Beispiele 23.11.2023

20231123/alignment-01.c

+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+int main (void)
+{
+  uint8_t a;
+  uint16_t b;
+  uint8_t c;
+  memset (&a, 0xff, 4);
+  printf ("a = %d\nb = %d\nc = %d\n", a, b, c);
+  return 0;
+}

20231123/alignment-02.c

+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+uint8_t a;
+uint16_t b;
+uint8_t c;
+
+int main (void)
+{
+  memset (&a, 0xff, 4);
+  printf ("a = %d\nb = %d\nc = %d\n", a, b, c);
+  return 0;
+}

20231123/alignment-03.c

+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+uint8_t a;
+uint16_t b;
+uint8_t c;
+
+int main (void)
+{
+  memset (&a, 0xff, 8);
+  printf ("a = %d\nb = %d\nc = %d\n", a, b, c);
+  return 0;
+}

20231123/alignment-04.c

+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+uint8_t a;
+uint16_t b;
+uint8_t c;
+
+int main (void)
+{
+  memset (&a, 0xff, 5);
+  printf ("a = %d\nb = %d\nc = %d\n", a, b, c);
+  return 0;
+}

20231123/alignment-05.c

+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+uint8_t a;
+uint64_t b;
+uint8_t c;
+
+int main (void)
+{
+  memset (&a, 0xff, 5);
+  printf ("a = %d\nb = %d\nc = %d\n", a, b, c);
+  return 0;
+}

20231123/alignment-06.c

+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+uint8_t a;
+uint64_t b;
+uint8_t c;
+
+int main (void)
+{
+  memset (&a, 0xff, 9);
+  printf ("a = %d\nb = %d\nc = %d\n", a, b, c);
+  return 0;
+}

20231123/deriv-01.c

+#include <stdio.h>
+
+float f (float x)
+{
+  return x * x;
+}
+
+float df_a (float x)
+{
+  return 2.0 * x;
+}
+
+float df_n (float x)
+{
+  float dx = 0.0000001;
+  float df = f (x + 0.5 * dx) - f (x - 0.5 * dx);
+  return df / dx;
+}
+
+int main (void)
+{
+  for (float x = -3.0; x <= 3.0; x += 0.1)
+    printf ("%10f%10f%10f%10f\n", x, f (x), df_a (x), df_n (x));
+  return 0;
+}

