xorg-server/patches/xorg-server-1.16.1-glamor-upstream-fix.patch

From 3c0431b8911241552a15a43e4279c50658b50a18 Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@keithp.com>
Date: Wed, 16 Jul 2014 23:03:23 +0000
Subject: glamor: Fix temp picture coordinates in glamor_composite_clipped_region

To understand this patch, let's start at the protocol interface where
the relationship between the coordinate spaces is documented:

        static Bool
        _glamor_composite(CARD8 op,
                          PicturePtr source,
                          PicturePtr mask,
                          PicturePtr dest,
                          INT16 x_source,
                          INT16 y_source,
                          INT16 x_mask,
                          INT16 y_mask,
                          INT16 x_dest, INT16 y_dest,
                          CARD16 width, CARD16 height, Bool fallback)

The coordinates are passed to this function directly off the wire and
are all relative to their respective drawables. For Windows, this means
that they are relative to the upper left corner of the window, in
whatever pixmap that window is getting drawn to.

_glamor_composite calls miComputeCompositeRegion to construct a clipped
region to actually render to. In reality, miComputeCompositeRegion clips
only to the destination these days; source clip region based clipping
would have to respect the transform, which isn't really possible. The
returned region is relative to the screen in which dest lives; offset by
dest->drawable.x and dest->drawable.y.

What is important to realize here is that, because of clipping, the
composite region may not have the same position within the destination
drawable as x_dest, y_dest. The protocol coordinates now exist solely to
'pin' the three objects together.

        extents->x1,y1		Screen origin of clipped operation
        width,height            Extents of the clipped operation
        x_dest,y_dest		Unclipped destination-relative operation coordinate
        x_source,y_source	Unclipped source-relative operation coordinate
        x_mask,y_mask		Unclipped mask-relative operation coordinate

One thing we want to know is what the offset is from the original
operation origin to the clipped origin

        Destination drawable relative coordinates of the clipped operation:

               x_dest_clipped = extents->x1 - dest->drawable.x
               y_dest_clipped = extents->y1 - dest->drawable.y

        Offset from the original operation origin:

                x_off_clipped = x_dest_clipped - x_dest
                y_off_clipped = y_dest_clipped - y_dest

        Source drawable relative coordinates of the clipped operation:

                x_source_clipped = x_source + x_off_clipped;
                y_source_clipped = y_source + y_off_clipped;

        Mask drawable relative coordinates of the clipped operation:

                x_mask_clipped = x_source + x_off_clipped;
                y_mask_clipped = y_source + y_off_clipped;

This is where the original code fails -- it doesn't subtract the
destination drawable location when computing the distance that the
operation has been moved by clipping. Here's what it does when
constructing a temporary source picture:

        temp_src =
            glamor_convert_gradient_picture(screen, source,
                                            extent->x1 + x_source - x_dest,
                                            extent->y1 + y_source - y_dest,
                                            width, height);
        ...
        x_temp_src = -extent->x1 + x_dest;
        y_temp_src = -extent->y1 + y_dest;

glamor_convert_gradient_picture needs source drawable relative
coordinates, but that is not what it's getting; it's getting
screen-relative coordinates for the destination, adjusted by the
distance between the provided source and destination operation
coordinates. We want x_source_clipped and y_source_clipped:

        x_source_clipped = x_source + x_off_clipped
                         = x_source + x_dest_clipped - x_dest
                         = x_source + extents->x1 - dest->drawable.x - x_dest

x_temp_src/y_temp_src are supposed to be the coordinates of the original
operation translated to the temporary picture:

        x_temp_src = x_source - x_source_clipped;
        y_temp_src = y_source - y_source_clipped;

Note that x_source_clipped/y_source_clipped will never be less than
x_source/y_source because all we're doing is clipping. This means that
x_temp_src/y_temp_src will always be non-positive; the original source
coordinate can never be strictly *inside* the temporary image or we
could have made the temporary image smaller.

        x_temp_src = x_source - x_source_clipped
                   = x_source - (x_source + x_off_clipped)
                   = -x_off_clipped
                   = x_dest - x_dest_clipped
                   = x_dest - (extents->x1 - dest->drawable.x)

Again, this is off by the destination origin within the screen
coordinate space.

The code should look like:

        temp_src =
            glamor_convert_gradient_picture(screen, source,
                                            extent->x1 + x_source - x_dest - dest->pDrawable->x,
                                            extent->y1 + y_source - y_dest - dest->pDrawable->y,
                                            width, height);

        x_temp_src = -extent->x1 + x_dest + dest->pDrawable->x;
        y_temp_src = -extent->y1 + y_dest + dest->pDrawable->y;

