Scanners like gtk-doc and g-ir-scanner get confused by:
typedef struct _Foo {
...
} Foo;
And expect instead:
typedef struct _Foo Foo;
struct _Foo {
...
};
CoglMatrix definition should be changed to avoid the former type.
In order to validate the sequence of:
XResizeWindow
ConfigureNotify
glViewport
that should happen on X11 we need to add debug annotations to the
calls to glViewport() done through COGL.
This avoids some calls to glGetFloatv, which have at least proven to be very
in-efficient in mesa at this point in time, since it always updates all derived
state even when it may not relate to the state being requested.
Fixes and adds a unit test for creating and drawing using materials with
COGL_INVALID_HANDLE texture layers.
This may be valid if for example the user has set a texture combine string
that only references a constant color.
_cogl_material_flush_layers_gl_state will bind the fallback texture for any
COGL_INVALID_HANDLE layer, later though we could explicitly check when the
current blend mode does't actually reference a texture source in which case
binding the fallback texture is redundant.
This tests drawing using cogl_rectangle, cogl_polygon and
cogl_vertex_buffer_draw.
Although we wouldn't recommend developers try and interleve OpenGL drawing
with Cogl drawing - we would prefer patches that improve Cogl to avoid this
if possible - we are providing a simple mechanism that will at least give
developers a fighting chance if they find it necissary.
Note: we aren't helping developers change OpenGL state to modify the
behaviour of Cogl drawing functions - it's unlikley that can ever be
reliably supported - but if they are trying to do something like:
- setup some OpenGL state.
- draw using OpenGL (e.g. glDrawArrays() )
- reset modified OpenGL state.
- continue using Cogl to draw
They should surround their blocks of raw OpenGL with cogl_begin_gl() and
cogl_end_gl():
cogl_begin_gl ();
- setup some OpenGL state.
- draw using OpenGL (e.g. glDrawArrays() )
- reset modified OpenGL state.
cogl_end_gl ();
- continue using Cogl to draw
Again; we aren't supporting code like this:
- setup some OpenGL state.
- use Cogl to draw
- reset modified OpenGL state.
When the internals of Cogl evolves, this is very liable to break.
cogl_begin_gl() will flush all internally batched Cogl primitives, and emit
all internal Cogl state to OpenGL as if it were going to draw something
itself.
The result is that the OpenGL modelview matrix will be setup; the state
corresponding to the current source material will be setup and other world
state such as backface culling, depth and fogging enabledness will be also
be sent to OpenGL.
Note: no special material state is flushed, so if developers want Cogl to setup
a simplified material state it is the their responsibility to set a simple
source material before calling cogl_begin_gl. E.g. by calling
cogl_set_source_color4ub().
Note: It is the developers responsibility to restore any OpenGL state that they
modify to how it was after calling cogl_begin_gl() if they don't do this then
the result of further Cogl calls is undefined.
This function should only need to be called in exceptional circumstances
since Cogl can normally determine internally when a flush is necessary.
As an optimization Cogl drawing functions may batch up primitives
internally, so if you are trying to use raw GL outside of Cogl you stand a
better chance of being successful if you ask Cogl to flush any batched
geometry before making your state changes.
cogl_flush() ensures that the underlying driver is issued all the commands
necessary to draw the batched primitives. It provides no guarantees about
when the driver will complete the rendering.
This provides no guarantees about the GL state upon returning and to avoid
confusing Cogl you should aim to restore any changes you make before
resuming use of Cogl.
If you are making state changes with the intention of affecting Cogl drawing
primitives you are 100% on your own since you stand a good chance of
conflicting with Cogl internals. For example clutter-gst which currently
uses direct GL calls to bind ARBfp programs will very likely break when Cogl
starts to use ARBfb programs internally for the material API, but for now it
can use cogl_flush() to at least ensure that the ARBfp program isn't applied
to additional primitives.
This does not provide a robust generalized solution supporting safe use of
raw GL, its use is very much discouraged.
Previously we would call _cogl_material_pre_change_notify unconditionally, but
now we wait until we really know we are removing a layer before notifying the
change, which will require a journal flush.
Since the convenience functions cogl_set_source_color4ub and
cogl_set_source_texture share a single material, cogl_set_source_color4ub
always calls cogl_material_remove_layer. Often this is a NOP though and
shouldn't require a journal flush.
This gets performance back to where it was before reverting the per-actor
material commits.
Before any cogl vertex buffer drawing we call
enable_state_for_drawing_buffer which sets up the GL state, but we weren't
disabling unsed client texture coord arrays.
This simplifies the vertex data uploading in the journal, and could improve
performance. Modifying a VBO mid-scene could reqire synchronizing with the
GPU or some form of shadowing/copying to avoid modifying data that the GPU
is currently processing; the buffer was also being marked as GL_STATIC_DRAW
which could have made things worse.
