Better scrolling

1 files changed, 22 insertions, 13 deletions

diff --git a/daemon.c b/daemon.c
index 3f6b891..885c74a 100644
--- a/daemon.c
+++ b/daemon.c
@@ -708,20 +708,19 @@ static int next_surface = 1;
 static int font_surface;
 
 static int
-alloc_surface(void)
+alloc_surface(GOutputStream *out, int w, int h)
 {
-  return next_surface++;
+  int id = next_surface++;
+  send_new_surface(out, id, w, h);
+  return id;
 }
 
 static void
 send_font (GOutputStream *out)
 {
-  font_surface = alloc_surface();
-
-  send_new_surface(out, font_surface, font_w, font_h);
+  font_surface = alloc_surface(out, font_w, font_h);
   send_select_surface(out, font_surface);
   send_image_a (out, 0, 0, font_w, font_h, font_w, font_data);
-  send_select_surface(out, 0);
 }
 
 static void
@@ -734,6 +733,9 @@ send_text (GOutputStream *out, char *str, int x, int y)
   }
 }
 
+#define SCROLL_DX 3
+#define SCROLL_H 30
+
 static gboolean
 demo (GOutputStream *out)
 {
@@ -741,7 +743,7 @@ demo (GOutputStream *out)
   GOutputStream *cout;
   char *header;
   int i;
-  int ball;
+  int ball, save;
 
   header =
     "HTTP/1.1 200 OK\r\n"
@@ -755,25 +757,28 @@ demo (GOutputStream *out)
   compressor = g_zlib_compressor_new (G_ZLIB_COMPRESSOR_FORMAT_GZIP, -1);
   cout = g_converter_output_stream_new (out, G_CONVERTER (compressor));
 
+  /* Need an initial multipart boundary */
   send_boundary (cout);
 
-  i = 0;
-
-  ball = alloc_surface();
-  send_new_surface(cout, ball, ball_w, ball_h);
+  ball = alloc_surface(cout, ball_w, ball_h);
   send_select_surface(cout, ball);
   send_image_rgba (cout, 0, 0, ball_w, ball_h, ball_w, ball_data);
-  send_select_surface(cout, 0);
 
   send_font(cout);
 
+  save = alloc_surface(cout, SCROLL_DX, SCROLL_H);
+
+  send_select_surface(cout, 0);
+
   send_rgb (cout, 0x0000ff);
   send_text(cout, "welcome to ajax broadway", 400, 400);
   send_rgb (cout, 0x4000ff00);
   send_text(cout, "welcome to ajax broadway", 403, 403);
 
+  i = 0;
   while (1)
     {
+      send_select_surface(cout, 0);
       send_rgb (cout, 0xff0000 + i * 32);
       send_rect (cout, i*10, i*10, 15, 15);
       send_rgba (cout, 0x80ff0000 + i * 32);
@@ -784,7 +789,11 @@ demo (GOutputStream *out)
 
       i ++;
 
-      send_copyrect (cout, 3, 400, 800 - 3, 30, 0, 400);
+      send_select_surface(cout, save);
+      send_blit (cout, 0, 0, 400, SCROLL_DX, SCROLL_H, 0, 0);
+      send_select_surface(cout, 0);
+      send_copyrect (cout, SCROLL_DX, 400, 800 - SCROLL_DX, SCROLL_H, 0, 400);
+      send_blit (cout, save, 0, 0, SCROLL_DX, SCROLL_H, 800 - SCROLL_DX, 400);
 
       flush (cout);