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.
Conflicts:
clutter/cogl/gl/cogl-texture.c
clutter/cogl/gles/cogl-primitives.c
* cogl-material:
clutter-{clone-,}texture weren't updating their material opacity.
Updates GLES1 support for CoglMaterial
Normalizes gl vs gles code in preperation for synching material changes
Removes cogl_blend_func and cogl_alpha_func
Fully integrates CoglMaterial throughout the rest of Cogl
[cogl-material] Restore the GL_TEXTURE_ENV_MODE after material_rectangle
[cogl-material] Make the user_tex_coords parameter of _rectangle const
[test-cogl-material] Remove return value from material_rectangle_paint
Add cogl-material.h and cogl-matrix.h to libclutterinclude_HEADERS
[cogl-material] improvements for cogl_material_rectangle
[cogl-material] Adds a cogl_material_set_color function
[cogl-material] Some improvements for how we sync CoglMaterial state with OpenGL
[cogl-material] Converts clutter-texture/clutter-clone-texture to the material API
[doc] Hooks up cogl-material reference documentation
Updates previous GLES multi-texturing code to use CoglMaterial
Adds a CoglMaterial abstraction, which includes support for multi-texturing
[doc] Hooks up cogl-matrix reference documentation
Adds CoglMatrix utility code
[tests] Adds an interactive unit test for multi-texturing
[multi-texturing] This adds a new cogl_multi_texture API for GL,GLES1 + GLES2
This updates cogl/gles in line with the integration of CoglMaterial throughout
Cogl that has been done for cogl/gl.
Note: This is still buggy, but at least it builds again and test-actors works.
Some GLES2 specific changes were made, but these haven't been tested yet.
This changes all GLES code to use the OpenGL function names instead of
the cogl_wrap_* names. For GLES2 we now define the OpenGL name to point
to the wrapper, as opposed to defining the wrapper to point to the
OpenGL name for GLES1.
I've also done a quick pass through gl/cogl.c and gles/cogl.c to make
them more easily comparable. (most of the code is now identical)
The GL blend function and alpha function are now controlled by the material
code, and even internally Cogl should now be using the material API when
it needs control of these.
This glues CoglMaterial in as the fundamental way that Cogl describes how to
fill in geometry.
It adds cogl_set_source (), which is used to set the material which will be
used by all subsequent drawing functions
It adds cogl_set_source_texture as a convenience for setting up a default
material with a single texture layer, and cogl_set_source_color is now also
a convenience for setting up a material with a solid fill.
"drawing functions" include, cogl_rectangle, cogl_texture_rectangle,
cogl_texture_multiple_rectangles, cogl_texture_polygon (though the
cogl_texture_* funcs have been renamed; see below for details),
cogl_path_fill/stroke and cogl_vertex_buffer_draw*.
cogl_texture_rectangle, cogl_texture_multiple_rectangles and
cogl_texture_polygon no longer take a texture handle; instead the current
source material is referenced. The functions have also been renamed to:
cogl_rectangle_with_texture_coords, cogl_rectangles_with_texture_coords
and cogl_polygon respectivly.
Most code that previously did:
cogl_texture_rectangle (tex_handle, x, y,...);
needs to be changed to now do:
cogl_set_source_texture (tex_handle);
cogl_rectangle_with_texture_coords (x, y,....);
In the less likely case where you were blending your source texture with a color
like:
cogl_set_source_color4ub (r,g,b,a); /* where r,g,b,a isn't just white */
cogl_texture_rectangle (tex_handle, x, y,...);
you will need your own material to do that:
mat = cogl_material_new ();
cogl_material_set_color4ub (r,g,b,a);
cogl_material_set_layer (mat, 0, tex_handle));
cogl_set_source_material (mat);
Code that uses the texture coordinates, 0, 0, 1, 1 don't need to use
cog_rectangle_with_texure_coords since these are the coordinates that
cogl_rectangle will use.
For cogl_texture_polygon; as well as dropping the texture handle, the
n_vertices and vertices arguments were transposed for consistency. So
code previously written as:
cogl_texture_polygon (tex_handle, 3, verts, TRUE);
need to be written as:
cogl_set_source_texture (tex_handle);
cogl_polygon (verts, 3, TRUE);
All of the unit tests have been updated to now use the material API and
test-cogl-material has been renamed to test-cogl-multitexture since any
textured quad is now technically a test of CoglMaterial but this test
specifically creates a material with multiple texture layers.
