Commit Graph

2290 Commits

Author SHA1 Message Date
Robert Bragg
7bcea1c64e Start eradicating the CoglHandle typedef
CoglHandle is a common source of complaints and confusion because people
expect a "handle" to be some form of integer type with some indirection
to lookup the corresponding objects as opposed to a direct pointer.

This patch starts by renaming CoglHandle to CoglObject * and creating
corresponding cogl_object_ APIs to replace the cogl_handle ones.

The next step though is to remove all use of CoglHandle in the Cogl APIs
and replace with strongly typed pointer types such as CoglMaterial * or
CoglTexture * etc also all occurrences of COGL_INVALID_HANDLE can just
use NULL instead.

After this we will consider switching to GTypeInstance internally so we
can have inheritance for our types and hopefully improve how we handle
bindings.

Note all these changes will be done in a way that maintains the API and
ABI.
2010-05-28 18:39:22 +01:00
Neil Roberts
0f32fb4acd cogl-texture-2d: Regenerate the mipmaps when the texture is modified
When the texture is modified by cogl_texture_set_region, it wasn't
setting mipmaps_dirty so it would never update the mipmaps.
2010-05-28 18:13:53 +01:00
Robert Bragg
4c1a12d824 [material] fix _set_alpha_test_function: missing a glEnable(GL_ALPHA_TEST)
Since the default alpha test function of GL_ALWAYS is equivalent to
GL_ALPHA_TEST being disabled we don't need to worry about Enabling/Disabling
it when flushing material state, instead it's enough to leave it always
enabled.  We will assume that any driver worth its salt wont incur any
additional cost for glEnable (GL_ALPHA_TEST) + GL_ALWAYS vs
glDisable (GL_ALPHA_TEST).

This patch simply calls glEnable (GL_ALPHA_TEST) in cogl_create_context
2010-05-28 15:35:23 +01:00
Neil Roberts
5a1cffd0bb cogl-vertex-buffer: Don't disable any texture coord arrays
The enabled state of the texture coord arrays is cached in the cogl
context so there is no need to disable them when we've finished
rendering a vbo.
2010-05-27 14:54:14 +01:00
Neil Roberts
97fd2c368e cogl: Record new enabled arrays in _cogl_disable_other_texcoord_arrays
When _cogl_disable_other_texcoord_arrays is called it disables the
neccessary texcoord arrays and then removes the bits for the disabled
arrays in ctx->texcoord_arrays_enabled. However none of the places
that call the function then set any bits in ctx->texcoord_arrays_enabled
so the arrays would never get marked and they would never get disabled
again.

This patch just changes it so that _cogl_disable_other_texcoord_arrays
also sets the corresponding bits in ctx->texcoord_arrays_enabled.
2010-05-27 14:51:44 +01:00
Neil Roberts
aaf5600b2d cogl: Use a CoglBitmask to store the list of used texcoord arrays
Instead of directly using a guint32 to store a bitmask for each used
texcoord array, it now stores them in a CoglBitmask. This removes the
limitation of 32 layers (although there are still other places in Cogl
that imply this restriction). To disable texcoord arrays code should
call _cogl_disable_other_texcoord_arrays which takes a bitmask of
texcoord arrays that should not be disabled. There are two extra
bitmasks stored in the CoglContext which are used temporarily for this
function to avoid allocating a new bitmask each time.

http://bugzilla.openedhand.com/show_bug.cgi?id=2132
2010-05-24 16:10:57 +01:00
Neil Roberts
4fb784d111 cogl: Add an internal CoglBitmask type
This implements a growable array of bits called CoglBitmask. The
CoglBitmask is intended to be cheap if less than 32 bits are used. If
more bits are required it will allocate a GArray. The type is meant to
be allocated on the stack but because it can require additional
resources it also has a destroy function.

http://bugzilla.openedhand.com/show_bug.cgi?id=2132
2010-05-24 16:10:56 +01:00
Neil Roberts
52cbc93b18 cogl-material: Fix the count of the number of layers
Previously the counter for the number of layers was only updated
whenever the texture handle for a layer changes. However there are
many other ways for a new layer to be created for example by setting a
layer combine constant. Also by default the texture on a layer is
COGL_INVALID_HANDLE so if the application tries to create an explicit
layer with no texture by calling cogl_material_set_layer with
COGL_INVALID_HANDLE then it also wouldn't update the count.

