Commit Graph

199 Commits

Author SHA1 Message Date
Robert Bragg
7571cc1923 cogl: expose the semantic differences of gl/gles2 npot textures
This adds three new feature flags COGL_FEATURE_TEXTURE_NPOT_BASIC,
COGL_FEATURE_TEXTURE_NPOT_MIPMAP and COGL_FEATURE_TEXTURE_NPOT_REPEAT
that can tell you if your hardware supports non power of two textures,
npot textures + mipmaps and npot textures + wrap modes other than
CLAMP_TO_EDGE.

The pre-existing COGL_FEATURE_TEXTURE_NPOT feature implies all of the
above.

By default GLES 2 core supports npot textures but mipmaps and repeat
modes can only be used with power of two textures. This patch also makes
GLES check for the GL_OES_texture_npot extension to determine if mipmaps
and repeating are supported with npot textures.
2010-07-07 13:26:41 +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
9d0962098f cogl-defines.h: Add a COGL_HAS_X11 define
This will be defined in cogl-defines.h whenever Cogl is built using a
winsys that supports X11. This implies CoglTexturePixmapX11 will be
available.

To make this work the two separate cogl-defines.h.in files have been
merged into one. The configure script now makes a @COGL_DEFINES@
substitution variable which contains the #define lines to put in
rather than directly having them in the seperate files.
2010-06-22 12:22:47 +01:00
Neil Roberts
31b5beb2c0 cogl: Add the infrastructure for checking for winsys extensions
This adds the framework needed to check for winsys specific extensions
(such as GLX extensions) using a similar mechanism to the
cogl-feature-functions header. There is a separate
cogl-winsys-feature-functions header which will contain macros to list
the extensions and functions. cogl_create_context_winsys now calls
_cogl_feature_check for each of these functions. _cogl_feature_check
has had to be changed to accept the driver prefix as the first
parameter so that it can prepend "GLX" rather than "GL" in this case.
2010-06-22 12:22:43 +01:00
Neil Roberts
9a1aa08fda cogl: Add an internal CoglTextureRectangle backend
This adds an internal rectangle texture backend which is mostly based
on the CoglTexture2D backend. It will throw assert failures if any
operations are attempted that rectangle textures don't support, such
as mipmapping or hardware repeating.
2010-06-22 11:47:33 +01:00
Neil Roberts
5a5b3914ba cogl: Fix the include path in driver/*/Makefile.am
The include path for the winsys and driver folder was given relative
to $(srcdir) so it would end up relative to the driver folder which is
wrong. It is now specified as $(srcdir)/../../winsys to get the right
location. The driver folder is removed because it is actually just
$(srcdir) and that is already included.
2010-06-22 11:47:32 +01:00
Neil Roberts
cc7722389c cogl-program: Add cogl_program_uniform_1i to GLES
The GLES 1.1 backend was missing a stub for cogl_program_uniform_1i.
2010-06-11 16:06:31 +01:00
Neil Roberts
9343cb849a cogl-gles2: Prefix internal GLES 2 wrapper symbols with _
Some internal symbols used for the GLES 2 wrapper were accidentally
being exported. This prepends an underscore to them so they won't
appear in the shared library.
2010-06-11 16:06:31 +01:00
Emmanuele Bassi
7a7dedebd5 cogl-framebuffer: Use the FBO extension for color sizes
OpenGL 3.0 deprecated querying of the GL_{RED,GREEN,BLUE}_BITS
constants, and the FBO extension provides a mechanism to query for the
color buffer sizes which *should* work even with the default
framebuffer. Unfortunately, this doesn't seem to hold for Mesa - so we
just use this for the offscreen CoglFramebuffer type, and we fall back
to glGetIntegerv() for the onscreen one.

http://bugzilla.openedhand.com/show_bug.cgi?id=2094
2010-06-10 19:53:39 +01:00
Robert Bragg
82e80e6765 material: Avoid redundant glBindTexture calls
This adds a _cogl_bind_gl_texture_transient function that should be used
instead of glBindTexture so we can have a consistent cache of the
textures bound to each texture unit so we can avoid some redundant
binding.
2010-06-09 17:26:15 +01:00
Robert Bragg
acc44161c1 material: Adds backend abstraction for fragment processing
As part of an effort to improve the architecture of CoglMaterial
internally this overhauls how we flush layer state to OpenGL by adding a
formal backend abstraction for fragment processing and further
formalizing the CoglTextureUnit abstraction.