Note: The GLES backend has not been updated yet; that will be done in a
following commit.
The Cogl primitives broke for GLES 1.1 and 2 after the cogl-float
branch merge.
CoglPathNode was still being declared as GLfixed for the GLES backend
but it was being filled with float values so they were all ending up
as numbers < 1.
glDrawArrays was being called with GL_FIXED so this has been changed
to GL_FLOAT.
The scanline rasterizer had a leftover hardcoded ClutterFixed constant
to add a small amount to the height of each line.
struct _CoglFloatVec2 has been removed because it is no longer used
anywhere.
The maintainer compiler flags we use trigger warnings and errors
in the autogenerated code that gtk-doc creates to scan the header
and source files. Since we cannot control that, and we must run
a distcheck with both --enable-gtk-doc and --enable-maintainer-flags
turned on, we need to use less-strict compiler flags when inside
the doc/reference subdirectories.
The way to do this is to split the maintainer compiler flags into
their own Makefile variable, called MAINTAINER_CFLAGS. The we
can use $(MAINTAINER_CFLAGS) in the INCLUDES or _CFLAGS sections
of each part of the source directories we wish to check with the
anal retentiveness suited for maintainers.
The script converted calls to COGL_FIXED_MUL(x,y) to (x*y). However
this fails for cases like this:
COGL_FIXED_MUL(a + b, c)
which become
(a + b * c)
The meaning of this is of course different because multiplication has
a higher precedence than addition.
This was causing breakages in cogl_texture_quad_sw when the vertex
coordinates are not in increasing order. This was the case in
test-backface-culling when NPOTs are not available.
Improve clutter_sinx() by replacing the low precision CFX_SIN_STEP
with a multiply/divide pair. This reduces the maximum error from
1.8e-04 to 2.4e-05.
http://bugzilla.openedhand.com/show_bug.cgi?id=1314
Based on a patch by Owen W. Taylor <otaylor@fishsoup.net>
Compute the value of the camera distance as exactly half the xx
component of the projection matrix. The heuristically derived
value for 60 degrees was off by about 0.016%, causing noticeable
blurring, and other field of view angles which didn't have the
heuristic adjustment off by much more.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Boolean arguments for functions are pretty evil and usually
lead to combinatorial explosion of parameters in case multiple
settings are added.
In the case of the COGL texture constructors we have a boolean
argument for enabling the auto-mipmapping; it is conceivable that
we might want to add more settings for a COGL texture without
breaking API or ABI compatibility, so the boolean argument should
become a bitmask.
The internals have not been changed: instead of checking for
a non-zero value, we check for a bitmask being set.
This better reflects the fact that the api manages sets of vertex attributes,
and the attributes really have no implied form. It is only when you use the
attributes to draw that they become mesh like; when you specify how they should
be interpreted, e.g. as triangle lists or fans etc. This rename frees up the
term "mesh", which can later be applied to a concept slightly more fitting.
E.g. at some point it would be nice to have a higher level abstraction that
sits on top of cogl vertex buffers that adds the concept of faces. (Somthing
like Blender's mesh objects.) There have also been some discussions over
particle engines, and these can be defined in terms of emitter faces; so some
other kind of mesh abstraction might be usefull here.
To deal with all the corner cases that couldn't be scripted a number of patches
were written for the remaining 10% of the effort.
Note: again no API changes were made in Clutter, only in Cogl.
This is the result of running a number of sed and perl scripts over the code to
do 90% of the work in converting from 16.16 fixed to single precision floating
point.
Note: A pristine cogl-fixed.c has been maintained as a standalone utility API
so that applications may still take advantage of fixed point if they
desire for certain optimisations where lower precision may be acceptable.
Note: no API changes were made in Clutter, only in Cogl.
Overview of changes:
- Within clutter/* all usage of the COGL_FIXED_ macros have been changed to use
the CLUTTER_FIXED_ macros.
- Within cogl/* all usage of the COGL_FIXED_ macros have been completly stripped
and expanded into code that works with single precision floats instead.