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Markus Wick <markus@selfnet.de>
(cherry picked from commit 55f5bfb578e934319d1308cbb56c900c5ac7cfa7)
Signed-off-by: Julien Cristau <jcristau@debian.org>
---
diff --git a/glamor/glamor_render.c b/glamor/glamor_render.c
index 14ab738..e5d5d2c 100644
--- a/glamor/glamor_render.c
+++ b/glamor/glamor_render.c
@@ -1450,8 +1450,8 @@ glamor_composite_clipped_region(CARD8 op,
                     || source_pixmap->drawable.height != height)))) {
         temp_src =
             glamor_convert_gradient_picture(screen, source,
-                                            extent->x1 + x_source - x_dest,
-                                            extent->y1 + y_source - y_dest,
+                                            extent->x1 + x_source - x_dest - dest->pDrawable->x,
+                                            extent->y1 + y_source - y_dest - dest->pDrawable->y,
                                             width, height);
         if (!temp_src) {
             temp_src = source;
@@ -1459,8 +1459,8 @@ glamor_composite_clipped_region(CARD8 op,
         }
         temp_src_priv =
             glamor_get_pixmap_private((PixmapPtr) (temp_src->pDrawable));
-        x_temp_src = -extent->x1 + x_dest;
-        y_temp_src = -extent->y1 + y_dest;
+        x_temp_src = -extent->x1 + x_dest + dest->pDrawable->x;
+        y_temp_src = -extent->y1 + y_dest + dest->pDrawable->y;
     }
 
     if (mask
@@ -1474,8 +1474,8 @@ glamor_composite_clipped_region(CARD8 op,
          * to do reduce one convertion. */
         temp_mask =
             glamor_convert_gradient_picture(screen, mask,
-                                            extent->x1 + x_mask - x_dest,
-                                            extent->y1 + y_mask - y_dest,
+                                            extent->x1 + x_mask - x_dest - dest->pDrawable->x,
+                                            extent->y1 + y_mask - y_dest - dest->pDrawable->y,
                                             width, height);
         if (!temp_mask) {
             temp_mask = mask;
@@ -1483,8 +1483,8 @@ glamor_composite_clipped_region(CARD8 op,
         }
         temp_mask_priv =
             glamor_get_pixmap_private((PixmapPtr) (temp_mask->pDrawable));
-        x_temp_mask = -extent->x1 + x_dest;
-        y_temp_mask = -extent->y1 + y_dest;
+        x_temp_mask = -extent->x1 + x_dest + dest->pDrawable->x;
+        y_temp_mask = -extent->y1 + y_dest + dest->pDrawable->y;
     }
     /* Do two-pass PictOpOver componentAlpha, until we enable
      * dual source color blending.
--
cgit v0.9.0.2-2-gbebe