There are three backends: "glsl", "arbfp" and "fixed". The fixed backend
uses the OpenGL fixed function APIs to setup the fragment processing,
the arbfp backend uses code generation to handle fragment processing
using an ARBfp program, and the GLSL backend is currently only there as
a formality to handle user programs associated with a material. (i.e.
the glsl backend doesn't yet support code generation)

The GLSL backend has highest precedence, then arbfp and finally the
fixed. If a backend can't support some particular CoglMaterial feature
then it will fallback to the next backend.

This adds three new COGL_DEBUG options:
* "disable-texturing" as expected should disable all texturing
* "disable-arbfp" always make the arbfp backend fallback
* "disable-glsl" always make the glsl backend fallback
* "show-source" show code generated by the arbfp/glsl backends
2010-06-09 17:15:59 +01:00
Damien Lespiau
56dd71dba0 cogl: Introduce private feature flags and check for ARB_fp
The Cogl context has now a feature_flags_private enum that will allow us
to query and use OpenGL features without exposing them in the public
API.

The ARB_fragment_program extension is the first user of those flags.
Looking for this extension only happens in the gl driver as the gles
drivers will not expose them.

One can use _cogl_features_available_private() to check for the
availability of such private features.

While at it, reindent cogl-internal.h as described in CODING_STYLE.
2010-06-09 15:19:30 +01:00
Neil Roberts
8836c868a4 cogl-gles2-wrapper: Fix some cases using the wrong texture unit
At two places in cogl_wrap_prepare_for_draw it was trying to loop over
the texture units to flush some state. However it was retrieving the
texture unit pointer using w->active_texture_unit instead of the loop
index so it would end up with the wrong state.

Also in glEnableClientState it was using the active unit instead of
the client active unit.
2010-06-08 17:26:26 +01:00
Damien Lespiau
58b0028b52 analysis: FALSE/0 used in pointer context
While this is totally fine (0 in the pointer context will be converted
in the right internal NULL representation, which could be a value with
some bits to 1), I believe it's clearer to use NULL in the pointer
context.

It seems that, in most case, it's more an overlook than a deliberate
choice to use FALSE/0 as NULL, eg. copying a _COGL_GET_CONTEXT (ctx, 0)
or a g_return_val_if_fail (cond, 0) from a function returning a
gboolean.
2010-06-01 12:08:18 +01:00
Neil Roberts
36298bbe30 gles: Fix the functions names for the GL_OES_framebuffer_object ext
In 91cde78a7 I accidentally changed the function names that get looked
up for the framebuffer extension under GLES so that they didn't have
any suffix. The spec for extension specifies that they should have the
OES suffix.
2010-05-05 12:24:11 +01:00
Emmanuele Bassi
72f4ddf532 Remove mentions of the FSF address
Since using addresses that might change is something that finally
the FSF acknowledge as a plausible scenario (after changing address
twice), the license blurb in the source files should use the URI
for getting the license in case the library did not come with it.

Not that URIs cannot possibly change, but at least it's easier to
set up a redirection at the same place.

As a side note: this commit closes the oldes bug in Clutter's bug
report tool.

http://bugzilla.openedhand.com/show_bug.cgi?id=521
2010-03-01 12:56:10 +00:00
Neil Roberts
82fd07c54a cogl-vertex-buffer: Add support for unsigned int indices
This adds a COGL_INDICES_TYPE_UNSIGNED_INT enum value so that unsigned
ints can be used with cogl_vertex_buffer_indices_new.  Unsigned ints
are not supported in core on GLES so a feature flag has also been
added to advertise this. GLES only sets the feature if the
GL_OES_element_index_uint extension is available. It is an error to
call indices_new() with unsigned ints unless the feature is
advertised.

http://bugzilla.openedhand.com/show_bug.cgi?id=1998
2010-02-26 10:56:35 +00:00
Neil Roberts
b583083a3f gles2: Remove the special wrapper for glBindTexture
Previously the GLES2 backend needed a special wrapper for
glBindTexture because it needed to know the internal GL format of the
texture in order to correctly implement the GL_MODULATE texture env
mode. When GL_MODULATE is used then the RGB values are taken from the
previous texture layer rather than being fetched from the
texture. However since the material API was added Cogl no longer uses
the GL_MODULATE texture env mode but instead always uses GL_COMBINE.