20231123/deriv-01.dat

+ -3.000000  9.000000 -6.000000  0.000000
+ -2.900000  8.410001 -5.800000  0.000000
+ -2.800000  7.840001 -5.600000  0.000000
+ -2.700000  7.290001 -5.400001  0.000000
+ -2.600000  6.760002 -5.200001  0.000000
+ -2.500000  6.250002 -5.000001  0.000000
+ -2.400001  5.760003 -4.800001  0.000000
+ -2.300001  5.290003 -4.600001  0.000000
+ -2.200001  4.840003 -4.400002  0.000000
+ -2.100001  4.410004 -4.200002  0.000000
+ -2.000001  4.000004 -4.000002  0.000000
+ -1.900001  3.610003 -3.800002  0.000000
+ -1.800001  3.240003 -3.600002  0.000000
+ -1.700001  2.890003 -3.400002  0.000000
+ -1.600001  2.560003 -3.200002  0.000000
+ -1.500001  2.250003 -3.000002  0.000000
+ -1.400001  1.960002 -2.800002  0.000000
+ -1.300001  1.690002 -2.600002  0.000000
+ -1.200001  1.440002 -2.400002  0.000000
+ -1.100001  1.210002 -2.200001  0.000000
+ -1.000001  1.000001 -2.000001  0.000000
+ -0.900001  0.810001 -1.800001 -2.384186
+ -0.800001  0.640001 -1.600001 -1.788139
+ -0.700001  0.490001 -1.400001 -1.788139
+ -0.600001  0.360001 -1.200001 -1.490116
+ -0.500001  0.250001 -1.000001 -1.192093
+ -0.400001  0.160000 -0.800001 -1.043081
+ -0.300001  0.090000 -0.600001 -0.670552
+ -0.200001  0.040000 -0.400001 -0.372529
+ -0.100001  0.010000 -0.200001 -0.204891
+ -0.000001  0.000000 -0.000001 -0.000001
+  0.099999  0.010000  0.199999  0.214204
+  0.199999  0.040000  0.399999  0.372529
+  0.299999  0.090000  0.599999  0.745058
+  0.399999  0.160000  0.799999  0.894070
+  0.499999  0.249999  0.999999  1.192093
+  0.599999  0.359999  1.199999  1.192093
+  0.699999  0.489999  1.399999  1.788139
+  0.799999  0.639999  1.599999  1.788139
+  0.899999  0.809999  1.799999  2.384186
+  0.999999  0.999999  1.999999  2.384186
+  1.099999  1.209999  2.199999  0.000000
+  1.199999  1.439999  2.399999  0.000000
+  1.299999  1.689999  2.599999  0.000000
+  1.399999  1.959999  2.799999  0.000000
+  1.500000  2.249999  2.999999  0.000000
+  1.600000  2.559999  3.199999  0.000000
+  1.700000  2.889998  3.399999  0.000000
+  1.800000  3.239999  3.599999  0.000000
+  1.900000  3.609998  3.799999  0.000000
+  2.000000  3.999999  3.999999  0.000000
+  2.100000  4.409998  4.199999  0.000000
+  2.200000  4.839998  4.399999  0.000000
+  2.299999  5.289998  4.599999  0.000000
+  2.399999  5.759997  4.799999  0.000000
+  2.499999  6.249997  4.999999  0.000000
+  2.599999  6.759996  5.199998  0.000000
+  2.699999  7.289995  5.399998  0.000000
+  2.799999  7.839994  5.599998  0.000000
+  2.899999  8.409993  5.799998  0.000000
+  2.999999  8.999993  5.999998  0.000000

20231123/deriv-01.gp

+plot "deriv-01.dat" using 1:2 with lines title "f(x)", \
+     "deriv-01.dat" using 1:3 with lines title "df_a(x)", \
+     "deriv-01.dat" using 1:4 with lines lc "red" dashtype "-" title "df_n(x)"
+pause -1

20231123/deriv-02.c

+#include <stdio.h>
+
+float f (float x)
+{
+  return x * x * x;
+}
+
+float df_a (float x)
+{
+  return 3.0 * x * x;
+}
+
+float df_n (float x)
+{
+  float dx = 0.1;
+  float df = f (x + 0.5 * dx) - f (x - 0.5 * dx);
+  return df / dx;
+}
+
+int main (void)
+{
+  for (float x = -3.0; x <= 3.0; x += 0.1)
+    printf ("%11f %11f %11f %11f\n", x, f (x), df_a (x), df_n (x));
+  return 0;
+}

