Fixed the state array sizes at 3 (instead of PIPE_SHADER_TYPES)
because we'll never have domain and hull shaders on nv50; also
the numbering doesn't correspond to the hw numbering.

There was very little use for this beyond permitting the
pipe_context::tex_transfer_destroy() function to omit the pipe_context
argument.

This change adds the pipe_context argument into tex_transfer_destroy()
so that it looks like other pipe_context functions, and removes the
pipe_context pointer from pipe_transfer.

We could use single 1 bit conditions for scalar masks, but a lot of code
expects masks. The compiler easily optimzes away masks
extensions/truncations so consistency is preferable.

We can revisit this when LLVM backends have more support for vector
conditions.

Without the validation, the function might draw with outdated textures.

st_DrawTex calls util_draw_vertex_buffer.  Since
ac4abaecd5f52e416c89bfe19b34ed7f4e014b21, the caller is expected to set
vertex elements before calling.

commit 7a2ee04629
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Mar 11 14:19:17 2010 +0000

    nv: convert to context transfers

commit 188a3f5331
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Mar 11 14:11:10 2010 +0000

    nouveau: remove unused variable

commit 5c8e880ab4
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Mar 11 12:31:21 2010 +0000

    mesa/st: fix compilation after merge

commit c552595333
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Mar 11 12:31:06 2010 +0000

    util: fix compilation after merge

commit e80836878a
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Mar 11 12:30:47 2010 +0000

    r300g: fix compilation after merge

commit 0e4883e951
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Mar 11 12:18:45 2010 +0000

    i965g: fix incorrect merge

commit 17d74133d8
Merge: cb81c79 aa311ae
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Mar 11 12:08:32 2010 +0000

    Merge commit 'origin/master' into gallium-context-transfers

    Conflicts:
    	src/gallium/drivers/i965/brw_screen_texture.c
    	src/gallium/drivers/r300/r300_screen.c
    	src/gallium/drivers/softpipe/sp_texture.c
    	src/gallium/drivers/svga/svga_screen_texture.c
    	src/gallium/state_trackers/egl/x11/native_ximage.c

commit cb81c79098
Author: Keith Whitwell <keithw@vmware.com>
Date:   Tue Mar 2 16:04:01 2010 +0000

    egl/x11: hack for context transfers

    There is a better approach to this in the winsys-handle branch, but
    for now avoid using transfers at all by always allocating our own
    backing store directly.

commit f44a24e1d4
Author: Keith Whitwell <keithw@vmware.com>
Date:   Tue Mar 2 16:03:16 2010 +0000

    llvmpipe: context transfers

commit 4d7475ef81
Author: Keith Whitwell <keithw@vmware.com>
Date:   Tue Mar 2 16:02:50 2010 +0000

    llvmpipe: disable testprogs build

    Not working.

commit a9bf98c4d3
Merge: ee0f97e 0c616da
Author: Keith Whitwell <keithw@vmware.com>
Date:   Tue Mar 2 15:28:25 2010 +0000

    Merge commit 'origin/master' into gallium-context-transfers

    Conflicts:
    	src/mesa/state_tracker/st_cb_accum.c
    	src/mesa/state_tracker/st_cb_bitmap.c

commit ee0f97e8d9
Merge: a7f078e 828f545
Author: Keith Whitwell <keithw@vmware.com>
Date:   Fri Feb 19 13:00:29 2010 +0000