This patch fixes that by incrementing the count in
cogl_material_get_layer instead. This function is called by all
functions that may end up creating a layer so it seems like the most
appropriate place.

http://bugzilla.openedhand.com/show_bug.cgi?id=2132
2010-05-24 16:10:56 +01:00
Neil Roberts
992d5f7fb6 cogl-vertex-buffer: Don't disable layers with no texture coords
It should be quite acceptable to use a texture without defining any
texture coords. For example a shader may be in use that is doing
texture lookups without referencing the texture coordinates. Also it
should be possible to replace the vertex colors using a texture layer
without a texture but with a constant layer color.

enable_state_for_drawing_buffer no longer sets any disabled layers in
the overrides. Instead of counting the number of units with texture
coordinates it now keeps them in a mask. This means there can now be
gaps in the list of enabled texture coordinate arrays. To cope with
this, the Cogl context now also stores a mask to track the enabled
arrays. Instead of code manually iterating each enabled array to
disable them, there is now an internal function called
_cogl_disable_texcoord_arrays which disables a given mask.

I think this could also fix potential bugs when a vertex buffer has
gaps in the texture coordinate attributes that it provides. For
example if the vertex buffer only had texture coordinates for layer 2
then the disabling code would not disable the coordinates for layers 0
and 1 even though they are not used. This could cause a crash if the
previous data for those arrays is no longer valid.

http://bugzilla.openedhand.com/show_bug.cgi?id=2132
2010-05-24 16:10:56 +01:00
Emmanuele Bassi
99c7e51145 Merge branch 'wip/state-machine'
* wip/state-machine:
  Do not use wildcards in test-state
  script: Implement State deserialization
  state: added a "target-state" property
  state: documented data structures
  Add State interactive tests to the ignore file
  state: Documentation and introspection annotation fixes
  state: Minor coding style fixes
  state: Clean up the header's documentation
  state: Constify StateKey accessors
  Do not include clutter.h from a Clutter header file
  state-machine: made clutter_state_change take a boolean animate argument
  state-machine: use clutter_timeline_get_progress
  state-machine: add completed signal
  state machine: added state machine

Conflicts:
	.gitignore
2010-05-24 10:42:03 +01:00
Emmanuele Bassi
94c1614164 Merge branch 'wip/framebuffer-bits'
* wip/framebuffer-bits:
  Implement accessors for the color bits in a framebuffer
2010-05-21 14:38:37 +01:00
Emmanuele Bassi
6696b4ff43 Merge branch 'wip/constraints'
* wip/constraints: (24 commits)
  Add the Cogl API reference to the fixxref extra directories
  Document the internal MetaGroup class
  Remove the construct-only flag from ActorMeta:name
  doc: Remove gtk-doc annotations from the json-glib copy
  doc: Fix parameter documentation
  Add named modifiers for Action and Constraint
  Remove a redundant animation
  Set the stage resizable in test-constraints
  Use a 9 grid for the constraints test
  Miscellaneous documentation fixes
  docs: Document animating action and constraint properties
  docs: Document BindConstraint and AlignConstraint
  constraint: Rename BindConstraint:bind-axis
  constraints: Add AlignConstraint
  tests: Add a constraints interactive test
  constraint: Add BindConstraint
  actor: Implement Animatable
  animation: Use the new Animatable API for custom properties
  animatable: Add custom properties to Animatable
  constraint: Add ClutterConstraint base class
  ...