- Uses of cogl_fixed_* have been replaced with single precision math.h
alternatives.
- Uses of COGL_ANGLE_* and cogl_angle_* have been replaced so we use a float for
angles and math.h replacements.
It looks like the changes to cogl-gles2-wrapper.h were accidentally
committed to the actual file instead of the patch in commit
de27da0e. This commit moves the changes back into the patch so
cogl-gles2-wrapper.h is reverted back to master.
The patches have been updated to apply cleanly.
The patches for the g_warnings in clutter-actor.c have been removed
because master now uses CLUTTER_UNITS_FORMAT so they aren't
necessary. The clutter-units.h patch now sets CLUTTER_UNITS_FORMAT to
'f'.
The changes from the GL version of cogl-texture.c have been mirrored
in the GLES version. This adds the cogl_texture_new_from_bitmap
function and fixes the build errors.
* async-textures:
Whitespace fixes in ClutterTexture
[async-loading] Do not force the texture size on async load
[async-loading] Update asynchronous image loading
Add API for extracting image size from a file
Update/clean and apply the async-texture patch from bug #1144
The GLES 2 wrapper needs to set up some state before each
draw. Previously this was acheived by wrapping glDrawArrays. Since the
multiple-texture-rectangle branch merge, glDrawElements is used
instead so we also need a wrapper for that.
It was also directly calling glBindTexture. GLES 2 uses a wrapper for
this function so that it can cope with GL_ALPHA format textures. The
format of the current texture needs to be stored as well as the target
and object number for this to work.
For the asynchronous loading we need a function call that parses
a file, given its path, and retrieves the image width and height.
This commit adds cogl_bitmap_get_size_from_file() to the CoglBitmap
API.
Bug 1289 - Draw multiple glyphs at once
The multiple-texture-rectangle branch adds a new Cogl texture function
called cogl_texture_multiple_rectangles which is used to draw multiple
rectangles out of a texture using a single GL call. This is
significantly faster than drawing the rectangles with individual calls
on some platforms. The Pango renderer now uses this to speed up
rendering.
The conflicts are just due to the whitespace fixes in cb569a5.
Conflicts:
clutter/cogl/gl/cogl-context.c
clutter/cogl/gl/cogl-context.h
clutter/cogl/gl/cogl-texture.c
The rest of Cogl expects the texture mode to be GL_MODULATE so it
needs to be restored after calling cogl_material_rectangle. Otherwise
cogl_texture_rectangle will fail to blend with the Cogl color properly
and all of the labels will be black.
The API has been changed to take an explicit length for the number of
texture coordinates passed, and it's now documented that if there are
more layers to the current material than the number of texture coords
passed, then default coordinates will be generated for the other
layers.
cogl_material_rectangle should now handle the case where a single
sliced texture is supplied as a material layer by falling back to
cogl_texture_rectangle. We are nearly at the point that
cogl_texture_rectangle could be deprecated. A few issues remain
though, such as not considering waste in cogl_material_rectangle.
The other colors of a material; such as the ambient and diffuse color are
only relevent when we can enable lighting. This adds a basic unlit
color property.
Later cogl_set_source_color can be integrated to either modify the color
of the current source material, or maintain a special singlton CoglMaterial
that is modified by calls to cogl_set_source_color and implicitly made
current.
This flattens the three functions: cogl_material_flush_gl_material_state,
.._flush_gl_alpha_func and .._flush_gl_blend_func into one:
cogl_flush_material_gl_state which doesn't takes a material handle. (the handle
is instead taken from the context.)
This has allows us to avoid re-submitting some state to OpenGL when the
material has not been replaced.
Note: Avoiding redundant state changes for material layers isn't dealt with
in this patch.
