Commit Graph

99 Commits

Author SHA1 Message Date
wm4 fbcf2bf207 vo_gpu: fix anamorphic video screenshots (second try)
This passed the display size as source size to the renderer, which is of
course nonsense. I don't know what I was doing in 569383bc54.

Yet another fix for those damn anamorphic videos.

As a somewhat redundant/cosmetic change, use image_params instead of
real_image_params in the code above. They should have the same, dimensions
(but possibly different formats when doing hw decdoing), and mixing them
is confusing. p->image_params wins because it's shorter.

Actually fixes #5619.
2018-03-16 23:00:45 +02:00
wm4 569383bc54 vo_gpu: fix anamorphic screenshots
We took the storage size instead of the display size for "unscaled"
screenshots. Even if it's called "unscaled", it's still supposed to
scale to compensate for aspect ratio.

(How many commits fixing anamorphic screenshots in various situations
are there?)

Fixes #5619.
2018-03-15 23:13:53 -07:00
wm4 ecf4d7a843 vo_gpu: error out if there were rendering errors when taking screenshot 2018-03-03 02:38:01 +02:00
wm4 1b786a71c1 vo_gpu: fix taking screenshots of rotated videos
Good old 90° rotation logic messing everything up.
2018-03-03 02:38:01 +02:00
Niklas Haas 441e384390 vo_gpu: introduce --target-peak
This solves a number of problems simultaneously:

1. When outputting HLG, this allows tuning the OOTF based on the display
   characteristics.
2. When outputting PQ or other HDR curves, this allows soft-limiting the
   output brightness using the tone mapping algorithm.
3. When outputting SDR, this allows HDR-in-SDR style output, by
   controlling the output brightness directly.

Closes #5521
2018-02-20 22:02:51 +02:00
Niklas Haas b9e7478760 vo_gpu: simplify and correct color scale handling
The primary need for this change is the fact that the OOTF was
incorrectly scaled, due to the fact that the application of the OOTF can
itself change the required normalization peak. (Plus, an oversight in
pass_inverse_ootf meant we forgot to normalize at the end of it)

The linearize/delinearize functions still normalize the scale since it's
used in a number of places throughout gpu/video.c, but the color
management function now converts to absolute scale right away, instead
of in an awkward way inside the tone mapping branch. The OOTF functions
now work in absolute scale only.

In addition, minor changes have been made to the way normalization is
handled for tone mapping - we now divide out the dst_peak *after* peak
detection, in order to make the scale of the peak detection buffer
consistent even if the dst_peak were to (hypothetically) change
mid-stream. In theory, we could also do this for desaturation, but doing
the desaturation before tone mapping has the advantage of preserving
much more brightness than the other way around - and even mid-stream
changes are not that drastic here.

Finally, some preparation work has been done for allowing the user to
customize the `dst.sig_peak` in the future.
2018-02-20 22:02:51 +02:00
James Ross-Gowan 7d2228c673 vo_gpu: use a variable for the RA_CAP_FRAGCOORD flag
This is just a cosmetic change. Now the RA_CAP_FRAGCOORD check looks
like all the others.
2018-02-13 00:21:26 +02:00
James Ross-Gowan 44dc79dcb0 vo_gpu: check for HDR peak detection in dumb mode too
Similar spirit to edb4970ca8. check_gl_features() has a confusing
early-return. This also adds compute_hdr_peak to the list of options
that is copied to the dumb-mode options struct, since it seems to make a
difference. Otherwise it would be impossible to disable HDR peak
detection in dumb mode.
2018-02-13 00:21:26 +02:00
wm4 9f595f3a80 vo_gpu: make screenshots use the GL renderer
Using the GL renderer for color conversion will make sure screenshots
will use the same conversion as normal video rendering. It can do this
for all types of screenshots.

The logic when to write 16 bit PNGs changes. To approximate the old
behavior, we decide by looking whether the source video format has more
than 8 bits per component. We apply this logic even for window
screenshots. Also, 16 bit PNGs now always include an unused alpha
channel. The reason is that FFmpeg has RGB48 and RGBA64 formats, but no
RGB064. RGB48 is 3 bytes and usually not supported by GPUs for
rendering, so we have to use RGBA64, which forces an alpha channel.

Will break for users who use --target-trc and similar options.