Compiling the GLES2 backend broke since the more-texture-backends
branch merge because the cogl_get_internal_gl_format function was
removed and there was one place in GLES2 specific code that was using
this to bind the texture.
2010-02-25 12:50:52 +00:00
Neil Roberts
cb7a99ac69 cogl-gles2-wrapper: Add support for the layer combine operations
The texture layer combine functions are now hard coded to GL_COMBINE
instead of GL_MODULATE. The combine function can be customized with
all the parameters of GL_COMBINE. A shader is generated to implement
the given parameters.

Currently it will try to generate code for the constant color but it
will use a uniform which does not exist.
2010-02-25 12:50:52 +00:00
Neil Roberts
7dce5d9372 gles2: Implement a wrapper for glGetIntegerv(GL_MAX_TEXTURE_UNITS)
The GLES2 backend for Cogl is failing to compile because
GL_MAX_TEXTURE_UNITS is not defined. Let's define it and provide a
wrapper which uses GL_MAX_TEXTURE_IMAGE_UNITS or
COGL_GLES2_MAX_TEXTURE_UNITS, whichever is the smallest.
2010-02-25 12:50:52 +00:00
Robert Bragg
ba4b00be42 cogl: remove redundant _cogl_journal_flush prototype
There was a redundant _cogl_journal_flush function prototype in
cogl-primitives.h
2010-02-12 14:05:01 +00:00
Robert Bragg
0f5f4e8645 cogl: improves header and coding style consistency
We've had complaints that our Cogl code/headers are a bit "special" so
this is a first pass at tidying things up by giving them some
consistency. These changes are all consistent with how new code in Cogl
is being written, but the style isn't consistently applied across all
code yet.

There are two parts to this patch; but since each one required a large
amount of effort to maintain tidy indenting it made sense to combine the
changes to reduce the time spent re indenting the same lines.

The first change is to use a consistent style for declaring function
prototypes in headers. Cogl headers now consistently use this style for
prototypes:

 return_type
 cogl_function_name (CoglType arg0,
                     CoglType arg1);

Not everyone likes this style, but it seems that most of the currently
active Cogl developers agree on it.

The second change is to constrain the use of redundant glib data types
in Cogl. Uses of gint, guint, gfloat, glong, gulong and gchar have all
been replaced with int, unsigned int, float, long, unsigned long and char
respectively. When talking about pixel data; use of guchar has been
replaced with guint8, otherwise unsigned char can be used.

The glib types that we continue to use for portability are gboolean,
gint{8,16,32,64}, guint{8,16,32,64} and gsize.

The general intention is that Cogl should look palatable to the widest
range of C programmers including those outside the Gnome community so
- especially for the public API - we want to minimize the number of
foreign looking typedefs.
2010-02-12 14:05:00 +00:00
Robert Bragg
10fa7c7ce9 cogl: deprecates cogl_check_extension
OpenGL is an implementation detail for Cogl so it's not appropriate to
expose OpenGL extensions through the Cogl API.

Note: Clutter is currently still using this API, because it is still
doing raw GL calls in ClutterGLXTexturePixmap, so this introduces a
couple of (legitimate) build warnings while compiling Clutter.
2010-02-12 14:05:00 +00:00
Damien Lespiau
ca80e8802b cogl-pixel-buffer: Add a fallback path
First, let's add a new public feature called, surprisingly,
COGL_FEATURE_PBOS to check the availability of PBOs and provide a
fallback path when running on older GL implementations or on OpenGL ES

In case the underlying OpenGL implementation does not provide PBOs, we
need a fallback path (a malloc'ed buffer). The CoglPixelBufer
constructors will instanciate a subclass of CoglBuffer that handles
map/unmap and set_data() with a malloc'ed buffer.

