1 files changed, 103 insertions, 0 deletions
diff --git a/plugins/shotwell-transitions/CrumbleEffect.vala b/plugins/shotwell-transitions/CrumbleEffect.vala
new file mode 100644
index 0000000..a458811
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+++ b/plugins/shotwell-transitions/CrumbleEffect.vala
@@ -0,0 +1,103 @@
+/* Copyright 2010 Maxim Kartashev
+ * Copyright 2011-2014 Yorba Foundation
+ *
+ * This software is licensed under the GNU Lesser General Public License
+ * (version 2.1 or later).  See the COPYING file in this distribution.
+ */
+
+using Spit;
+
+private class CrumbleEffectDescriptor : ShotwellTransitionDescriptor {
+    public CrumbleEffectDescriptor(GLib.File resource_directory) {
+        base(resource_directory);
+    }
+
+    public override unowned string get_id() {
+        return "org.yorba.shotwell.transitions.crumble";
+    }
+    
+    public override unowned string get_pluggable_name() {
+        return _("Crumble");
+    }
+    
+    public override Transitions.Effect create(Spit.HostInterface host) {
+        return new CrumbleEffect();
+    }
+}
+
+private class CrumbleEffect : Object, Transitions.Effect {
+    private const int DESIRED_FPS = 25;
+    private const int MIN_FPS = 15;
+    
+    private const int STRIPE_WIDTH = 10;
+    
+    private Cairo.ImageSurface[] from_stripes;
+    private double[] accelerations;
+    private int stripes_count;
+    
+    public CrumbleEffect() {
+    }
+    
+    public void get_fps(out int desired_fps, out int min_fps) {
+        desired_fps = CrumbleEffect.DESIRED_FPS;
+        min_fps = CrumbleEffect.MIN_FPS;
+    }
+    
+    public bool needs_clear_background() {
+        return true;
+    }
+    
+    public void start(Transitions.Visuals visuals, Transitions.Motion motion) {
+        Rand rand = new Rand();
+        
+        // Cut original image into stripes of STRIPE_WIDTH width; also prepare
+        // acceleration for each stripe.
+        if (visuals.from_pixbuf != null) {
+            stripes_count = visuals.from_pixbuf.width / STRIPE_WIDTH;
+            from_stripes = new Cairo.ImageSurface[stripes_count];
+            accelerations = new double[stripes_count];
+            for (int i = 0; i < stripes_count; ++i) {
+                from_stripes[i] = new Cairo.ImageSurface(Cairo.Format.RGB24, STRIPE_WIDTH,
+                    visuals.from_pixbuf.height);
+                Cairo.Context ctx = new Cairo.Context(from_stripes[i]);
+                Gdk.cairo_set_source_pixbuf(ctx, visuals.from_pixbuf, - i * STRIPE_WIDTH, 0);
+                ctx.paint();
+                accelerations[i] = rand.next_double();
+            }
+        }
+    }
+    
+    public void paint(Transitions.Visuals visuals, Transitions.Motion motion, Cairo.Context ctx,
+        int width, int height, int frame_number) {
+        double alpha = motion.get_alpha(frame_number);
+        
+        if (alpha < 0.5) {
+            // First part: draw stripes that go down with pre-calculated acceleration
+            alpha = alpha * 2; // stretch alpha to [0, 1]
+            
+            // tear down from_pixbuf first 
+            for (int i = 0; i < stripes_count; ++i) {
+                int x = visuals.from_pos.x + i * STRIPE_WIDTH;
+                double a = alpha + alpha * accelerations[i];
+                int y = visuals.from_pos.y + (int) (visuals.from_pixbuf.height * a * a);
+                
+                ctx.set_source_surface(from_stripes[i], x, y);
+                ctx.paint();
+            }
+        } else if (visuals.to_pixbuf != null) {
+            // Second part: fade in next image ("to_pixbuf")
+            alpha = (alpha - 0.5) * 2; // stretch alpha to [0, 1]
+            Gdk.cairo_set_source_pixbuf(ctx, visuals.to_pixbuf, visuals.to_pos.x, visuals.to_pos.y);
+            ctx.paint_with_alpha(alpha);
+        } else {
+            // TODO: fade in background color
+        }
+    }
+    
+    public void advance(Transitions.Visuals visuals, Transitions.Motion motion, int frame_number) {
+    }
+    
+    public void cancel() {
+    }
+}
+