Many operations, like mixing two textures together or alpha-blending
onto a destination with alpha, are done most logically if texture data
is in premultiplied form. We also have many sources of premultiplied
texture data, like X pixmaps, FBOs, cairo surfaces. Rather than trying
to work with two different types of texture data, simplify things by
always premultiplying texture data before uploading to GL.
Because the default blend function is changed to accommodate this,
uses of pure-color CoglMaterial need to be adapted to add
premultiplication.
gl/cogl-texture.c gles/cogl-texture.c: Always premultiply
non-premultiplied texture data before uploading to GL.
cogl-material.c cogl-material.h: Switch the default blend functions
to ONE, ONE_MINUS_SRC_ALPHA so they work correctly with premultiplied
data.
cogl.c: Make cogl_set_source_color() premultiply the color.
cogl.h.in color-material.h: Add some documentation about
premultiplication and its interaction with color values.
cogl-pango-render.c clutter-texture.c tests/interactive/test-cogl-offscreen.c:
Use premultiplied colors.
http://bugzilla.openedhand.com/show_bug.cgi?id=1406
Signed-off-by: Robert Bragg <robert@linux.intel.com>
cogl-bitmap.c cogl-bitmap-pixbuf.c cogl-bitmap-fallback.c cogl-bitmap-private.h:
Add _cogl_bitmap_can_premult(), _cogl_bitmap_premult() and implement
a reasonably fast implementation in the "fallback" code.
http://bugzilla.openedhand.com/show_bug.cgi?id=1406
Signed-off-by: Robert Bragg <robert@linux.intel.com>
It's very common that there's no reasonable fallback to do if the
blend or combine string you set isn't supported. So, rather than
requiring everybody to pass in a GError purely to catch syntax erorrs,
automatically g_warning() if a parse error is encountered and @error
is NULL.
http://bugzilla.openedhand.com/show_bug.cgi?id=1642
Signed-off-by: Robert Bragg <robert@linux.intel.com>
The texture filters are now a property of the material layer rather
than the texture object. Whenever a texture is painted with a material
it sets the filters on all of the GL textures in the Cogl texture. The
filter is cached so that it won't be changed unnecessarily.
The automatic mipmap generation has changed so that the mipmaps are
only generated when the texture is painted instead of every time the
data changes. Changing the texture sets a flag to mark that the
mipmaps are dirty. This works better if the FBO extension is available
because we can use glGenerateMipmap. If the extension is not available
it will temporarily enable automatic mipmap generation and reupload
the first pixel of each slice. This requires tracking the data for the
first pixel.
The COGL_TEXTURE_AUTO_MIPMAP flag has been replaced with
COGL_TEXTURE_NO_AUTO_MIPMAP so that it will default to
auto-mipmapping. The mipmap generation is now effectively free if you
are not using a mipmap filter mode so you would only want to disable
it if you had some special reason to generate your own mipmaps.
ClutterTexture no longer has to store its own copy of the filter
mode. Instead it stores it in the material and the property is
directly set and read from that. This fixes problems with the filters
getting out of sync when a cogl handle is set on the texture
directly. It also avoids the mess of having to rerealize the texture
if the filter quality changes to HIGH because Cogl will take of
generating the mipmaps if needed.
It was previously possible to create a material layer with no texture
by setting some property on it such as the matrix. However it was not
possible to get back to that state without removing the layer and
recreating it. It is useful to be able to remove the texture to free
resources without forgetting the state of the layer so we can put a
different texture in later.
Instead of using GL_TRIANGLES and uploading the indices every time, it
now uses GL_QUADS instead on OpenGL. Under GLES it still uses indices
but it uses the new cogl_vertex_buffer_indices_get_for_quads function
to avoid uploading the vertices every time.
This requires the _cogl_vertex_buffer_indices_pointer_from_handle
function to be exposed privately to the rest of Cogl.
The static_indices array has been removed from the Cogl context.
This function can be used as an efficient way of drawing groups of
quads without using GL_QUADS. It generates a VBO containing the
indices needed to render using pairs of GL_TRIANGLES. The VBO is
globally cached so that it only needs to be uploaded whenever more
indices are requested than ever before.
We avoid rebuilding cogl-enum-types.h and cogl-enum-types.c by
using a "guard" -- a stamp file that will block Makefile. Since
we need cogl-enum-types.h into /clutter/cogl as well for the
cogl.h include to work, if we copy the cogl-enum-types.h
unconditionally it will cause a rebuild of the whole COGL; which
will cause a full rebuild.