The public feature is useful to check before using set_data() on a
buffer as it will mean doing a memcpy() when not supporting PBOs (in
that case, it's better to create the texture directly instead of using a
CoglBuffer).
2010-02-08 17:14:49 +00:00
Damien Lespiau
dbef77cd8b cogl: new textures sould have GL_TEXTURE_MIN_FILTER set to GL_LINEAR
The only way the user has to set the mipmap filters is through the
material/layer API. This API defaults to GL_LINEAR/GL_LINEAR for the max
and min filters. With the main use case of cogl being 2D interfaces, it
makes sense do default to GL_LINEAR for the min filter.

When creating new textures, we did not set any filter on them, using
OpenGL defaults': GL_NEAREST_MIPMAP_LINEAR for the min filter and
GL_LINEAR for the max filter. This will make the driver allocate memory
for the mipmap tree, memory that will not be used in the nominal case
(as the material API defaults to GL_LINEAR).

This patch tries to ensure that the min filter is set to GL_LINEAR
before any glTexImage*() call is done on the texture by setting the
filter when generating new OpenGL handles.
2010-02-08 17:14:49 +00:00
Neil Roberts
f5d809f1e8 Merge branch 'master' into more-texture-backends 2010-01-15 12:15:46 +00:00
Neil Roberts
dfc3dd9c43 cogl: Remove the CGL_* defines
These macros used to define Cogl wrappers for the GLenum values. There are
now Cogl enums everywhere in the API where these were required so we
shouldn't need them anymore. They were in the public headers but as
they are not neccessary and were not in the API docs for Clutter 1.0
it should be safe to remove them.
2010-01-12 17:10:15 +00:00
Neil Roberts
f17767e4c1 cogl: Add _cogl_texture_driver_upload_to_gl
This provides a way to upload the entire data for a texture without
having to first call glTexImage and then glTexSubImage. This should be
faster especially with indirect rendering where it would needlessy
send the data for the texture twice.
2009-12-02 22:03:26 +00:00
Neil Roberts
5030356e0e cogl: Move data only used for upload out of CoglTexture
The CoglTexture struct previously contained some fields which are only
used to upload data such as the CoglBitmap and the source GL
format. These are now moved to a separate CoglTextureUploadData struct
which only exists for the duration of one of the cogl_texture_*_new
functions. In cogl-texture there are utility functions which operate
on this new struct rather than on CoglTexture directly.

Some of the fields that were previously stored in the CoglBitmap
struct are now copied to the CoglTexture such as the width, height,
format and internal GL format.

The rowstride was previously stored in CoglTexture and this was
publicly accessible with the cogl_texture_get_rowstride
function. However this doesn't seem to be a useful function because
there is no need to use the same rowstride again when uploading or
downloading new data. Instead cogl_texture_get_rowstride now just
calculates a suitable rowstride from the format and width of the
texture.
2009-12-02 22:03:07 +00:00
Robert Bragg
78fb882a4b [cogl] remove unused gles/cogl-utils.[c,h]
The only function in gles/cogl-utils.c was cogl_util_next_p2() and it's
redundant since we also have a cogl/cogl-utils.[c,h]
2009-11-24 17:58:22 +00:00
Neil Roberts
b4fc8faaab cogl: Use APIENTRY for GL function pointer declarations
This matters for platforms such as Windows that use a different
calling covention from the default for GL functions.
2009-11-18 19:24:09 +00:00
Emmanuele Bassi
7372e1d4f9 build: Add cogl-feature-functions.h to the dist 2009-11-18 14:43:46 +00:00
Neil Roberts
0e112c3371 cogl: Add the missing terminators for the arrays of feature functions
_cogl_feature_check expects the array of function names to be
terminated with a NULL pointer but I forgot to add this. This was
causing crashes depending on what happened to be in memory after the
array.
2009-11-18 13:23:10 +00:00
Neil Roberts
0927f35e7a cogl: Use the GL_EXT_blend_{func,equation}_separate extensions
We should use these extensions to check for glBlendFuncSeparate and
glBlendEquationSeparate as well as checking the GL version number.
2009-11-17 18:06:31 +00:00
Neil Roberts
2a53b84d18 cogl: Don't bother checking for NPOTs or VBOs on later GLs
For VBOs, we don't need to check for the extension if the GL version
is greater than 1.5. Non-power-of-two textures are given in 2.0.

