f);
   glColor4ub(star[loop].r, star[loop].g, star[loop].b, 255);
   glBegin(GL_QUADS);
    glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 0.0f);
    glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, -1.0f, 0.0f);
    glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, 0.0f);
    glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 0.0);
   glEnd();

spini += 0.01f;
   star[loop].angle += float(loop)/num;
   star[loop].dist -= 0.01f;
   if (star[loop].dist <0.0f)
   {
    star[loop].dist += 5.0f;
    star[loop].r = rand()%256;
    star[loop].g = rand()%256;
    star[loop].b = rand()%256;
   }
}
glutSwapBuffers();

}

void keyboard(unsigned char key, int x, int y)
{
switch(key)
{
case 't':
case 'T':
   {
    twinkle != twinkle;
    break;
   }
}
}

int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);
glutInitWindowPosition(10,10);
glutInitWindowSize(1000,1000);
glutCreateWindow("star");

init();

glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutKeyboardFunc(keyboard);
glutIdleFunc(display);
glutMainLoop();

return 0;
}