Chaos Game

Data de publicació: Mar 15, 2018 8:58:4 AM

//gcc cairo_poligon_fractal.c -lm `pkg-config --cflags gtk+-3.0 --libs gtk+-3.0` -o cairo_poligon_fractal

#include <gtk/gtk.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <math.h>

//Screen dimension in pixels

#define WIDTH 1000

#define HEIGHT 1000

//Polygon type and radius dimension

#define N_POL 3

#define RADI ( WIDTH / 2 )

#define DIV 2

//N_PLACES 0, Next vertex selected not the same vertex, 1: Not the next vertex in order, and so on ...

#define N_PLACES 2

//Anula N_PLACES. ALL 1, all vertex possible selected

#define ALL 1

typedef struct punt{

    int x;

    int y;

} t_punt;

t_punt POLIGON[N_POL], punt;

int    _genera_poligon(t_punt POLIGON[], int n, int r){

int i;

for (i = 0; i < n; i++) {

    POLIGON[i].x = (int)(r - r * sinf(2 * M_PI * i / n));

    POLIGON[i].y = (int)(r - r * cosf(2 * M_PI * i / n));

    }

}

void    _init_aleat(){srand(time(NULL));}

int    _aleat(int n){return rand() % n;}

void    _wait_for(int n){int i; for ( i = 0; i < n; i++ );}

int    _aleat_diff(int n_pol, int vertex){

        int v;

        v = _aleat(n_pol);

        while ( v == vertex ) v = _aleat(N_POL);

        return v;

 }

int _nplaces_away_from_vertex(int vertex, int n_places, int n_pol){return ( (vertex + n_places) % n_pol );}

gboolean draw_callback(GtkWidget *widget,cairo_t *cr,gpointer data){

guint width, height;

GdkRGBA color;

GtkStyleContext *context;

int i, vertex;

context = gtk_widget_get_style_context(widget);

width = gtk_widget_get_allocated_width(widget);

height = gtk_widget_get_allocated_height(widget);

gtk_render_background(context, cr, 0, 0, width, height);

 //Constructing and painting the polygon

 _genera_poligon(POLIGON, N_POL, RADI);

 for ( i = 0; i < N_POL; i++ ){

    cairo_move_to (cr, POLIGON[i].x, POLIGON[i].y);

   cairo_line_to (cr, POLIGON[(i+1)%N_POL].x, POLIGON[(i+1)%N_POL].y);

 } 

//Set source color black, and the line width    

cairo_set_source_rgb (cr, 0, 0, 0);

cairo_set_line_width (cr, 1.0);

//Paint the polygon

cairo_stroke (cr);

vertex = _aleat(N_POL);

for ( i = 0; i < 100000; i++ ) {

    _wait_for(1);

    cairo_move_to (cr, punt.x, punt.y);

    cairo_arc(cr, punt.x, punt.y, 0.05, 0, 2*G_PI);

    switch ( ALL ){

        case 1:    vertex = _aleat( N_POL ); break;

        case 0:    vertex = _aleat_diff(N_POL, _nplaces_away_from_vertex(vertex, N_PLACES, N_POL));break;

        default:    break;

    }

    punt.x = punt.x + (POLIGON[vertex].x - punt.x) / DIV;

    punt.y = punt.y + (POLIGON[vertex].y - punt.y) / DIV;

    cairo_stroke (cr);

    cairo_fill(cr);

 }

gtk_style_context_get_color(context,gtk_style_context_get_state(context),&color);

gdk_cairo_set_source_rgba(cr,&color);

//gdk_cairo_set_source_rgba(cr,&color);

cairo_fill (cr);

return FALSE;

}

//-------------------------------------------------------------------

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

{

GtkWidget *window,*drawing_area;

gtk_init(&argc,&argv);

window = gtk_window_new(GTK_WINDOW_TOPLEVEL);

g_signal_connect(window,"destroy",G_CALLBACK(gtk_main_quit),NULL);

drawing_area=gtk_drawing_area_new();

gtk_container_add (GTK_CONTAINER (window),drawing_area);

gtk_widget_set_size_request(drawing_area, WIDTH, HEIGHT);

g_signal_connect(G_OBJECT(drawing_area),"draw", G_CALLBACK(draw_callback),NULL);

gtk_widget_show_all(window);

gtk_main();

return 0;

}