Commit Graph

1476 Commits

Author SHA1 Message Date
Emmanuele Bassi
ffd47f5b56 [docs] texture_polygon() is called polygon()
Remove the mentions to the old name of cogl_polygon().
2009-08-18 11:11:29 +01:00
Götz Waschk
7f1659f9c7 Update Clutter to use G-I 0.6.4
Following bug #1762, the syntax of g-ir-scanner was changed in
gobject-introspection, so Clutter does not build anymore with 0.6.4.

See the bugzilla bug:

  http://bugzilla.gnome.org/show_bug.cgi?id=591669

GObject-Introspection now uses a different mechanism to extract the
SONAME when building the gir file and it needs the libtool archive as
option.

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2009-08-17 14:14:18 +01:00
Emmanuele Bassi
7feae67026 [docs] Remove the version number from the title
The version number in the title made sense when we were breaking
API with every minor release. Now that we're API stable we can
drop that and make the output in Devhelp and on the website slightly
more good looking.
2009-08-13 16:15:04 +01:00
zhou jiangwei
c460786e9e [cogl] Fix the GLES 2.0 backend
Update the GLES 2.0 backend to the new COGL API after the breakage
introduced by the journal.

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2009-08-11 14:19:24 +01:00
Robert Bragg
1bdfb9e6d4 [cogl_clear] Also pass the alpha component of the CoglColor to glClearColor
Previously we were passing a constant of 0.0 for the alpha component which
wasn't as flexible.
2009-08-11 14:15:44 +01:00
Emmanuele Bassi
23bd5ecd47 Merge branch 'system-json-glib'
* system-json-glib:
  [script] Simplify the parser code
  Update JSON-GLib dependency
2009-08-10 17:21:20 +01:00
Emmanuele Bassi
ac5314c6d2 [docs] Fix a missing parameter 2009-08-04 11:38:48 +01:00
Emmanuele Bassi
ff833fa068 [cogl] Expose cogl_is_vertex_buffer()
The function is public and available in the shared object, but
it's not present in the header, so this is not an API/ABI change.
2009-08-04 11:15:05 +01:00
Emmanuele Bassi
68f3c87f96 Fix compiler warnings when COGL debug level=minimum 2009-07-28 13:57:46 +01:00
Ole André Vadla Ravnås
05dabd1aa5 Avoid near/far identifier names.
Leads to conflict with system headers on Windows, where macros named
"near" and "far" are defined.
2009-07-28 12:13:44 +01:00
Ole André Vadla Ravnås
237553984e Call glClientActiveTexture() through COGL context.
Fixes build issues on systems with OpenGL header older than 1.3.
2009-07-28 12:13:43 +01:00
Ole André Vadla Ravnås
243b22640d Avoid C99 to fix compilation with compilers like MSVC. 2009-07-28 12:13:43 +01:00
Haakon Sporsheim
584eca5eee Reposition variable declarations to avoid C99. 2009-07-28 12:13:42 +01:00
Emmanuele Bassi
ab88c0a888 [build] Use API_VERSION, not MAJORMINOR
The correct macro for Clutter's API version is CLUTTER_API_VERSION,
not CLUTTER_MAJORMINOR anymore.
2009-07-28 11:42:58 +01:00
Emmanuele Bassi
d1b8cab65d [doc] Miscellaneous documentation fixes
Remove private symbols, and add missing public ones.
2009-07-20 12:49:35 +01:00
Emmanuele Bassi
1da8ce3429 [cogl] Make the blend string error domain public
The error domain and codes must present in a publicly installed header
otherwise they won't be usable to match a GError.
2009-07-20 12:47:53 +01:00
Robert Bragg
afe10f9897 [doc] Remove references to cogl_vertex_buffer_delete_indices
These referencese were left over from before indices got CoglHandles to
uniquely identify them.  cogl_handle_unref can be used to delete indices
now.
2009-07-19 10:23:00 +01:00
Emmanuele Bassi
c570014360 [cogl/gles] Fix missing symbols in CoglContext
Keep the CoglContext in sync between GL and GLES backends. We ought
to find a way to have a generic context, though, and have backend
specific sections.