Conflicts:
	configure.ac
2010-05-21 10:55:09 +01:00
Robert Bragg
fa22ee0e8d math: Adds an experimental cogl_vector3_* API
This adds a math utility API for handling 3 component, single precision
float vectors with the following; mostly self explanatory functions:

cogl_vector3_init
cogl_vector3_init_zero
cogl_vector3_equal
cogl_vector3_equal_with_epsilon
cogl_vector3_copy
cogl_vector3_free
cogl_vector3_invert
cogl_vector3_add
cogl_vector3_subtract
cogl_vector3_multiply_scalar
cogl_vector3_divide_scalar
cogl_vector3_normalize
cogl_vector3_magnitude
cogl_vector3_cross_product
cogl_vector3_dot_product
cogl_vector3_distance

Since the API is experimental you will need to define
COGL_ENABLE_EXPERIMENTAL_API before including cogl.h if you want to use
the API.
2010-05-20 17:18:24 +01:00
Neil Roberts
af591f5c09 cogl-texture-2d: Optimise _cogl_texture_2d_is_pot
This takes the simple algorithm from here:

http://graphics.stanford.edu/~seander/bithacks.html#DetermineIfPowerOf2

This avoids a loop and is much faster.
2010-05-20 12:40:59 +01:00
Robert Bragg
76d5a1a858 Stubs out _cogl_xlib_handle_event
This stubs out an xlib event handling mechanism for Cogl. The intention
is for Clutter to use this to forward all x11 events to Cogl. As we move
winsys functionality down into Cogl, Cogl will become responsible for
handling a number of X events: ConfigureNotify events for onscreen
framebuffers, swap events and Damage events for cogl_x11_texture_pixmap.
2010-05-19 15:28:04 +01:00
Robert Bragg
1ed1d4fc6a build: expose automake conditionals for cogl winsys
Expose the ./configured window system/backend options to the Cogl
automake files via some new SUPPORT_XYZ conditionals.
2010-05-19 15:08:14 +01:00
Brian Tarricone
5f94a6bf6e eglx: implement cogl_get_proc_address()
http://bugzilla.openedhand.com/show_bug.cgi?id=2124
2010-05-18 17:30:31 +01:00
Neil Roberts
1eddbe8e1b cogl-material: Set the blend equation even if blend funcs are the same
Previously it would only try to set the blend equation if the RGB and
alpha blending functions were different. However it's completely valid
to use a non-standard blending function when the functions are the
same. This patch moves the blending equation to outside the if
statement.
2010-05-17 16:31:28 +01:00
Neil Roberts
9ca68bc37a cogl-material: Set blend constant even if alpha and rgb factors are the same
Previously it would only set the blend constant if glBlendFuncSeparate
was used but it is perfectly acceptable to use the blend constant when
the same factor is used for each. It now sets the blend constant
whenever one of the factors would use the constant.
2010-05-17 16:31:28 +01:00
Neil Roberts
837eb54db4 cogl-blend-string: Don't split combined blend statements into two
When a single statement is used to specify the factors for both the
RGB and alpha parts it previously split up the statement into
two. This works but it ends up unnecessarily using glBlendFuncSeparate
when glBlendFunc would suffice.

For example, the blend statement

 RGBA = ADD(SRC_COLOR*(SRC_COLOR), DST_COLOR*(1-SRC_COLOR))

would get split into the two statements

 RGBA = ADD(SRC_COLOR*(SRC_COLOR[RGB]), DST_COLOR*(1-SRC_COLOR[RGB]))
 A    = ADD(SRC_COLOR*(SRC_COLOR[A]), DST_COLOR*(1-SRC_COLOR[A]))

That translates to:

 glBlendFuncSeparate (GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR,
                      GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

This patch makes it so that arg_to_gl_blend_factor can handle the
combined RGBA mask instead. That way the single statement gets
translated to the equivalent call:

 glBlendFunc (GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR);
2010-05-17 16:31:28 +01:00
Neil Roberts
8193e12546 cogl-path: Use true copy-on-write semantics
Previously a path copy was implemented such that only the array of
path nodes was shared with the source and the rest of the data is
copied. This was so that the copy could avoid a deep copy if the
source path is appended to because the copy keeps track of its own
length. This optimisation is probably not worthwhile because it makes
the copies less cheap. Instead the CoglPath struct now just contains a
single pointer to a new CoglPathData struct which is separately
ref-counted. When the path is modified it will be copied if the ref
count on the data is not 1.
2010-05-11 16:10:39 +01:00
Owen W. Taylor
582bd409dd cogl-framebuffer: Flush journal when creating fbo
Since framebuffer state is not flushed prior to replaying the journal,
the trick of marking the framebuffer dirty prior to calling
glBindFramebuffer() doesn't work... the outstanding journal entries
will get replayed to the newly created framebuffer.