Now we simply create a GL_STATIC_DRAW VBO for each flush and and delete it
when we are finished.
Using cogl_rectangle (and thus the journal) in
_cogl_add_path_to_stencil_buffer means we have to consider all the state
that the journal may change in case it may interfer with the direct GL calls
used. This has proven to be error prone and in this case the journal is an
unnecissary overhead. We now simply call glRectf instead of using
cogl_rectangle.
We were missing the simplest test of all: are the two CoglHandles equal and
are the flush option flags for each material equal? This should improve
batching for some common cases.
Whenever we modify a material we call _cogl_material_pre_change_notify which
checks to see if the material is referenced by the journal and if so flushes
if before we modify the material.
Since the journal logs material colors directly into a vertex array (to
avoid us repeatedly calling glColor) then we know we never need to flush
the journal when material colors change.
Since most Clutter actors aren't much more than textured quads; flushing the
journal typically involves lots of 'change modelview; draw quad' sequences.
The amount of overhead involved in uploading a new modelview and queuing
that primitive is huge in comparison to simply transforming 4 vertices by
the current modelview when logging quads. (Note if your GPU supports HW
vertex transform, then it still does the projective and viewport transforms)
At the same time a --cogl-debug=disable-software-transform option has been
added for comparison and debugging.
This change allows typical pick scenes to be batched into a single draw call
and I'm seeing test-pick run over 200% faster with this. (i965 + Mesa
7.6-devel)
Enabling this option makes Cogl trace how the journal is managing to batch
your rectangles. The journal staggers how it emmits state to the GL driver
and the batches will normally get smaller for each stage, but ideally you
don't want to be in a situation where Cogl is only able to draw one quad per
modelview change and draw call.
E.g. this is a fairly ideal example:
BATCHING: journal len = 101
BATCHING: vbo offset batch len = 101
BATCHING: material batch len = 101
BATCHING: modelview batch len = 101
This isn't:
BATCHING: journal len = 1
BATCHING: vbo offset batch len = 1
BATCHING: material batch len = 1
BATCHING: modelview batch len = 1
BATCHING: journal len = 1
BATCHING: vbo offset batch len = 1
BATCHING: material batch len = 1
BATCHING: modelview batch len = 1
<repeat>
When this option is used Cogl will print a trace of all quads that get
logged into the journal, and a trace of quads as they get flushed.
If you are seeing a bug with the geometry being drawn by Cogl this may give
some clues by letting you sanity check the numbers being logged vs the
numbers being emitted.
For testing the VBO fallback paths it helps to be able to disable the
COGL_FEATURE_VBOS feature flag. When VBOs aren't available Cogl should use
client side malloc()'d buffers instead.
Previously we only used the Cogl matrix stack API for indirect contexts, but
it's too costly to keep on requesting modelview matrices from GL (for
logging in the journal) even for direct rendering.
I also experimented with a patch for mesa to improve performance and
discussed this with upstream, but we agreed to consider the GL matrix API
essentially deprecated. (For reference the GLES 2 and GL 3 specs have
removed the matrix APIs)
CoglColors shouldn't be compared using memcmp since they may contain
uninitialized padding bytes.
The prototype is also suitable for passing to g_hash_table_new as the
key_equal_func.
_cogl_pango_display_list_add_texture now uses this instead of memcmp.
We now put the color of materials into the vertex array used by the journal
instead of calling glColor() but the number of requests for the material
color were quite expensive so we have changed the material color to
internally be byte components instead of floats to avoid repeat conversions
and added _cogl_material_get_colorubv as a fast-path for the journal to
copy data into the vertex array.
The number of material layers enabled when logging a quad in the journal
determines the stride of the corresponding vertex data (since we need a set
of texture coordinates for each layer.) By padding data in the case where we
have only one layer we can avoid a change in stride if we are mixing single
and double layer primitives in a scene (e.g. relevent for a composite
manager that may use 2 layers for all shaped windows) Avoiding stride
changes means we can minimize calls to gl{Vertex,Color}Pointer when flushing
the journal.
Since we need to update the texcoord pointers when the actual number of
layers changes, this adds another batch_and_call() stage to deal with
glTexCoordPointer and enabling/disabling the client arrays.
Previously the journal was always flushed at the end of
_cogl_rectangles_with_multitexture_coords, (i.e. the end of any
cogl_rectangle* calls) but now we have broadened the potential for batching
geometry. In ideal circumstances we will only flush once per scene.
