X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=xoboot.c;h=1feb5dccbcb3059b4d445821168f4ef96e6079db;hb=75e8d26e33f0a990a79a48f0a382b26fe0da63f8;hp=2d7fe962b2026458ee27fde5b72933747f252132;hpb=7d4ecd60b1bf1dcef2932c7c004e2271e0d754e2;p=xoboot

diff --git a/xoboot.c b/xoboot.c
index 2d7fe96..1feb5dc 100644
--- a/xoboot.c
+++ b/xoboot.c
@@ -19,6 +19,23 @@
  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA."
  */
 
+/* This is simply a proof-of-concept for using cairo to implement a
+ * design idea for an OLPC boot-time animation. The animation here is
+ * implemented to mimic an animation originally provided as a
+ * Quicktime movie by Rebecca Allen <rallen@arts.ucla.edu>.
+ *
+ * So far, this animation has been developed exclusively on an x86
+ * laptop with GTK+ targeting the X Window System. No guarantees are
+ * provided as to how this might perform on an OLPC XO machine. What's
+ * likely desired is to write the application to use cairo image
+ * surfaces, and augment cairo to support targeting the XO's 565 image
+ * format directly.
+ *
+ * And obviously, to serve as a real boot-time animation, code will
+ * have to be written to advance the animation according to various
+ * system events, instead of using the hard-coded timeline below.
+ */
+
 #include <gtk/gtk.h>
 #include <cairo.h>
 #include <math.h>
@@ -127,6 +144,8 @@ draw_head (cairo_t *cr, double extra)
 static void
 draw_body (cairo_t *cr, double extra, double spin_transition)
 {
+    double angle, x, y;
+
     cairo_save (cr);
 
     cairo_move_to (cr,
@@ -136,7 +155,13 @@ draw_body (cairo_t *cr, double extra, double spin_transition)
     cairo_rel_line_to (cr, XO_BODY_DELTA, XO_BODY_DELTA);
 
     cairo_translate (cr, XO_HEAD_CENTER_X, XO_HEAD_CENTER_Y);
-    cairo_rotate (cr, 2 * M_PI * spin_transition);
+
+    angle = 2 * M_PI * spin_transition;
+    y = cos (angle) * XO_DOTS_POSITION_RADIUS;
+    x = sin (angle) * XO_DOTS_POSITION_RADIUS;
+    angle = atan2 (x, y + XO_BODY_CENTER_Y - XO_HEAD_CENTER_Y);
+
+    cairo_rotate (cr, angle);
     cairo_translate (cr, -XO_HEAD_CENTER_X, -XO_HEAD_CENTER_Y);
 	
     cairo_move_to (cr,
@@ -164,7 +189,7 @@ draw_dots (cairo_t *cr, double num_dots)
     cairo_translate (cr, XO_DOTS_CENTER_X, XO_DOTS_CENTER_Y);
     cairo_rotate (cr, - 1.5 * M_PI);
 
-    for (i = 0; i < num_dots; i++) {
+    for (i = 0; i <= num_dots; i++) {
 	if (i != 0) {
 	    cairo_arc (cr,
 		       XO_DOTS_POSITION_RADIUS, 0,
@@ -250,7 +275,7 @@ xoboot_expose_event (GtkWidget      *widget,
 	goto DONE;
 
     if (anim_stage < ANIM_FADE) {
-	draw_dots (cr, (XO_DOTS_NUM_DOTS + 1) * spin_transition);
+	draw_dots (cr, (XO_DOTS_NUM_DOTS) * spin_transition);
     } else {
 	draw_ring (cr);
     }