Commit Graph

91 Commits

Author SHA1 Message Date
Neil Roberts
c8ddb3b55a cogl-atlas: Try 4 different approaches for migrating textures
Instead of directly banging GL to migrate textures the atlas now uses
the CoglFramebuffer API. It will use one of four approaches; it can
set up two FBOs and use _cogl_blit_framebuffer to copy between them;
it can use a single target fbo and then render the source texture to
the FBO using a Cogl draw call; it can use a single FBO and call
glCopyTexSubImage2D; or it can fallback to reading all of the texture
data back to system memory and uploading it again with a sub texture
update.

Previously GL calls were used directly because Cogl wasn't able to
create a framebuffer without a stencil and depth buffer. However there
is now an internal version of cogl_offscreen_new_to_texture which
takes a set of flags to disable the two buffers.

The code for blitting has now been moved into a separate file called
cogl-blit.c because it has become quite long and it may be useful
outside of the atlas at some point.

The 4 different methods have a fixed order of preference which is:

* Texture render between two FBOs
* glBlitFramebuffer
* glCopyTexSubImage2D
* glGetTexImage + glTexSubImage2D

Once a method is succesfully used it is tried first for all subsequent
blits. The default default can be overridden by setting the
environment variable COGL_ATLAS_DEFAULT_BLIT_MODE to one of the
following values:

* texture-render
* framebuffer
* copy-tex-sub-image
* get-tex-data
2011-02-15 12:10:54 +00:00
Robert Bragg
9b0fd92527 cogl: rename CoglVertexAttribute CoglAttribute
This is part of a broader cleanup of some of the experimental Cogl API.
One of the reasons for this particular rename is to reduce the verbosity
of using the API. Another reason is that CoglVertexArray is going to be
renamed CoglAttributeBuffer and we want to help emphasize the
relationship between CoglAttributes and CoglAttributeBuffers.
2011-01-21 16:24:14 +00:00
Robert Bragg
1f0826543e cogl: Adds _cogl_util_point_in_polygon API
This adds a utility function that can determine if a given point
intersects an arbitrary polygon, by counting how many edges a
"semi-infinite" horizontal ray crosses from that point. The plan is to
use this for a software based read-pixel fast path that avoids using the
GPU to rasterize journaled primitives and can instead intersect a point
being read with quads in the journal to determine the correct color.
2011-01-21 16:18:11 +00:00
Neil Roberts
dc1f1949d0 Remove the GLES2 wrapper
The GLES2 wrapper is no longer needed because the shader generation is
done within the GLSL fragend and vertend and any functions that are
different for GLES2 are now guarded by #ifdefs.
2010-12-13 17:29:14 +00:00
Neil Roberts
fa13f6c107 cogl: Add a vertend to generate GLSL
The GLSL vertend is mostly only useful for GLES2. The fixed function
vertend is kept at higher priority than the GLSL vertend so it is
unlikely to be used in any other circumstances.
2010-12-13 17:28:28 +00:00
Neil Roberts
3cf9159769 cogl: Add a fixed function vertend
The vertends are intended to flush state that would be represented in
a vertex program. Code to handle the layer matrix, lighting and
point size has now been moved from the common cogl-pipeline-opengl
backend to the fixed vertend.
2010-12-13 17:22:57 +00:00
Neil Roberts
9b1ab9f0ec cogl: Add a GLSL 'progend'
'progend' is short for 'program backend'. The progend is intended to
operate on combined state from a fragment backend and a vertex
backend. The progend has an 'end' function which is run whenever the
pipeline is flushed and the two pipeline change notification
functions. All of the progends are run whenever the pipeline is
flushed instead of selecting a single one because it is possible that
multiple progends may be in use for example if the vertends and
fragends are different. The GLSL progend will take the shaders
generated by the fragend and vertend and link them into a single
program. The fragend code has been changed to only generate the shader
and not the program. The idea is that pipelines can share fragment
shader objects even if their vertex state is different. The authority
for the progend needs to be the combined authority on the vertend and
fragend state.
2010-12-13 17:22:57 +00:00
Neil Roberts
0098dc7acc Rename CoglPipelineBackend to CoglPipelineFragend
The current Cogl pipeline backends are entirely concerned with the
fragment processing state. We also want to eventually have separate
backends to generate shaders for the vertex processing state so we
need to rename the fragment backends. 'Fragend' is a somewhat weird
name but we wanted to avoid ending up with illegible symbols like
CoglPipelineFragmentBackendGlslPrivate.
2010-12-13 17:22:57 +00:00
Robert Bragg
fd10e3a545 matrix gtype: registers a boxed type for CoglMatrix
To allow us to have gobject properties that accept a CoglMatrix value we
need to register a GType. This adds a cogl_gtype_matrix_get_type function
that will register a static boxed type called "CoglMatrix".