I considered creating a new gl_video context, but it could double GPU
memory use, so I didn't.

This uses FBOs instead of glGetTexImage(), because that increases the
chance it could work on GLES (e.g. ANGLE). Untested. No support for the
Vulkan and D3D11 backends yet.

Fixes #5498. Also fixes #5240, because the code for reading back is not
used with the new code path.
2018-02-11 17:45:51 -08:00
wm4 7b1e73139f vo_gpu: add internal ability to skip osd/subs for rendering
Needed for the following commit.
2018-02-11 17:45:51 -08:00
wm4 bff8cfe3f0 vo_gpu: use blit() only if target ra_tex supports it
Even if RA_CAP_BLIT is set, this might just not be enabled for the
target ra_tex.
2018-02-11 17:45:51 -08:00
Niklas Haas 4e7f4f10ce vo_gpu: correctly infer HDR peak detection support
The re-ordering of commits e3d93fd and 0870859 ended up swallowing the
change which made the HDR tone mapping algorithm actually check for
RA_CAP_NUM_GROUPS support.
2018-02-11 16:45:20 -08:00
Niklas Haas 4c2edecd7d vo_gpu: refactor HDR peak detection algorithm
The major changes are as follows:

1. Use `uint32_t` instead of `unsigned int` for the SSBO size
   calculation. This doesn't really matter, since a too-big buffer will
   still work just fine, but since `uint` is a 32-bit integer by
   definition this is the correct way to do it.

2. Pre-divide the frame_sum by the num_wg immediately at the end of a
   frame. This change was made to prevent overflow. At 4K screen size,
   this code is currently already very at risk of overflow, especially
   once I started playing with longer averaging sizes. Pre-dividing this
   out makes it just about fit into 32-bit even for worst-case PQ
   content. (It's technically also faster and easier this way, so I
   should have done it to begin with). Rename `frame_sum` to `frame_avg`
   to clearly signal the change in semantics.

3. Implement a scene transition detection algorithm. This basically
   compares the current frame's average brightness against the
   (averaged) value of the past frames. If it exceeds a threshold, which
   I experimentally configured, we reset the peak detection SSBO's state
   immediately - so that it just contains the current frame. This
   prevents annoying "eye adaptation"-like effects on scene transitions.

4. As a result of the previous change, we can now use a much larger
   buffer size by default, which results in a more stable and less
   flickery result. I experimented with values between 20 and 256 and
   settled on the new value of 64. (I also switched to a power-of-2
   array size, because I like powers of two)
2018-02-11 16:45:20 -08:00
Niklas Haas e3d93fde2f vo_gpu: port HDR tone mapping algorithm from libplacebo
The current peak detection algorithm was very bugged (which contributed
to the excessive cross-frame flicker without long normalization) and
also didn't take into account the frame average brightness level.

The new algorithm both takes into account frame average brightness (in
addition to peak brightness), and also computes the values in a more
stable/correct way. (The old path was basically undefined behavior)

In addition to improving the algorithm, we also switch to hable tone
mapping by default, and try to enable peak computation automatically
whever possible (compute shaders + SSBOs supported). We also make the
desaturation milder, after extensive testing during libplacebo
development.

I also had to compensate a bit for the representational differences
between mpv and libplacebo (libplacebo treats 1.0 as the reference peak,
but mpv treats it as the nominal peak), but it shouldn't have caused any
problems.

This is still not quite the same as libplacebo, since libplacebo also
allows tagging the desired scene average brightness on the output, and
it also supports reading the scene average brightness from static
metadata (MaxFALL) where available. But those changes are a bit more
involved. It's possible we could also read this from metadata in the
future, but we have problems communicating with AVFrames as it is and I
don't want to touch the mpv colorimetry structs for the time being.
2018-02-05 23:11:18 -08:00
James Ross-Gowan edb4970ca8 vo_gpu: check for RA_CAP_FRAGCOORD in dumb mode too
The RA_CAP_FRAGCOORD checks apply to dumb mode as well, but they were
after the check for dumb mode, which returns early, so they never ran.

Fixes #5436
2018-01-30 20:22:58 +11:00
wm4 3c1566e736 video: fix crash with vdpau when reinitializing rendering
Using vdpau will allocate additional textures for the reinterleaving
step, which uninit_rendering() will free. This is a problem because the
hwdec image remains mapped when reinitializing, so the reinterleaving
textures are turned into dangling pointers. Fix this by freeing the
reinterleave textures on full uninit instead.