In summary the journal works like this:
When you use any of the cogl_rectangle* APIs then nothing is emitted to the
GPU at this point, we just log one or more quads into the journal. A
journal entry consists of the quad coordinates, an associated material
reference, and a modelview matrix. Ideally the journal only gets flushed
once at the end of a scene, but in fact there are things to consider that
may cause unwanted flushing, including:
- modifying materials mid-scene
This is because each quad in the journal has an associated material
reference (i.e. not copy), so if you try and modify a material that is
already referenced in the journal we force a flush first)
NOTE: For now this means you should avoid using cogl_set_source_color()
since that currently uses a single shared material. Later we
should change it to use a pool of materials that is recycled
when the journal is flushed.
- modifying any state that isn't currently logged, such as depth, fog and
backface culling enables.
The first thing that happens when flushing, is to upload all the vertex data
associated with the journal into a single VBO.
We then go through a process of splitting up the journal into batches that
have compatible state so they can be emitted to the GPU together. This is
currently broken up into 3 levels so we can stagger the state changes:
1) we break the journal up according to changes in the number of material layers
associated with logged quads. The number of layers in a material determines
the stride of the associated vertices, so we have to update our vertex
array offsets at this level. (i.e. calling gl{Vertex,Color},Pointer etc)
2) we further split batches up according to material compatability. (e.g.
materials with different textures) We flush material state at this level.
3) Finally we split batches up according to modelview changes. At this level
we update the modelview matrix and actually emit the actual draw command.
This commit is largely about putting the initial design in-place; this will be
followed by other changes that take advantage of the extended batching.
Use signed integers while combining window space clip rectangles, so we avoid
arithmatic errors later resulting in glScissor getting negative width and
height arguments.
Previously this was RGBA_8888. It souldn't really make a difference but for
consistency we expect almost all textures in use to have an internaly
premultiplied pixel format.
_cogl_texture_download_from_gl needs to create transient CoglBitmaps when
downloading sliced textures from GL, and then copies these as subregions
into the final target_bitmap. _cogl_texture_download_from_gl also supports
target_bitmaps with a different format to the source CoglTexture being
downloaded.
The problem was that in the case of slice textures we were always looking
at the format of the CoglTexture, not of the target_bitmap when setting
up the transient slice bitmap.
To allow for flushing of batched geometry within Cogl we can't support users
directly calling glReadPixels. glReadPixels is also awkward, not least
because it returns upside down image data.
All the unit tests have been swithed over and clutter_stage_read_pixels now
sits on top of this too.
We were calculating our vertex stride and allocating our vertex array
differently depending on whether the user passed TRUE for use_color or not.
The problem was that we were always writting color data to the array
regardless of use_color.
There was also a bug with _cogl_texture_sliced_polygon in that it was
writing byte color components but we were expecting float components. We
now use byte components in _cogl_multitexture_unsliced_polygon too and pass
GL_UNSIGNED_BYTE to glColorPointer.
Cogl already add similar defines but with the CLUTTER namespace
(CLUTTER_COGL_HAS_GL and CLUTTER_COGL_HAS_GLES). Let's just add two
similar defines with the COGL namespace. Removing the CLUTTER_COGL ones
could break applications silently for no real good reason.
HAVE_COGL_GLES2 is defined in config.h through the configure script and
should not be used in public headers.
The patch makes configure generate the right define that can be used
later in the header.
In order to be ready for the next major version of GLib we need to
disable single header inclusion by using the G_DISABLE_SINGLE_INCLUDES
define in the build process.
My patch to choose a premultiplied format when the user gives
COGL_PIXEL_FORMAT_ANY for the internal_format broke the case where the data
in question doesn't have and alpha channel.
This was accidentally missed when merging the premultiplication branch
since I merged a local version of the branch that missed this commit.
Although the underlying materials should allow layers with INVALID_HANDLES
it shouldn't be necissary to expose that via cogl_set_source_texture() and
it's easier to resolve a warning/crash here than odd artefacts/crashes later
in the pipeline.
Merge branch 'premultiplication'
[cogl-texture docs] Improves the documentation of the internal_format args
[test-premult] Adds a unit test for texture upload premultiplication semantics
[fog] Document that fogging only works with opaque or unmultipled colors
[test-blend-strings] Explicitly request RGBA_888 tex format for test textures
[premultiplication] Be more conservative with what data gets premultiplied
[bitmap] Fixes _cogl_bitmap_fallback_unpremult
[cogl-bitmap] Fix minor copy and paste error in _cogl_bitmap_fallback_premult
Avoid unnecesary unpremultiplication when saving to local data
Don't unpremultiply Cairo data
Default to a blend function that expects premultiplied colors
Implement premultiplication for CoglBitmap
Use correct texture format for pixmap textures and FBO's
Add cogl_color_premultiply()
Clarifies that if you give COGL_PIXEL_FORMAT_ANY as the internal format for
cogl_texture_new_from_file or cogl_texture_new_from_data then Cogl will
choose a premultiplied internal format.
