Snow White and the Pharaoh (mac rendering)

Once upon a time there was a beautiful Apple tree in palace of
GtkAnkhAmun in Cairo...

diff --git a/libs/canvas/canvas.cc b/libs/canvas/canvas.cc
index 97e001abba750f846543e5862808ee2a54b0f160..a72700b94af1707cc87a190bb4f3fa17e7a30e7a 100644 (file)
--- a/libs/canvas/canvas.cc
+++ b/libs/canvas/canvas.cc
@@ -784,6 +784,10 @@ GtkCanvas::on_expose_event (GdkEventExpose* ev)
                return true;
        }
 
+#ifdef CANVAS_PROFILE
+       const int64_t start = g_get_monotonic_time ();
+#endif
+
 #ifdef OPTIONAL_CAIRO_IMAGE_SURFACE
        Cairo::RefPtr<Cairo::Context> draw_context;
        Cairo::RefPtr<Cairo::Context> window_context;
@@ -806,10 +810,27 @@ GtkCanvas::on_expose_event (GdkEventExpose* ev)
        Cairo::RefPtr<Cairo::Context> draw_context = get_window()->create_cairo_context ();
 #endif
 
-       /* draw background color */
+       draw_context->rectangle (ev->area.x, ev->area.y, ev->area.width, ev->area.height);
+       draw_context->clip();
 
+#ifdef __APPLE__
+       /* group calls cairo_quartz_surface_create() which
+        * effectively uses a CGBitmapContext + image-surface
+        *
+        * This avoids expensive argb32_image_mark_image() during drawing.
+        * Although the final paint() operation still takes the slow path
+        * through image_mark_image instead of ColorMaskCopyARGB888_sse :(
+        *
+        * profiling indicates a speed up of factor 2. (~ 5-10ms render time,
+        * instead of 10-20ms, which is still slow compared to XCB and win32 surfaces (~0.2 ms)
+        *
+        * Fixing this for good likely involves changes to GdkQuartzWindow, GdkQuartzView
+        */
+       draw_context->push_group ();
+#endif
+
+       /* draw background color */
        draw_context->rectangle (ev->area.x, ev->area.y, ev->area.width, ev->area.height);
-       draw_context->clip_preserve ();
        set_source_rgba (draw_context, _bg_color);
        draw_context->fill ();
 
@@ -830,6 +851,11 @@ GtkCanvas::on_expose_event (GdkEventExpose* ev)
                g_free (rects);
        }
 
+#ifdef __APPLE__
+       draw_context->pop_group_to_source ();
+       draw_context->paint ();
+#endif
+
 #ifdef OPTIONAL_CAIRO_IMAGE_SURFACE
        if (getenv("ARDOUR_IMAGE_SURFACE")) {
 #endif
@@ -846,6 +872,12 @@ GtkCanvas::on_expose_event (GdkEventExpose* ev)
        }
 #endif
 
+#ifdef CANVAS_PROFILE
+       const int64_t end = g_get_monotonic_time ();
+       const int64_t elapsed = end - start;
+       printf ("GtkCanvas::on_expose_event %f ms\n", elapsed / 1000.f);
+#endif
+
        return true;
 }