Removed trailing white space from the following files:
- clutter-clone-texture.c
- clutter-texture.c
- clutter-texture.h
- cogl/cogl-texture.h
- cogl/gl/cogl-context.c
- cogl/gl/cogl-texture.c
- cogl/gl/cogl-context.h
test-cogl-material now runs on GLES 1 using the PVR GLES1 SDK (though since
only 2 texture units are supported the third rotating light map doesn't show)
Note: It currently doesn't build for GLES 2.0
My previous work to provide muti-texturing support has been extended into
a CoglMaterial abstraction that adds control over the texture combine
functions (controlling how multiple texture layers are blended together),
the gl blend function (used for blending the final primitive with the
framebuffer), the alpha function (used to discard fragments based on
their alpha channel), describing attributes such as a diffuse, ambient and
specular color (for use with the standard OpenGL lighting model), and
per layer rotations. (utilizing the new CoglMatrix utility API)
For now the only way this abstraction is exposed is via a new
cogl_material_rectangle function, that is similar to cogl_texture_rectangle
but doesn't take a texture handle (the source material is pulled from
the context), and the array of texture coordinates is extended to be able
to supply coordinates for each layer.
Note: this function doesn't support sliced textures; supporting sliced
textures is a non trivial problem, considering the ability to rotate layers.
Note: cogl_material_rectangle, has quite a few workarounds, for a number of
other limitations within Cogl a.t.m.
Note: The GLES1/2 multi-texturing support has yet to be updated to use
the material abstraction.
Multitexturing allows blending multiple layers of texture data when texturing
some geometry. A common use is for pre-baked light maps which can give nice
lighting effects relativly cheaply. Another is for dot-3 bump mapping, and
another is applying alpha channel masks.
The dot-3 bump mapping would be really nice one day, but currently cogl doesn't
support lighting so that's not dealt with in this patch.
notable limitations:
- It can only texture rectangles a.t.m - and like cogl_texture_rectangle there
is no support for rotated texturing.
- Sliced textures are not supported. I think I've figured out how to handle
layers with different slice sizes at least for rectangular geometry, but I'm
not sure how complex it becomes once rotations are possible and texturing
arbitrary cogl_polygons.
- Except for this new API, cogl still doesn't know about more than one texture
unit, and so has no way of caching any enables related to other units. So that
things don't break it's currently necessary to disable anything to do with
additional units as soon as we are done with them which isn't ideal.
- No clutter API yet.
* clutter/cogl/gl/cogl-defines.h.in:
* clutter/cogl/gl/cogl-context.h:
* clutter/cogl/common/cogl-mesh.c: Rename the glBufferDataSub
function to glBufferSubData. When calling glXGetProcAddress with
the former Mesa returns a stub dispatch function which will
segfault if you try to use it. With NVIDIA it returns NULL so
_cogl_features_init decides the card doesn't have VBO support.
There's no point in clearing the index array because it is always the
same sequence of indices regardless of the vertices. Instead it is
just added to when there are more vertices than ever before.
* clutter/cogl/gl/cogl-texture.c (cogl_texture_new_from_foreign,
(_cogl_texture_quad_hw, cogl_texture_polygon),
(_cogl_texture_quad_sw): Support GL_ARB_texture_rectangle textures
* clutter/glx/clutter-glx-texture-pixmap.c: Use rectangle textures
when NPOTs are not available or it is forced by the
CLUTTER_PIXMAP_TEXTURE_RECTANGLE environment variable.
* clutter/cogl/gl/cogl.c (cogl_enable): Allow enabling
GL_TEXTURE_RECTANGLE_ARB.
* clutter/cogl/cogl-path.h:
* clutter/cogl/common/cogl-primitives.c:
* clutter/cogl/common/cogl-primitives.h:
* clutter/cogl/gl/cogl-primitives.c:
* clutter/cogl/gles/cogl-primitives.c: Changed the semantics of
cogl_path_move_to. Previously this always started a new path but
now it instead starts a new disjoint sub path. The path isn't
cleared until you call either cogl_path_stroke, cogl_path_fill or
cogl_path_new. There are also cogl_path_stroke_preserve and
cogl_path_fill_preserve functions.
* clutter/cogl/gl/cogl-context.c:
* clutter/cogl/gl/cogl-context.h:
* clutter/cogl/gles/cogl-context.c:
* clutter/cogl/gles/cogl-context.h: Convert the path nodes array
to a GArray.
* clutter/cogl/gl/cogl-texture.c:
* clutter/cogl/gles/cogl-texture.c: Call cogl_clip_ensure
* clutter/cogl/common/cogl-clip-stack.c:
* clutter/cogl/common/cogl-clip-stack.h: Simplified the clip
stack code quite a bit to make it more maintainable. Previously
whenever you added a new clip it would go through a separate route
to immediately intersect with the current clip and when you
removed it again it would immediately rebuild the entire clip. Now
when you add or remove a clip it doesn't do anything immediately
but just sets a dirty flag instead.