To solve this, we can copy the header file when generating it
under the stamp file.
Just like we do with GObject types and G_DEFINE_TYPE, we should
use the g_once_init_enter/g_once_init_leave mechanism to make the
GType registration of enumeration types thread safe.
The setup_viewport() function should only be used by Clutter and
not by application code.
It can be emulated by changing the Stage size and perspective and
requeueing a redraw after calling clutter_stage_ensure_viewport().
Previously indices were tightly bound to a particular Cogl vertex buffer
but we would like to be able to share indices so now we have
cogl_vertex_buffer_indices_new () which returns a CoglHandle.
In particular we could like to have a shared set of indices for drawing
lists of quads that can be shared between the pango renderer and the
Cogl journal.
At the moment Cogl doesn't do much batching of quads so most of the time we
are flushing a single quad at a time. This patch simplifies how we submit
those quads to OpenGL by using glDrawArrays with GL_TRIANGLE_FAN mode
instead of sending indexed vertices using GL_TRIANGLES mode.
Note: I hope to follow up soon with changes that improve our batching and
also move the indices into a VBO so they don't need to be re-validated every
time we call glDrawElements.
cogl_enable_depth_test and cogl_enable_backface_culling have been renamed
and now have corresponding getters, the new functions are:
cogl_set_depth_test_enabled
cogl_get_depth_test_enabled
cogl_set_backface_culling_enabled
cogl_get_backface_culling_enabled
This adds cogl_matrix api for multiplying matrices either by a perspective
or ortho projective transform. The internal matrix stack and current-matrix
APIs also have corresponding support added.
New public API:
cogl_matrix_perspective
cogl_matrix_ortho
cogl_ortho
cogl_set_modelview_matrix
cogl_set_projection_matrix
Originally cogl_vertex_buffer_add_indices let the user pass in their own unique
ID for the indices; now the Id is generated internally and returned to the
caller.
It's now possible to add arrays of indices to a Cogl vertex buffer and
they will be put into an OpenGL vertex buffer object. Since it's quite
common for index arrays to be static it saves the OpenGL driver from
having to validate them repeatedly.
This changes the cogl_vertex_buffer_draw_elements API: It's no longer
possible to provide a pointer to an index array at draw time. So
cogl_vertex_buffer_draw_elements now takes an indices identifier that
should correspond to an idendifier returned when calling
cogl_vertex_buffer_add_indices ()
This is being removed before we release Clutter 1.0 since the implementation
wasn't complete, and so we assume no one is using this yet. Util we have
someone with a good usecase, we can't pretend to support breaking out into
raw OpenGL.
There were a number of functions intended to support creating of new
primitives using materials, but at this point they aren't used outside of
Cogl so until someone has a usecase and we can get feedback on this
API, it's being removed before we release Clutter 1.0.
This removes the following API:
cogl_material_set_blend_factors
cogl_material_set_layer_combine_function
cogl_material_set_layer_combine_arg_src
cogl_material_set_layer_combine_arg_op
These were rather awkward to use, so since it's expected very few people are
using them at this point and it should be straight forward to switch over
to blend strings, the API is being removed before we release Clutter 1.0.
Setting up layer combine functions and blend modes is very awkward to do
programatically. This adds a parser for string based descriptions which are
more consise and readable.
E.g. a material layer combine function could now be given as:
"RGBA = ADD (TEXTURE[A], PREVIOUS[RGB])"
or
"RGB = REPLACE (PREVIOUS)"
"A = MODULATE (PREVIOUS, TEXTURE)"
The simple syntax and grammar are only designed to expose standard fixed
function hardware, more advanced combining must be done with shaders.
This includes standalone documentation of blend strings covering the aspects
that are common to blending and texture combining, and adds documentation
with examples specific to the new cogl_material_set_blend() and
cogl_material_layer_set_combine() functions.
Note: The hope is to remove the now redundant bits of the material API
before 1.0
The CoglTexture constructors expose the "max-waste" argument for
controlling the maximum amount of wasted areas for slicing or,
if set to -1, disables slicing.
Slicing is really relevant only for large images that are never
repeated, so it's a useful feature only in controlled use cases.
Specifying the amount of wasted area is, on the other hand, just
a way to mess up this feature; 99% the times, you either pull this
number out of thin air, hoping it's right, or you try to do the
right thing and you choose the wrong number anyway.
Instead, we can use the CoglTextureFlags to control whether the
texture should not be sliced (useful for Clutter-GST and for the
texture-from-pixmap actors) and provide a reasonable value for
enabling the slicing ourself. At some point, we might even
provide a way to change the default at compile time or at run time,
for particular platforms.