Fix this by flushing the journal as well.

http://bugzilla.openedhand.com/show_bug.cgi?id=2110

Signed-off-by: Robert Bragg <robert@linux.intel.com>
2010-05-10 14:38:10 +01:00
Neil Roberts
11532f79ec cogl-clip-stack: Set *stencil_used_p when the stack is empty
If the clip stack is empty then _cogl_clip_stack_flush exits
immediately. This was missing out the assignment of *stencil_used_p at
the bottom of the function. If a path is then used after the clip is
cleared then it would think it needs to merge with the clip so the
stencil would not be cleared correctly.
2010-05-06 14:15:04 +01:00
Emmanuele Bassi
676c8a5fd4 Implement accessors for the color bits in a framebuffer
Instead of using cogl_get_bitmasks() to query the GL machinery for the
size of the color bits, we should store the values inside the
CoglFramebuffer object and query them the first time we set the framebuffer
as the current one.

Currently, cogl_get_bitmasks() is re-implemented in terms of
cogl_framebuffer_get_*_bits(). As soon as we are able to expose the
CoglOnscreen framebuffer object in the public API we'll be able to
deprecate cogl_get_bitmasks() altogether.

http://bugzilla.openedhand.com/show_bug.cgi?id=2094
2010-05-05 12:25:16 +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
Damien Lespiau
6243a5dc34 debug: Use G_UNLIKELY in the tests
Debugging code is not meant to be run in the nominal code path. Use
G_UNLIKELY to be reduce the number of bubbles in the instruction
pipeline.

Took the opportunity to re-indent the macros.
2010-05-04 17:01:14 +01:00
Robert Bragg
dc4c0e3d3e debug: wrap glClear calls with the GE macro
This adds a GE macro wrapper around our calls to glClear so we can
print a warning for any errors reported by the driver.
2010-04-30 12:10:16 +01:00
Neil Roberts
ebe86985fd cogl-texture-2d-sliced: Use the converted bitmap when uploading
When uploading texture data the cogl-texture-2d-sliced backend was
using _cogl_texture_prepare_for_upload to create a bitmap suitable for
upload but then it was using the original bitmap instead of the new
bitmap for the data. This was causing any format conversions performed
by cogl_texture_prepare_for_upload to be ignored.

http://bugzilla.openedhand.com/show_bug.cgi?id=2059
2010-04-29 13:15:36 +01:00
Neil Roberts
dae6ab7d79 cogl-texture: Don't attempt to use GL to convert formats under GLES
In commit abe91784c4 I changed cogl-texture so that it would use the
OpenGL mechanism to specify a different internal texture format from
the image format so that it can do the conversion instead of
Cogl. However under GLES the internal format and the image format must
always be the same and it only supports a limited set of formats. This
patch changes _cogl_texture_prepare_for_upload so that it does the
conversion using the cogl bitmap code when compiling for GLES.

http://bugzilla.openedhand.com/show_bug.cgi?id=2059
2010-04-29 13:15:35 +01:00
Neil Roberts
3e88dee1a3 cogl-material: Fix the check to prevent using too many layers
There was a check at the bottom of the loop which sets up the state
for each of the layers so that it would break from the loop when the
maximum number of layers is reached. However after doing this it would
not increment 'i'. 'i' is later used to disable the remaining layers
so it would end up disabling the last layer it just set up.