    Merge commit 'origin/master' into gallium-context-transfers

    Conflicts:
    	src/gallium/auxiliary/util/u_debug.h
    	src/gallium/drivers/i915/i915_context.h
    	src/gallium/drivers/llvmpipe/lp_flush.c
    	src/gallium/drivers/nv30/nv30_screen.h
    	src/gallium/drivers/nv40/nv40_context.h
    	src/gallium/drivers/nv40/nv40_screen.h
    	src/gallium/drivers/nv50/nv50_context.h
    	src/gallium/drivers/r300/r300_screen.c
    	src/gallium/drivers/r300/r300_winsys.h
    	src/gallium/drivers/softpipe/sp_context.c
    	src/gallium/drivers/trace/tr_context.c
    	src/gallium/state_trackers/dri/dri_context.c
    	src/gallium/state_trackers/egl/common/egl_g3d.c
    	src/gallium/state_trackers/python/st_device.c
    	src/gallium/winsys/drm/radeon/core/radeon_drm.c

commit a7f078e16d
Author: Keith Whitwell <keithw@vmware.com>
Date:   Fri Feb 5 14:16:11 2010 +0000

    gallium: move texture transfers to pipe_context

commit 7b2ffc2019
Merge: 51e190e c036d13
Author: Keith Whitwell <keithw@vmware.com>
Date:   Fri Feb 5 09:55:02 2010 +0000

    Merge commit 'origin/master' into gallium-screen-context

    Conflicts:
    	src/gallium/winsys/drm/nouveau/drm/nouveau_drm_api.c

    This branch has got a pretty tortured history now, I expect
    a squash merge will be appropriate when it is done.

commit 51e190e95a
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 17:58:02 2010 +0000

    gallium: fix some build issues

commit f524bdaa72
Merge: f906212 3aba0a2
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 17:51:32 2010 +0000

    Merge commit 'origin/master' into gallium-screen-context

commit f906212688
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 17:17:12 2010 +0000

    gallium/docs: small description of screen::create_context

commit efcb37bd3d
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:42:42 2010 +0000

    drm/radeon: more dead create_context wrapper removal

commit 6badc0dd9e
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:42:30 2010 +0000

    drm/i965: more dead create_context wrapper removal

commit cf04ebd5a5
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:42:05 2010 +0000

    st/python: more dead create_context wrapper removal

commit 444f114c35
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:37:58 2010 +0000

    idenity: wrapped context creation

commit 5a6d09cb9e
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:28:47 2010 +0000

    ws/gdi: remove dead context_create wrapper

commit 132b55f4be
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:27:52 2010 +0000

    ws/gdi: remove dead context_create wrapper

commit 56d2d21a0c
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:25:38 2010 +0000

    st/xorg: use screen::context_create

commit 838c5cfe56
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:23:20 2010 +0000

    glx/xlib: simplify creation of trace-wrapped contexts

    Trace screen knows how to properly wrap context creation in the
    wrapped screen, so nothing special to do here.

commit c99404c03e
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:18:24 2010 +0000

    st/python: no need to special case context creation for trace

commit 193a527a68
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:15:30 2010 +0000

    drm/radeon: remove dead create_context declaration

commit bb984eecc2
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:14:58 2010 +0000

    nv/drm: remove dead create_context ref

commit e809313a44
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:12:51 2010 +0000

    st/egl: remove a layer of wrappers around screen::create_context

commit 39caa6672a
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:05:28 2010 +0000

    r300g: fill in screen::context_create

commit 407f12556d
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 16:04:04 2010 +0000

    cell: adapt for screen::create_context, untested

commit d02b0c6ce3
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 15:50:24 2010 +0000

    drm/nv: adapt for screen::create_context

    All contexts now created directly through the screen, so remove
    equivalent code here.

    Remove apparently un-needed array of contexts in the winsys.

commit 53eec5b134
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 15:50:08 2010 +0000

    stw: adapt for screen::create_context, untested

commit c6a64de3eb
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 15:49:20 2010 +0000

    trace: expose the wrapped context's priv data

    If we are going to keep this priv idea, really want an accessor
    function for it so that trace and other drivers can wrap that.

commit 75d6104e11
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 15:47:55 2010 +0000

    nv30: adapt to screen::context_create

commit 12f5deb6ed
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 15:44:47 2010 +0000

    nv40: adapt to screen::context_create

commit 14baccaa3b
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 15:35:27 2010 +0000

    nv50: adapt to screen::create_context

    Not build tested.  Need to figure out how to build nouveau.