Fixes #5447.
2018-01-27 03:31:53 -08:00
Akemi 828f38e10d video: change some remaining vo_opengl mentions to vo_gpu 2018-01-20 14:43:49 -08:00
wm4 342e36ea11 vo_gpu: skip DR for unsupported image formats
DR (direct rendering) works by having the decoder decode into the GPU
staging buffers, instead of copying the video data on texture upload. We
did this even for formats unsupported by the GPU or the renderer. This
"worked" because the staging memory is untyped, and the video frame was
converted by libswscale to a supported format, and then uploaded with a
copy using the normal non-DR texture upload path.

Even though it "works", we don't gain anything from using the staging
buffers for decoding, since we can't use them for upload anyway. Also,
staging memory might be potentially limited (what really happens is up
to the driver). It's easy to avoid, so just skip it in these cases.
2018-01-18 00:25:00 -08:00
wm4 07753bbb4a vo_gpu: fix broken 10 bit via integer textures playback
The check_gl_features(p) call here checks whether dumb mode can be used.
It uses the field use_integer_conversion, which is set _after_ the call
in the same function. Move check_gl_features() to the end of the
function, when use_integer_conversion is finally set.

Fixes that it tried to use bilinear filtering with integer textures. The
bug disabled the code that is supposed to convert it to non-integer
textures.
2018-01-17 22:59:15 -08:00
Niklas Haas a42b8b1142 vo_gpu: attempt re-using the FBO format for p->output_tex
This allows RAs with support for non-opaque FBO formats to use a more
appropriate FBO format for the output tex, possibly enabling a more
efficient blit operation.

This requires distinguishing between real formats (which can be used to
create textures) and fake formats (e.g. ra_gl's FBO hack).
2017-12-25 00:47:53 +01:00
Niklas Haas dcda8bd36a vo_gpu: aggressively prefer async compute
On AMD devices, we only get one graphics pipe but several compute pipes
which can (in theory) run independently. As such, we should prefer
compute shaders over fragment shaders in scenarios where we expect them
to be better for parallelism.

This is amusingly trivial to do, and actually improves performance even
in a single-queue scenario.
2017-12-25 00:47:53 +01:00
Niklas Haas a3c9685257 vo_gpu: invalidate fbotex before drawing
Don't discard the OSD or pass_draw_to_screen passes though. Could be
faster on some hardware.
2017-12-25 00:47:53 +01:00
Niklas Haas ba1943ac00 msg: reinterpret a bunch of message levels
I've decided that MP_TRACE means “noisy spam per frame”, whereas
MP_DBG just means “more verbose debugging messages than MSGL_V”.
Basically, MSGL_DBG shouldn't create spam per frame like it currently
does, and MSGL_V should make sense to the end-user and provide mostly
additional informational output.

MP_DBG is basically what I want to make the new default for --log-file,
so the cut-off point for MP_DBG is if we probably want to know if for
debugging purposes but the user most likely doesn't care about on the
terminal.

Also, the debug callbacks for libass and ffmpeg got bumped in their
verbosity levels slightly, because being external components they're a
bit less relevant to mpv debugging, and a bit too over-eager in what
they consider to be relevant information.

I exclusively used the "try it on my machine and remove messages from
MSGL_* until it does what I want it to" approach of refactoring, so
YMMV.
2017-12-15 22:28:47 -08:00
wm4 6047333f0b video: remove code duplication by calling a hwdec loader helper
Make gl_video_load_hwdecs() call gl_video_load_hwdecs_all() when
all HW decoders should be loaded.
2017-12-11 20:44:59 +02:00
wm4 5196c34aec video: properly initialize and set hwdec_interop
Don't reset --gpu-hwdec-interop if vo_gpu uses dumb mode.
2017-12-11 20:44:59 +02:00
wm4 91586c3592 vo_gpu: make it possible to load multiple hwdec interop drivers
Make the VO<->decoder interface capable of supporting multiple hwdec
APIs at once. The main gain is that this simplifies autoprobing a lot.
Before this change, it could happen that the VO loaded the "wrong" hwdec
API, and the decoder was stuck with the choice (breaking hw decoding).
With the change applied, the VO simply loads all available APIs, so
autoprobing trickery is left entirely to the decoder.

