mesa.git
17 years agoadd progs/glsl/ to DEMO_FILES, s/pre/rc1/
Brian [Wed, 18 Apr 2007 14:52:18 +0000 (08:52 -0600)]
add progs/glsl/ to DEMO_FILES, s/pre/rc1/

17 years agofig segment fault issue in TAG(triangle), (see bug 10589)
Xiang, Haihao [Wed, 18 Apr 2007 04:37:09 +0000 (12:37 +0800)]
fig segment fault issue in TAG(triangle), (see bug 10589)

Bit SS_TWOSIDE_BIT is set if  gl_FrontFacing lives in
fragment input (see commit 10b5895597d5e069183cb647d17eb412effceb4f).
However, VB->ColorPtr[1] isn't assigned after that.

17 years agoomit the glide/svga sources from stand-alone libGL (anyone using them?)
Brian [Tue, 17 Apr 2007 22:00:17 +0000 (16:00 -0600)]
omit the glide/svga sources from stand-alone libGL (anyone using them?)

17 years agoEnable texture sampling for vertex programs/shaders.
Brian [Tue, 17 Apr 2007 21:56:46 +0000 (15:56 -0600)]
Enable texture sampling for vertex programs/shaders.

This is a bit of a hack for now because the tnl module is using the swrast
module to fetch texels.  The texture fetch/filter code should probably be
moved into the main/ module since it doesn't really depend upon other
swrast code.

17 years agoIn bind_inputs() set VB->EdgeFlag to NULL if it's not needed.
Brian [Tue, 17 Apr 2007 16:19:47 +0000 (10:19 -0600)]
In bind_inputs() set VB->EdgeFlag to NULL if it's not needed.

Otherwise, the clip/interp code was finding VB->EdgeFlag to be non-null and
reading/writing it when the memory may have been freed earlier in free_space().
This fixes several VTK segfaults/failures reported by Brad King @ Kitware.

17 years agoregenerated
Brian [Tue, 17 Apr 2007 15:16:59 +0000 (09:16 -0600)]
regenerated

17 years agofix/simplify some texture functions
Brian [Tue, 17 Apr 2007 15:16:30 +0000 (09:16 -0600)]
fix/simplify some texture functions

17 years agomore matrix function updates
Brian [Tue, 17 Apr 2007 15:15:57 +0000 (09:15 -0600)]
more matrix function updates

17 years agodon't set GL_TEXTURE_MAX_LEVEL for GL_TEXTURE_RECTANGLE_ARB as that generates an...
Brian [Tue, 17 Apr 2007 14:29:37 +0000 (08:29 -0600)]
don't set GL_TEXTURE_MAX_LEVEL for GL_TEXTURE_RECTANGLE_ARB as that generates an error

17 years agoDefer buffer pool creation to the first context creation.
Thomas Hellstrom [Tue, 17 Apr 2007 13:21:54 +0000 (15:21 +0200)]
Defer buffer pool creation to the first context creation.
This way we have a hw context so that we can take the hardware lock.
Also, at this point, AIGLX isn't locked with the X server context as it is
at screen creation.

17 years agocleanups for t_vb_program.c
Roland Scheidegger [Tue, 17 Apr 2007 12:01:42 +0000 (14:01 +0200)]
cleanups for t_vb_program.c

use VertexProgram._Current instead of VertexProgram.Current in a few more places.
Only fixup fogc and psiz in case this is really a nv program (others are fine
if undefined), and fix this case up so the values actually get written.

17 years agor300: r300_render.c:391: warning: unused variable 'i'
Oliver McFadden [Tue, 17 Apr 2007 07:05:15 +0000 (07:05 +0000)]
r300: r300_render.c:391: warning: unused variable 'i'

17 years agolots of changes, fixes, clean-ups
Brian [Mon, 16 Apr 2007 23:56:13 +0000 (17:56 -0600)]
lots of changes, fixes, clean-ups

17 years agojust clean-ups
Brian [Mon, 16 Apr 2007 23:36:39 +0000 (17:36 -0600)]
just clean-ups

17 years agomove GL_EXT_stencil_two_side into alphabetical position
Brian [Mon, 16 Apr 2007 23:18:39 +0000 (17:18 -0600)]
move GL_EXT_stencil_two_side into alphabetical position

17 years agoFix glActiveStencilFaceEXT dispatch problem (bug 10523).
Brian [Mon, 16 Apr 2007 23:16:46 +0000 (17:16 -0600)]
Fix glActiveStencilFaceEXT dispatch problem (bug 10523).