Fixes bug:

  http://bugzilla.openedhand.com/show_bug.cgi?id=1698
2009-07-18 16:59:54 +01:00
Owen W. Taylor
b00fb8598a Fix building introspection when dolt is not in use
On some platforms (anything but Linux, and on obscure Linux
architectures) dolt isn't used, so $(top_builddir)/doltlibtool
won't exist. $(top_builddir)/libtool will always be generated
even if dolt is used, so just use that unconditionally. We don't
need the extra speed when linking the single program for
introspection.

http://bugzilla.openedhand.com/show_bug.cgi?id=1699

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2009-07-18 16:52:57 +01:00
Evan Martin
ec89082e4b [docs] Fix typos and remove mentions of SVN
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2009-07-12 01:38:40 +01:00
Robert Bragg
af49769b33 [cogl] Fix more brokeness with _cogl_material_equal
commit e2c4a2a9f8 fixed one thing but broke many others things :-/
hopfully this fixes that.

It turned out that the journal was mistakenly setting the OVERRIDE_LAYER0
flush option for all entries, but some other logic errors were also
uncovered in _cogl_material_equal.
2009-07-10 19:00:16 +01:00
Robert Bragg
a8e93e8588 [cogl] Fix drawing with sliced textures using material layer0 overrides
To help us handle sliced textures; When flushing materials there is an
override option that can be given to replace the texture name for layer0
so we may iterate the slices without needing to modify the material
in use.

Since improving the journal's ability to batch state changes we added a
_cogl_material_equals function that is used by the journal to compare
materials and identify when a state change is required, but this wasn't
correctly considering the layer0 override resulting in false positives that
meant the journal wouldn't update the GL state and the first texture name
was used for all slices.
2009-07-07 10:34:37 +01:00
Robert Bragg
fffcf579d5 [cogl matrix stack] Create a client side matrix stack for the projection matrix
The cost of glGetFloatv with Mesa is still representing a majority of our
time in OpenGL for some applications, and the last thing left using this is
the current-matrix API when getting the projection matrix.

This adds a matrix stack for the projection matrix, so all getting, setting
and modification of the projection matrix is now managed by Cogl and it's only
when we come to draw that we flush changes to the matrix to OpenGL.

This also brings us closer to being able to drop internal use of the
deprecated OpenGL matrix functions, re: commit 54159f5a1d
2009-07-07 10:32:56 +01:00
Emmanuele Bassi
fcc3d56209 Split the typdef to avoid confusing scanners
Scanners like gtk-doc and g-ir-scanner get confused by:

  typedef struct _Foo {
    ...
  } Foo;

And expect instead:

  typedef struct _Foo Foo;

  struct _Foo {
    ...
  };

CoglMatrix definition should be changed to avoid the former type.
2009-07-01 15:30:21 +01:00
Emmanuele Bassi
a6880643a0 Add debug notes for calls to glViewport()
In order to validate the sequence of:

        XResizeWindow
        ConfigureNotify
        glViewport

that should happen on X11 we need to add debug annotations to the
calls to glViewport() done through COGL.
2009-07-01 15:30:18 +01:00
Robert Bragg
82ef6b51b9 [cogl] cache the viewport width and height
This avoids some calls to glGetFloatv, which have at least proven to be very
in-efficient in mesa at this point in time, since it always updates all derived
state even when it may not relate to the state being requested.
2009-07-01 15:23:10 +01:00
Robert Bragg
fdc048ddd0 [cogl] Ensure well defined semantics for COGL_INVALID_HANDLE material layers
Fixes and adds a unit test for creating and drawing using materials with
COGL_INVALID_HANDLE texture layers.

This may be valid if for example the user has set a texture combine string
that only references a constant color.

_cogl_material_flush_layers_gl_state will bind the fallback texture for any
COGL_INVALID_HANDLE layer, later though we could explicitly check when the
current blend mode does't actually reference a texture source in which case
binding the fallback texture is redundant.

