Introduce a new compositor architecture

Having spent the last dev cycle looking at how we could specialize the
compositors for various backends, we once again look for the
commonalities in order to reduce the duplication. In part this is
motivated by the idea that spans is a good interface for both the
existent GL backend and pixman, and so they deserve a dedicated
compositor. xcb/xlib target an identical rendering system and so they
should be using the same compositor, and it should be possible to run
that same compositor locally against pixman to generate reference tests.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

P.S. This brings massive upheaval (read breakage) I've tried delaying in
order to fix as many things as possible but now this one patch does far,
far, far too much. Apologies in advance for breaking your favourite
backend, but trust me in that the end result will be much better. :)

1 files changed, 48 insertions, 21 deletions

diff --git a/src/cairo-path-fill.c b/src/cairo-path-fill.c
index ce4c86a45..83393070b 100644
--- a/src/cairo-path-fill.c
+++ b/src/cairo-path-fill.c
@@ -40,9 +40,14 @@
 #include "cairo-error-private.h"
 #include "cairo-path-fixed-private.h"
 #include "cairo-region-private.h"
+#include "cairo-traps-private.h"
 
 typedef struct cairo_filler {
     cairo_polygon_t *polygon;
+    double tolerance;
+
+    cairo_box_t limit;
+    cairo_bool_t has_limits;
 
     cairo_point_t current_point;
     cairo_point_t last_move_to;
@@ -86,13 +91,38 @@ _cairo_filler_move_to (void *closure,
     if (unlikely (status))
 	return status;
 
-    /* make sure that the closure represents a degenerate path */
+        /* make sure that the closure represents a degenerate path */
     filler->current_point = *point;
     filler->last_move_to = *point;
 
     return CAIRO_STATUS_SUCCESS;
 }
 
+static cairo_status_t
+_cairo_filler_curve_to (void		*closure,
+			const cairo_point_t	*p1,
+			const cairo_point_t	*p2,
+			const cairo_point_t	*p3)
+{
+    cairo_filler_t *filler = closure;
+    cairo_spline_t spline;
+
+    if (filler->has_limits) {
+	if (! _cairo_spline_intersects (&filler->current_point, p1, p2, p3,
+					&filler->limit))
+	    return _cairo_filler_line_to (filler, p3);
+    }
+
+    if (! _cairo_spline_init (&spline,
+			      (cairo_spline_add_point_func_t)_cairo_filler_line_to, filler,
+			      &filler->current_point, p1, p2, p3))
+    {
+	return _cairo_filler_line_to (closure, p3);
+    }
+
+    return _cairo_spline_decompose (&spline, filler->tolerance);
+}
+
 cairo_status_t
 _cairo_path_fixed_fill_to_polygon (const cairo_path_fixed_t *path,
 				   double tolerance,
@@ -102,18 +132,25 @@ _cairo_path_fixed_fill_to_polygon (const cairo_path_fixed_t *path,
     cairo_status_t status;
 
     filler.polygon = polygon;
+    filler.tolerance = tolerance;
+
+    filler.has_limits = FALSE;
+    if (polygon->num_limits) {
+	filler.has_limits = TRUE;
+	filler.limit = polygon->limit;
+    }
 
     /* make sure that the closure represents a degenerate path */
     filler.current_point.x = 0;
     filler.current_point.y = 0;
     filler.last_move_to = filler.current_point;
 
-    status = _cairo_path_fixed_interpret_flat (path,
-					       _cairo_filler_move_to,
-					       _cairo_filler_line_to,
-					       _cairo_filler_close,
-					       &filler,
-					       tolerance);
+    status = _cairo_path_fixed_interpret (path,
+					  _cairo_filler_move_to,
+					  _cairo_filler_line_to,
+					  _cairo_filler_curve_to,
+					  _cairo_filler_close,
+					  &filler);
     if (unlikely (status))
 	return status;
 
@@ -179,7 +216,7 @@ _cairo_path_fixed_fill_rectilinear_to_polygon (const cairo_path_fixed_t *path,
     cairo_status_t status;
 
     if (antialias != CAIRO_ANTIALIAS_NONE)
-	    return _cairo_path_fixed_fill_to_polygon (path, 0., polygon);
+	return _cairo_path_fixed_fill_to_polygon (path, 0., polygon);
 
     filler.polygon = polygon;
 
@@ -213,22 +250,12 @@ _cairo_path_fixed_fill_to_traps (const cairo_path_fixed_t *path,
 	return CAIRO_STATUS_SUCCESS;
 
     _cairo_polygon_init (&polygon, traps->limits, traps->num_limits);
-
-    status = _cairo_path_fixed_fill_to_polygon (path,
-						tolerance,
-						&polygon);
+    status = _cairo_path_fixed_fill_to_polygon (path, tolerance, &polygon);
     if (unlikely (status || polygon.num_edges == 0))
 	goto CLEANUP;
 
-    if (_cairo_path_fixed_fill_is_rectilinear (path)) {
-	status = _cairo_bentley_ottmann_tessellate_rectilinear_polygon (traps,
-									&polygon,
-									fill_rule);
-    } else {
-	status = _cairo_bentley_ottmann_tessellate_polygon (traps,
-							    &polygon,
-							    fill_rule);
-    }
+    status = _cairo_bentley_ottmann_tessellate_polygon (traps,
+							&polygon, fill_rule);
 
   CLEANUP:
     _cairo_polygon_fini (&polygon);