Commit Graph

16 Commits

Author SHA1 Message Date
Neil Roberts
a05c701e6b cogl: upload matrices with uniforms on GLES2
Once the GLES2 wrapper is removed we won't be able to upload the
matrices with the fixed function API any more. The fixed function API
gives a global state for setting the matrix but if a custom shader
uniform is used for the matrices then the state is per
program. _cogl_matrix_stack_flush_to_gl is called in a few places and
it is assumed the current pipeline doesn't need to be flushed before
it is called. To allow these semantics to continue to work, on GLES2
the matrix flush now just stores a reference to the matrix stack in
the CoglContext. A pre_paint virtual is added to the progend which is
called whenever a pipeline is flushed, even if the same pipeline was
flushed already. This gives the GLSL progend a chance to upload the
matrices to the uniforms. The combined modelview/projection matrix is
only calculated if it is used. The generated programs end up never
using the modelview or projection matrix so it usually only has to
upload the combined matrix. When a matrix stack is flushed a reference
is taked to it by the pipeline progend and the age is stored so that
if the same state is used with the same program again then we don't
need to reupload the uniform.
2010-12-13 17:29:13 +00:00
Neil Roberts
35b07f6b83 cogl-matrix-stack: Add _cogl_matrix_stack_has_identity_flag
This adds an internal function to quickly determine whether the top of
the matrix stack is known to be the identity matrix.
2010-12-13 17:28:52 +00:00
Neil Roberts
c11f72fd6d cogl-matrix-stack: Convert to be a CoglObject
We will want to use ref-counting on the CoglMatrixStack so it might as
well be a CoglObject.
2010-12-13 17:28:29 +00:00
Robert Bragg
d678125dd4 matrix-stack: Make header style consistent
Cogl doesn't follow the Clutter/GTK+ columnized function prototype style
so this updates cogl-matrix-stack.h to match the other Cogl headers.
2010-12-13 17:28:29 +00:00
Robert Bragg
104961de6a matrix-stack: Adds a stack age counter
Sometimes it would be useful if we could efficiently track when a matrix
stack has been modified. For example on GLES2 we have to upload the
modelview as a uniform to our glsl programs but because the modelview
state is part of the framebuffer state it becomes a bit more tricky to
know when to re-sync the value of the uniform with the framebuffer
state. This adds an "age" counter to CoglMatrixStack which is
incremented for any operation that effectively modifies the top of the
stack so now we can save the age of the stack inside the pipeline
whenever we update modelview uniform and later compare that with the
stack to determine if it has changed.
2010-12-13 17:28:29 +00:00
Robert Bragg
117ef6baff matrix-stack: use GArray instead of GSList for stack
In some micro-benchmarks testing journal throughput the list
manipulation jumps pretty high in the profile. This replaces the GSList
usage with a GArray instead which is effectively a grow only allocation
that means we avoid ongoing allocations while manipulating the stack
mid-scene.
2010-11-04 18:35:16 +00:00
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
Emmanuele Bassi
0145562cad Fix some compiler warnings
GCC complains that some variable might be used uninitialized.
2010-02-09 16:58:03 +00:00
Robert Bragg
944423a8d9 cogl: deprecate cogl_draw_buffer API and replace with a cogl_framebuffer API
cogl_push_draw_buffer, cogl_set_draw_buffer and cogl_pop_draw_buffer are now
deprecated and new code should use the new cogl_framebuffer_* API instead.

Code that previously did:
    cogl_push_draw_buffer ();
    cogl_set_draw_buffer (COGL_OFFSCREEN_BUFFER, buffer);
    /* draw */
    cogl_pop_draw_buffer ();
should now be re-written as:
    cogl_push_framebuffer (buffer);
    /* draw */
    cogl_pop_framebuffer ();

As can be seen from the example above the rename has been used as an
opportunity to remove the redundant target argument from
cogl_set_draw_buffer; it now only takes one call to redirect to an offscreen
buffer, and finally the term framebuffer may be a bit more familiar to
anyone coming from an OpenGL background.
2009-11-26 19:33:14 +00:00
Robert Bragg
28c7e940bf [matrix] Adds cogl_matrix_get_inverse API
This new API takes advantage of the recently imported Mesa code to support
inverse matrix calculation.  The matrix code keeps track (via internal
flags) of the transformations a matrix represents so that it can select an
optimized inversion function.