This adds a new section to the reference manual for GType integration
functions.
2010-12-07 12:16:50 +00:00
Neil Roberts
c50cb72748 Remove the fragment shader generation from the GLES2 wrapper
The GLES2 wrapper no longer needs to generate any fragment shader
state because the GLSL pipeline backend will always give the wrapper a
custom fragment shader. This simplifies a lot of the state comparison
done by the wrapper. The fog generation is also removed even though
it's actually part of the vertex shader because only the fixed
function pipeline backend actually calls the fog functions so it would
be disabled when using any of the other backends anyway. We can fix
this when the two shader backends also start generating vertex
shaders.
2010-11-24 18:06:44 +00:00
Evan Nemerson
3be05abf60 cogl: Include exported pacakges information in GIR
http://bugzilla.clutter-project.org/show_bug.cgi?id=2438
2010-11-24 17:18:17 +00:00
Emmanuele Bassi
ebdf112732 build: Add missing cogl-shader-boilerplate.h 2010-11-20 10:47:22 +00:00
Emmanuele Bassi
13561e2e2d build: Add a missing file 2010-11-19 18:30:06 +00:00
Emmanuele Bassi
05f5ae1a97 build: Don't reference non-existing files 2010-11-19 18:15:49 +00:00
Robert Bragg
cce8645aba path 2.0: update path API for experimental 2.0 API
When COGL_ENABLE_EXPERIMENTAL_2_0_API is defined cogl.h will now include
cogl2-path.h which changes cogl_path_new() so it can directly return a
CoglPath pointer; it no longer exposes a prototype for
cogl_{get,set}_path and all the remaining cogl_path_ functions now take
an explicit path as their first argument.

The idea is that we want to encourage developers to retain path objects
for as long as possible so they can take advantage of us uploading the
path geometry to the GPU. Currently although it is possible to start a
new path and query the current path, it is not convenient.

The other thing is that we want to get Cogl to the point where nothing
depends on a global, current context variable. This will allow us to one
day define a sensible threading model if/when that is ever desired.
2010-11-11 13:17:26 +00:00
Neil Roberts
caa991d7a1 cogl: Don't flush the journal when flushing clip state
Flushing the clip state no longer does anything that would cause the
journal to flush. The clip state is only flushed when flushing the
framebuffer state and in all cases this ends up flushing the journal
in one way or another anyway. Avoiding flushing the journal will make
it easier to log the clip state in the journal.

Previously when trying to set up a rectangle clip that can't be
scissored or when using a path clip the code would use cogl_rectangle
as part of the process to fill the stencil buffer. This is now changed
to use a new internal _cogl_rectangle_immediate function which
directly uses the vertex array API to draw a triangle strip without
affecting the journal. This should be just as efficient as the
previous journalled code because these places would end up flushing
the journal immediately before and after submitting the single
rectangle anyway and flushing the journal always creates a new vbo so
it would effectively do the same thing.

Similarly there is also a new internal _cogl_clear function that does
not flush the journal.
2010-11-04 18:10:08 +00:00
Robert Bragg
f80cb197a9 cogl: rename CoglMaterial -> CoglPipeline
This applies an API naming change that's been deliberated over for a
while now which is to rename CoglMaterial to CoglPipeline.

For now the new pipeline API is marked as experimental and public
headers continue to talk about materials not pipelines. The CoglMaterial
API is now maintained in terms of the cogl_pipeline API internally.
Currently this API is targeting Cogl 2.0 so we will have time to
integrate it properly with other upcoming Cogl 2.0 work.

The basic reasons for the rename are:
- That the term "material" implies to many people that they are
  constrained to fragment processing; perhaps as some kind of high-level
  texture abstraction.
    - In Clutter they get exposed by ClutterTexture actors which may be
      re-inforcing this misconception.
- When comparing how other frameworks use the term material, a material
  sometimes describes a multi-pass fragment processing technique which
  isn't the case in Cogl.
- In code, "CoglPipeline" will hopefully be a much more self documenting
  summary of what these objects represent; a full GPU pipeline
  configuration including, for example, vertex processing, fragment
  processing and blending.
- When considering the API documentation story, at some point we need a
  document introducing developers to how the "GPU pipeline" works so it
  should become intuitive that CoglPipeline maps back to that
  description of the GPU pipeline.
- This is consistent in terminology and concept to OpenGL 4's new
  pipeline object which is a container for program objects.