OK, _all_ extensions that might get enabled by the driver need to be in the
card_extensions[] list.  driInitExtensions() is called at least twice: first
during screen creation, then once for each context that's created.
The first call sets up the dispatch table.  The second call just sets the
extension enable/disable flags.

17 years agoremove _tnl_arb_vertex_program_stage
Brian [Mon, 16 Apr 2007 21:15:53 +0000 (15:15 -0600)]
remove _tnl_arb_vertex_program_stage

17 years agoremove _tnl_arb_vertex_program_stage
Brian [Mon, 16 Apr 2007 21:15:23 +0000 (15:15 -0600)]
remove _tnl_arb_vertex_program_stage

17 years agoneed to clamp MAD for linear fog
Brian [Mon, 16 Apr 2007 21:09:39 +0000 (15:09 -0600)]
need to clamp MAD for linear fog

17 years agoremoved unused t_vb_arbprogram stage
Brian [Mon, 16 Apr 2007 17:03:14 +0000 (11:03 -0600)]
removed unused t_vb_arbprogram stage

17 years agoremove t_vb_arbprogram.c
Brian [Mon, 16 Apr 2007 16:59:00 +0000 (10:59 -0600)]
remove t_vb_arbprogram.c

17 years agounhook t_vb_arbprogram.c code - it's going away
Brian [Mon, 16 Apr 2007 16:58:30 +0000 (10:58 -0600)]
unhook t_vb_arbprogram.c code - it's going away

17 years agoUse generic program limits instead of NV-specific ones to init program constants.
Brian [Mon, 16 Apr 2007 16:36:28 +0000 (10:36 -0600)]
Use generic program limits instead of NV-specific ones to init program constants.

Previously, this limited us to 12 temp regs for vertex programs.  Many vertex
shaders could exceed that.  This forces us to stop using t_vb_arbprogram.c
for now because of its particular register indexing scheme.  Need to increase
bits allocated for register indexing, etc.

17 years agoFix some assertions that could occur when an error was earlier logged.
Brian [Mon, 16 Apr 2007 16:32:48 +0000 (10:32 -0600)]
Fix some assertions that could occur when an error was earlier logged.

17 years agouse b->display instead of b->xm_visual->display to fix some problems detected w/...
Brian [Mon, 16 Apr 2007 15:11:20 +0000 (09:11 -0600)]
use b->display instead of b->xm_visual->display to fix some problems detected w/ valgrind

17 years agoMake sure we are locked when creating drm buffer objects.
Thomas Hellstrom [Mon, 16 Apr 2007 14:04:12 +0000 (16:04 +0200)]
Make sure we are locked when creating drm buffer objects.
Don't place buffer objects on unfenced list when newly created.
Fix a buffer object wait-for-idle deadlock.

17 years agoillegal to set GL_TEXTURE_MAX_LEVEL w/ GL_TEXTURE_RECTANGLE_ARB
Brian [Sat, 14 Apr 2007 15:38:20 +0000 (09:38 -0600)]
illegal to set GL_TEXTURE_MAX_LEVEL w/ GL_TEXTURE_RECTANGLE_ARB

17 years agoimplement shadow2DRect functions
Brian [Sat, 14 Apr 2007 15:36:17 +0000 (09:36 -0600)]
implement shadow2DRect functions

17 years agoFix sample_depth_texture() to handle texture rectangle coords.
Brian [Sat, 14 Apr 2007 15:33:20 +0000 (09:33 -0600)]
Fix sample_depth_texture() to handle texture rectangle coords.