Note: although other aspects of the Cogl matrix API have followed a similar
style to Cairo's matrix API we haven't added a cogl_matrix_invert API
because the inverse of a CoglMatrix is actually cached as part of the
CoglMatrix structure meaning a destructive API like cogl_matrix_invert
doesn't let users take advantage of this caching design.
2009-11-04 03:34:05 +00:00
Robert Bragg
2d610c2300 [cogl] Make sure we draw upside down to offscreen draw buffers
First a few notes about Cogl coordinate systems:
- Cogl defines the window origin, viewport origin and texture coordinates
origin to be top left unlike OpenGL which defines them as bottom left.
- Cogl defines the modelview and projection identity matrices in exactly the
same way as OpenGL.
- I.e. we believe that for 2D centric constructs: windows/framebuffers,
viewports and textures developers are more used to dealing with a top left
origin, but when modeling objects in 3D; an origin at the center with y
going up is quite natural.

The way Cogl handles textures is by uploading data upside down in OpenGL
terms so that bottom left becomes top left.  (Note: This also has the
benefit that we don't need to flip the data we get from image decoding
libraries since they typically also consider top left to be the image
origin.)

The viewport and window coords are mostly handled with various y =
height - y tweaks before we pass y coordinates to OpenGL.

Generally speaking though the handling of coordinate spaces in Cogl is a bit
fragile.  I guess partly because none of it was design to be, it just
evolved from how Clutter defines its coordinates without much consideration
or testing.  I hope to improve this over a number of commits; starting here.

This commit deals with the fact that offscreen draw buffers may be bound to
textures but we don't "upload" the texture data upside down, and so if you
texture from an offscreen draw buffer you need to manually flip the texture
coordinates to get it the right way around.  We now force offscreen
rendering to be flipped upside down by tweaking the projection matrix right
before we submit it to OpenGL to scale y by -1.  The tweak is entirely
hidden from the user such that if you call cogl_get_projection you will not
see this scale.
2009-11-04 03:23:19 +00:00
Robert Bragg
01887460f6 [matrix-stack] Adds ctx->flushed_matrix_mode to cache the gl matrix mode
This cache of the gl matrix mode lets us avoid repeat calls to glMatrixMode
in _cogl_matrix_stack_flush_to_gl when we have lots of sequential modelview
matrix modifications.
2009-10-20 12:32:50 +01:00
Robert Bragg
43f8032a7f matrix-stack: more optimization for load_identity case
This goes a bit further than the previous patch, and as a special case
we now simply represent identity matrices using a boolean, and only
lazily initialize them when they need to be modified.
2009-10-20 12:32:50 +01:00
Robert Bragg
d153316045 [matrix-stack] avoid redundant clearing of matrix when using load_identity
The journal always uses an identity matrix since it uses software
transformation.  Currently it manually uses glLoadMatrix since previous
experimentation showed that the cogl-matrix-stack gave bad performance, but
it would be nice to fix performance so we only have to care about one path
for loading matrices.

For the common case where we do:
cogl_matrix_stack_push()
cogl_matrix_stack_load_identity()
we were effectively initializing the matrix 3 times. Once due to use of
g_slice_new0, then we had a cogl_matrix_init_identity in
_cogl_matrix_state_new for good measure, and then finally in
cogl_matrix_stack_load_identity we did another cogl_matrix_init_identity.

We don't use g_slice_new0 anymore, _cogl_matrix_state_new is documented as
not initializing the matrix (instead _cogl_matrix_stack_top_mutable now
takes a boolean to choose if new stack entries should be initialised) and so
we now only initialize once in cogl_matrix_stack_load_identity.
2009-10-20 12:32:49 +01:00
Robert Bragg
1402d1eb3c [current-matrix] Adds texture matrix stacks + removes GL matrix API usage
This relates back to an earlier commitment to stop using the OpenGL matrix
API which is considered deprecated. (ref 54159f5a1d)

The new texture matrix stacks are hung from a list of (internal only)
CoglTextureUnit structures which the CoglMaterial code internally references
via _cogl_get_texure_unit ().

So we would be left with only the cogl-matrix-stack code being responsible
for glMatrixMode, glLoadMatrix and glLoadIdentity this commit updates the
journal code so it now uses the matrix-stack API instead of GL directly.
2009-10-20 12:32:45 +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