Commit Graph

17 Commits

Author SHA1 Message Date
Neil Roberts
5e8ff248d2 Add functions to directly transform from a euler or a quaternion
This adds the following new functions to apply a rotation described by
a euler or a quaternion to either a CoglMatrix or directly to the
modelview stack of a framebuffer:

cogl_matrix_rotate_quaternion
cogl_matrix_rotate_euler
cogl_framebuffer_rotate_quaternion
cogl_framebuffer_rotate_euler

The direct framebuffer functions have corresponding functions in the
CoglMatrixStack to store an entry describing the rotation.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 5064315678b496395e1d01f266f322d73e55e324)
2012-08-06 14:27:43 +01:00
Robert Bragg
e3d6bc36d3 Re-design the matrix stack using a graph of ops
This re-designs the matrix stack so we now keep track of each separate
operation such as rotating, scaling, translating and multiplying as
immutable, ref-counted nodes in a graph.

Being a "graph" here means that different transformations composed of
a sequence of linked operation nodes may share nodes.

The first node in a matrix-stack is always a LOAD_IDENTITY operation.

As an example consider if an application where to draw three rectangles
A, B and C something like this:

cogl_framebuffer_scale (fb, 2, 2, 2);
cogl_framebuffer_push_matrix(fb);

  cogl_framebuffer_translate (fb, 10, 0, 0);

  cogl_framebuffer_push_matrix(fb);

    cogl_framebuffer_rotate (fb, 45, 0, 0, 1);
    cogl_framebuffer_draw_rectangle (...); /* A */

  cogl_framebuffer_pop_matrix(fb);

  cogl_framebuffer_draw_rectangle (...); /* B */

cogl_framebuffer_pop_matrix(fb);

cogl_framebuffer_push_matrix(fb);
  cogl_framebuffer_set_modelview_matrix (fb, &mv);
  cogl_framebuffer_draw_rectangle (...); /* C */
cogl_framebuffer_pop_matrix(fb);

That would result in a graph of nodes like this:

LOAD_IDENTITY
      |
    SCALE
    /     \
SAVE       LOAD
  |           |
TRANSLATE    RECTANGLE(C)
  |     \
SAVE    RECTANGLE(B)
  |
ROTATE
  |
RECTANGLE(A)

Each push adds a SAVE operation which serves as a marker to rewind too
when a corresponding pop is issued and also each SAVE node may also
store a cached matrix representing the composition of all its ancestor
nodes. This means if we repeatedly need to resolve a real CoglMatrix
for a given node then we don't need to repeat the composition.

Some advantages of this design are:
- A single pointer to any node in the graph can now represent a
  complete, immutable transformation that can be logged for example
  into a journal. Previously we were storing a full CoglMatrix in
  each journal entry which is 16 floats for the matrix itself as well
  as space for flags and another 16 floats for possibly storing a
  cache of the inverse. This means that we significantly reduce
  the size of the journal when drawing lots of primitives and we also
  avoid copying over 128 bytes per entry.
- It becomes much cheaper to check for equality. In cases where some
  (unlikely) false negatives are allowed simply comparing the pointers
  of two matrix stack graph entries is enough. Previously we would use
  memcmp() to compare matrices.
- It becomes easier to do comparisons of transformations. By looking
  for the common ancestry between nodes we can determine the operations
  that differentiate the transforms and use those to gain a high level
  understanding of the differences. For example we use this in the
  journal to be able to efficiently determine when two rectangle
  transforms only differ by some translation so that we can perform
  software clipping.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit f75aee93f6b293ca7a7babbd8fcc326ee6bf7aef)
2012-08-06 14:27:40 +01:00
Robert Bragg
54735dec84 Switch use of primitive glib types to c99 equivalents
The coding style has for a long time said to avoid using redundant glib
data types such as gint or gchar etc because we feel that they make the
code look unnecessarily foreign to developers coming from outside of the
Gnome developer community.

Note: When we tried to find the historical rationale for the types we
just found that they were apparently only added for consistent syntax
highlighting which didn't seem that compelling.

Up until now we have been continuing to use some of the platform
specific type such as gint{8,16,32,64} and gsize but this patch switches
us over to using the standard c99 equivalents instead so we can further
ensure that our code looks familiar to the widest range of C developers
who might potentially contribute to Cogl.

So instead of using the gint{8,16,32,64} and guint{8,16,32,64} types this
switches all Cogl code to instead use the int{8,16,32,64}_t and
uint{8,16,32,64}_t c99 types instead.

Instead of gsize we now use size_t

For now we are not going to use the c99 _Bool type and instead we have
introduced a new CoglBool type to use instead of gboolean.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit 5967dad2400d32ca6319cef6cb572e81bf2c15f0)
2012-08-06 14:27:39 +01:00
Neil Roberts
185630085c Add -Wmissing-declarations to maintainer flags and fix problems
This option to GCC makes it give a warning whenever a global function
is defined without a declaration. This should catch cases were we've
defined a function but forgot to put it in a header. In that case it
is either only used within one file so we should make it static or we
should declare it in a header.