This tests drawing using cogl_rectangle, cogl_polygon and
cogl_vertex_buffer_draw.
2009-06-30 17:35:07 +01:00
Robert Bragg
4d55d146b3 Merge branch 'cogl-journal-batching'
[cogl] Improve ability to break out into raw OpenGL via begin/end mechanism
Adds a cogl_flush() to give developers breaking into raw GL a fighting chance
[cogl-material] Be more carefull about flushing in cogl_material_remove_layer
Revert "[rectangle] Avoid modifying materials mid scene"
Revert "[actor] Avoid modifying materials mid-scene to improve journal batching"
[cogl-vertex-buffer] Disable unused client tex coord arrays
[cogl] disable all client tex coord arrays in _cogl_add_path_to_stencil_buffer
[cogl] flush matrices in _cogl_add_path_to_stencil_buffer
[journal] Don't resize a singlton VBO; create and destroy a VBO each flush
[cogl] avoid using the journal in _cogl_add_path_to_stencil_buffer
[pango-display-list] Use the Cogl journal for short runs of text
[material] _cogl_material_equal: catch the simplest case of matching handles
[material] avoid flushing the journal when just changing the color
[cogl journal] Perform software modelview transform on logged quads.
[Cogl journal] use G_UNLIKLEY around runtime debugging conditions
[cogl journal] Adds a --cogl-debug=batching option to trace batching
[Cogl journal] Adds a --cogl-debug=journal option for tracing the journal
[cogl] Adds a debug option for disabling use of VBOs --cogl-debug=disable-vbos
[cogl] Force Cogl to always use the client side matrix stack
[cogl-debug] Adds a "client-side-matrices" Cogl debug option
[cogl-color] Adds a cogl_color_equal() function
[cogl material] optimize logging of material colors in the journal
[rectangle] Avoid modifying materials mid scene
[actor] Avoid modifying materials mid-scene to improve journal batching
[journal] Always pad our vertex data as if at least 2 layers are enabled
[cogl] Improving Cogl journal to minimize driver overheads + GPU state changes

The Cogl journal is a mechanism Cogl uses to batch geometry resulting from
any of the cogl_rectangle* functions before sending it to OpenGL.  This aims
to improve the Cogl journal so that it can reduce the number of state
changes and draw calls we issue to the OpenGL driver and hopfully improve
performance.

Previously each call to any of the cogl_rectangle* functions would imply an
immediate GL draw call, as well as a corresponding modelview change;
material state changes and gl{Vertex,Color,TexCoord}Pointer calls.  Now
though we have tried to open the scope for batching up as much as possible
so we only have to flush the geometry either before calling glXSwapBuffers,
or when we change state that isn't tracked by the journal.

As a basic example, it's now possible for us to batch typical picking
renders into a single draw call for the whole scene.

Some key points about this change:
- We now perform transformations of quads in software (except for long runs of
  text which continue to use VBOs)
    * It might seem surprising at first, but when you consider that so many
      Clutter actors are little more than textured quads and each actor
      typically implies a modelview matrix change; the costs involved in
      setting up the GPU with the new modelview can easily out weigh the cost
      of simply transforming 4 vertices.
- We always use Cogl's own client side matrix API now.
    * We found the performance of querying the OpenGL driver for matrix state
      was often worse than using the client matrix code, and also - discussing
      with Mesa developers - agreed that since khronos has essentially
      deprecated the GL matrix API (by removing it from OpenGL 3 and
      OpenGL-ES 2) it was appropriate to take full responsibility for all our
      matrix manipulation.
- Developers should avoid modifying materials mid-scene.
    * With the exception of material color changes, if you try and modify a
      material that is referenced in the journal we will currently force a
      journal flush. Note: you can assume that re-setting the same value for
      a material property won't require a flush though.
- Several new --cogl-debug options have been added
    * "disable-batching" can be used to identify bugs in the way that the
      journal does its batching; of could this shouldn't ever be needed :-)
    * "disable-vbos" can be used to test the VBO fallback paths where we
      simply use malloc()'d buffers instead.
    * "batching" lets you get an overview of how the journal is batching
      your geometry and may help you identify ways to improve your
      application performance.
    * "journal" lets you trace all the geometry as it gets logged in the
      journal, and all the geometry as its flushed from the journal.
      Obviously an inconsistency can identify a bug, but the numbers may
      help you verify application logic too.
    * "disable-software-transform" as implied will instead use the driver
      /GPU to transform quads by the modelview matrix.
    Although committed separately a --clutter-debug=nop-picking option was
    also added that lets you remove picking from the equation, which can
    sometimes help make problem analysis more deterministic.
2009-06-30 17:26:31 +01:00
Robert Bragg
b4bc9eb458 [cogl] Improve ability to break out into raw OpenGL via begin/end mechanism
Although we wouldn't recommend developers try and interleve OpenGL drawing
with Cogl drawing - we would prefer patches that improve Cogl to avoid this
if possible - we are providing a simple mechanism that will at least give
developers a fighting chance if they find it necissary.