20231123/deriv-02.dat

+  -3.000000  -27.000000   27.000000   27.002468
+  -2.900000  -24.389004   25.230001   25.232487
+  -2.800000  -21.952005   23.520002   23.522472
+  -2.700000  -19.683006   21.870005   21.872482
+  -2.600000  -17.576008   20.280006   20.282497
+  -2.500000  -15.625009   18.750008   18.752489
+  -2.400001  -13.824010   17.280008   17.282486
+  -2.300001  -12.167011   15.870009   15.872488
+  -2.200001  -10.648011   14.520010   14.522505
+  -2.100001   -9.261011   13.230011   13.232498
+  -2.000001   -8.000011   12.000011   12.002497
+  -1.900001   -6.859010   10.830010   10.832500
+  -1.800001   -5.832009    9.720010    9.722505
+  -1.700001   -4.913008    8.670009    8.672500
+  -1.600001   -4.096007    7.680008    7.682502
+  -1.500001   -3.375006    6.750008    6.752501
+  -1.400001   -2.744005    5.880007    5.882499
+  -1.300001   -2.197004    5.070006    5.072502
+  -1.200001   -1.728003    4.320005    4.322501
+  -1.100001   -1.331003    3.630005    3.632501
+  -1.000001   -1.000002    3.000004    3.002503
+  -0.900001   -0.729002    2.430004    2.432504
+  -0.800001   -0.512001    1.920003    1.922504
+  -0.700001   -0.343001    1.470003    1.472503
+  -0.600001   -0.216001    1.080002    1.082503
+  -0.500001   -0.125000    0.750002    0.752502
+  -0.400001   -0.064000    0.480001    0.482502
+  -0.300001   -0.027000    0.270001    0.272501
+  -0.200001   -0.008000    0.120001    0.122501
+  -0.100001   -0.001000    0.030000    0.032500
+  -0.000001   -0.000000    0.000000    0.002500
+   0.099999    0.001000    0.030000    0.032500
+   0.199999    0.008000    0.119999    0.122499
+   0.299999    0.027000    0.269999    0.272499
+   0.399999    0.064000    0.479998    0.482499
+   0.499999    0.125000    0.749998    0.752498
+   0.599999    0.215999    1.079998    1.082498
+   0.699999    0.342999    1.469997    1.472498
+   0.799999    0.511999    1.919997    1.922498
+   0.899999    0.728999    2.429997    2.432498
+   0.999999    0.999998    2.999997    3.002497
+   1.099999    1.330998    3.629996    3.632492
+   1.199999    1.727998    4.319996    4.322493
+   1.299999    2.196997    5.069996    5.072492
+   1.399999    2.743997    5.879996    5.882490
+   1.500000    3.374997    6.749996    6.752491
+   1.600000    4.095996    7.679996    7.682493
+   1.700000    4.912996    8.669995    8.672490
+   1.800000    5.831996    9.719995    9.722486
+   1.900000    6.858996   10.829996   10.832486
+   2.000000    7.999996   11.999996   12.002501
+   2.100000    9.260995   13.229996   13.232479
+   2.200000   10.647994   14.519995   14.522486
+   2.299999   12.166991   15.869993   15.872469
+   2.399999   13.823989   17.279991   17.282476
+   2.499999   15.624988   18.749989   18.752470
+   2.599999   17.575983   20.279987   20.282459
+   2.699999   19.682980   21.869986   21.872482
+   2.799999   21.951977   23.519983   23.522453
+   2.899999   24.388971   25.229980   25.232468
+   2.999999   26.999969   26.999979   27.002430

20231123/deriv-02.gp

+plot "deriv-02.dat" using 1:2 with lines title "f(x)", \
+     "deriv-02.dat" using 1:3 with lines title "df_a(x)", \
+     "deriv-02.dat" using 1:4 with lines lc "red" dashtype "-" title "df_n(x)"
+pause -1

20231123/wurf-01.c

+#include <gtk/gtk.h>
+
+double x = 137;
+double y = 255;
+
+static void draw (GtkDrawingArea *drawing_area, cairo_t *c,
+                  int width, int height, gpointer user_data)
+{
+  GdkRGBA blue = { 0.0, 0.5, 1.0, 1.0 };
+
+  gdk_cairo_set_source_rgba (c, &blue);
+  cairo_arc (c, x, y, 10, 0, 2 * G_PI);
+  cairo_fill (c);
+}
+
+static void activate (GtkApplication *app, gpointer user_data)
+{
+  GtkWidget *window = gtk_application_window_new (app);
+  gtk_window_set_title (GTK_WINDOW (window), "Hello");
+
+  GtkWidget *vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
+  gtk_window_set_child (GTK_WINDOW (window), vbox);
+
+  GtkWidget *drawing_area = gtk_drawing_area_new ();
+  gtk_widget_set_size_request (drawing_area, 1024, 768);
+  gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (drawing_area), draw, NULL, NULL);
+  gtk_box_append (GTK_BOX (vbox), drawing_area);
+
+  GtkWidget *quit_button = gtk_button_new_with_label ("Quit");
+  g_signal_connect_swapped (quit_button, "clicked", G_CALLBACK (gtk_window_destroy), window);
+  gtk_box_append (GTK_BOX (vbox), quit_button);
+
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+int main (int argc, char **argv)
+{
+  GtkApplication *app = gtk_application_new ("de.hs-bochum.cvh.hp.hello-gtk", G_APPLICATION_DEFAULT_FLAGS);
+  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
+  int status = g_application_run (G_APPLICATION (app), argc, argv);
+  g_object_unref (app);
+  return status;
+}