The fixed function fogging provided by OpenGL only works with unmultiplied
colors (or if the color has an alpha of 1.0) so since we now premultiply
textures and colors by default a note to this affect has been added to
clutter_stage_set_fog and cogl_set_fog.
test-depth.c no longer uses clutter_stage_set_fog for this reason.
In the future when we can depend on fragment shaders we should also be
able to support fogging of premultiplied primitives.
We don't want to force texture data to be premultipled if the user
explicitly specifies a non premultiplied internal_format such as
COGL_PIXEL_FORMAT_RGBA_8888. So now Cogl will only automatically
premultiply data when COGL_PIXEL_FORMAT_ANY is given for the
internal_format, or a premultiplied internal format such as
COGL_PIXEL_FORMAT_RGBA_8888_PRE is requested but non-premultiplied source
data is given.
This approach is consistent with OpenVG image formats which have already
influenced Cogl's pixel format semantics.
The _cogl_unpremult_alpha_{first,last} functions which
_cogl_bitmap_fallback_unpremult depends on were incorrectly casting each
of the byte components of a texel to a gulong and performing shifts as
if it were dealing with the whole texel.
It now just uses array indexing to access the byte components without
needing to cast or manually shift any bits around.
Even though we used to depend on unpremult whenever we used a
ClutterCairoTexture, clutter_cairo_texture_context_destroy had it's own
unpremult code which worked which is why this bug wouldn't have been noticed
before.
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>
Otherwise if there is an error before the slices are created it will
try to free the first_pixels array and crash.
It now also checks whether first_pixels has been created before using
it to update the mipmaps. This should only happen for
cogl_texture_new_from_foreign and doesn't matter if the FBO extension
is available. It would be better in this case to fetch the first pixel
using glGetTexImage as Owen mentioned in the last commit.
tex->first_pixels was never set for foreign textures, leading
to a crash when the texture object is freed.
As a quick fix, simply set to NULL. A more complete fix would
require remembering if we had ever seen the first pixel uploaded,
and if not, doing a glReadPixel to get it before triggering the
mipmap update.
http://bugzilla.openedhand.com/show_bug.cgi?id=1645
Signed-off-by: Neil Roberts <neil@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>
* 1.0-integration: (138 commits)
[x11] Disable XInput by default
[xinput] Invert the XI extension version check
[cogl-primitives] Fix an unused variable warning when building GLES
[clutter-stage-egl] Pass -1,-1 to clutter_stage_x11_fix_window_size
Update the GLES backend to have the layer filters in the material
[gles/cogl-shader] Add a missing semicolon
[cogl] Move the texture filters to be a property of the material layer
[text] Fix Pango unit to pixels conversion
[actor] Force unrealization on destroy only for non-toplevels
[x11] Rework map/unmap and resizing
[xinput] Check for the XInput entry points
[units] Validate units against the ParamSpec
[actor] Add the ::allocation-changed signal
[actor] Use flags to control allocations
[units] Rework Units into logical distance value
Remove a stray g_value_get_int()
Remove usage of Units and macros
[cogl-material] Allow setting a layer with an invalid texture handle
[timeline] Remove the concept of frames from timelines
[gles/cogl-shader] Fix parameter spec for cogl_shader_get_info_log
...
Conflicts:
configure.ac
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.
When creating a Cogl texture from a Cogl bitmap it would steal the
data by setting the bitmap_owner flag and clearing the data pointer
from the bitmap. The data would be freed by the time the
new_from_bitmap is finished. There is no reason to do this because the
data will be freed when the Cogl bitmap is unref'd and it is confusing
not to be able to reuse the bitmap for creating multiple textures.
The cogl_shader_get_info_log() function is very inconvenient for
language bindings and for regular use, as it requires a static
buffer to be filled -- basically just providing a wrapper around
glGetInfoLogARB().
Since COGL aims to be a more convenient API than raw GL we should
just make cogl_shader_get_info_log() return an allocated string
with the GLSL compiler log.
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.
The cogl-enum-types.h file is created by glib-mkenums under
/clutter/cogl/common, and then copied in /clutter/cogl in order
to make the inclusion of that file work inside cogl.h.
Since we're copying it in a different location, the Makefile
for that location has to clean up the copy.
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.
The libclutter-cogl internal object should be the only dependency
for Clutter, since we are already copying it inside clutter/cogl
for the introspection scanner. For this reason, the backend-specific,
real internal object should be built with the backend encoded into
the file name, like libclutter-common. This makes the build output
a little bit more clear: instead of having two:
LINK libclutter-cogl-common.la
...