We could also assume shader support in GL 2.0 except that the function
names are different from those in the extension so it wouldn't work
well with the current mechanism.
2009-11-17 17:22:22 +00:00
Neil Roberts
058d79dce2 cogl: Make it easier to add checks for GL extensions
Previously if you need to depend on a new GL feature you had to:

- Add typedefs for all of the functions in cogl-defines.h.in

- Add function pointers for each of the functions in
  cogl-context-driver.h

- Add an initializer for the function pointers in
  cogl-context-driver.c

- Add a check for the extension and all of the functions in
  cogl_features_init. If the extension is available under multiple
  names then you have to duplicate the checks.

This is quite tedious and error prone. This patch moves all of the
features and their functions into a list of macro invocations in
cogl-feature-functions.h. The macros can be redefined to implement all
of the above tasks from the same header.

The features are described in a struct with a pointer to a table of
functions. A new function takes the feature description from this
struct and checks for its availability. The feature can take a list of
extension names with a list of alternate namespaces (such as "EXT" or
"ARB"). It can also detect the feature from a particular version of
GL.

The typedefs are now gone and instead the function pointer in the Cogl
context just directly contains the type.

Some of the functions in the context were previously declared with the
'ARB' extension. This has been removed so that now all the functions
have no suffix. This makes more sense when the extension could
potentially be merged into GL core as well.
2009-11-17 15:11:26 +00:00
Neil Roberts
8b4a861093 Use the GL_ARB_multitexture extension on GL 1.2
Cogl requires multi-texturing support. This is only available as an
extension in GL 1.2 so we should check for it before accepting the
driver.

http://bugzilla.openedhand.com/show_bug.cgi?id=1875
2009-11-13 15:56:01 +00:00
Neil Roberts
a50907848f Validate that the GL version is >= 1.2
There is a new internal Cogl function called _cogl_check_driver_valid
which looks at the value of the GL_VERSION string to determine whether
the driver is supported. Clutter now calls this after the stage is
realized. If it fails then the stage is marked as unrealized and a
warning is shown.

_cogl_features_init now also checks the version number before getting
the function pointers for glBlendFuncSeparate and
glBlendEquationSeparate. It is not safe to just check for the presence
of the functions because some drivers may define the function without
fully implementing the spec.

The GLES version of _cogl_check_driver_valid just always returns TRUE
because there are no version requirements yet.

Eventually the function could also check for mandatory extensions if
there were any.

http://bugzilla.openedhand.com/show_bug.cgi?id=1875
2009-11-13 15:55:48 +00:00
Robert Bragg
b49f90acb6 [cogl-primitives] Get rid of driver specific cogl-primitives code
These files were practically identical, except the gles code had additional
support for filling paths without a stencil buffer.  All the driver code has
now been moved into cogl/cogl-primitives.c
2009-11-04 16:02:34 +00:00
Robert Bragg
bb3a008318 [draw-buffers] First pass at overhauling Cogl's framebuffer management
Cogl's support for offscreen rendering was originally written just to support
the clutter_texture_new_from_actor API and due to lack of documentation and
several confusing - non orthogonal - side effects of using the API it wasn't
really possible to use directly.

This commit does a number of things:
- It removes {gl,gles}/cogl-fbo.{c,h} and adds shared cogl-draw-buffer.{c,h}
  files instead which should be easier to maintain.
- internally CoglFbo objects are now called CoglDrawBuffers. A
  CoglDrawBuffer is an abstract base class that is inherited from to
  implement CoglOnscreen and CoglOffscreen draw buffers.  CoglOffscreen draw
  buffers will initially be used to support the
  cogl_offscreen_new_to_texture API, and CoglOnscreen draw buffers will
  start to be used internally to represent windows as we aim to migrate some
  of Clutter's backend code to Cogl.
- It makes draw buffer objects the owners of the following state:
  - viewport
  - projection matrix stack
  - modelview matrix stack
  - clip state
(This means when you switch between draw buffers you will automatically be
 switching to their associated viewport, matrix and clip state)

