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.
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.
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.
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.
With ARB_multi_bind it is needed to associate the texture with some
target before calling glBindTextures(), otherwise the texture is
treated as invalid.
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.
*Texture::bind() is now meant to be used only internally from shaders,
thus this function is not needed at all, as we should query directly the
particular shader type for the limits.
The name also somehow clashes with layered textures, which should be
avoided.
Why did I do this:
* It is more clean, shorter and nice looking with method chaining,
i.e. instead of:
shader.setColor(...)
.setOtherParam(5);
texture1.bind(MyShader::Texture1Layer);
texture2.bind(MyShader::Texture2Layer);
We now have this:
shader.setColor(...)
.setOtherParam(5)
.setTexture1(texture1)
.setTexture2(texture2);
* It is now also clear which texture type is expected, the layer
constant did not say anything about type.
* Also it is possible to use new features (multi bind, bindless
textures etc.) while preserving the same public API.
The only potential disadvantage is that the textures don't stay bound
like uniform values do, but this become a non-issue with bindless
textures. As usual, the old way is now deprecated and will be removed in
some future release.
Each texture has slightly different usage requirements and having
everything under one generic class is not worth the additional runtime
checks and whatnot. The current way with Texture::Target enum
(hopefully not too widely used) is now deprecated and will be removed in
some future release. However general Texture1D/2D/3D usage is not
changed in any way.
Vladimír Vondruš