LINK libclutter-cogl.la
LINK libclutter-cogl.la
We'll have:
LINK libclutter-cogl-common.la
...
LINK libclutter-cogl-gl.la
LINK libclutter-cogl.la
Same applies for the GLES backend.
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().
The backface culling enabling function was split and renamed, just
like the depth testing one, so we need to add the macro to the
cogl-deprecated.h header.
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.
To assist people porting code from 0.8, the cogl_texture_* functions that
have been replaced now have defines that give some hint as to how they
should be replaced.
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
cogl_create_context is dealt with internally when _cogl_get_default context
is called, and cogl_destroy_context is currently never called.
It might be nicer later to get an object back when creating a context so
Cogl can support multiple contexts, so these functions are being removed
from the API until we get a chance to address context management properly.
For now cogl_destroy_context is still exported as _cogl_destroy_context so
Clutter could at least install a library deinit handler to call it.
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>
The required "fake" libclutter-cogl.la upon with the main clutter
shared object depends is only built with introspection enabled
instead of being built unconditionally.
Passing:
--library=clutter-@CLUTTER_FLAVOUR@-@CLUTTER_API_VERSION@
to g-ir-scanner, when building Cogl was causing g-ir-scanner to
link the introspection program against the installed clutter library,
if it existed or fail otherwise. Instead copy the handling from
the json/ directory where we link against the convenience library
to scan, and do the generation of the typelib later in the
main clutter/directory.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1594
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.
COGLenum, COGLint and COGLuint which were simply typedefs for GL{enum,int,uint}
have been removed from the API and replaced with specialised enum typedefs, int
and unsigned int. These were causing problems for generating bindings and also
considered poor style.
The cogl texture filter defines CGL_NEAREST and CGL_LINEAR etc are now replaced
by a namespaced typedef 'CoglTextureFilter' so they should be replaced with
COGL_TEXTURE_FILTER_NEAREST and COGL_TEXTURE_FILTER_LINEAR etc.
The shader type defines CGL_VERTEX_SHADER and CGL_FRAGMENT_SHADER are handled by
a CoglShaderType typedef and should be replaced with COGL_SHADER_TYPE_VERTEX and
COGL_SHADER_TYPE_FRAGMENT.
cogl_shader_get_parameteriv has been replaced by cogl_shader_get_type and
cogl_shader_is_compiled. More getters can be added later if desired.
Commit 43fa38fcf5 broke out-of-tree builds by removing some of the
builddir directories from the include path. builddir/clutter/cogl and
builddir/clutter are needed because cogl.h and cogl-defines-gl.h are
automatically generated by the configure script. The main clutter
headers are in the srcdir so this needs to be in the path too.
When building Clutter with introspection enabled everything stops
at Cogl GIR generation because it depends on the installed library
to work. Since we still require some changes in the API to be able
to build the GIR and the typelib for Cogl we should disable the
generation of the GIR as well.
Currently, the introspection data for Cogl is built right into
Clutter's own typelib. This makes functions like:
cogl_path_round_rectangle()
Appear as:
Clutter.cogl_path_round_rectangle()
It should be possible, instead, to have a Cogl namespace and:
Cogl.path_round_rectangle()
This means building introspection data for Cogl alone. Unfortunately,
there are three types defined in Cogl that confuse the introspection
scanner, and make it impossible to build a typelib:
COGLint
COGLuint
COGLenum
These three types should go away before 1.0, substituted by int,
unsigned int and proper enumeration types. For this reason, we can
just set up the GIR build and wait until the last moment to create
the typelib. Once that has been done, we will be able to safely
remove the Cogl API from the Clutter GIR and typelib and let
people import Cogl if they want to use the Cogl API via introspection.
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.
These are necessary if nesting redirections to an fbo,
otherwise there's no way to know how to restore
previous state.
glPushAttrib(GL_COLOR_BUFFER_BIT) would save draw buffer
state, but also saves a lot of other stuff, and
cogl_draw_buffer() relies on knowing about all draw
buffer state changes. So we have to implement a
draw buffer stack ourselves.
Signed-off-by: Robert Bragg <robert@linux.intel.com>
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
Buffer objects aren't currently available for glx indirect contexts, so we
now have a fallback that simply allocates fake client side vbos to store the
attributes.
This makes the #if 0'd debug code that was in _cogl_journal_flush_quad_batch
- which we have repeatedly found usefull for debugging various geometry
issues in Clutter apps - a runtime debug option.
The outline colors rotate in order from red to green to blue which can also
help confirm the order that your geometry really drawn.
The outlines are not affected by the current material state, so if you e.g.
have a blending bug where geometry mysteriously disappears this can confirm
if the underlying rectangles are actually being emitted but blending is
causing them to be invisible.