This patch moves the check to be part of the loop condition so that
the check is performed after incrementing 'i'.

http://bugzilla.openedhand.com/show_bug.cgi?id=2064
2010-04-29 12:15:17 +01:00
Neil Roberts
d5d98500be cogl-material: Fix the warning for when too many layers are used
The warning displayed when too many layers are used had an off-by-one
error so that it would display even if exactly the maximum number is
used. There was also a missing space at the end of the line in the
message which looked wrong when displayed on the terminal.

http://bugzilla.openedhand.com/show_bug.cgi?id=2064
2010-04-29 12:15:11 +01:00
Neil Roberts
edf2bf3d8a cogl-path: Make cogl_path_arc_rel static
cogl_path_arc_rel was never in any public headers so it isn't part of
the public API. It also has a slightly inconsistent name because the
rest of the relative path functions are called cogl_path_rel_*. This
patch makes it static for now to make it more obvious that it isn't
public. The name has changed to _cogl_path_rel_arc.
2010-04-22 18:17:59 +01:00
Neil Roberts
2b8abbdaa8 cogl-path: Add documentation for the angles of cogl_path_arc
This adds documentation for how Cogl interprets the angles given to
cogl_path_arc.
2010-04-22 18:17:59 +01:00
Neil Roberts
308ca6cb14 cogl-path: Fix the truncation when adding to a copied path
If a path is copied and then appended to, the copy needs to have the
last sub path truncated so that it fits in the total path size in case
the original path was modified. However the path size check was broken
so if the copied path had more than one sub path it would fail.
2010-04-21 22:36:43 +01:00
Neil Roberts
9d93e250d1 cogl-clip-stack: Use orientation of the polygon to set clip planes
Previously the clip stack code was trying to detect when the
orientation of the on-screen rectangle had changed by checking if the
order of the y-coordinates on the left edge was different from the
order the x-coordinates on the top edge. This doesn't work for some
rotations which was causing the clip planes to clip the wrong side of
the line. This patch makes it detect the orientation by calculating
the signed area which is a standard computer graphics algorithm.

http://bugzilla.openedhand.com/show_bug.cgi?id=2079
2010-04-21 13:24:59 +01:00
Neil Roberts
17a1595cb0 cogl-path: Document how a shape is filled
This adds some documentation to cogl_path_fill() describing the fill
rule Cogl uses.
2010-04-21 13:20:23 +01:00
Neil Roberts
8afea98437 cogl-path: Don't try to union sub paths
When drawing a path with only a single sub path, Cogl uses the
'even-odd' fill rule which means that if a part of the path intersects
with another part then the intersection would be inverted. However
when combining sub paths it treats them as separate paths and then
unions them together. This doesn't match the semantics of the even-odd
rule in SVG and Cairo. This patch makes it so that a new sub path is
just drawn as another triangle fan so that it will continue to invert
the stencil buffer. This is also much simpler and more efficient as
well as being more correct.

http://bugzilla.openedhand.com/show_bug.cgi?id=2088
2010-04-21 11:39:28 +01:00
Neil Roberts
7f629f626e cogl_read_pixels: Always use GL_RGBA/GL_UNSIGNED_BYTE under GLES
Under GLES glReadPixels is documented to only support GL_RGBA with
GL_UNSIGNED_BYTE and an implementation specfic format which can be
fetched with glGet, GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES and
GL_IMPLEMENTATION_COLOR_READ_TYPE_OES. This patch makes it always read
using GL_RGBA and GL_UNSIGNED_BYTE and then convert the results if
neccessary.

This has some room for improvement because it doesn't attempt to use
the implementation specific format. Also the conversion is somewhat
wasteful because there are currently no cogl_bitmap_* functions to
convert without allocating a new buffer so it ends up doing an
intermediate copy.

http://bugzilla.openedhand.com/show_bug.cgi?id=2057
2010-04-21 10:56:21 +01:00
Neil Roberts
f944d419a3 cogl-bitmap: Fix converting formats with and without alpha channels
_cogl_bitmap_convert_format_and_premult was failing when converting
from RGBA to RGB and vice versa. _cogl_bitmap_fallback_convert
converts without altering the premult status so when choosing a new
format it would copy over the premult bit. However, it did this
regardless of whether the new format had an alpha channel so when
converting from RGBA_8888_PRE to RGB_888 it would end up inventing a
new meaningless format which would be RGB_888_PRE. This patch makes it
avoid copying the premult flag if the destination has no alpha. It
doesn't matter if it copies when the source format has no alpha
because it will always be unset.

