#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#ifdef _WIN32

#include "windows.h"

#endif

#include "GL/glut.h"

#include "sor.h"

#include "grid.h"

const int w = 1024;

const int h = 768;

const int ROWS = N, COLS = N;

const int BORDER = 24;

const int DELAY = 100;

int CW, CH;

int xoffset;

int stepDelay;

char convtext[128];

char itertext[32];

cell_colour_t gridcolour = RED;

unsigned char converged = 0, paused = 1, boundary = 0;

void *font = GLUT_BITMAP_HELVETICA_12;

const char *convstr = "Convergence in %d iterations for %dx%d grid with tolerance %5.3f and omega %.8f";

const char *iterstr = "Iteration %d e: %.8f";

void drawcell(int x, int y, double v)

{

if(gridcolour == RED)

glColor3f(v, v/2.0, v/3.5); /* Flame */

else if(gridcolour == GREEN)

glColor3f(v/2.5, v, v/2.0); /* Absinthe */

else if(gridcolour == BLUE)

glColor3f(v/3.0, v/2.5, v); /* Cherenkov */

glBegin(GL_QUADS);

glVertex2i(x*CW+BORDER+xoffset, y*CH+BORDER);

glVertex2i((x+1)*CW+BORDER+xoffset, y*CH+BORDER);

glVertex2i((x+1)*CW+BORDER+xoffset, (y+1)*CH+BORDER);

glVertex2i(x*CW+BORDER+xoffset, (y+1)*CH+BORDER);

glEnd();

}

void bitmapString(void *font, char *str, int x, int y)

{

glColor3f(1.0, 1.0, 1.0);

glRasterPos2i(x, y);

if(str && strlen(str)){

while(*str){

glutBitmapCharacter(font, *str);

str++;

}

}

}

void initRendering(void)

{

glClearColor(0.0, 0.0, 0.0, 0.0);

glShadeModel(GL_FLAT);

gluOrtho2D(0, w, h, 0);

}

void handleKeyPress(unsigned char key, int wx, int wy)

{

(void)wx; /* Unused */

(void)wy; /* Unused */

switch(key){

/* q */ case 'q':

/* ESC */ case 27:

exit(0);

break;

/* Space */ case 32:

/* p */ case 'p':

paused = (paused ? 0 : 1);

break;

/* b */ case 'b': boundary = (boundary ? 0 : 1);

break;

/* s */ case 's': paused = 1;

if((epsilon = calcerror()) >= tol){

runsor();

glutPostRedisplay();

}else{

paused = 0;

}

break;

/* r */ case 'r': iter = 0;

paused = 1;

converged = 0;

epsilon = 0.0;

stepDelay = DELAY;

initgrid();

glutPostRedisplay();

break;

/* c */ case 'c': gridcolour = ((gridcolour << 1) % 7);

break;

/* i */ case 'i': stepDelay = (stepDelay ? 0 : DELAY);

paused = 0;

/* Can time here... glutTimerFunc(stepDelay, update, 0); */

break;

}

}

void handleResize(int wx, int hx)

{

glViewport(0, 0, wx, hx);

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D(0, w, h, 0);

glMatrixMode(GL_MODELVIEW);

glLoadIdentity();

}

void drawScene(void)

{

int i, j;

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glMatrixMode(GL_MODELVIEW);

glLoadIdentity();

for(i=0; i<N+boundary; i++){

for(j=0; j<N+boundary; j++){

drawcell(j, i, x[i+1][j+1]);

}

}

glBegin(GL_LINES);

glColor3f(1.0, 1.0, 1.0);

glVertex2i(xoffset-BORDER, BORDER);

glVertex2i(w-xoffset+BORDER, BORDER);

glVertex2i(w-xoffset+BORDER, BORDER);

glVertex2i(w-xoffset+BORDER, ROWS*CH+BORDER);

glVertex2i(w-xoffset+BORDER, ROWS*CH+BORDER);

glVertex2i(xoffset-BORDER, ROWS*CH+BORDER);

glVertex2i(xoffset-BORDER, ROWS*CH+BORDER);

glVertex2i(xoffset-BORDER, BORDER);

glEnd();

snprintf(itertext, 32, iterstr, iter, epsilon);

bitmapString(font, itertext, w-w/5, h-BORDER/3);

if(converged){

snprintf(convtext, 128, convstr, iter, N, N, tol, omega);

bitmapString(font, convtext, 48, h-BORDER/3);

}

if(paused){

bitmapString(font, "-=: PAUSED :=-", w/2-40, BORDER/2);

}

glutSwapBuffers();

}

void update(int v)

{

(void)v; /* Unused */

if(paused){

glutTimerFunc(stepDelay, update, 0);

glutPostRedisplay();

return;

}

if((epsilon = calcerror()) >= tol){

runsor();

glutPostRedisplay();

glutTimerFunc(stepDelay, update, 0);

}else{

converged = 1;

glutTimerFunc(stepDelay, update, 0);

glutPostRedisplay();

}

}

int main(int argc, char *argv[])

{

CW = (MIN(w,h)-2*BORDER)/COLS;

CH = CW;

xoffset = (w-(CW*COLS))/2;

stepDelay = DELAY;

initgrid();

glutInit(&argc, argv);

glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);

glutInitWindowSize(w, h);

glutCreateWindow("SOR Grid");

initRendering();

glutDisplayFunc(drawScene);

glutKeyboardFunc(handleKeyPress);

glutReshapeFunc(handleResize);

glutTimerFunc(stepDelay, update, 0);

glutMainLoop();

return 0;

}