Note: The cogl-material.[ch] files have been renamed to
cogl-material-compat.[ch] because otherwise git doesn't seem to treat
the change as a moving the old cogl-material.c->cogl-pipeline.c and so
we loose all our git-blame history.
2010-11-03 18:09:23 +00:00
Robert Bragg
9498d505dd cogl: Adds experimental CoglPrimitive API
A CoglPrimitive is a retainable object for drawing a single primitive,
such as a triangle strip, fan or list.

CoglPrimitives build on CoglVertexAttributes and CoglIndices which
themselves build on CoglVertexArrays and CoglIndexArrays respectively.

A CoglPrimitive encapsulates enough information such that it can be
retained in a queue (e.g. the Cogl Journal, or renderlists in the
future) and drawn at some later time.
2010-11-03 18:04:31 +00:00
Robert Bragg
070d90937b cogl: Adds experimental CoglVertexAttribute API
A CoglVertexAttribute defines a single attribute contained in a
CoglVertexArray. I.e. a CoglVertexArray is simply a buffer of N bytes
intended for containing a collection of attributes (position, color,
normals etc) and a CoglVertexAttribute defines one such attribute by
specifying its start offset in the array, its type, the number of
components and the stride etc.
2010-11-03 18:04:26 +00:00
Robert Bragg
6e620e94b6 cogl: Adds experimental CoglIndices API
CoglIndices define a range of indices inside a CoglIndexArray. I.e. a
CoglIndexArray is simply a buffer of N bytes and you can then
instantiate multiple CoglIndices collections that define a sub-region of
a CoglIndexArray by specifying a start offset and an index data type.
2010-11-03 18:04:00 +00:00
Robert Bragg
296d14e946 cogl: Adds experimental CoglVertexArray type
This adds a new CoglVertexArray object which is a subclass of CoglBuffer
used to hold vertex attributes. A later commit will add a
CoglVertexAttribute API which will be used to describe the attributes
inside a CoglVertexArray.
2010-11-03 18:04:00 +00:00
Robert Bragg
4d990a93a8 cogl: Adds experimental CoglIndexArray type
A CoglIndexArray is a subclass of CoglBuffer and will be used to hold
vertex indices. A later commit will add a CoglIndices API which will
allow describing a range of indices inside a CoglIndexArray.
2010-11-03 18:04:00 +00:00
Neil Roberts
63206a208b Merge cogl-program-{gl,gles}.c into one cogl-program.c
This merges the two implementations of CoglProgram for the GLES2 and
GL backends into one. The implementation is more like the GLES2
version which would track the uniform values and delay sending them to
GL. CoglProgram is now effectively just a GList of CoglShaders along
with an array of stored uniform values. CoglProgram never actually
creates a GL program, instead this is left up to the GLSL material
backend. This is necessary on GLES2 where we may need to relink the
user's program with different generated shaders depending on the other
emulated fixed function state. It will also be necessary in the future
GLSL backends for regular OpenGL. The GLSL and ARBfp material backends
are now the ones that create and link the GL program from the list of
shaders. The linked program is attached to the private material state
so that it can be reused if the CoglProgram is used again with the
same material. This does mean the program will get relinked if the
shader is used with multiple materials. This will be particularly bad
if the legacy cogl_program_use function is used because that
effectively always makes one-shot materials. This problem will
hopefully be alleviated if we make a hash table with a cache of
generated programs. The cogl program would then need to become part of
the hash lookup.

Each CoglProgram now has an age counter which is incremented every
time a shader is added. This is used by the material backends to
detect when we need to create a new GL program for the user program.

The internal _cogl_use_program function now takes a GL program handle
rather than a CoglProgram. It no longer needs any special differences
for GLES2. The GLES2 wrapper function now also uses this function to
bind its generated shaders.

The ARBfp shaders no longer store a copy of the program source but
instead just directly create a program object when cogl_shader_source
is called. This avoids having to reupload the source if the same
shader is used in multiple materials.