_cogl_bitmap_convert_format_and_premult was also breaking when
converting from RGBA_8888_PRE to RGB_888 because it would think
RGB_888 is unpremultiplied and try to convert but then
_cogl_bitmap_fallback_premult wouldn't know how to do the conversion.

http://bugzilla.openedhand.com/show_bug.cgi?id=2057
2010-04-21 10:56:21 +01:00
Neil Roberts
30c4678ff4 cogl: Implement retained clip stacks
This adds three new internal API functions which can be used to retain
the clip stack state and restore it later:

 _cogl_get_clip_stack
 _cogl_set_clip_stack
 _cogl_clip_stack_copy

The functions are currently internal and not yet used but we may want
to make them public in future to replace the cogl_clip_stack_save()
and cogl_clip_stack_restore() APIs.

The get function just returns the handle to the clip stack at the top
of the stack of stacks and the set function just replaces it.

The copy function makes a cheap copy of an existing stack by taking a
reference to the top stack entry. This ends up working like a deep
copy because there is no way to modify entries of a stack but it
doesn't actually copy the data.
2010-04-15 14:51:01 +01:00
Neil Roberts
84b87e811e cogl-clip-stack: Convert to be a CoglHandle
CoglClipStacks can now be reference counted via a CoglHandle. The
ClipClipState now stores handles in the list rather than CoglClipStack
pointers.
2010-04-15 14:51:01 +01:00
Neil Roberts
f6f375cb36 Separate out CoglClipStackState from cogl-clip-stack.c
CoglClipStackState has now been renamed to CoglClipState and is moved
to a separate file. CoglClipStack now just maintains a stack and
doesn't worry about the rest of the state. CoglClipStack sill contains
the code to flush the stack to GL.
2010-04-15 14:51:00 +01:00
Neil Roberts
07a76aacfb cogl-slip-stack: Store clip window rect entries in Cogl coordinates
When glScissor is called it needs to pass coordinates in GL's
coordinate space where the origin is the bottom left. Previously this
conversion was done before storing the window rect in the clip
stack. However this might make it more difficult if we want to be able
to grab a handle to a clip stack and use it in different circumstances
later. This patch moves the coordinate conversion to inside the clip
state flushing code.
2010-04-15 14:50:55 +01:00
Neil Roberts
2f63146474 cogl-clip-stack: Store window rect entries as ints not floats
The window rectangles are passed in as integers so there is no point
in converting them to floats when storing a stack entry for them.
2010-04-15 14:50:26 +01:00
Neil Roberts
71fdc54dde cogl-clip-stack: Use reference counted stack entries
The stack is now stored as a list of reference counted entries.
Instead of using a GList, each entry now contains a link with a
reference to its parent. The idea is that this would allow copying
stacks with a shared ancestry.

Previously the code flushed the state by finding the bottom of the
stack and then applying each entry by walking back up to the top. This
is slightly harder to do now because the list is no longer
doubly-linked. However I don't think it matters which order the
entries are applied so I've just changed it to apply them in reverse
order.

There was also a restriction that if ever the stencil buffer is used
then we could no longer use clip planes for any subsequent entries. I
don't think this makes sense because it should always work as long as
it doesn't attempt to use the clip planes more than once. I've
therefore removed the restriction.
2010-04-15 14:47:01 +01:00
Neil Roberts
ecf65cd4a5 cogl-atlas-texture: Fix a memory leak
The CoglAtlasTexture struct was not being freed in
_cogl_atlas_texture_free so there would be a small leak whenever a
texture was destroyed.