The following changes where made to fix problems:

• Some functions were made static

• cogl-path.h (the one containing the 1.0 API) was split into two
  files, one defining the functions and one defining the enums so that
  cogl-path.c can include the enum and function declarations from the
  2.0 API as well as the function declarations from the 1.0 API.

• cogl2-clip-state has been removed. This only had one experimental
  function called cogl_clip_push_from_path but as this is unstable we
  might as well remove it favour of the equivalent cogl_framebuffer_*
  API.

• The GLX, SDL and WGL winsys's now have a private header to define
  their get_vtable function instead of directly declaring in the C
  file where it is called.

• All places that were calling COGL_OBJECT_DEFINE need to have the
  cogl_is_whatever function declared so these have been added either
  as a public function or in a private header.

• Some files that were not including the header containing their
  function declarations have been fixed to do so.

• Any unused error quark functions have been removed. If we later want
  them we should add them back one by one and add a declaration for
  them in a header.

• _cogl_is_framebuffer has been renamed to cogl_is_framebuffer and
  made a public function with a declaration in cogl-framebuffer.h

• Similarly for CoglOnscreen.

• cogl_vdraw_indexed_attributes is called
  cogl_framebuffer_vdraw_indexed_attributes in the header. The
  definition has been changed to match the header.

• cogl_index_buffer_allocate has been removed. This had no declaration
  and I'm not sure what it's supposed to do.

• CoglJournal has been changed to use the internal CoglObject macro so
  that it won't define an exported cogl_is_journal symbol.

• The _cogl_blah_pointer_from_handle functions have been removed.
  CoglHandle isn't used much anymore anyway and in the few places
  where it is used I think it's safe to just use the implicit cast
  from void* to the right type.

• The test-utils.h header for the conformance tests explicitly
  disables the -Wmissing-declaration option using a pragma because all
  of the tests declare their main function without a header. Any
  mistakes relating to missing declarations aren't really important
  for the tests.

• cogl_quaternion_init_from_quaternion and init_from_matrix have been
  given declarations in cogl-quaternion.h

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2012-03-06 18:45:44 +00:00
Neil Roberts
f005f517fe Flush matrices in the progend and flip with a vector
Previously flushing the matrices was performed as part of the
framebuffer state. When on GLES2 this matrix flushing is actually
diverted so that it only keeps a reference to the intended matrix
stack. This is necessary because on GLES2 there are no builtin
uniforms so it can't actually flush the matrices until the program for
the pipeline is generated. When the matrices are flushed it would
store the age of modifications on the matrix stack so that it could
detect when the matrix hasn't changed and avoid flushing it.

This patch changes it so that the pipeline is responsible for flushing
the matrices even when we are using the GL builtins. The same
mechanism for detecting unmodified matrix stacks is used in all
cases. There is a new CoglMatrixStackCache type which is used to store
a reference to the intended matrix stack along with its last flushed
age. There are now two of these attached to the CoglContext to track
the flushed state for the global matrix builtins and also two for each
glsl progend program state to track the flushed state for a
program. The framebuffer matrix flush now just updates the intended
matrix stacks without actually trying to flush.

When a vertex snippet is attached to the pipeline, the GLSL vertend
will now avoid using the projection matrix to flip the rendering. This
is necessary because any vertex snippet may cause the projection
matrix not to be used. Instead the flip is done as a forced final step
by multiplying cogl_position_out by a vec4 uniform. This uniform is
updated as part of the progend pre_paint depending on whether the
framebuffer is offscreen or not.

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-12-06 19:02:06 +00:00
Robert Bragg
104a6be84c cogl-matrix-stack: remove flush avoidance checks
The aim is to make cogl-framebuffer.c responsible for avoiding redundant
flushing of its matrix stacks so this removes the checks done directly
within cogl-matrix-stack.c.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-12-06 18:51:57 +00:00
Robert Bragg
39a7bcff67 matrix-stack: Avoid referencing the default CoglContext
This removes the use of _COGL_GET_CONTEXT() from cogl-matrix-stack.c
as part of the ongoing effort to evolve cogl to get rid of the need for
a default context.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-12-06 18:51:56 +00:00
Robert Bragg
595311ba55 cogl-matrix-stack: Adds _cogl_matrix_stack_equal
Adds a function for comparing the top matrix entries of two matrix
stacks.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-12-06 18:51:56 +00:00
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
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
ade4e5839d build: Move CoglMatrixMode to cogl-matrix-stack.h
This avoids a redeclaration of _cogl_matrix_stack_flush_to_gl() from
using GLenum to CoglMatrixMode.

http://bugzilla.openedhand.com/show_bug.cgi?id=1928
2010-01-04 11:58:32 +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
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