There are currently a few gross hacks to get the GLES2 backend to work
with this. The problem is that the GLSL material backend is now
generating a complete GL program but the GLES2 wrapper still needs to
add its fixed function emulation shaders if the program doesn't
provide either a vertex or fragment shader. There is a new function in
the GLES2 wrapper called _cogl_gles2_use_program which replaces the
previous cogl_program_use implementation. It extracts the GL shaders
from the GL program object and creates a new GL program containing all
of the shaders plus its fixed function emulation. This new program is
returned to the GLSL material backend so that it can still flush the
custom uniforms using it. The user_program is attached to the GLES2
settings struct as before but its stored using a GL program handle
rather than a CoglProgram pointer. This hack will go away once the
GLSL material backend replaces the GLES2 wrapper by generating the
code itself.

Under Mesa this currently generates some GL errors when glClear is
called in test-cogl-shader-glsl. I think this is due to a bug in Mesa
however. When the user program on the material is changed the GLSL
backend gets notified and deletes the GL program that it linked from
the user shaders. The program will still be bound in GL
however. Leaving a deleted shader bound exposes a bug in Mesa's
glClear implementation. More details are here:

https://bugs.freedesktop.org/show_bug.cgi?id=31194
2010-10-28 19:51:42 +01:00
Kristian Høgsberg
963a0662b4 Add wayland backend
This adds a clutter backend for running under the wayland window system.
Initial cogl framebuffer integration by Robert Bragg.
2010-10-14 16:23:05 +01:00
Emmanuele Bassi
d9e1821501 build: Unconditionally add GLES2 shaders to EXTRA_DIST 2010-10-04 08:57:29 +01:00
Emmanuele Bassi
eb179d4b67 build: Start moving to a non-recursive layout
*** WARNING: THIS COMMIT CHANGES THE BUILD ***

Do not recurse into the backend directories to build private, internal
libraries.

We only recurse from clutter/ into the cogl sub-directory; from there,
we don't recurse any further. All the backend-specific code in Cogl and
Clutter is compiled conditionally depending on the macros defined by the
configure script.

We still recurse from the top-level directory into doc, clutter and
tests, because gtk-doc and tests do not deal nicely with non-recursive
layouts.

This change makes Clutter compile slightly faster, and cleans up the
build system, especially when dealing with introspection data.

Ideally, we also want to make Cogl part of the top-level build, so that
we can finally drop the sed trick to change the shared library from the
GIR before compiling it.

Currently disabled:

  ‣ OSX backend
  ‣ Fruity backend

Currently enabled but untested:

  ‣ EGL backend
  ‣ Windows backend
2010-09-29 14:40:15 +01:00
Emmanuele Bassi
c8f83525ce build: Add cogl-debug-options.h 2010-09-15 16:12:56 +01:00
Emmanuele Bassi
bc4be1c673 build: Add tesselator to the include paths 2010-09-13 11:31:46 +01:00
Emmanuele Bassi
a856003791 build: Remove gir files from dist
The introspection data is going to be generated, so it should never be
in the dist.
2010-09-13 02:10:35 +01:00
Emmanuele Bassi
8f049b360a build: Do not build a noinst library for the tesselator
Let's try to keep Cogl's build as non-recursive as possible, in the hope
that one day we'll be able to make it fully non-recursive along with the
rest of Clutter.
2010-09-12 19:25:47 +01:00
Emmanuele Bassi
08eb738c93 build: Use Makefile.introspection
Whenever possible, instead of writing our own rules for generating GIR
files and typelibs.
2010-09-03 11:38:22 +01:00
Colin Walters
d4d899fa27 introspection: Build fixes
This patch merges in substantial work from
Emmanuele Bassi <ebassi@linux.intel.com>

* Use new introspection --include-uninstalled API since we don't want
  to try to find the clutter-1.0.pc file before it's installed.
* Use --pkg-export for Clutter-1.0.gir, since we want the .gir file to
  contain the associated pkg-config file.
* Drop the use of --pkg for dependencies; those come from the associated
  .gir files.  (Actually, --pkg is almost never needed)
* Add --quiet

http://bugzilla.clutter-project.org/show_bug.cgi?id=2292
2010-09-03 11:38:22 +01:00
Damien Lespiau
7e158c6bc5 cex100: Add a Clutter EGL backend for CE3100/CE4100 SoCs
Intel CE3100 and CE4100 SoCs are designed for TVs. They have separate
framebuffers that are blended together by a piece of hardware to make
the final output. The library that allows you to initialize and
configure those planes is called GDL. A EGL GDL winsys can then be
use with those planes as NativeWindowType to select which plane to use.