Thanks to Robert Bragg for spotting this.
2010-04-13 17:26:03 +01:00
Neil Roberts
3769862323 cogl-material: Use CLAMP_TO_EDGE for WRAP_AUTOMATIC unless overriden
CoglMaterial now sets GL_CLAMP_TO_EDGE if WRAP_MODE_AUTOMATIC is used
unless it is overridden when the material is flushed. The primitives
are still expected to expose repeat semantics so no user visible
changes are made. The idea is that drawing non-repeated textures is
the most common case so if we make clamp_to_ege the default then we
will reduce the number of times we have to override the
material. Avoiding overrides will become important if the overriding
mechanism is replaced with one where the primitive is expected to copy
the material and change that instead.
2010-04-12 15:44:23 +01:00
Neil Roberts
e007bc5358 cogl-material: Add support for setting the wrap mode for a layer
Previously, Cogl's texture coordinate system was effectively always
GL_REPEAT so that if an application specifies coordinates outside the
range 0→1 it would get repeated copies of the texture. It would
however change the mode to GL_CLAMP_TO_EDGE if all of the coordinates
are in the range 0→1 so that in the common case that the whole texture
is being drawn with linear filtering it will not blend in edge pixels
from the opposite sides.

This patch adds the option for applications to change the wrap mode
per layer. There are now three wrap modes: 'repeat', 'clamp-to-edge'
and 'automatic'. The automatic map mode is the default and it
implements the previous behaviour. The wrap mode can be changed for
the s and t coordinates independently. I've tried to make the
internals support setting the r coordinate but as we don't support 3D
textures yet I haven't exposed any public API for it.

The texture backends still have a set_wrap_mode virtual but this value
is intended to be transitory and it will be changed whenever the
material is flushed (although the backends are expected to cache it so
that it won't use too many GL calls). In my understanding this value
was always meant to be transitory and all primitives were meant to set
the value before drawing. However there were comments suggesting that
this is not the expected behaviour. In particular the vertex buffer
drawing code never set a wrap mode so it would end up with whatever
the texture was previously used for. These issues are now fixed
because the material will always set the wrap modes.

There is code to manually implement clamp-to-edge for textures that
can't be hardware repeated. However this doesn't fully work because it
relies on being able to draw the stretched parts using quads with the
same values for tx1 and tx2. The texture iteration code doesn't
support this so it breaks. This is a separate bug and it isn't
trivially solved.

When flushing a material there are now extra options to set wrap mode
overrides. The overrides are an array of values for each layer that
specifies an override for the s, t or r coordinates. The primitives
use this to implement the automatic wrap mode. cogl_polygon also uses
it to set GL_CLAMP_TO_BORDER mode for its trick to render sliced
textures. Although this code has been added it looks like the sliced
trick has been broken for a while and I haven't attempted to fix it
here.

I've added a constant to represent the maximum number of layers that a
material supports so that I can size the overrides array. I've set it
to 32 because as far as I can tell we have that limit imposed anyway
because the other flush options use a guint32 to store a flag about
each layer. The overrides array ends up adding 32 bytes to each flush
options struct which may be a concern.

http://bugzilla.openedhand.com/show_bug.cgi?id=2063
2010-04-12 15:44:23 +01:00
Neil Roberts
fb7f1a7fd6 Split the wrap mode of _cogl_texture_set_wrap_mode into three
GL supports setting different wrap modes for the s, t and r
coordinates so we should design the backend interface to support that
also. The r coordinate is not currently used by any of the backends
but we might as well have it to make life easier if we ever add
support for 3D textures.

http://bugzilla.openedhand.com/show_bug.cgi?id=2063
2010-04-12 15:44:23 +01:00
Neil Roberts
908be0480c cogl: Make private members really hard to accidentally use
CoglColor and CoglMatrix have public declarations with private members
so that we are free to change the implementation but the structures
could still be allocated on the stack in applications. However it's
quite easy not to realise the members are private and then access them
directly. This patch wraps the members in a macro which redefines the
symbol name when including the header outside of the clutter source.

http://bugzilla.openedhand.com/show_bug.cgi?id=2065
2010-04-12 15:38:58 +01:00