Aside from hopefully making cogl_offscreen_new_to_texture be more useful
short term by having simpler and well defined semantics for
cogl_set_draw_buffer, as mentioned above this is the first step for a couple
of other things:
- Its a step toward moving ownership for windows down from Clutter backends
  into Cogl, by (internally at least) introducing the CoglOnscreen draw
  buffer.  Note: the plan is that cogl_set_draw_buffer will accept on or
  offscreen draw buffer handles, and the "target" argument will become
  redundant since we will instead query the type of the given draw buffer
  handle.
- Because we have a common type for on and offscreen framebuffers we can
  provide a unified API for framebuffer management. Things like:
  - blitting between buffers
  - managing ancillary buffers (e.g. attaching depth and stencil buffers)
  - size requisition
  - clearing
2009-11-03 17:23:03 +00:00
Robert Bragg
6b2ff320ca [cogl-fbo] Bring the gles code more in line with gl code
Over time the two cogl-fbo.c files have needlessly diverged as bug fixes or
cleanups went into one version but not the other.  This tries to bring them
back in line with each other.  It should actually be simple enough to move
cogl-fbo.c to be a common file, and simply not build it for GLES 1.1, so
maybe I'll follow up with such a patch soon.
2009-11-02 16:55:02 +00:00
Robert Bragg
cc0af441f2 [cogl-fbo] Remove poorly documented workaround for unknown driver/hardware
The comment just said: "Some implementation require a clear before drawing
to an fbo.  Luckily it is affected by scissor test." and did a scissored
clear, which is clearly a driver bug workaround, but for what driver?  The
fact that it was copied into the gles backend (or vica versa is also
suspicious since it seems unlikely that the workaround is necessary for both
backends.)

We can easily restore the workaround with a better comment if this problem
really still exists on current drivers, but for now I'd rather minimize
hand-wavey workaround code that can't be tested.
2009-11-02 16:55:02 +00:00
Emmanuele Bassi
df920a42df build: Add missing gles/cogl-context-driver.h to dist
The gles/cogl-context-driver.h header file is missing from the
dist target, which means it's not in the tarballs.
2009-10-30 12:11:19 +00:00
Neil Roberts
6cff24f437 Fix some compilation errors in cogl-gles2-wrapper.c
The changes in 74f2122b6 introduced some syntax errors which were
preventing the GLES2 backend from compiling.
2009-10-22 18:04:59 +01:00
Robert Bragg
c02e10c688 [gles2] remove lots of redundant matrix stack code
Since we no longer depend on the GL matrix API in Cogl we can remove a lot
of wrapper code from the GLES 2 backend.  This is particularly nice given
that there was no code shared between the cogl-matrix-stack API and gles2
wrappers so we had a lot of duplicated logic.
2009-10-20 12:32:51 +01:00
Robert Bragg
eed2479556 [cogl] Removes the cogl-current-matrix abstraction
The indirection through this API isn't necessary since we no longer
arbitrate between the OpenGL matrix API and Cogl's client side API.  Also it
doesn't help to maintain an OpenGL style matrix mode API for internal use
since it's awkward to keep restoring the MODELVIEW mode and easy enough to
directly work with the matrix stacks of interest.

This replaces use of the _cogl_current_matrix API with direct use of the
_cogl_matrix_stack API.  All the unused cogl_current_matrix API is removed
and the matrix utility code left in cogl-current-matrix.c was moved to
cogl.c.
2009-10-20 12:32:50 +01:00
Vladimir Nadvornik
65015a137e [cogl-texture] Split CoglTexture into an abstract class + CoglTexture2dSliced
cogl-texture-2d-sliced provides an implementation of CoglTexture and this
seperation lays the foundation for potentially supporting atlas textures,
pixmap textures (as in GLX_EXT_texture_from_pixmap) and fast-path
GL_TEXTURE_{1D,2D,3D,RECTANGLE} textures in a maintainable fashion.
2009-10-16 18:58:51 +01:00
Robert Bragg
c40d5ae9ea [cogl-texture] Seal CoglTexture internals from cogl-primitives.c
cogl-primitives.c was previously digging right into CoglTextures so it could
manually iterate the texture slices for texturing quads and polygons and
because we were missing some state getters we were lazily just poking into
the structures directly.