Note: we aren't helping developers change OpenGL state to modify the
behaviour of Cogl drawing functions - it's unlikley that can ever be
reliably supported - but if they are trying to do something like:

   - setup some OpenGL state.
   - draw using OpenGL (e.g. glDrawArrays() )
   - reset modified OpenGL state.
   - continue using Cogl to draw

They should surround their blocks of raw OpenGL with cogl_begin_gl() and
cogl_end_gl():

   cogl_begin_gl ();
   - setup some OpenGL state.
   - draw using OpenGL (e.g. glDrawArrays() )
   - reset modified OpenGL state.
   cogl_end_gl ();
   - continue using Cogl to draw

Again; we aren't supporting code like this:
   - setup some OpenGL state.
   - use Cogl to draw
   - reset modified OpenGL state.
When the internals of Cogl evolves, this is very liable to break.

cogl_begin_gl() will flush all internally batched Cogl primitives, and emit
all internal Cogl state to OpenGL as if it were going to draw something
itself.

The result is that the OpenGL modelview matrix will be setup; the state
corresponding to the current source material will be setup and other world
state such as backface culling, depth and fogging enabledness will be also
be sent to OpenGL.

Note: no special material state is flushed, so if developers want Cogl to setup
a simplified material state it is the their responsibility to set a simple
source material before calling cogl_begin_gl. E.g. by calling
cogl_set_source_color4ub().

Note: It is the developers responsibility to restore any OpenGL state that they
modify to how it was after calling cogl_begin_gl() if they don't do this then
the result of further Cogl calls is undefined.
2009-06-30 17:13:38 +01:00
Robert Bragg
99f53c3922 Adds a cogl_flush() to give developers breaking into raw GL a fighting chance
This function should only need to be called in exceptional circumstances
since Cogl can normally determine internally when a flush is necessary.

As an optimization Cogl drawing functions may batch up primitives
internally, so if you are trying to use raw GL outside of Cogl you stand a
better chance of being successful if you ask Cogl to flush any batched
geometry before making your state changes.

cogl_flush() ensures that the underlying driver is issued all the commands
necessary to draw the batched primitives.  It provides no guarantees about
when the driver will complete the rendering.

This provides no guarantees about the GL state upon returning and to avoid
confusing Cogl you should aim to restore any changes you make before
resuming use of Cogl.

If you are making state changes with the intention of affecting Cogl drawing
primitives you are 100% on your own since you stand a good chance of
conflicting with Cogl internals.  For example clutter-gst which currently
uses direct GL calls to bind ARBfp programs will very likely break when Cogl
starts to use ARBfb programs internally for the material API, but for now it
can use cogl_flush() to at least ensure that the ARBfp program isn't applied
to additional primitives.

This does not provide a robust generalized solution supporting safe use of
raw GL, its use is very much discouraged.
2009-06-30 17:13:38 +01:00
Robert Bragg
cf621948a7 [cogl-material] Be more carefull about flushing in cogl_material_remove_layer
Previously we would call _cogl_material_pre_change_notify unconditionally, but
now we wait until we really know we are removing a layer before notifying the
change, which will require a journal flush.

Since the convenience functions cogl_set_source_color4ub and
cogl_set_source_texture share a single material, cogl_set_source_color4ub
always calls cogl_material_remove_layer.  Often this is a NOP though and
shouldn't require a journal flush.

This gets performance back to where it was before reverting the per-actor
material commits.
2009-06-30 17:13:38 +01:00
Robert Bragg
2ae3d4b1c1 [cogl-vertex-buffer] Disable unused client tex coord arrays
Before any cogl vertex buffer drawing we call
enable_state_for_drawing_buffer which sets up the GL state, but we weren't
disabling unsed client texture coord arrays.
2009-06-30 17:13:37 +01:00
Robert Bragg
186a26eb26 [cogl] disable all client tex coord arrays in _cogl_add_path_to_stencil_buffer
After flushing the journal an unknown number of client side texture arrays
may be left enabled. Disable them all before using glDrawArrays.
2009-06-30 17:13:37 +01:00
Robert Bragg
4dada4c49e [cogl] flush matrices in _cogl_add_path_to_stencil_buffer
Before calling glRectf we need to ensure we flush the modelview and
projection matrices.
2009-06-30 17:13:37 +01:00
Robert Bragg
a7974f8e6f [journal] Don't resize a singlton VBO; create and destroy a VBO each flush
This simplifies the vertex data uploading in the journal, and could improve
performance.  Modifying a VBO mid-scene could reqire synchronizing with the
GPU or some form of shadowing/copying to avoid modifying data that the GPU
is currently processing; the buffer was also being marked as GL_STATIC_DRAW
which could have made things worse.