17 years agoset osmesa renderbuffer refcount=1 upon creation, free renderbuffer in OSMesaDestroyC...
Brian [Sat, 14 Apr 2007 14:09:12 +0000 (08:09 -0600)]
set osmesa renderbuffer refcount=1 upon creation, free renderbuffer in OSMesaDestroyContext()

17 years agomore _mesa_unreference_framebuffer() calls, remove dead code
Brian [Sat, 14 Apr 2007 14:06:54 +0000 (08:06 -0600)]
more _mesa_unreference_framebuffer() calls, remove dead code

17 years agofix negative zoom factor bug (10636), more comments
Brian [Sat, 14 Apr 2007 13:49:21 +0000 (07:49 -0600)]
fix negative zoom factor bug (10636), more comments

17 years agor300: emit different clear paths for non-TCL, this gets the clear color correct
Dave Airlie [Sat, 14 Apr 2007 07:44:33 +0000 (17:44 +1000)]
r300: emit different clear paths for non-TCL, this gets the clear color correct

17 years agor300: remove unneeded semicolon from macro
Dave Airlie [Sat, 14 Apr 2007 07:42:59 +0000 (17:42 +1000)]
r300: remove unneeded semicolon from macro

17 years agor300: if we don't have TCL don't setup state emissions for vertex shaders
Dave Airlie [Sat, 14 Apr 2007 03:52:27 +0000 (04:52 +0100)]
r300: if we don't have TCL don't setup state emissions for vertex shaders

17 years agopatch for Digital/Tru64 (bug 10635) - forwarded to OpenGL ARB as well
Brian [Fri, 13 Apr 2007 15:55:35 +0000 (09:55 -0600)]
patch for Digital/Tru64 (bug 10635) - forwarded to OpenGL ARB as well

17 years agoxmesa: drop unused XMesaPutImageHelper.
George Sapountzis [Fri, 13 Apr 2007 15:13:08 +0000 (18:13 +0300)]
xmesa: drop unused XMesaPutImageHelper.

It could only be called from XMesaCopySubBuffer but this function is not used
by XFree86.

It seems that XMesaPutImageHelper would handle sub-images but never got
finished. Proper sub-image helpers should be written if need be.

17 years agoxmesa: export xmesa functions used by xfree86.
George Sapountzis [Fri, 13 Apr 2007 15:12:37 +0000 (18:12 +0300)]
xmesa: export xmesa functions used by xfree86.

This uses xmesa.h as the GLcore interface and avoids adding an explicit GLcore
inteface which would not be a proper interface anyway.

It puts the declarations of the three functions specific for XMesa/XFree86 in
xmesa.h, we can push them down to xmesa_xf86.h if hiding behind XFree86Server
ifdef's is not enough.

17 years agos/version/vertex/
Brian [Thu, 12 Apr 2007 22:18:27 +0000 (16:18 -0600)]
s/version/vertex/

17 years agofix bug in _playback_copy_to_current(): need to skip version position data (see bug...
Brian [Thu, 12 Apr 2007 22:17:01 +0000 (16:17 -0600)]
fix bug in _playback_copy_to_current(): need to skip version position data (see bug 10587)

17 years agodisable debug printfs
Brian [Thu, 12 Apr 2007 21:45:02 +0000 (15:45 -0600)]
disable debug printfs

17 years agoAdded sanity checking in _slang_sizeof_type_specifier() to be sure sizes are what...
Brian [Thu, 12 Apr 2007 21:23:55 +0000 (15:23 -0600)]
Added sanity checking in _slang_sizeof_type_specifier() to be sure sizes are what's expected.

17 years agouse _mesa_clear_shader_program_data()
Brian [Thu, 12 Apr 2007 21:22:53 +0000 (15:22 -0600)]
use _mesa_clear_shader_program_data()

17 years agoNew _mesa_reference_shader/program() function to consolidate refcounting.
Brian [Thu, 12 Apr 2007 21:22:32 +0000 (15:22 -0600)]
New _mesa_reference_shader/program() function to consolidate refcounting.

Note that (unlike texture objects), shader handles remain valid (in the
hash table) after glDeleteShader/Program() if the refcount isn't zero.

17 years agorestore 200x200 window size, animation, version check
Brian [Wed, 11 Apr 2007 20:09:32 +0000 (14:09 -0600)]
restore 200x200 window size, animation, version check

17 years agoregenerated
Brian [Wed, 11 Apr 2007 18:30:31 +0000 (12:30 -0600)]
regenerated

17 years agocheckpoint: updating non-square matrix constructors and operators
Brian [Wed, 11 Apr 2007 18:30:03 +0000 (12:30 -0600)]
checkpoint: updating non-square matrix constructors and operators

17 years agomove/fix texture sampling funcs
Brian [Wed, 11 Apr 2007 18:29:38 +0000 (12:29 -0600)]
move/fix texture sampling funcs