This adds some extra state getter functions, and adds a higher level
_cogl_texture_foreach_slice () API that hopefully simplifies the way in
which sliced textures may be used to render primitives.  This lets you
specify a rectangle in "virtual" texture coords and it will call a given
callback for each slice that intersects that rectangle giving the virtual
coords of the current slice and corresponding "real" texture coordinates for
the underlying gl texture.

At the same time a noteable bug in how we previously iterated sliced
textures was fixed, whereby we weren't correctly handling inverted texture
coordinates.  E.g.  with the previous code if you supplied texture coords of
tx1=100,ty1=0,tx2=0,ty2=100 (inverted along y axis) that would result in a
back-facing quad, which could be discarded if using back-face culling.
2009-10-16 18:58:51 +01:00
Robert Bragg
0bce7eac53 Intial Re-layout of the Cogl source code and introduction of a Cogl Winsys
As part of an incremental process to have Cogl be a standalone project we
want to re-consider how we organise the Cogl source code.

Currently this is the structure I'm aiming for:
cogl/
    cogl/
	<put common source here>
	winsys/
	   cogl-glx.c
	   cogl-wgl.c
	driver/
	    gl/
	    gles/
	os/ ?
    utils/
	cogl-fixed
	cogl-matrix-stack?
        cogl-journal?
        cogl-primitives?
    pango/

The new winsys component is a starting point for migrating window system
code (i.e.  x11,glx,wgl,osx,egl etc) from Clutter to Cogl.

The utils/ and pango/ directories aren't added by this commit, but they are
noted because I plan to add them soon.

Overview of the planned structure:

* The winsys/ API is the API that binds OpenGL to a specific window system,
  be that X11 or win32 etc.  Example are glx, wgl and egl. Much of the logic
  under clutter/{glx,osx,win32 etc} should migrate here.

* Note there is also the idea of a winsys-base that may represent a window
  system for which there are multiple winsys APIs.  An example of this is
  x11, since glx and egl may both be used with x11.  (currently only Clutter
  has the idea of a winsys-base)

* The driver/ represents a specific varient of OpenGL. Currently we have "gl"
  representing OpenGL 1.4-2.1 (mostly fixed function) and "gles" representing
  GLES 1.1 (fixed funciton) and 2.0 (fully shader based)

* Everything under cogl/ should fundamentally be supporting access to the
  GPU.  Essentially Cogl's most basic requirement is to provide a nice GPU
  Graphics API and drawing a line between this and the utility functionality
  we add to support Clutter should help keep this lean and maintainable.

* Code under utils/ as suggested builds on cogl/ adding more convenient
  APIs or mechanism to optimize special cases. Broadly speaking you can
  compare cogl/ to OpenGL and utils/ to GLU.

* clutter/pango will be moved to clutter/cogl/pango

How some of the internal configure.ac/pkg-config terminology has changed:
backendextra -> CLUTTER_WINSYS_BASE # e.g. "x11"
backendextralib -> CLUTTER_WINSYS_BASE_LIB # e.g. "x11/libclutter-x11.la"
clutterbackend -> {CLUTTER,COGL}_WINSYS # e.g. "glx"
CLUTTER_FLAVOUR -> {CLUTTER,COGL}_WINSYS
clutterbackendlib -> CLUTTER_WINSYS_LIB
CLUTTER_COGL -> COGL_DRIVER # e.g. "gl"

Note: The CLUTTER_FLAVOUR and CLUTTER_COGL defines are kept for apps

As the first thing to take advantage of the new winsys component in Cogl;
cogl_get_proc_address() has been moved from cogl/{gl,gles}/cogl.c into
cogl/common/cogl.c and this common implementation first trys
_cogl_winsys_get_proc_address() but if that fails then it falls back to
gmodule.
2009-10-16 18:58:50 +01:00