xorg-server/patches/xorg-server-1.17.1-mi-partial-pie-slice-filled-arcs-may-need-more-space.patch

From 41932dfbc841a1adc6512d41085ea3f8ebecb42c Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@keithp.com>
Date: Wed, 8 Apr 2015 07:45:28 -0700
Subject: [PATCH] mi: Partial pie-slice filled arcs may need more space for
 spans

The mi filled arc code estimates that a filled arc will produce no
more spans than the arc is tall. This is true for most arcs except
for pie-slice arcs strictly between 180 and 360 degrees where the missing
portion of the arc faces up or down such that we get two spans on some
scanlines.

For those, we need to reserve room for another height/2 spans. This
patch just does it for all partial pie-sliced arcs to make the test
easier to understand; it's just over-allocating a bit of memory, so
that's safe.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
---
 mi/mifillarc.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mi/mifillarc.c b/mi/mifillarc.c
index 246d70f..888519e 100644
--- a/mi/mifillarc.c
+++ b/mi/mifillarc.c
@@ -660,6 +660,11 @@ miPolyFillArc(DrawablePtr pDraw, GCPtr pGC, int narcs_all, xArc * parcs)
             if (narcs && nspans + arc->height > MAX_SPANS_PER_LOOP)
                 break;
             nspans += arc->height;
+
+            /* A pie-slice arc may add another pile of spans */
+            if (pGC->arcMode == ArcPieSlice &&
+                (-FULLCIRCLE < arc->angle2 && arc->angle2 < FULLCIRCLE))
+                nspans += (arc->height + 1) >> 1;
         }
 
         pts = points = malloc (sizeof (DDXPointRec) * nspans +
-- 
2.3.5

1	From 41932dfbc841a1adc6512d41085ea3f8ebecb42c Mon Sep 17 00:00:00 2001
2	From: Keith Packard <keithp@keithp.com>
3	Date: Wed, 8 Apr 2015 07:45:28 -0700
4	Subject: [PATCH] mi: Partial pie-slice filled arcs may need more space for
5	spans
6
7	The mi filled arc code estimates that a filled arc will produce no
8	more spans than the arc is tall. This is true for most arcs except
9	for pie-slice arcs strictly between 180 and 360 degrees where the missing
10	portion of the arc faces up or down such that we get two spans on some
11	scanlines.
12
13	For those, we need to reserve room for another height/2 spans. This
14	patch just does it for all partial pie-sliced arcs to make the test
15	easier to understand; it's just over-allocating a bit of memory, so
16	that's safe.
17
18	Signed-off-by: Keith Packard <keithp@keithp.com>
19	Reviewed-by: Adam Jackson <ajax@redhat.com>
20	---
21	mi/mifillarc.c \| 5 +++++
22	1 file changed, 5 insertions(+)
23
24	diff --git a/mi/mifillarc.c b/mi/mifillarc.c
25	index 246d70f..888519e 100644
26	--- a/mi/mifillarc.c
27	+++ b/mi/mifillarc.c
28	@@ -660,6 +660,11 @@ miPolyFillArc(DrawablePtr pDraw, GCPtr pGC, int narcs_all, xArc * parcs)
29	if (narcs && nspans + arc->height > MAX_SPANS_PER_LOOP)
30	break;
31	nspans += arc->height;
32	+
33	+ /* A pie-slice arc may add another pile of spans */
34	+ if (pGC->arcMode == ArcPieSlice &&
35	+ (-FULLCIRCLE < arc->angle2 && arc->angle2 < FULLCIRCLE))
36	+ nspans += (arc->height + 1) >> 1;
37	}
38
39	pts = points = malloc (sizeof (DDXPointRec) * nspans +
40	--
41	2.3.5
42