Now we simply create a GL_STATIC_DRAW VBO for each flush and and delete it
when we are finished.
2009-06-30 17:13:37 +01:00
Robert Bragg
1ecfd72936 [cogl] avoid using the journal in _cogl_add_path_to_stencil_buffer
Using cogl_rectangle (and thus the journal) in
_cogl_add_path_to_stencil_buffer means we have to consider all the state
that the journal may change in case it may interfer with the direct GL calls
used.  This has proven to be error prone and in this case the journal is an
unnecissary overhead.  We now simply call glRectf instead of using
cogl_rectangle.
2009-06-30 17:13:37 +01:00
Robert Bragg
ac4f7f0bfe [material] _cogl_material_equal: catch the simplest case of matching handles
We were missing the simplest test of all: are the two CoglHandles equal and
are the flush option flags for each material equal?  This should improve
batching for some common cases.
2009-06-30 17:13:36 +01:00
Robert Bragg
3369c5138b [material] avoid flushing the journal when just changing the color
Whenever we modify a material we call _cogl_material_pre_change_notify which
checks to see if the material is referenced by the journal and if so flushes
if before we modify the material.

Since the journal logs material colors directly into a vertex array (to
avoid us repeatedly calling glColor) then we know we never need to flush
the journal when material colors change.
2009-06-30 17:13:36 +01:00
Robert Bragg
f2f4f5f06f [cogl journal] Perform software modelview transform on logged quads.
Since most Clutter actors aren't much more than textured quads; flushing the
journal typically involves lots of 'change modelview; draw quad' sequences.

The amount of overhead involved in uploading a new modelview and queuing
that primitive is huge in comparison to simply transforming 4 vertices by
the current modelview when logging quads.  (Note if your GPU supports HW
vertex transform, then it still does the projective and viewport transforms)

At the same time a --cogl-debug=disable-software-transform option has been
added for comparison and debugging.

This change allows typical pick scenes to be batched into a single draw call
and I'm seeing test-pick run over 200% faster with this.  (i965 + Mesa
7.6-devel)
2009-06-30 17:13:36 +01:00
Robert Bragg
9d1bd46daf [Cogl journal] use G_UNLIKLEY around runtime debugging conditions
May as well improve the branch prediction around runtime debugging code.
2009-06-30 17:13:36 +01:00
Robert Bragg
839c466d62 [cogl journal] Adds a --cogl-debug=batching option to trace batching
Enabling this option makes Cogl trace how the journal is managing to batch
your rectangles.  The journal staggers how it emmits state to the GL driver
and the batches will normally get smaller for each stage, but ideally you
don't want to be in a situation where Cogl is only able to draw one quad per
modelview change and draw call.

E.g. this is a fairly ideal example:
BATCHING: journal len = 101
BATCHING:  vbo offset batch len = 101
BATCHING:   material batch len = 101
BATCHING:    modelview batch len = 101

This isn't:
BATCHING: journal len = 1
BATCHING:  vbo offset batch len = 1
BATCHING:   material batch len = 1
BATCHING:    modelview batch len = 1
BATCHING: journal len = 1
BATCHING:  vbo offset batch len = 1
BATCHING:   material batch len = 1
BATCHING:    modelview batch len = 1
<repeat>
2009-06-30 17:13:36 +01:00
Robert Bragg
121bcd6dfe [Cogl journal] Adds a --cogl-debug=journal option for tracing the journal
When this option is used Cogl will print a trace of all quads that get
logged into the journal, and a trace of quads as they get flushed.

If you are seeing a bug with the geometry being drawn by Cogl this may give
some clues by letting you sanity check the numbers being logged vs the
numbers being emitted.
2009-06-30 17:13:35 +01:00
Robert Bragg
540a91c7fc [cogl] Adds a debug option for disabling use of VBOs --cogl-debug=disable-vbos
For testing the VBO fallback paths it helps to be able to disable the
COGL_FEATURE_VBOS feature flag.  When VBOs aren't available Cogl should use
client side malloc()'d buffers instead.
2009-06-30 17:13:35 +01:00
Robert Bragg
491ceaae07 [cogl] Force Cogl to always use the client side matrix stack
Previously we only used the Cogl matrix stack API for indirect contexts, but
it's too costly to keep on requesting modelview matrices from GL (for
logging in the journal) even for direct rendering.

