kc3-lang/kc3

diff --git a/libc3/window/sdl2/demo/lightspeed.c b/libc3/window/sdl2/demo/lightspeed.c
new file mode 100644
index 0000000..0eb76ad
--- /dev/null
+++ b/libc3/window/sdl2/demo/lightspeed.c
@@ -0,0 +1,87 @@
+/* c3
+ * Copyright 2022,2023 kmx.io <contact@kmx.io>
+ *
+ * Permission is hereby granted to use this software granted the above
+ * copyright notice and this permission paragraph are included in all
+ * copies and substantial portions of this software.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS-IS" WITHOUT ANY GUARANTEE OF
+ * PURPOSE AND PERFORMANCE. IN NO EVENT WHATSOEVER SHALL THE
+ * AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
+ * THIS SOFTWARE.
+ */
+#include <libc3/c3.h>
+#include "lightspeed.h"
+
+static void star_init (s_tag *star)
+{
+  f64 x;
+  f64 y;
+  f64_random(&x);
+  f64_random(&y);
+  tag_init_map(star, 3);
+  tag_init_sym(star->data.map.keys, sym_1("speed"));
+  tag_init_f64(star->data.map.values, 0.0);
+  tag_init_sym(star->data.map.keys + 1, sym_1("x"));
+  tag_init_f64(star->data.map.values + 1, 2.0 * x - 1.0);
+  tag_init_sym(star->data.map.keys + 2, sym_1("y"));
+  tag_init_f64(star->data.map.values + 2, 2.0 * y - 1.0);
+}
+
+static void star_render (s_tag *star, s_sequence *seq)
+{
+  f64 q;
+  f64 *speed;
+  f64 *x;
+  f64 *y;
+  speed = &star->data.map.values[0].data.f64;
+  x = &star->data.map.values[1].data.f64;
+  y = &star->data.map.values[2].data.f64;
+  glVertex2d(*x, *y);
+  q = (1 + *speed / 20);
+  glVertex2d(*x * q, *y * q);
+  q = (1 + *speed / 100);
+  *x = *x * q;
+  *y = *y * q;
+  *speed += seq->dt;
+  if (*x < -1.0 || *x > 1.0 || *y < -1.0 || *y > 1.0)
+    star_init(star);
+}
+
+bool lightspeed_load (s_sequence *seq, s_window_sdl2 *window)
+{
+  uw i;
+  (void) window;
+  tag_tuple(&seq->tag, LIGHTSPEED_STARS);
+  i = 0;
+  while (i < LIGHTSPEED_STARS) {
+    star_init(seq->tag.data.tuple.tag + i);
+    i++;
+  }
+  return true;
+}
+
+bool lightspeed_render (s_sequence *seq, s_window_sdl2 *window,
+                        void *context)
+{
+  uw i;
+  (void) window;
+  (void) context;
+  glMatrixMode(GL_PROJECTION);
+  glLoadIdentity();
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
+  //glScale2d(window->w / 2.0, window->h / 2.0);
+  //glTranslatef(1.0f, 1.0f, 0.0f);
+  glClearColor(0, 0, 0, 1);
+  glClear(GL_COLOR_BUFFER_BIT);
+  glLineWidth(0.004);
+  glColor3f(1, 1, 1);
+  glBegin(GL_LINES);
+  i = 0;
+  while (i < LIGHTSPEED_STARS) {
+    star_render(seq->tag.data.tuple.tag + i, seq);
+    i++;
+  }
+  return true;
+}
diff --git a/libc3/window/sdl2/demo/lightspeed.h b/libc3/window/sdl2/demo/lightspeed.h
new file mode 100644
index 0000000..bda531a
--- /dev/null
+++ b/libc3/window/sdl2/demo/lightspeed.h
@@ -0,0 +1,24 @@
+/* c3
+ * Copyright 2022,2023 kmx.io <contact@kmx.io>
+ *
+ * Permission is hereby granted to use this software granted the above
+ * copyright notice and this permission paragraph are included in all
+ * copies and substantial portions of this software.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS-IS" WITHOUT ANY GUARANTEE OF
+ * PURPOSE AND PERFORMANCE. IN NO EVENT WHATSOEVER SHALL THE
+ * AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
+ * THIS SOFTWARE.
+ */
+#ifndef LIGHTSPEED_H
+#define LIGHTSPEED_H
+
+#include "../types.h"
+
+#define LIGHTSPEED_STARS 2000
+
+bool lightspeed_load (s_sequence *seq, s_window_sdl2 *window);
+bool lightspeed_render (s_sequence *seq, s_window_sdl2 *window,
+                        void *context);
+
+#endif /* LIGHTSPEED_H */
diff --git a/libc3/window/sdl2/demo/sources.mk b/libc3/window/sdl2/demo/sources.mk
index 23edeee..37f994f 100644
--- a/libc3/window/sdl2/demo/sources.mk
+++ b/libc3/window/sdl2/demo/sources.mk
@@ -1,8 +1,10 @@
 # sources.mk generated by update_sources
 HEADERS = \
 	bg_rect.h \
+	lightspeed.h \
 
 SOURCES = \
 	bg_rect.c \
+	lightspeed.c \
 	window_sdl2_demo.c \
 
diff --git a/libc3/window/sdl2/demo/sources.sh b/libc3/window/sdl2/demo/sources.sh
index 029f297..6e630ef 100644
--- a/libc3/window/sdl2/demo/sources.sh
+++ b/libc3/window/sdl2/demo/sources.sh
@@ -1,3 +1,3 @@
 # sources.sh generated by update_sources
-HEADERS='bg_rect.h '
-SOURCES='bg_rect.c window_sdl2_demo.c '
+HEADERS='bg_rect.h lightspeed.h '
+SOURCES='bg_rect.c lightspeed.c window_sdl2_demo.c '
diff --git a/libc3/window/sdl2/demo/window_sdl2_demo.c b/libc3/window/sdl2/demo/window_sdl2_demo.c
index 4622693..8a10345 100644
--- a/libc3/window/sdl2/demo/window_sdl2_demo.c
+++ b/libc3/window/sdl2/demo/window_sdl2_demo.c
@@ -17,8 +17,9 @@
 #include "../window_sdl2.h"
 #include "../sdl2_font.h"
 #include "bg_rect.h"
+#include "lightspeed.h"
 
-#define WINDOW_SDL2_DEMO_SEQUENCE_COUNT 1
+#define WINDOW_SDL2_DEMO_SEQUENCE_COUNT 2
 
 //static s_sdl2_font g_font_computer_modern;
 static s_sdl2_font g_font_courier_new;
@@ -129,10 +130,10 @@ bool window_sdl2_demo_load (s_window_sdl2 *window)
   window_sdl2_sequence_init(window->sequence, 8.0,
                             "01. Background rectangles",
                             bg_rect_load, bg_rect_render);
-  /*
   window_sdl2_sequence_init(window->sequence + 1, 20.0,
                             "02. Lightspeed",
                             lightspeed_load, lightspeed_render);
+  /*
   if (! sdl2_sprite_init(&g_toaster_sprite,
                          sdl2_png_1("img/flaps.png"),
                          4, 1, 4))
@@ -220,7 +221,7 @@ bool window_sdl2_demo_render (s_window_sdl2 *window, void *context)
           12 + 2);
   /* fps */
   s8 fps[32];
-  snprintf(fps, sizeof(fps), "%f", (f64) seq->frame / seq->t);
+  snprintf(fps, sizeof(fps), "%.2f", (f64) seq->frame / seq->t);
   render_text(&g_font_courier_new, 20, window->h - 30, fps);
   return true;
 }