17 years agos/Shadow/SHADOW/
Brian [Wed, 11 Apr 2007 17:13:37 +0000 (11:13 -0600)]
s/Shadow/SHADOW/

17 years agoas with prev commit, also fix color index mode zoomed depth copies (bug 10608)
Brian [Wed, 11 Apr 2007 15:04:18 +0000 (09:04 -0600)]
as with prev commit, also fix color index mode zoomed depth copies (bug 10608)

17 years agofix invalid error detection problem in _mesa_bind_attrib_location(), bug 10602
Brian [Wed, 11 Apr 2007 15:00:56 +0000 (09:00 -0600)]
fix invalid error detection problem in _mesa_bind_attrib_location(), bug 10602

17 years agofix zoomed depth copies (bug 10608)
Brian [Wed, 11 Apr 2007 14:47:05 +0000 (08:47 -0600)]
fix zoomed depth copies (bug 10608)

17 years agouse _mesa_reference_renderbuffer(), fix typo
Brian [Wed, 11 Apr 2007 14:11:52 +0000 (08:11 -0600)]
use _mesa_reference_renderbuffer(), fix typo

17 years agofix/work-around allocation bugs for non-square matrices
Brian [Wed, 11 Apr 2007 03:51:27 +0000 (21:51 -0600)]
fix/work-around allocation bugs for non-square matrices

17 years agoupdate SLANG version test
Brian [Wed, 11 Apr 2007 03:50:53 +0000 (21:50 -0600)]
update SLANG version test

17 years agors480: set vap cntl to what fglrx uses for non-TCL cards
Dave Airlie [Tue, 10 Apr 2007 10:46:58 +0000 (11:46 +0100)]
rs480: set vap cntl to what fglrx uses for non-TCL cards

17 years agoi915: Bring test for vsync to pipe B in line with i915tex.
Michel Dänzer [Tue, 10 Apr 2007 09:05:17 +0000 (11:05 +0200)]
i915: Bring test for vsync to pipe B in line with i915tex.

17 years agoAdd missing generated file.
Michel Dänzer [Tue, 10 Apr 2007 09:04:19 +0000 (11:04 +0200)]
Add missing generated file.

17 years agoNULL ptr check
Brian [Tue, 10 Apr 2007 01:07:13 +0000 (19:07 -0600)]
NULL ptr check

17 years agoplug in GLSL 1.20 unit
Brian [Tue, 10 Apr 2007 01:04:45 +0000 (19:04 -0600)]
plug in GLSL 1.20 unit

17 years agoundo a debug/test change
Brian [Tue, 10 Apr 2007 00:36:55 +0000 (18:36 -0600)]
undo a debug/test change

17 years agor300: don't enable VAP/TCL on cards that don't support it
Dave Airlie [Mon, 9 Apr 2007 23:32:13 +0000 (09:32 +1000)]
r300: don't enable VAP/TCL on cards that don't support it

17 years agoremove unneeded initialization code (see bug 10569)
Brian [Mon, 9 Apr 2007 17:21:51 +0000 (11:21 -0600)]
remove unneeded initialization code (see bug 10569)

17 years agoallocate __GLXdisplayPrivate w/ Xcalloc instead of Xmalloc (bug 10569)
Brian [Mon, 9 Apr 2007 14:49:26 +0000 (08:49 -0600)]
allocate __GLXdisplayPrivate w/ Xcalloc instead of Xmalloc (bug 10569)

17 years agoi915tex: Fix some mismatches between texels or bytes for pitch/stride.
Michel Dänzer [Mon, 9 Apr 2007 12:57:08 +0000 (14:57 +0200)]
i915tex: Fix some mismatches between texels or bytes for pitch/stride.

17 years agoi915tex: Make sure texture format fetch hooks are initialized.
Michel Dänzer [Mon, 9 Apr 2007 12:52:18 +0000 (14:52 +0200)]
i915tex: Make sure texture format fetch hooks are initialized.