20231123/wurf-02.c

+#include <gtk/gtk.h>
+
+#define WIDTH 1024
+#define HEIGHT 768
+
+double x = 137;
+double y = 255;
+
+static void draw (GtkDrawingArea *drawing_area, cairo_t *c,
+                  int width, int height, gpointer user_data)
+{
+  GdkRGBA blue = { 0.0, 0.5, 1.0, 1.0 };
+
+  gdk_cairo_set_source_rgba (c, &blue);
+  cairo_arc (c, x, y, 10, 0, 2 * G_PI);
+  cairo_fill (c);
+}
+
+gboolean timer (GtkWidget *widget)
+{
+  x += 3;
+  y += 2;
+  gtk_widget_queue_draw (widget);
+  g_timeout_add (50, (GSourceFunc) timer, widget);
+  return FALSE;
+}
+
+static void activate (GtkApplication *app, gpointer user_data)
+{
+  GtkWidget *window = gtk_application_window_new (app);
+  gtk_window_set_title (GTK_WINDOW (window), "Hello");
+
+  GtkWidget *vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
+  gtk_window_set_child (GTK_WINDOW (window), vbox);
+
+  GtkWidget *drawing_area = gtk_drawing_area_new ();
+  gtk_widget_set_size_request (drawing_area, WIDTH, HEIGHT);
+  gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (drawing_area), draw, NULL, NULL);
+  gtk_box_append (GTK_BOX (vbox), drawing_area);
+
+  GtkWidget *quit_button = gtk_button_new_with_label ("Quit");
+  g_signal_connect_swapped (quit_button, "clicked", G_CALLBACK (gtk_window_destroy), window);
+  gtk_box_append (GTK_BOX (vbox), quit_button);
+
+  g_timeout_add (50, (GSourceFunc) timer, drawing_area);
+
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+int main (int argc, char **argv)
+{
+  GtkApplication *app = gtk_application_new ("de.hs-bochum.cvh.hp.hello-gtk", G_APPLICATION_DEFAULT_FLAGS);
+  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
+  int status = g_application_run (G_APPLICATION (app), argc, argv);
+  g_object_unref (app);
+  return status;
+}

20231123/wurf-03.c

+#include <gtk/gtk.h>
+
+#define WIDTH 1024
+#define HEIGHT 768
+
+double x = 137;
+double y = 255;
+
+static void draw (GtkDrawingArea *drawing_area, cairo_t *c,
+                  int width, int height, gpointer user_data)
+{
+  GdkRGBA blue = { 0.0, 0.5, 1.0, 1.0 };
+
+  gdk_cairo_set_source_rgba (c, &blue);
+  cairo_arc (c, x, y, 10, 0, 2 * G_PI);
+  cairo_fill (c);
+}
+
+gboolean timer (GtkWidget *widget)
+{
+  x += 3;
+  y += 2;
+  gtk_widget_queue_draw (widget);
+  return TRUE;
+}
+
+static void activate (GtkApplication *app, gpointer user_data)
+{
+  GtkWidget *window = gtk_application_window_new (app);
+  gtk_window_set_title (GTK_WINDOW (window), "Hello");
+
+  GtkWidget *vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
+  gtk_window_set_child (GTK_WINDOW (window), vbox);
+
+  GtkWidget *drawing_area = gtk_drawing_area_new ();
+  gtk_widget_set_size_request (drawing_area, WIDTH, HEIGHT);
+  gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (drawing_area), draw, NULL, NULL);
+  gtk_box_append (GTK_BOX (vbox), drawing_area);
+
+  GtkWidget *quit_button = gtk_button_new_with_label ("Quit");
+  g_signal_connect_swapped (quit_button, "clicked", G_CALLBACK (gtk_window_destroy), window);
+  gtk_box_append (GTK_BOX (vbox), quit_button);
+
+  g_timeout_add (50, (GSourceFunc) timer, drawing_area);
+
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+int main (int argc, char **argv)
+{
+  GtkApplication *app = gtk_application_new ("de.hs-bochum.cvh.hp.hello-gtk", G_APPLICATION_DEFAULT_FLAGS);
+  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
+  int status = g_application_run (G_APPLICATION (app), argc, argv);
+  g_object_unref (app);
+  return status;
+}

