From b51884cd24b7c74b0c5d89731d93221b022de62a Mon Sep 17 00:00:00 2001
From: Ivan Mahonin <bh@icystar.com>
Date: Dec 20 2019 16:13:13 +0000
Subject: gtk3: life


---

diff --git a/c/gtk3/life/life.c b/c/gtk3/life/life.c
new file mode 100644
index 0000000..8e66357
--- /dev/null
+++ b/c/gtk3/life/life.c
@@ -0,0 +1,120 @@
+#include <stdlib.h>
+#include <time.h>
+#include <gtk/gtk.h>
+
+#define ROWS 20
+#define COLS 30
+
+const double pi = 3.141592653589793;
+
+const int size = 20;
+
+int field1[COLS][ROWS];
+int field2[COLS][ROWS];
+GtkWidget *drawing_area;
+GtkWidget *toggle_button;
+
+
+int get_cell(int x, int y) {
+  x = (x + COLS)%COLS;
+  y = (y + ROWS)%ROWS;
+  return field1[x][y];
+}
+
+gboolean timeout(gpointer data) {
+  if (gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(toggle_button))) {
+    for(int i = 0; i < COLS; ++i) {
+      for(int j = 0; j < ROWS; ++j) {
+        int count = 0;
+        count += get_cell(i-1, j-1);
+        count += get_cell(i-1, j);
+        count += get_cell(i-1, j+1);
+        count += get_cell(i, j-1);
+        count += get_cell(i, j+1);
+        count += get_cell(i+1, j-1);
+        count += get_cell(i+1, j);
+        count += get_cell(i+1, j+1);
+        if (field1[i][j]) {
+          field2[i][j] = (count == 2 || count == 3);
+        } else {
+          field2[i][j] = (count == 3);
+        }
+      }
+    }
+    for(int i = 0; i < COLS; ++i)
+      for(int j = 0; j < ROWS; ++j)
+        field1[i][j] = field2[i][j];
+    gtk_widget_queue_draw(drawing_area);
+  }  
+  return TRUE;
+}
+
+gboolean draw(GtkWidget *widget, cairo_t *cr, gpointer data) {
+  cairo_set_source_rgba(cr, 0.9, 0.9, 0.9, 1);
+  cairo_paint(cr);
+
+  cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1);
+  for(int i = 0; i <= COLS; ++i) {
+    cairo_move_to(cr, i*size, 0.0);
+    cairo_line_to(cr, i*size, ROWS*size);
+  }
+  for(int j = 0; j < ROWS; ++j) {
+    cairo_move_to(cr, 0.0, j*size);
+    cairo_line_to(cr, COLS*size, j*size);
+  }
+  cairo_stroke(cr);
+
+  for(int i = 0; i < COLS; ++i) {
+    for(int j = 0; j < ROWS; ++j) {
+      if (field1[i][j]) {
+        cairo_arc(cr, (i + 0.5)*size, (j + 0.5)*size, 0.5*size, 0.0, 2.0*pi);
+        cairo_fill(cr);
+      }
+    }
+  }
+  
+  return TRUE;
+}
+
+gboolean button_press(GtkWidget *widget, GdkEventButton *event, gpointer data) {
+  int x = (int)(event->x)/size;
+  int y = (int)(event->y)/size;
+  if (x >= 0 && y >= 0 && x < COLS && y < ROWS) {
+    field1[x][y] = !field1[x][y];
+    gtk_widget_queue_draw(drawing_area);
+  }
+  return TRUE;
+}
+
+void activate(GtkApplication* app, gpointer data) {
+  srand(time(NULL));
+
+  GtkWidget *window = gtk_application_window_new (app);
+
+  GtkWidget *hbox = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 10);
+  gtk_container_add(GTK_CONTAINER(window), hbox);
+  
+  drawing_area = gtk_drawing_area_new();
+  gtk_widget_set_size_request(GTK_WIDGET(drawing_area), COLS*size, ROWS*size);
+  gtk_widget_set_hexpand(drawing_area, TRUE);
+  gtk_widget_add_events(drawing_area, GDK_BUTTON_PRESS_MASK);
+  g_signal_connect(drawing_area, "draw", G_CALLBACK(draw), NULL);
+  g_signal_connect(drawing_area, "button-press-event", G_CALLBACK(button_press), NULL);
+  gtk_container_add(GTK_CONTAINER(hbox), drawing_area);
+
+  toggle_button = gtk_toggle_button_new_with_label("Start/Stop");
+  gtk_widget_set_valign(toggle_button, GTK_ALIGN_START);
+  gtk_container_add(GTK_CONTAINER(hbox), toggle_button);
+  
+  gtk_widget_show_all(window);
+  
+  g_timeout_add(100, timeout, NULL);
+}
+
+int main(int argc, char **argv) {
+  GtkApplication *application = gtk_application_new(NULL, 0);
+  g_signal_connect(application, "activate", G_CALLBACK(activate), NULL);
+  int status = g_application_run(G_APPLICATION(application), argc, argv);
+  g_object_unref(application);
+  return status;
+}