17 years agothe RS400 definitely doesn't work at this point so don't let it init
Dave Airlie [Mon, 9 Apr 2007 12:03:31 +0000 (22:03 +1000)]
the RS400 definitely doesn't work at this point so don't let it init

17 years agoenable GLSL 1.20
Brian [Mon, 9 Apr 2007 03:48:19 +0000 (21:48 -0600)]
enable GLSL 1.20

17 years agosupport for GLSL 1.20 non-square matrices
Brian [Sun, 8 Apr 2007 22:47:32 +0000 (16:47 -0600)]
support for GLSL 1.20 non-square matrices

17 years agoadd glsl to PROGRAM_DIRS
Brian [Sun, 8 Apr 2007 21:50:31 +0000 (15:50 -0600)]
add glsl to PROGRAM_DIRS

17 years agofix some dependencies, remove some CFLAGS
Brian [Sun, 8 Apr 2007 21:42:26 +0000 (15:42 -0600)]
fix some dependencies, remove some CFLAGS

17 years agoadd 2.1 functions
Brian [Sun, 8 Apr 2007 21:41:02 +0000 (15:41 -0600)]
add 2.1 functions

17 years agoMake sure GLX entrypoints are marked PUBLIC.
Adam Jackson [Sun, 8 Apr 2007 18:40:03 +0000 (14:40 -0400)]
Make sure GLX entrypoints are marked PUBLIC.

Fedora bug #229808.

17 years agofix bug 9823: GL_CLIENT_ATTRIB_STACK_DEPTH query fails for indirect rendering
Wei Wang [Sun, 8 Apr 2007 17:24:08 +0000 (11:24 -0600)]
fix bug 9823: GL_CLIENT_ATTRIB_STACK_DEPTH query fails for indirect rendering

17 years agoi915tex: Clean up resizing of renderbuffers.
Michel Dänzer [Sun, 8 Apr 2007 12:04:15 +0000 (14:04 +0200)]
i915tex: Clean up resizing of renderbuffers.

17 years agodriUpdateFramebufferSize: Use ctx->Driver.ResizeBuffers.
Michel Dänzer [Sun, 8 Apr 2007 12:02:14 +0000 (14:02 +0200)]
driUpdateFramebufferSize: Use ctx->Driver.ResizeBuffers.

17 years agoMAX_TEXTURE_COORDS_ARB and MAX_TEXTURE_IMAGE_UNITS_ARB had wrong glGet info.
Brian [Sun, 8 Apr 2007 02:38:25 +0000 (20:38 -0600)]
MAX_TEXTURE_COORDS_ARB and MAX_TEXTURE_IMAGE_UNITS_ARB had wrong glGet info.

Fixes bug 10371.

17 years agofix etags command to find headers
Brian [Sun, 8 Apr 2007 01:36:58 +0000 (19:36 -0600)]
fix etags command to find headers

17 years agoDrop XFree86Server from execmem.c
George Sapountzis [Sat, 7 Apr 2007 15:41:14 +0000 (18:41 +0300)]
Drop XFree86Server from execmem.c

This is a remnant from the libcwrapper days that can be removed now. It is the
last XFree86 glitch in Mesa core.

Reverts the following commit (thanks to Brian Paul for pointing to it):

commit 8b1dc68662f2a18ea4e02c6d3247c5d1da741aa8
Author: Alan Hourihane <alanh@tungstengraphics.com>
Date:   Tue Jan 24 21:40:53 2006 +0000

    pull in fix from 6.4 branch for XFree86Server definition

commit cc7b6810e2fe6ab485fd96d5f17bf5d9329bd153
Author: Ian Romanick <idr@us.ibm.com>
Date:   Fri Oct 21 18:09:24 2005 +0000

    Make execmem.c compile in the server (libGLcore).  Since xf86mmap
    doesn't know about MAP_ANONYMOUS, this is the only viable fix.  This
    issue will likely have to be revisited at some point.

17 years agoset version for tarballs to 6.5.3pre for now
Richard Hughes [Sat, 7 Apr 2007 14:48:07 +0000 (08:48 -0600)]
set version for tarballs to 6.5.3pre for now

17 years agofix references to non-existant sz4 field
Richard Hughes [Sat, 7 Apr 2007 14:46:44 +0000 (08:46 -0600)]
fix references to non-existant sz4 field

17 years agofix some CHAN_TYPE==GL_FLOAT breakage
Richard Hughes [Sat, 7 Apr 2007 14:46:10 +0000 (08:46 -0600)]
fix some CHAN_TYPE==GL_FLOAT breakage

17 years agofix comment typo
Brian [Sat, 7 Apr 2007 14:43:40 +0000 (08:43 -0600)]
fix comment typo