20231123/wurf-04.c

+#include <gtk/gtk.h>
+
+#define WIDTH 1024
+#define HEIGHT 768
+
+double x = 0.0;
+double y = 2.0;
+double vx = 2.0;
+double vy = 1.0;
+double dt = 0.05;
+
+static void draw (GtkDrawingArea *drawing_area, cairo_t *c,
+                  int width, int height, gpointer user_data)
+{
+  GdkRGBA blue = { 0.0, 0.5, 1.0, 1.0 };
+
+  gdk_cairo_set_source_rgba (c, &blue);
+  cairo_arc (c, x * 10.0, HEIGHT - y * 10, 10, 0, 2 * G_PI);
+  cairo_fill (c);
+}
+
+gboolean timer (GtkWidget *widget)
+{
+  x += vx * dt;
+  y += vy * dt;
+  gtk_widget_queue_draw (widget);
+  return TRUE;
+}
+
+static void activate (GtkApplication *app, gpointer user_data)
+{
+  GtkWidget *window = gtk_application_window_new (app);
+  gtk_window_set_title (GTK_WINDOW (window), "Hello");
+
+  GtkWidget *vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
+  gtk_window_set_child (GTK_WINDOW (window), vbox);
+
+  GtkWidget *drawing_area = gtk_drawing_area_new ();
+  gtk_widget_set_size_request (drawing_area, WIDTH, HEIGHT);
+  gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (drawing_area), draw, NULL, NULL);
+  gtk_box_append (GTK_BOX (vbox), drawing_area);
+
+  GtkWidget *quit_button = gtk_button_new_with_label ("Quit");
+  g_signal_connect_swapped (quit_button, "clicked", G_CALLBACK (gtk_window_destroy), window);
+  gtk_box_append (GTK_BOX (vbox), quit_button);
+
+  g_timeout_add (50, (GSourceFunc) timer, drawing_area);
+
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+int main (int argc, char **argv)
+{
+  GtkApplication *app = gtk_application_new ("de.hs-bochum.cvh.hp.hello-gtk", G_APPLICATION_DEFAULT_FLAGS);
+  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
+  int status = g_application_run (G_APPLICATION (app), argc, argv);
+  g_object_unref (app);
+  return status;
+}

20231123/wurf-05.c

+#include <gtk/gtk.h>
+
+#define WIDTH 1024
+#define HEIGHT 768
+
+double x = 0.0;
+double y = 2.0;
+double vx = 2.0;
+double vy = 1.0;
+double dt = 0.2;
+
+static void draw (GtkDrawingArea *drawing_area, cairo_t *c,
+                  int width, int height, gpointer user_data)
+{
+  GdkRGBA blue = { 0.0, 0.5, 1.0, 1.0 };
+
+  gdk_cairo_set_source_rgba (c, &blue);
+  cairo_arc (c, x * 10.0, HEIGHT - y * 10, 10, 0, 2 * G_PI);
+  cairo_fill (c);
+}
+
+gboolean timer (GtkWidget *widget)
+{
+  x += vx * dt;
+  y += vy * dt;
+  gtk_widget_queue_draw (widget);
+  return TRUE;
+}
+
+static void activate (GtkApplication *app, gpointer user_data)
+{
+  GtkWidget *window = gtk_application_window_new (app);
+  gtk_window_set_title (GTK_WINDOW (window), "Hello");
+
+  GtkWidget *vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
+  gtk_window_set_child (GTK_WINDOW (window), vbox);
+
+  GtkWidget *drawing_area = gtk_drawing_area_new ();
+  gtk_widget_set_size_request (drawing_area, WIDTH, HEIGHT);
+  gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (drawing_area), draw, NULL, NULL);
+  gtk_box_append (GTK_BOX (vbox), drawing_area);
+
+  GtkWidget *quit_button = gtk_button_new_with_label ("Quit");
+  g_signal_connect_swapped (quit_button, "clicked", G_CALLBACK (gtk_window_destroy), window);
+  gtk_box_append (GTK_BOX (vbox), quit_button);
+
+  g_timeout_add (50, (GSourceFunc) timer, drawing_area);
+
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+int main (int argc, char **argv)
+{
+  GtkApplication *app = gtk_application_new ("de.hs-bochum.cvh.hp.hello-gtk", G_APPLICATION_DEFAULT_FLAGS);
+  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
+  int status = g_application_run (G_APPLICATION (app), argc, argv);
+  g_object_unref (app);
+  return status;
+}