I also experimented with a patch for mesa to improve performance and
discussed this with upstream, but we agreed to consider the GL matrix API
essentially deprecated.  (For reference the GLES 2 and GL 3 specs have
removed the matrix APIs)
2009-06-30 17:13:35 +01:00
Robert Bragg
f4516e4057 [cogl-debug] Adds a "client-side-matrices" Cogl debug option
This allows us to force Cogl to use the client side matrix stack even when
direct rendering.
2009-06-30 17:13:35 +01:00
Robert Bragg
7b85da8b28 [cogl-color] Adds a cogl_color_equal() function
CoglColors shouldn't be compared using memcmp since they may contain
uninitialized padding bytes.

The prototype is also suitable for passing to g_hash_table_new as the
key_equal_func.

_cogl_pango_display_list_add_texture now uses this instead of memcmp.
2009-06-30 17:13:35 +01:00
Robert Bragg
827798233a [cogl material] optimize logging of material colors in the journal
We now put the color of materials into the vertex array used by the journal
instead of calling glColor() but the number of requests for the material
color were quite expensive so we have changed the material color to
internally be byte components instead of floats to avoid repeat conversions
and added _cogl_material_get_colorubv as a fast-path for the journal to
copy data into the vertex array.
2009-06-30 17:13:35 +01:00
Robert Bragg
2f367cc802 [journal] Always pad our vertex data as if at least 2 layers are enabled
The number of material layers enabled when logging a quad in the journal
determines the stride of the corresponding vertex data (since we need a set
of texture coordinates for each layer.) By padding data in the case where we
have only one layer we can avoid a change in stride if we are mixing single
and double layer primitives in a scene (e.g.  relevent for a composite
manager that may use 2 layers for all shaped windows) Avoiding stride
changes means we can minimize calls to gl{Vertex,Color}Pointer when flushing
the journal.

Since we need to update the texcoord pointers when the actual number of
layers changes, this adds another batch_and_call() stage to deal with
glTexCoordPointer and enabling/disabling the client arrays.
2009-06-30 17:13:34 +01:00
Robert Bragg
2b9478a665 [cogl] Improving Cogl journal to minimize driver overheads + GPU state changes
Previously the journal was always flushed at the end of
_cogl_rectangles_with_multitexture_coords, (i.e.  the end of any
cogl_rectangle* calls) but now we have broadened the potential for batching
geometry.  In ideal circumstances we will only flush once per scene.

In summary the journal works like this:

When you use any of the cogl_rectangle* APIs then nothing is emitted to the
GPU at this point, we just log one or more quads into the journal.  A
journal entry consists of the quad coordinates, an associated material
reference, and a modelview matrix.  Ideally the journal only gets flushed
once at the end of a scene, but in fact there are things to consider that
may cause unwanted flushing, including:

- modifying materials mid-scene
    This is because each quad in the journal has an associated material
    reference (i.e. not copy), so if you try and modify a material that is
    already referenced in the journal we force a flush first)

    NOTE: For now this means you should avoid using cogl_set_source_color()
	      since that currently uses a single shared material. Later we
	  should change it to use a pool of materials that is recycled
	  when the journal is flushed.

- modifying any state that isn't currently logged, such as depth, fog and
  backface culling enables.

The first thing that happens when flushing, is to upload all the vertex data
associated with the journal into a single VBO.

We then go through a process of splitting up the journal into batches that
have compatible state so they can be emitted to the GPU together.  This is
currently broken up into 3 levels so we can stagger the state changes:

1) we break the journal up according to changes in the number of material layers
   associated with logged quads. The number of layers in a material determines
   the stride of the associated vertices, so we have to update our vertex
   array offsets at this level. (i.e. calling gl{Vertex,Color},Pointer etc)
2) we further split batches up according to material compatability. (e.g.
   materials with different textures) We flush material state at this level.
3) Finally we split batches up according to modelview changes. At this level
   we update the modelview matrix and actually emit the actual draw command.

This commit is largely about putting the initial design in-place; this will be
followed by other changes that take advantage of the extended batching.
2009-06-30 17:13:34 +01:00
Robert Bragg
096c1df0f4 [clip-stack] Use signed integers while combining window space clip rectangles
Use signed integers while combining window space clip rectangles, so we avoid
arithmatic errors later resulting in glScissor getting negative width and
height arguments.
2009-06-30 10:16:29 +01:00