17 years agoremove array_cache/, add vbo/
Richard Hughes [Sat, 7 Apr 2007 14:39:24 +0000 (08:39 -0600)]
remove array_cache/, add vbo/

17 years agoadded glActiveStencilFaceEXT
Brian [Sat, 7 Apr 2007 14:38:36 +0000 (08:38 -0600)]
added glActiveStencilFaceEXT

17 years agofor evaluators, loop to VBO_ATTRIB_TEX7, not VBO_ATTRIB_INDEX. See bug 10543
Brian [Fri, 6 Apr 2007 21:45:11 +0000 (15:45 -0600)]
for evaluators, loop to VBO_ATTRIB_TEX7, not VBO_ATTRIB_INDEX.  See bug 10543

17 years agoxmesa: use newly added xm_image.[hc]
George Sapountzis [Fri, 6 Apr 2007 10:28:39 +0000 (13:28 +0300)]
xmesa: use newly added xm_image.[hc]

Keep external includes to glxheader.h and xmesa includes to xmesaP.h.

Drop the following from xm_image.h:
- dix-config.h (comes from glheader.h)
- xfree86 includes (come from GL/xmesa_xf86.h)
- ifdef __CYGWIN__ (leftover ? xm_api.c has something similar)

17 years agoxmesa: add xf86glx_util.[hc] from xserver as xm_image.[hc]
George Sapountzis [Fri, 6 Apr 2007 10:27:43 +0000 (13:27 +0300)]
xmesa: add xf86glx_util.[hc] from xserver as xm_image.[hc]

17 years agoDrop the funky SSE exception test on linux.
George Sapountzis [Fri, 6 Apr 2007 10:22:41 +0000 (13:22 +0300)]
Drop the funky SSE exception test on linux.

Replace the check for IN_DRI_DRIVER with the appropriate kernel version check
and just disable SSE on older (pre 2.4) kernels.

17 years agofix color storage bug in convolution path
Brian [Fri, 6 Apr 2007 03:12:44 +0000 (21:12 -0600)]
fix color storage bug in convolution path

17 years agoinclude points.h to fix warnings
Brian [Thu, 5 Apr 2007 17:43:07 +0000 (11:43 -0600)]
include points.h to fix warnings

17 years agoRemove SI imports/exports remnants.
George Sapountzis [Thu, 5 Apr 2007 16:01:51 +0000 (19:01 +0300)]
Remove SI imports/exports remnants.

17 years agoglx: minor cosmetic in glcontextmodes.c
George Sapountzis [Thu, 5 Apr 2007 16:00:47 +0000 (19:00 +0300)]
glx: minor cosmetic in glcontextmodes.c

move memory macros to separate block and unwrap malloc/free for miniglx towards
cleaning Mesa core glitches in glx...

17 years agoMove glcontextmodes.c to glx.
George Sapountzis [Thu, 5 Apr 2007 15:59:42 +0000 (18:59 +0300)]
Move glcontextmodes.c to glx.

It is no longer linked with DRI drivers, libGL passes function pointers through
the DRI interface.

17 years agotemporary add some extra renderbuffer debug code
Brian [Thu, 5 Apr 2007 15:28:09 +0000 (09:28 -0600)]
temporary add some extra renderbuffer debug code

17 years agoRemove the never-used SI-style imports/exports code.
Brian [Thu, 5 Apr 2007 04:18:53 +0000 (22:18 -0600)]
Remove the never-used SI-style imports/exports code.

17 years agoassorted updates
Brian [Wed, 4 Apr 2007 15:33:12 +0000 (09:33 -0600)]
assorted updates

17 years agoassorted documentation updates
Brian [Wed, 4 Apr 2007 15:31:41 +0000 (09:31 -0600)]
assorted documentation updates

17 years agoinit span.y=0 to silence warnings
Brian [Wed, 4 Apr 2007 15:30:28 +0000 (09:30 -0600)]
init span.y=0 to silence warnings

17 years agoOverlapping copies with zoomZ=-1 were broken. See bug 10521.
Brian [Wed, 4 Apr 2007 14:48:06 +0000 (08:48 -0600)]
Overlapping copies with zoomZ=-1 were broken.  See bug 10521.

Need to check for overlapping src/dest regions before computing bottom-to-top
vs. top-to-bottom order.