20231123/wurf-06.c

+#include <gtk/gtk.h>
+
+#define WIDTH 1024
+#define HEIGHT 768
+
+double x = 0.0;
+double y = 2.0;
+double vx = 2.0;
+double vy = 1.0;
+double dt = 0.2;
+double g = 9.81;
+
+static void draw (GtkDrawingArea *drawing_area, cairo_t *c,
+                  int width, int height, gpointer user_data)
+{
+  GdkRGBA blue = { 0.0, 0.5, 1.0, 1.0 };
+
+  gdk_cairo_set_source_rgba (c, &blue);
+  cairo_arc (c, x * 10.0, HEIGHT - y * 10, 10, 0, 2 * G_PI);
+  cairo_fill (c);
+}
+
+gboolean timer (GtkWidget *widget)
+{
+  x += vx * dt;
+  y += vy * dt;
+  vx += 0.0 * dt;
+  vy += -g * dt;
+  gtk_widget_queue_draw (widget);
+  return TRUE;
+}
+
+static void activate (GtkApplication *app, gpointer user_data)
+{
+  GtkWidget *window = gtk_application_window_new (app);
+  gtk_window_set_title (GTK_WINDOW (window), "Hello");
+
+  GtkWidget *vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
+  gtk_window_set_child (GTK_WINDOW (window), vbox);
+
+  GtkWidget *drawing_area = gtk_drawing_area_new ();
+  gtk_widget_set_size_request (drawing_area, WIDTH, HEIGHT);
+  gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (drawing_area), draw, NULL, NULL);
+  gtk_box_append (GTK_BOX (vbox), drawing_area);
+
+  GtkWidget *quit_button = gtk_button_new_with_label ("Quit");
+  g_signal_connect_swapped (quit_button, "clicked", G_CALLBACK (gtk_window_destroy), window);
+  gtk_box_append (GTK_BOX (vbox), quit_button);
+
+  g_timeout_add (50, (GSourceFunc) timer, drawing_area);
+
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+int main (int argc, char **argv)
+{
+  GtkApplication *app = gtk_application_new ("de.hs-bochum.cvh.hp.hello-gtk", G_APPLICATION_DEFAULT_FLAGS);
+  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
+  int status = g_application_run (G_APPLICATION (app), argc, argv);
+  g_object_unref (app);
+  return status;
+}

