The original problem was that I was using 3D wrapping mode (S, T, R) for
cube map textures, but GL_TEXTURE_WRAP_R was not defined on ES2 so it
seemed rather suspicious.
Google seems to be lost on this and most of the online tutorials seem to
be setting GL_TEXTURE_WRAP_R even for cube map textures, so I need to
investigate myself. As seen in the rather old ARB_texture_cube_map
extension, there is no new GL_TEXTURE_WRAP_R token added, it is defined
only for 3D textures and there is no apparent dependency between these
two. The wrap mode for cube maps is defined as follows:
* The sampler determines one of the six faces and then employs
conventional 2D texture mapping on given face.
Thus wrapping mode for CubeMapTexture is now changed to be only
two-dimensional (instead of 3D).
For texture arrays the mode is also only one- or two-dimensional (not
two- or three-dimensional), because, as said in the (also rather old)
EXT_texture_array extension, the texture layer is _always_
(independently of any sampling state) selected as follows:
l = clamp(round(t), 0, num_layers - 1)
Thus wrapping mode for Texture1DArray is now changed to be only
one-dimensional (instead of 2D) and for Texture2DArray only
two-dimensional (instead of 3D).
Wrapping for CubeMapTextureArray is now also two-dimensional instead of
3D (with the original way of thinking it would have needed to be 4D!).
ARB_DSA is now preferred in single-bind cases, as it is easier to use
than passing pointers to ARB_multi_bind. ARB_multi_bind was preferred
for single-bind previously simply because EXT_DSA was not in core.
Because there is a lot to say about feature selection for each function,
I took this as a opportunity to remove redundant documentation blocks,
just refer to Texture documentation from everywhere and add extension
requirements and deprecation where needed, so it's clear for each class
what needs what.
ARB_DSA also took the opportunity to finally remove all target enum
values from function calls and because of that the CubeMapTexture has to
handle a bunch of special cases. In order:
- CubeMapTexture::imageSize() now doesn't take face parameter and
returns one value for all faces. I'm thus now also assuming that the
user is sane and called either setStorage() or setImage() with the
same size for all faces. In non-ARB_DSA path I'm thus querying only
size of +X face and returning it as size for all faces. The old
imageSize(Coordinate, Int) overload is still present, but ignores
the first parameter and calls imageSize(Int). It is marked as
deprecated and will be removed in some future release.
- CubeMapTexture::image() now needs to call glTextureSubImage() in
ARB_DSA path to make it possible to extract single face. Other code
paths (EXT_DSA, Robustness and "default") remain the same.
- CubeMapTexture::setSubImage() calls glTextureSubImage3D() in
ARB_DSA, because it is not possible to specify face index in
glTextureSubImage2D(). Other code paths (EXT_DSA and "default")
remain the same.
Implementation of these special cases is extracted into CubeMapTexture
class to avoid pollution of AbstractTexture with incompatible nonsense.
The comment was right, but the code was apparently copy-pasted. Sadly no
unit test covered this, because nearly every desktop impl has
ARB_texture_storage and on ES2 (which is the only that doesn't have
texture storage) it's not possible to query image size, heh.
ARB_direct_state_access doesn't have equivalent for glTexImage*D(),
which indicates that these calls should not be used anymore. Also
removed EXT_direct_state_access code path and kept just the plain
glBindTexture() + glTexImage*D(), as I assume that all implementations
which have EXT_DSA have also ARB_texture_storage, thus this alternative
would have no use.
The indexed binding is allowed for only some types (atomic counters,
uniforms, shader storage and transform feedback), thus we need separate
enum for that. Because the bind() function will be used far more often
than setTargetHint(), the original Target enum is now renamed to
TargetHint and the new Target enum contains (in non-deprecated build)
only three values.
For backwards compatibility, though, we need to have all original Target
values, thus the new Target enum contains also all other values from
TargetHint, but they are marked as deprecated and (at least) run-time
checked in bind() so they aren't accidentaly used for indexed binding.
Similarly there are also deprecated Target overloads of Buffer() and
setTargetHint(). It's ugly, but hopefully will suffice for now. This mess
will be removed as soon as possible in some upcoming version.
As glGen*() only reserves object name without creating it, it must be
ensured that the object is created before calling functions which expect
already created object (such as glObjectLabel() or glBindTextures()).
Allows me to remove quite a lot hacks in the tests.
There should be no need to use these directly (and in some cases it
might be harmful). The bind()/unbind() names will be used for
glBindBufferBase()/glBindBufferRange() later.
In most cases the label is set directly from code, e.g.:
texture.setLabel("diffuse-duck");
Avoiding conversion to std::string and passing char(&)[size] directly
will avoid one allocation and deallocation. Better solution would be to
use std::string_view everywhere, but we're not in C++17 yet.
Would cause random weird issues with texture configuration/upload if
ARB_multi_bind is available and EXT_direct_state_access is not. Probably
not an issue, since EXT_direct_state_access is probably available on all
drivers which support also ARB_multi_bind.
Until now the textures were bound to layers, which was rather confusing,
especially when binding layered textures to layers (gaah). Also the
wording might have implied that each texture must be in some layer in
order to make it usable in shader. This is no longer the case with (yet
unimplemented) bindless texture, so another reason to remove the
confusion.
All occurences of texture layers were replaced texture binding units to
follow OpenGL naming. It was mostly in the docs, except for
already-deprecated *Layer enums in shaders, but they will be removed
soon anyway.
Vladimír Vondruš