1 files changed, 77 insertions, 4 deletions

diff --git a/reduced_system_layer.c b/reduced_system_layer.c
index 7963a2d..19c8a0c 100755
--- a/reduced_system_layer.c
+++ b/reduced_system_layer.c
@@ -30,7 +30,7 @@
 #/  To-Do list
 #/
 #/  - Examples
-#/    - Conway's Game if Life
+#/    - Conway's Game of Life
 #/    - Julia Set
 #/    - Labyrinth
 #/    - Landscape
@@ -119,6 +119,10 @@ typedef double             f64;
 //
 //  ================================================================
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 enum {
   MAX_NUM_PIXELS        = 10 * 1024 * 1024,
   MAX_INPUT_SIZE        = 256,
@@ -225,6 +229,9 @@ i32  p_handle_events(void);
 i32  p_wait_events(void);
 void p_render_frame(void);
 
+//  User-defined proc
+void p_frame(void);
+
 //  Clipboard
 void p_clipboard_write(i64 size, c8 *data);
 
@@ -238,6 +245,10 @@ i64 p_send(u16 slot, IP_Address address, i64 size, u8 *data, u16 *local_port);
 
 extern Platform platform;
 
+#ifdef __cplusplus
+}
+#endif
+
 //  ================================================================
 
 #endif // REDUCED_SYSTEM_LAYER_HEADER_GUARD_
@@ -250,6 +261,27 @@ extern Platform platform;
 
 #ifdef REDUCED_SYSTEM_LAYER_EXAMPLE
 
+//  NOTE
+//  This procedure is required for the WebAssembly compatibility.
+void p_frame(void) {
+  p_handle_events();
+
+  i64 w = platform.frame_width  / 2;
+  i64 h = platform.frame_height / 2;
+  i64 x = w / 2;
+  i64 y = h / 2;
+
+  for (i64 j = 0; j < platform.frame_height; ++j)
+    for (i64 i = 0; i < platform.frame_width; ++i)
+      if (i < x || i >= x + w || j < y || j >= y + h)
+        platform.pixels[j * platform.frame_width + i] = 0xa0a0a0;
+      else
+        platform.pixels[j * platform.frame_width + i] = 0x131112;
+
+  p_render_frame();
+  p_sleep_for(0);
+}
+
 i32 main(i32 argc, c8 **argv) {
   (void) argc;
   (void) argv;
@@ -263,9 +295,7 @@ i32 main(i32 argc, c8 **argv) {
   p_init();
 
   while (!platform.done) {
-    p_handle_events();
-    p_render_frame();
-    p_sleep_for(0);
+    p_frame();
   }
 
   p_cleanup();
@@ -1164,6 +1194,49 @@ void p_queue_sound(i64 delay, i64 num_samples, f32 *samples) {
 #endif
 
 //  ================================================================
+//
+//  WebAssembly
+//
+//  ================================================================
+
+#ifdef __EMSCRIPTEN__
+
+static u32 _buffer[MAX_NUM_PIXELS] = {0};
+
+void p_render_frame_impl(void);
+
+void p_render_frame(void) {
+  //  Make the canvas data opaque.
+  i64 size = platform.frame_width * platform.frame_height;
+  for (i64 i = 0; i < size; ++i)
+    platform.pixels[i] |= 0xff000000;
+
+  p_render_frame_impl();
+}
+
+void js_main(c8 *href) {
+  main(1, &href);
+}
+
+void js_init(void) {
+  platform.pixels = _buffer;
+  platform.done   = 1;
+}
+
+void *js_pixels(void) {
+  return platform.pixels;
+}
+
+void js_frame(i32 frame_width, i32 frame_height) {
+  platform.frame_width  = frame_width;
+  platform.frame_height = frame_height;
+
+  p_frame();
+}
+
+#endif // __EMSCRIPTEN__
+
+//  ================================================================
 
 #endif // REDUCED_SYSTEM_LAYER_IMPL_GUARD_
 #endif // REDUCED_SYSTEM_LAYER_HEADER