20231123/wurf-07.c

+#include <gtk/gtk.h>
+
+#define WIDTH 1024
+#define HEIGHT 768
+
+double x = 0.0;
+double y = 2.0;
+double vx = 2.0;
+double vy = 1.0;
+double dt = 0.2;
+double g = 0.1;
+
+static void draw (GtkDrawingArea *drawing_area, cairo_t *c,
+                  int width, int height, gpointer user_data)
+{
+  GdkRGBA blue = { 0.0, 0.5, 1.0, 1.0 };
+
+  gdk_cairo_set_source_rgba (c, &blue);
+  cairo_arc (c, x * 10.0, HEIGHT - y * 10, 10, 0, 2 * G_PI);
+  cairo_fill (c);
+}
+
+gboolean timer (GtkWidget *widget)
+{
+  x += vx * dt;
+  y += vy * dt;
+  vx += 0.0 * dt;
+  vy += -g * dt;
+  gtk_widget_queue_draw (widget);
+  return TRUE;
+}
+
+static void activate (GtkApplication *app, gpointer user_data)
+{
+  GtkWidget *window = gtk_application_window_new (app);
+  gtk_window_set_title (GTK_WINDOW (window), "Hello");
+
+  GtkWidget *vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
+  gtk_window_set_child (GTK_WINDOW (window), vbox);
+
+  GtkWidget *drawing_area = gtk_drawing_area_new ();
+  gtk_widget_set_size_request (drawing_area, WIDTH, HEIGHT);
+  gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (drawing_area), draw, NULL, NULL);
+  gtk_box_append (GTK_BOX (vbox), drawing_area);
+
+  GtkWidget *quit_button = gtk_button_new_with_label ("Quit");
+  g_signal_connect_swapped (quit_button, "clicked", G_CALLBACK (gtk_window_destroy), window);
+  gtk_box_append (GTK_BOX (vbox), quit_button);
+
+  g_timeout_add (50, (GSourceFunc) timer, drawing_area);
+
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+int main (int argc, char **argv)
+{
+  GtkApplication *app = gtk_application_new ("de.hs-bochum.cvh.hp.hello-gtk", G_APPLICATION_DEFAULT_FLAGS);
+  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
+  int status = g_application_run (G_APPLICATION (app), argc, argv);
+  g_object_unref (app);
+  return status;
+}

20231123/wurf-08.c

+#include <gtk/gtk.h>
+
+#define WIDTH 1024
+#define HEIGHT 768
+
+double x = 0.0;
+double y = 6.0;
+double vx = 1.5;
+double vy = 4.0;
+double dt = 0.5;
+double g = 0.2;
+
+static void draw (GtkDrawingArea *drawing_area, cairo_t *c,
+                  int width, int height, gpointer user_data)
+{
+  GdkRGBA blue = { 0.0, 0.5, 1.0, 1.0 };
+
+  gdk_cairo_set_source_rgba (c, &blue);
+  cairo_arc (c, x * 10.0, HEIGHT - y * 10, 10, 0, 2 * G_PI);
+  cairo_fill (c);
+}
+
+gboolean timer (GtkWidget *widget)
+{
+  x += vx * dt;
+  y += vy * dt;
+  vx += 0.0 * dt;
+  vy += -g * dt;
+  gtk_widget_queue_draw (widget);
+  return TRUE;
+}
+
+static void activate (GtkApplication *app, gpointer user_data)
+{
+  GtkWidget *window = gtk_application_window_new (app);
+  gtk_window_set_title (GTK_WINDOW (window), "Hello");
+
+  GtkWidget *vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
+  gtk_window_set_child (GTK_WINDOW (window), vbox);
+
+  GtkWidget *drawing_area = gtk_drawing_area_new ();
+  gtk_widget_set_size_request (drawing_area, WIDTH, HEIGHT);
+  gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (drawing_area), draw, NULL, NULL);
+  gtk_box_append (GTK_BOX (vbox), drawing_area);
+
+  GtkWidget *quit_button = gtk_button_new_with_label ("Quit");
+  g_signal_connect_swapped (quit_button, "clicked", G_CALLBACK (gtk_window_destroy), window);
+  gtk_box_append (GTK_BOX (vbox), quit_button);
+
+  g_timeout_add (50, (GSourceFunc) timer, drawing_area);
+
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+int main (int argc, char **argv)
+{
+  GtkApplication *app = gtk_application_new ("de.hs-bochum.cvh.hp.hello-gtk", G_APPLICATION_DEFAULT_FLAGS);
+  g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
+  int status = g_application_run (G_APPLICATION (app), argc, argv);
+  g_object_unref (app);
+  return status;
+}