1	niro	2512	From 3c0431b8911241552a15a43e4279c50658b50a18 Mon Sep 17 00:00:00 2001
2			From: Keith Packard <keithp@keithp.com>
3			Date: Wed, 16 Jul 2014 23:03:23 +0000
4			Subject: glamor: Fix temp picture coordinates in glamor_composite_clipped_region
5
6			To understand this patch, let's start at the protocol interface where
7			the relationship between the coordinate spaces is documented:
8
9			static Bool
10			_glamor_composite(CARD8 op,
11			PicturePtr source,
12			PicturePtr mask,
13			PicturePtr dest,
14			INT16 x_source,
15			INT16 y_source,
16			INT16 x_mask,
17			INT16 y_mask,
18			INT16 x_dest, INT16 y_dest,
19			CARD16 width, CARD16 height, Bool fallback)
20
21			The coordinates are passed to this function directly off the wire and
22			are all relative to their respective drawables. For Windows, this means
23			that they are relative to the upper left corner of the window, in
24			whatever pixmap that window is getting drawn to.
25
26			_glamor_composite calls miComputeCompositeRegion to construct a clipped
27			region to actually render to. In reality, miComputeCompositeRegion clips
28			only to the destination these days; source clip region based clipping
29			would have to respect the transform, which isn't really possible. The
30			returned region is relative to the screen in which dest lives; offset by
31			dest->drawable.x and dest->drawable.y.
32
33			What is important to realize here is that, because of clipping, the
34			composite region may not have the same position within the destination
35			drawable as x_dest, y_dest. The protocol coordinates now exist solely to
36			'pin' the three objects together.
37
38			extents->x1,y1 Screen origin of clipped operation
39			width,height Extents of the clipped operation
40			x_dest,y_dest Unclipped destination-relative operation coordinate
41			x_source,y_source Unclipped source-relative operation coordinate
42			x_mask,y_mask Unclipped mask-relative operation coordinate
43
44			One thing we want to know is what the offset is from the original
45			operation origin to the clipped origin
46
47			Destination drawable relative coordinates of the clipped operation:
48
49			x_dest_clipped = extents->x1 - dest->drawable.x
50			y_dest_clipped = extents->y1 - dest->drawable.y
51
52			Offset from the original operation origin:
53
54			x_off_clipped = x_dest_clipped - x_dest
55			y_off_clipped = y_dest_clipped - y_dest
56
57			Source drawable relative coordinates of the clipped operation:
58
59			x_source_clipped = x_source + x_off_clipped;
60			y_source_clipped = y_source + y_off_clipped;
61
62			Mask drawable relative coordinates of the clipped operation:
63
64			x_mask_clipped = x_source + x_off_clipped;
65			y_mask_clipped = y_source + y_off_clipped;
66
67			This is where the original code fails -- it doesn't subtract the
68			destination drawable location when computing the distance that the
69			operation has been moved by clipping. Here's what it does when
70			constructing a temporary source picture:
71
72			temp_src =
73			glamor_convert_gradient_picture(screen, source,
74			extent->x1 + x_source - x_dest,
75			extent->y1 + y_source - y_dest,
76			width, height);
77			...
78			x_temp_src = -extent->x1 + x_dest;
79			y_temp_src = -extent->y1 + y_dest;
80
81			glamor_convert_gradient_picture needs source drawable relative
82			coordinates, but that is not what it's getting; it's getting
83			screen-relative coordinates for the destination, adjusted by the
84			distance between the provided source and destination operation
85			coordinates. We want x_source_clipped and y_source_clipped:
86
87			x_source_clipped = x_source + x_off_clipped
88			= x_source + x_dest_clipped - x_dest
89			= x_source + extents->x1 - dest->drawable.x - x_dest
90
91			x_temp_src/y_temp_src are supposed to be the coordinates of the original
92			operation translated to the temporary picture:
93
94			x_temp_src = x_source - x_source_clipped;
95			y_temp_src = y_source - y_source_clipped;
96
97			Note that x_source_clipped/y_source_clipped will never be less than
98			x_source/y_source because all we're doing is clipping. This means that
99			x_temp_src/y_temp_src will always be non-positive; the original source
100			coordinate can never be strictly inside the temporary image or we
101			could have made the temporary image smaller.
102
103			x_temp_src = x_source - x_source_clipped
104			= x_source - (x_source + x_off_clipped)
105			= -x_off_clipped
106			= x_dest - x_dest_clipped
107			= x_dest - (extents->x1 - dest->drawable.x)
108
109			Again, this is off by the destination origin within the screen
110			coordinate space.
111
112			The code should look like:
113
114			temp_src =
115			glamor_convert_gradient_picture(screen, source,
116			extent->x1 + x_source - x_dest - dest->pDrawable->x,
117			extent->y1 + y_source - y_dest - dest->pDrawable->y,
118			width, height);
119
120			x_temp_src = -extent->x1 + x_dest + dest->pDrawable->x;
121			y_temp_src = -extent->y1 + y_dest + dest->pDrawable->y;
122
123			Signed-off-by: Keith Packard <keithp@keithp.com>
124			Reviewed-by: Markus Wick <markus@selfnet.de>
125			(cherry picked from commit 55f5bfb578e934319d1308cbb56c900c5ac7cfa7)
126			Signed-off-by: Julien Cristau <jcristau@debian.org>
127			---
128			diff --git a/glamor/glamor_render.c b/glamor/glamor_render.c
129			index 14ab738..e5d5d2c 100644
130			--- a/glamor/glamor_render.c
131			+++ b/glamor/glamor_render.c
132			@@ -1450,8 +1450,8 @@ glamor_composite_clipped_region(CARD8 op,
133			\|\| source_pixmap->drawable.height != height)))) {
134			temp_src =
135			glamor_convert_gradient_picture(screen, source,
136			- extent->x1 + x_source - x_dest,
137			- extent->y1 + y_source - y_dest,
138			+ extent->x1 + x_source - x_dest - dest->pDrawable->x,
139			+ extent->y1 + y_source - y_dest - dest->pDrawable->y,
140			width, height);
141			if (!temp_src) {
142			temp_src = source;
143			@@ -1459,8 +1459,8 @@ glamor_composite_clipped_region(CARD8 op,
144			}
145			temp_src_priv =
146			glamor_get_pixmap_private((PixmapPtr) (temp_src->pDrawable));
147			- x_temp_src = -extent->x1 + x_dest;
148			- y_temp_src = -extent->y1 + y_dest;
149			+ x_temp_src = -extent->x1 + x_dest + dest->pDrawable->x;
150			+ y_temp_src = -extent->y1 + y_dest + dest->pDrawable->y;
151			}
152
153			if (mask
154			@@ -1474,8 +1474,8 @@ glamor_composite_clipped_region(CARD8 op,
155			* to do reduce one convertion. */
156			temp_mask =
157			glamor_convert_gradient_picture(screen, mask,
158			- extent->x1 + x_mask - x_dest,
159			- extent->y1 + y_mask - y_dest,
160			+ extent->x1 + x_mask - x_dest - dest->pDrawable->x,
161			+ extent->y1 + y_mask - y_dest - dest->pDrawable->y,
162			width, height);
163			if (!temp_mask) {
164			temp_mask = mask;
165			@@ -1483,8 +1483,8 @@ glamor_composite_clipped_region(CARD8 op,
166			}
167			temp_mask_priv =
168			glamor_get_pixmap_private((PixmapPtr) (temp_mask->pDrawable));
169			- x_temp_mask = -extent->x1 + x_dest;
170			- y_temp_mask = -extent->y1 + y_dest;
171			+ x_temp_mask = -extent->x1 + x_dest + dest->pDrawable->x;
172			+ y_temp_mask = -extent->y1 + y_dest + dest->pDrawable->y;
173			}
174			/* Do two-pass PictOpOver componentAlpha, until we enable
175			* dual source color blending.
176			--
177			cgit v0.9.0.2-2-gbebe
178