Since max_waste is gone, the :tile-waste property of ClutterTexture
becomes read-only, and it proxies the cogl_texture_get_max_waste()
function.
Inside Clutter, the only cases where the max_waste argument was
not set to -1 are in the Pango glyph cache (which is a POT texture
anyway) and inside the test cases where we want to force slicing;
for the latter we can create larger textures that will be bigger than
the threshold we set.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Signed-off-by: Robert Bragg <robert@linux.intel.com>
Signed-off-by: Neil Roberts <neil@linux.intel.com>
Before any rendering is done by Cogl it needs to ensure the clip stack
is set up correctly by calling cogl_clip_ensure. This was not being
done for the Cogl vertex buffer so it would still use the clip from
the previous render.
Backface culling is enabled as part of cogl_enable so the different
rendering functions in Cogl need to explicitly opt-in to have backface
culling enabled. Cogl vertex buffers should allow backface culling so
they should check whether it is enabled and then set the appropriate
cogl_enable flag.
Currently, COGL depends on defining debug symbols by manually
modifying the source code. When it's done, it will forcefully
print stuff to the console.
Since COGL has also a pretty, runtime selectable debugging API
we might as well switch everything to it.
In order for this to happen, configure needs a new:
--enable-cogl-debug
command line switch; this will enable COGL debugging, the
CoglHandle debugging and will also turn on the error checking
for each GL operation.
The default setting for the COGL debug defines is off, since
it slows down the GL operations; enabling it for a particular
debug build is trivial, though.
COGL has a debug message system like Clutter's own. In parallel,
it also uses a coupld of #defines. Spread around there are also
calls to printf() instead to the more correct g_log* wrappers.
This commit tries to unify and clean up the macros and the
debug message handling inside COGL to be more consistent.
The code for the conversion of the GL error enumeration code
into a string is not following the code style and conventions
we follow in Clutter and COGL.
The GE() macro is also using fprintf(stderr) directly instead
of using g_warning() -- which is redirectable to an alternative
logging system using the g_log* API.
We use math routines inside Cogl, so it's correct to have it in
the LIBADD line. In normal usage something else was pulling in
-lm, but the introspection is relying on linking against the
convenience library.
Based on a patch by: Colin Walters <walters@verbum.org>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Previously clipping could only be specified in object coordinates, now
rectangles can also be pushed in window coordinates.
Internally rectangles pushed this way are intersected and then clipped using
scissoring. We also transparently try to convert rectangles pushed in
object coordinates into window coordinates as we anticipate the scissoring
path will be faster then the clip planes and undoubtably it will be faster
than using the stencil buffer.
This is simply a wrapper around cogl_color_set_from_4f and
cogl_material_set_color. We already had a prototype for this, it was
an oversight that it wasn't already implemented.
There were several functions I believe no one is currently using that were
only implemented in the GL backend (cogl_offscreen_blit_region and
cogl_offscreen_blit) that have simply been removed so we have a chance to
think about design later with a real use case.
There was one nonsense function (cogl_offscreen_new_multisample) that
sounded exciting but in all cases it just returned COGL_INVALID_HANDLE
(though at least for GL it checked for multisampling support first!?)
it has also been removed.
The MASK draw buffer type has been removed. If we want to expose color
masking later then I think it at least would be nicer to have the mask be a
property that can be set on any draw buffer.
The cogl_draw_buffer and cogl_{push,pop}_draw_buffer function prototypes
have been moved up into cogl.h since they are for managing global Cogl state
and not for modifying or creating the actual offscreen buffers.
This also documents the API so for example desiphering the semantics of
cogl_offscreen_new_to_texture() should be a bit easier now.
It is valid in some situations to have a material layer with an invalid texture
handle (e.g. if you setup a texture combine mode before setting the texture)
and so _cogl_material_layer_free needs to check for a valid handle before
attempting to unref it.
Adds missing notices, and ensures all the notices are consistent. The Cogl
blurb also now reads:
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
Redundant clearing of depth and stencil buffers every render can be very
expensive, so cogl now gives control over which auxiliary buffers are
cleared.
Note: For now clutter continues to clear the color, depth and stencil buffer
each paint.
In unifying the {gl,gles}/cogl.c code recently, moving most of the code into
common/cogl.c the gmodule.h include was also mistakenly moved.
Thanks to Felix Rabe for reporting this issue.
Note: I haven't tested this fix myself, as I'm not set up to be able to
build for OS X