The debug macros for tracking reference counting of CoglHandles had
some typos introduced in c3d9f0 which meant it failed to compile when
COGL_DEBUG is 1.
The cogl_is_* functions were showing up quite high on profiles due to
iterating through arrays of cogl handles.
This does away with all the handle arrays and implements a simple struct
inheritance scheme. All cogl objects now add a CoglHandleObject _parent;
member to their main structures. The base object includes 2 members a.t.m; a
ref_count, and a klass pointer. The klass in turn gives you a type and
virtual function for freeing objects of that type.
Each handle type has a _cogl_##handle_type##_get_type () function
automatically defined which returns a GQuark of the handle type, so now
implementing the cogl_is_* funcs is just a case of comparing with
obj->klass->type.
Another outcome of the re-work is that cogl_handle_{ref,unref} are also much
more efficient, and no longer need extending for each handle type added to
cogl. The cogl_##handle_type##_{ref,unref} functions are now deprecated and
are no longer used internally to Clutter or Cogl. Potentially we can remove
them completely before 1.0.
A layer object may be instantiated when setting a combine mode, but before a
texture is associated. (e.g. this is done by the pango renderer) if this is the
case we shouldn't call cogl_texture_get_format() with an invalid cogl handle.
This patch skips over layers without a texture handle when determining if any
textures have an alpha channel.
The symbol name for cogl_vertex_buffer_draw_elements was wrong so it
ended up with no documentation. The name for the vertex attribute was
incorrect in cogl_vertex_buffer_add.
None of this code directly related to implementing CoglTextures, and the
code was needlessly duplicated between the GL and GLES backends. This moves
the cogl_rectangle* and cogl_polygon* code into common/cogl-primitives.c
makes which makes lot of sense since the two copies keep needlessly
diverging introducing or fixing bugs in one but not the other. For instance
I came accross one such bug regarding the enabling of texture units when
unifying the code.
The gtk-doc had a copy and paste error, saying the float array should be 8
elements per rectangle instead of 4. There was also no newline in the gles
code before the new function.
It's often nice to be able to draw a batch of vertices, even if these
have no texture coordinates. This add a cogl_rectangles, similar to
cogl_rectangles_with_texture_coords, only without.
There are various constraints for when we can support multi-texturing and
when they can't be met we try and print a clear warning explaining why the
operation isn't supported, but we shouldn't endlessly repeat the warning for
every primitive of every frame. This patch fixes that.
This function was renamed a while ago in the .c file from
cogl_vertex_buffer_draw_range_elements but the corresponding .h and
doc/reference/cogl changes weren't made.
For convenience it is now valid to avoid a seperate call to
cogl_vertex_buffer_submit() and assume that the _draw() calls will do this
for you (though of course if you do this you still need to ensure the
attribute pointers remain valid until your draw call.)
_cogl_add_path_to_stencil_buffer and _cogl_add_stencil_clip were leaving
the projection matrix current when calling cogl_rectangle which was
upsetting _cogl_current_matrix_state_flush.
Adds glFrustum wrappers (GLES only accepts floats not doubles, and GLES2
needs to use our internal cogl_wrap_glFrustumf)
Adds GL_TEXTURE_MATRIX getter code in cogl_wrap_glGetFloatv
Adds a GL_TEXTURE_MATRIX define for GLES2
Its not intended that users should use these with any other matrix mode, and
internally we now have the _cogl_current_matrix API if we need to play with
other modes.
If we later add internal flags to CoglMatrix then this code wouldn't
initialize those flags. The ways it's now done adds a redundant copy, but
if that turns out to be something worth optimizing we can look again at
using a cast but adding another way for initializing internal flags.
This is useful because sometimes we need to get the current matrix, which
is too expensive when indirect rendering.
In addition, this virtualization makes it easier to clean up the API in
the future.
The private CoglContext is created using g_malloc() and not
zeroed; this means we have to initialize the values we are
going to check, to avoid hitting garbage.
Thanks to Tommi Komulainen.
The type machinery for CoglFixed should be implemented by COGL
itself, now that COGL exports the GType of its types.
This allows moving most of what ClutterFixed did directly to
CoglFixed where it belongs.
Since the conversion of a floating point value to a fixed point
value is already done in double precision we can safely expose
a macro that converts a double precision floating point value to
a CoglFixed one.
COGL should ship its own pkg-config file, obviously still pointing
to Clutter's compiler flags and linking options, for COGL-specific
variables that might be queried at configure time.