This patch adds a new ClutterBackendCex100 backend that can be
selected at compile time with the new --with-flavour=cex100 option.
2010-09-03 11:13:35 +01:00
Damien Lespiau
64b5308d7f introspection: Use the --quiet flag conditionally
--quiet has been added to g-ir-scanner in the 0.9.1 cycle. We really
want to be able to compile clutter with 0.6.14 to be able to reuse
gir files that are distributed in current distributions.

Use the INTROSPECTION_SCANNER_ARGS (previously unused) variable to
convey --quiet when necessary.

Fixes: http://bugzilla.clutter-project.org/show_bug.cgi?id=2265
2010-08-12 16:43:07 +01:00
Neil Roberts
b2f2e69264 cogl-atlas-texture: Split out the atlas data structure
Instead of storing a pointer to the CoglRectangleMap and a handle to
the atlas texture in the context, there is a now a separate data
structure called a CoglAtlas to manage these two. The context just
contains a pointer to this. The code to reorganise the atlas has been
moved from cogl-atlas-texture.c to cogl-atlas.c
2010-08-12 11:56:59 +01:00
Neil Roberts
cb114f43ab cogl: Add an internal utility to maintain a list of callback functions
This adds an internal CoglCallbackList type which is just a GSList of
of function pointers along with a data pointer to form a
closure. There are functions to add and remove items and to invoke the
list of functions. This could be used in a number of places in Cogl.
2010-08-12 11:54:42 +01:00
Neil Roberts
bc20010582 cogl-atlas: Rename to CoglRectangleMap
This simply renames CoglAtlas to CoglRectangleMap without making any
functional changes. The old 'CoglAtlas' is just a data structure for
managing unused areas of a rectangle and it doesn't neccessarily have
to be used for an atlas so it wasn't a very good name.
2010-08-12 11:54:42 +01:00
Emmanuele Bassi
4be7310fb1 build: Make the introspection generation quiet (again) 2010-08-12 09:03:58 +01:00
Robert Bragg
7705469d2b cogl-shader: unifies the driver/{gl,gles} shader files
The per driver implementations of cogl-shader.c had become almost
identical we now have a single cogl/cogl-shader.c instead.
2010-08-03 12:41:37 +01:00
Robert Bragg
8640f527cb cogl: don't include cogl-debug.h in cogl.h or install
cogl-debug.h is an internal header so it shouldn't have been included by
cogl.h and the header shouldn't be installed either.
2010-08-02 17:41:42 +01:00
Robert Bragg
5442e429ba material: split the texture unit management out
In general cogl-material.c has become far to large to manage in one
source file. As one of the ways to try and break it down this patch
starts to move some of lower level texture unit state management out
into cogl-material-opengl.c. The naming is such because the plan is to
follow up and migrate the very GL specific state flushing code into the
same file.
2010-07-13 19:26:58 +01:00
Neil Roberts
5288f6d88d Add a Cogl texture 3D backend
This adds a publicly exposed experimental API for a 3D texture
backend. There is a feature flag which can be checked for whether 3D
textures are supported. Although we require OpenGL 1.2 which has 3D
textures in core, GLES only provides them through an extension so the
feature can be used to detect that.

The textures can be created with one of two new API functions :-

cogl_texture_3d_new_with_size

 and

cogl_texture_3d_new_from_data

There is also internally a new_from_bitmap function. new_from_data is
implemented in terms of this function.

The two constructors are effectively the only way to upload data to a
3D texture. It does not work to call glTexImage2D with the
GL_TEXTURE_3D target so the virtual for cogl_texture_set_region does
nothing. It would be possible to make cogl_texture_get_data do
something sensible like returning all of the images as a single long
image but this is not currently implemented and instead the virtual
just always fails. We may want to add API specific to the 3D texture
backend to get and set a sub region of the texture.

All of those three functions can throw a GError. This will happen if
the GPU does not support 3D textures or it does not support NPOTs and
an NPOT size is requested. It will also fail if the FBO extension is
not supported and the COGL_TEXTURE_NO_AUTO_MIPMAP flag is not
given. This could be avoided by copying the code for the
GL_GENERATE_MIPMAP TexParameter fallback, but in the interests of
keeping the code simple this is not yet done.