commit a0e94505cc
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 15:22:27 2010 +0000

    llvmpipe: update for screen::create_context, untested

commit 0eae17107c
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 15:16:57 2010 +0000

    xlib/llvmpipe: remove dead winsys context creation path

commit 2f69f9ffaa
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 14:58:27 2010 +0000

    gallium: convert most code to use screen::create_context

    I wish I could build all of gallium at once to find breakages.

commit d7b57f4061
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 12:46:21 2010 +0000

    glx: permit building with older protocol headers

    I'd like to be able to build mesa on current distro releases without
    having to upgrade from the standard dri2proto and glproto headers.  With
    this change I'm able to build on ancient releases such as Ubuntu 9-10...

    In general, it would be nice to be able to build-test mesa to check for
    unintended breakages without having to follow the external dependencies
    of every group working on the codebase.

commit 57adedd6fb
Merge: da71847 e1906ae
Author: Keith Whitwell <keithw@vmware.com>
Date:   Thu Feb 4 11:38:15 2010 +0000

    Merge commit 'origin/master' into gallium-screen-context

    Conflicts:
    	src/gallium/drivers/softpipe/sp_video_context.h
    	src/gallium/drivers/trace/tr_context.c
    	src/gallium/state_trackers/wgl/shared/stw_context.c
    	src/gallium/winsys/gdi/gdi_softpipe_winsys.c

commit da71847ea6
Author: José Fonseca <jfonseca@vmware.com>
Date:   Sat May 2 08:57:39 2009 +0100

    wgl: Use pipe_screen::context_create.

commit 2595a188f9
Author: José Fonseca <jfonseca@vmware.com>
Date:   Sat May 2 08:56:47 2009 +0100

    trace: Implement pipe_screen::context_create.

commit f3640e4ae3
Author: José Fonseca <jfonseca@vmware.com>
Date:   Sat May 2 08:56:17 2009 +0100

    softpipe: Implement pipe_screen::context_create.

commit 347266bddc
Author: José Fonseca <jfonseca@vmware.com>
Date:   Sat May 2 08:55:31 2009 +0100

    gallium: New pipe_screen::context_create callback.

It's more consistent with the rest of the interfaces.

Extensions were enabled in both st/mesa and st/dri, with st/dri completely
overriding the decisions of st/mesa and exposing even the extensions claimed
to be unsupported by a pipe driver.

This commit moves the differences between the two to st/mesa and removes
the responsibilty of advertising extensions from st/dri.

Memory for xm_dt was allocated twice.

The new lp_build_sample_general() function will handle all sampling
modes for all texture types.  Still incomplete, but a few additional
sampling modes are now supported.

1D textures should work and most of the code for 3D textures is in place.
No support for cube maps yet.  No support for different min/mag filters.

Time to start consolidating some code...

Reemitting dirty states on flush causes problems if the GL context
isn't fully consistent when we get to it. It didn't serve any specific
purpose, so, use nouveau_bo_state_emit instead.

Saves an instruction in PINTERP, LINTERP, and PIXEL_W from
brw_wm_glsl.c For non-GLSL it isn't used yet because the deltas have
to be laid out differently.

Fixes hangs with texturing in the non-GLSL path since
f6d210c284

Instead of testing each component individually, we can test the entire
vector at once.

makes loops work

Otherwise we use glRead/DrawPixels to copy the off-screen FBO image
into the window.

Looks like NVIDIA's broken when using -c (the image is upside down),
but OK with -c -t.

NVIDIA's driver requires that the texture that we're going to render into
be complete.  Need to set min/mag filters to non-mipmap modes.

Plus added other error/debug checks.

Fixes glean/logicOp (regressed after introducing hw accelerated support for ReadPixels)

Fixes #23532 and piglit/fbo-nodepth-test piglit/fbo-nostencil-test

Fixes piglit/fbo-blit and wine d3d9 unit test.

Only works well with LLVM >= 2.7

See fd.o bug 26970.  Also added sanity check assertions.