For instance, it's easier (and less verbose) to do:
PKG_CHECK_EXISTS([cogl-gl-1.0],
[has_gl_backend=yes],
[has_gl_backend=no])
Than doing:
AC_MSG_CHECKING([for GL support in COGL])
cogl_backend=`$PKG_CONFIG --variable=cogl clutter-0.9`
if test x$cogl_backend = xgl; then
has_gl_backend=yes
AC_MSG_RESULT([found])
else
has_gl_backend=no
AC_MSG_RESULT([not found])
fi
The CoglPango code falls under the COGL "jurisdiction"; this means
that it cannot include Clutter headers unless strictly necessary.
The CoglPangoRenderer code was using the CLUTTER_NOTE() macro. Now
that COGL has it's own COGL_NOTE() similar macro, CoglPango should
use that and avoid including clutter-debug.h (which pulls in
clutter-private.h which in turn pulls in clutter-actor.h).
A new flag, COGL_DEBUG_PANGO, has been added to the COGL debug
flags.
In the future if we want to annotate matrices with internal flags, and add
caching of the inverse matrix then we need to ensure that all matrix
modifications are done by cogl_matrix API so we'd know when to dirty the
cache or update the flags.
This just adds documentation to that effect, and assuming the most likley
case where someone would try and directly write to matrix members would
probably be to load a constant matrix other than the identity matrix; I
renamed cogl_matrix_init_from_gl_matrix to cogl_matrix_init_from_array to
make it seem more general purpose.
Bug 1473 - CoglPixelFormat enum data must be declared static
When registering an enumeration GType, the GEnumValue or GFlagsValue
arrays must be declared static; otherwise, you get a segmentation
fault when calling the function again.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Clutter is able to show debug messages written using the CLUTTER_NOTE()
macro at runtime, either by using an environment variable:
CLUTTER_DEBUG=...
or by using a command line switch:
--clutter-debug=...
--clutter-no-debug=...
Both are parsed during the initialization process by using the
GOption API.
COGL would benefit from having the same support.
In order to do this, we need a cogl_get_option_group() function in
COGL that sets up a GOptionGroup for COGL and adds a pre-parse hook
that will check the COGL_DEBUG environment variable. The OptionGroup
will also install two command line switches:
--cogl-debug
--cogl-no-debug
With the same semantics of the Clutter ones.
During Clutter initialization, the COGL option group will be attached
to the GOptionContext used to parse the command line options passed
to a Clutter application.
Every debug message written using:
COGL_NOTE (SECTION, "message format", arguments);
Will then be printed only if SECTION was enabled at runtime.
This whole machinery, like the equivalent one in Clutter, depends on
a compile time switch, COGL_ENABLE_DEBUG, which is enabled at the same
time as CLUTTER_ENABLE_DEBUG. Having two different symbols allows
greater granularity.
An assert to verify there was no error when generating a buffer object
for the vertex buffer API was being hit when running the GLES1 conformance
tests.
Bug #1457 - Creating a new texture messes up the cogl material state
cache; reported by Neil Roberts
We still don't have caching of bound texture state so we always have to
re-bind the texture when flushing the GL state of any material layers.
Bug #1460 - Handling of flags in cogl_material_set_color
Cogl automatically enables/disables blending based on whether the source color
has an alhpa < 1.0, or if any textures with an alpha component are in use, but
it wasn't doing it quite right.
At the same time I removed some of the dirty flags which on second thought
are nothing more than micro-optimsations that only helped clutter the code.
thanks to Owen Taylor for reporting the bug
Since the CoglMatrix type was added for supporting texture matrices recently
it made sense to be consistent accross the Cogl API and use the Cogl type
over the GL style GLfloat m[16] arrays.
cogl_wrap_glActiveTexture needs to call the GL version of
glActiveTexture otherwise the subsequent calls to glBindTexture will
all be using texture unit 0. This fixes test-cogl-multitexture.
Previously the texture unit settings were stored in growable GArrays
and every time a new texture unit was encountered it would expand the
arrays. However the array wasn't copied when stored in a
CoglGles2WrapperSettings struct so all settings had the same
array. This meant that it wouldn't detect that a different program is
needed if a texture unit is disabled or enabled.
The texture unit settings arrays are all now a fixed size and the
enabledness of each unit is stored in a bit mask. Therefore the
settings can just be copied around by assignment as before.
This puts a limit on the number of texture units accessible by Cogl
but I think it is worth it to make the code simpler and more
efficient. The material API already poses a limit on the number of
texture units it can use.
COGL types should be registered inside the GType system, for
bindings and type checking inside properties and signals.
CoglHandle is a boxed type with a ref+unref semantics; slightly evil
from a bindings perspective (we cannot associate custom data to it),
but better than nothing.
The rest of the exposed types are enumerations or bitmasks.
The COGL_DEFINE_HANDLE macro generates a cogl_is_<type> function
as well, to check whether a CoglHandle opaque pointer is of type
<type>.