This adds a couple of functions to cogl-texture-driver for uploading
3D data and querying the 3D proxy
texture. prep_gl_for_pixels_upload_full now also takes sets the
GL_UNPACK_IMAGE_HEIGHT parameter so that 3D textures can have padding
between the images. Whenever 3D texture is uploading, both the height
of the images and the height of all of the data is specified (either
explicitly or implicilty from the CoglBitmap) so that the image height
can be deduced by dividing by the depth.
2010-07-13 14:28:52 +01:00
Emmanuele Bassi
added497f4 Merge branch 'cally-merge'
* cally-merge:
  cally: Add introspection generation
  cally: Improving cally doc
  cally: Cleaning CallyText
  cally: Refactoring "window:create" and "window:destroy" emission code
  cally: Use proper backend information on CallyActor
  cally: Check HAVE_CONFIG_H on cally-util.c
  docs: Fix Cally documentation
  cally: Clean up the headers
  Add binaries of the Cally examples to the ignore file
  docs: Add Cally API reference
  Avoid to load cally module on a11y examples
  Add accessibility tests
  Initialize accessibility support on clutter_init
  Rename some methods and includes to avoid -Wshadow warnings
  Cally initialization code
  Add Cally
2010-07-07 16:06:30 +01:00
Emmanuele Bassi
0eb9fc04f5 cally: Add introspection generation
Toolkits and applications not written in C might still need access to
the Cally API to write accessibility extensions based on it for their
own native elements.
2010-07-07 15:57:43 +01:00
Alexandros Frantzis
bf56e798c6 build: Exclude built sources from the dist
http://bugzilla.clutter-project.org/show_bug.cgi?id=2169

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2010-07-06 13:24:00 +01:00
Robert Bragg
521d9ca203 rename CoglPixelBuffer to CoglPixelArray
This renames CoglPixelBuffer to CoglPixelArray to be consistent with the
new CoglVertexArray API.
2010-07-05 15:20:04 +01:00
Robert Bragg
17731b3af1 material: Split the fragment processing backends out
This splits the fragment processing backends (glsl, arbfp and fixed) out
from cogl-material.c into their own cogl-material-{glsl,arbfp,fixed}.c
files in an effort to help and keep cogl-material.c maintainable.
2010-06-30 15:04:10 +01:00
Neil Roberts
b86e330957 cogl: Pull in the code for GLU tesselator from Mesa/SGI
This copies the files for the GLU tesselator from Mesa. The Mesa code
is based on the original SGI code and is released under a BSD license.

The memalloc.h header has been replaced with one that forces the code
to use g_malloc and friends. The rest of the files are not altered
from the original so it should be possible to later upgrade the files
by simply overwriting them.

There is a tesselator.h header which is expected to be included by
rest of Cogl to use the tesselator. This contains a trimmed down
version of glu.h that only includes parts that pertain to the
tesselator. There is also a stub glu.h in the GL directory which is
just provided so that the tesselator code can include <GL/gl.h>
without depending on the system header. It just redirects to
tesselator.h
2010-06-29 20:37:13 +01:00
Neil Roberts
e33a94bff4 cogl: Remove cogl-defines.h.in from the driver make files
Commit 7fae8ac051 changed cogl-defines.h.in so there is only a
single copy in clutter/cogl/ instead of one for each driver. However
the old files were still mentioned in the EXTRA_DIST of the
Makefile.am so make distcheck was failing.
2010-06-23 17:44:09 +01:00
Neil Roberts
8458fb7e20 Add a CoglTexturePixmapX11 texture backend
This is a publicly exposed texture backend to create a texture which
contains the contents of an X11 pixmap. The API is currently marked as
experimental.

The backend internally holds a handle to another texture. All of the
backend virtuals simply redirect to the internal texture.

The texture can optionally be automatically updated if the
automatic_updates parameter is TRUE. If set then Cogl will listen for
damage events on the pixmap and update the texture accordingly.
Alternatively a damage object can be created externally and passed
down to Cogl.

The updates can be performed with XGetImage, XShmGetImage or the
GLX_EXT_texture_pixmap extension. If the TFP extension is used it will
optionally try to create a rectangle texture if the driver does not
support NPOTs or it is forced through the
COGL_PIXMAP_TEXTURE_RECTANGLE or CLUTTER_PIXMAP_TEXTURE_RECTANGLE
environment variables.

If the GLXFBConfig does not support mipmapping then it will fallback
to using X{Shm,}GetImage. It keeps a separate texture around for this
so that it can later start using the TFP texture again if the texture
is later drawn with mipmaps disabled.
2010-06-22 12:22:48 +01:00