#include <stdio.h>
#include <stdlib.h>
#include <GL/glut.h>



float coo[128][128][3];
float vel[128][128];
int q[127][127][4];

void init()
{
	int i,j;

	for(i=0;i<128;i++)
		for(j=0;j<128;j++)
		{
			coo[i][j][0]=(i-64.0f)/64.0f;
			coo[i][j][1]=(j-64.0f)/64.0f;
			vel[i][j]=coo[i][j][2]=0.0f;

		}

	for(i=0;i<127;i++)
		for(j=0;j<127;j++)
		{
			q[i][j][0]=i*128+j;
			q[i][j][1]=i*128+j+1;

			q[i][j][2]=i*128+j;
			q[i][j][3]=i*128+j+128;
		}

};


void step()
{
	int i,j;

	for(i=1;i<127;i++)
		for(j=1;j<127;j++)
		{
			vel[i][j]+=coo[i][j][2]-
				      (coo[i+1][j][2]+
					   coo[i-1][j][2]+
					   coo[i][j+1][2]+
					   coo[i][j-1][2])*0.25f;
				      
		}

	for(i=1;i<127;i++)
		for(j=1;j<127;j++)
		{
			coo[i][j][2]-=vel[i][j];
			coo[i][j][2]*=0.99f;
		}

	for(i=0;i<128;i++)
	{
		coo[i][0][2]=0;
		coo[i][127][2]=0;
		coo[0][i][2]=0;
		coo[127][i][2]=0;

	}



}


float a,b,c;

void blup(int x, int y)
{
	for(int x1=-10;x1<11;x1++)
		for(int y1=-10;y1<11;y1++)
		{
			float v=100.0f-x1*x1-y1*y1;
			if(v<0.0f)v=0.0f;
			coo[(x+x1)&127][(y+y1)&127][2]+=v*0.004f;
		}


}

void redraw()
{
    static char counter;
	

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	
	glLoadIdentity (); 
	glTranslatef (0.0f, 0.0f, -2.0f);
	
	glRotatef(-70,1,0,0);
	//glRotatef(10,0,1,0);

	glRotatef(c+=0.1f,0,0,1);


	if(counter++==0)
		blup(rand(),rand());
	


	step();

	glEnableClientState(GL_VERTEX_ARRAY);
	glVertexPointer(3,GL_FLOAT,0,&coo[0][0][0]);
	glDrawElements(GL_LINES, 127*127*4, GL_UNSIGNED_INT, &q[0][0][0]);
  
	glutSwapBuffers();
}



float w,h;

void motion(int x, int y)
{
	a=300.0f*x/w;
	b=300.0f*y/h;
}

void reshape(int width, int height)
{
    w=width;
	h=height;
	glMatrixMode (GL_PROJECTION);   
	glLoadIdentity ();  
	gluPerspective(60.0f,(width+0.1f)/(height+0.1f),0.1f,10.0f);
	glMatrixMode (GL_MODELVIEW);    
	glViewport (0, 0, width, height);   
}

int main(int argc, char *argv[])
{
	int i;
	init();
    glutInit(&argc, argv);
    glutInitWindowSize(800,600);
    glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
    glutCreateWindow("Peter Popov GLUT");
    glutIdleFunc(redraw);
    glutDisplayFunc(redraw);
    glutMotionFunc(motion);
    glutReshapeFunc(reshape);
	glutShowWindow();

	glClearColor(1.0f,0.5f,0.2f,0.0f);
    glutMainLoop();

    return 0;
}