The handle for CoglMaterial does not export cogl_is_material() in
its installed header.
cogl_paint_init was a bit too miscellaneous; it mainly cleared the color, depth
and stencil buffers but arbitrarily it also disabled fogging and lighting.
It no longer disables lighting, since we know Cogl never enables lighting and
disabling of fog is now handled with a seperate function.
Since I noticed cogl_set_fog was taking a density argument documented as
"Ignored" I've also added a mode argument to cogl_set_fog which exposes the
exponential fog modes which can make use of the density.
All GL functions that are defined in a version later than 1.1 need to
be called through cogl_get_proc_address because the Windows GL DLL
does not export them to directly link against.
The main COGL header file is generated at configure time. If something
changes in the template, though, the file will not be regenerated.
Adding cogl.h to the BUILT_SOURCES list will allow the regeneration to
happen.
This hides a number of internal structs and enums from the docs, and moves
some functions to more appropriate sections as well as misc description
updates (mostly for the vertex buffer api)
Fixes some blending issues when using color arrays since we were
conflicting with the cogl_enable state + fixes a texture layer
validation bug.
Adds a basic textured triangle to test-vertex-buffer-contiguous.
When the quad log contains multiple textures (such as when a sliced
texture is drawn) it dispatches the log with multiple calls to
flush_quad_batch and walks a pointer along the list of vertices.
However this pointer was being incremented by only one vertex so the
next quad would be drawn with three of the vertices from the last
quad.
The quad drawing code keeps track of the number of texture units that
have the tex coord array enabled so that in the next call it can
disabled any that are no longer enabled. However it was using 'i+1' as
the count but 'i' is already set to 'n_layers' from the previous for
loop.
Therefore it was disabling an extra texture unit. This doesn't
normally matter but it was causing GLES 2 to pointlessly realize an
extra unit.
- In cogl-material.h it directly sets the values of the
CoglMaterialLayerCombineFunc to some GL_* constants. However these
aren't defined in GLES 2 beacuse it has no fixed function texture
combining. Instead the CGL_* versions are now used. cogl-defines.h
now sets these to either the GL_* version if it is available,
otherwise it directly uses the number.
- Under GLES 2 cogl-material.c needs to access the CoglTexture struct
so it needs to include cogl-texture-private.h
- There are now #define's in cogl-gles2-wrapper.h to remap the GL
function names to the wrapper names. These are disabled in
cogl-gles2-wrapper.c by defining COGL_GLES2_WRAPPER_NO_REMAP.
- Added missing wrappers for glLoadMatrixf and glMaterialfv.
- Renamed the TexEnvf wrapper to TexEnvi because the latter is used
instead from the material API.
Cogl previously tried to cache the currently bound texture when
drawing through the material API to avoid excessive GL calls. However,
a few other places in Cogl and Clutter rebind the texture as well so
this can cause problems.
This was causing shaped windows to fail in Mutter because
ClutterGLXTexturePixmap was binding a different texture to update it
while the second texture unit was still active which meant the mask
texture would not be selected when the shaped window was drawn
subsequent times.
Ideally we would fix this by providing a wrapper around glBindTexture
which would affect the cached value. The cache would also have to be
cleared if a selected texture was deleted.
This tries to make a number of files more comparable with the intention of
moving some code into cogl/common/
Files normalized:
cogl.c
cogl-context.c
cogl-context.h
cogl-texture.c
Someone not sure which cogl_color_set_from_* version is "best" may use
set_from_4d because taking doubles implies higher precision. Currently
it doesn't have any advantage.
This makes it consistent with cogl_rectangle_with_{multi,}texture_coords.
Notably the reason cogl_rectangle_with_{multi,}texture_coords wasn't changed
instead is that the former approach lets you describe back facing rectangles.
(though technically you could pass negative width/height values to achieve
this; it doesn't seem as neat.)
The code is #if 0 guarded, but when uncommented it outlines all drawn
rectangles with an un-blended red, green or blue border. This may e.g. help
with debugging texture slicing issues or blending issues, plus it looks quite
cool.
When drawing a texture with waste in _cogl_multitexture_unsliced_quad
it scales the texture coordinates so that the waste is not
included. However the formula was the wrong way around so it was
calculating as if the texture coordinates are ordered x1,x2,y1,y2 but
it is actually x1,y1,x2,y2.
When the texture is sliced it drops back to a fallback function and
passes it the texture coordinates from the rectangle. However if no
tex coords are given it would crash. Now it passes the default
0.0->1.0 tex coords instead.
If no texture coordinates are given then texture_unsliced_quad tries
to generate its own coordinates. However it also tries to read the
texture coordinates to check if they are in [0.0,1.0] range so it will
crash before it reaches that.