* clutter/cogl/gl/cogl.c:
* clutter/cogl/gles/cogl.c: Taken away the code to intersect
stencil clips when there is exactly one stencil bit. It won't work
with path clips and I don't know of any platform that doesn't have
eight or zero stencil bits. It needs at least three bits to
intersect a path with an existing clip. cogl_features_init now
just decides you don't have a stencil buffer at all if you have
less than three bits.
* clutter/cogl/cogl.h.in: New functions and documentation.
* tests/interactive/test-clip.c: Replaced with a different test
that lets you add and remove clips. The three different mouse
buttons add clips in different shapes. This makes it easier to
test multiple levels of clipping.
* tests/interactive/test-cogl-primitives.c: Use
cogl_path_stroke_preserve when using the same path again.
* doc/reference/cogl/cogl-sections.txt: Document the new
functions.
border artifacts
* clutter/cogl/gl/cogl-texture.c: Set the wrap mode of a texture
on demand
Instead of setting the wrap mode once per texture at creation, it
is now changed whenever the texture is drawn. The previous value
is cached so that it isn't changed if the value is the same.
This is used in _cogl_texture_quad_hw to only enable GL_REPEAT
mode when the coordinates are not in the range [0,1]. Otherwise it
can pull in pixels from the other edge when the texture is
rendered off-pixel.
Most cards don't actually support GL_QUADS and they are deprecated in
GL 3.0 so there is a chance it will perform faster with GL_TRIANGLES
even though it has to submit two extra vertices.
This takes an array of sets of 8 floats to describe the rectangles. It
tries to send the geometry with a single glDrawArrays as far as
possible. cogl_texture_rectangle is now just a wrapper around
cogl_texture_multiple_rectangles.
cogl_texture_quad_hw and _sw now just add vertices to the vertex
array. The last texture used is stored and if a different texture is
encountered then flushes the vertices. cogl_texture_rectangle always
flushes the vertices after calling either of the functions.
the test for whether to use hardware tiling. Previously it assumed
that texture coordinates are in increasing order but this is not
the case since bug 1057 was fixed. The texture coordinates are now
sorted later. It also allowed negative coordinates which doesn't
make sense if the texture has waste.
`_glDrawRangeElements@24'
Resolve glDrawRangeElements with cogl_get_proc_address instead of
calling it directly because functions defined in GL > 1.1 are not
directly exported under Windows.
* clutter/cogl/common/cogl-mesh.c: Use the function pointer from
the context
* clutter/cogl/gl/cogl-context.c (cogl_create_context): Initialise
function pointer.
* clutter/cogl/gl/cogl-context.h (CoglContext): Add a function
pointer
* clutter/cogl/gl/cogl-defines.h.in: Add a typedef for the
function pointer.
* clutter/cogl/gl/cogl.c (_cogl_features_init): Resolve
glDrawRangeElements
differences and improve maintainability.
* clutter/cogl/gl/cogl-context.h:
Adds a CoglTextureGLVertex typedef + texture_vertices and
texture_vertices_size members to CoglContext for using vertex arrays
like GLES does
* clutter/cogl/gl/cogl-context.c:
Initializes texture_vertices + texture_vertices_size members
* clutter/cogl/gl/cogl-internal.h:
Adds COGL_ENABLE_COLOR_ARRAY
* clutter/cogl/gl/cogl.c:
Add COGL_ENABLE_COLOR_ARRAY support to cogl_enable
* clutter/cogl/gles/cogl-context.h:
Change the CoglTextureGLVertex to use GLfloat for the position
and texture coord attributes and GLubyte for the color.
* clutter/cogl/gles/cogl-texture-private.h:
Adds a wrap_mode member like GL has.
* clutter/cogl/gl/cogl-texture.c
* clutter/cogl/gles/cogl-texture.c:
Improves the comparability of the files, such that the remaining
differences, better reflect the fundamental differences needed
between GL and GLES. Notably GL no longer uses glBegin/glEnd for
submitting vertices, it uses vertex arrays like GLES and this gives
a small but measurable fps improvement for test-text.