In the past, we were quite careful about not accidentally loading the
wrong interop drivers. This was in part to make sure autoprobing works,
but also because libva had this obnoxious bug of dumping garbage to
stderr when using the API. libva was fixed, so this is not a problem
anymore.

The --opengl-hwdec-interop option is changed in various ways (again...),
and renamed to --gpu-hwdec-interop. It does not have much use anymore,
other than debugging. It's notable that the order in the hwdec interop
array ra_hwdec_drivers[] still matters if multiple drivers support the
same image formats, so the option can explicitly force one, if that
should ever be necessary, or more likely, for debugging. One example are
the ra_hwdec_d3d11egl and ra_hwdec_d3d11eglrgb drivers, which both
support d3d11 input.

vo_gpu now always loads the interop lazily by default, but when it does,
it loads them all. vo_opengl_cb now always loads them when the GL
context handle is initialized. I don't expect that this causes any
problems.

It's now possible to do things like changing between vdpau and nvdec
decoding at runtime.

This is also preparation for cleaning up vd_lavc.c hwdec autoprobing.
It's another reason why hwdec_devices_request_all() does not take a
hwdec type anymore.
2017-12-01 05:57:01 +01:00
wm4 4a6b04bdb9 vo_gpu: never pass flipped images to ra or ra backends
Seems like the last refactor to this code broke playing flipped images,
at least with --opengl-pbo --gpu-api=opengl.

Flipping is rather a shitmess. The main problem is that OpenGL does not
support flipped uploading. The original vo_gl implementation considered
it important to handle the flipped case efficiently, so instead of
uploading the image line by line backwards, it uploaded it flipped, and
then flipped it in the renderer (basically the upload path ignored the
flipping). The ra code and backends probably have an insane and
inconsistent mix of semantics, so fix this by never passing it flipped
images in the first place.

In the future, the backends should probably support flipped images
directly.

Fixes #5097.
2017-11-10 10:06:33 +01:00
James Ross-Gowan 9b2dae79b1 vo_gpu: d3d11: add RA caps for ra_d3d11
ra_d3d11 uses the SPIR-V compiler to translate GLSL to SPIR-V, which is
then translated to HLSL. This means it always exposes the same GLSL
version that the SPIR-V compiler supports (4.50 for shaderc/glslang.)

Despite claiming to support GLSL 4.50, some features that are tied to
the GLSL version in OpenGL are not supported by ra_d3d11 when targeting
legacy Direct3D feature levels.

This includes two features that mpv relies on:
- Reading from gl_FragCoord in the fragment shader (requires FL 10_0)
- textureGather from any texture component (requires FL 11_0)

These features have been exposed as new RA caps.
2017-11-07 20:27:13 +11:00
wm4 5261d1b099 vo_gpu: don't re-render hwdec frames when repeating frames
Repeating frames (for display-sync) is not supposed to render the entire
frame again. When using hardware decoding, it unfortunately did: the
renderer uses the frame ID to check whether the frame data changed, and
unmapping the hwdec frame clears it.

Essentially reverts commit 761eeacf54. Back then I probably
thought it would be a good idea to release the hwdec image quickly in
order to return it to the decoder, but they're referenced anyway.

This should increase the performance and reduce GPU work.
2017-11-03 15:11:56 +01:00
Niklas Haas c2d4fd0ef4 vo_gpu: change --tone-mapping-desaturate algorithm
Comparing mpv's implementation against the ACES ODR reference samples
and algorithms, it seems like they're happy desaturating highlights
_way_ more aggressively than mpv currently does. And indeed, looking at
some example clips like The Redwoods (which is actually well-mastered),
the current desaturation produces unnatural-looking brightness fringes
where the sky meets the treeline.

Adjust the algorithm to make it apply to a much larger, more gradual
brightness region; and change the interpretation of the parameter. As a
bonus, the new parameter is actually sanely scaled (higher values = more
desaturation). Also, make it scale based on the signal level instead of
the luminance, to avoid under-desaturating bright blues.
2017-10-25 17:24:27 +02:00
wm4 d3c022779a video: fix alpha handling
Regression since ec6e8a31e0. Removal of the explicit else case
always applies the conversion to premultiplied alpha in the else branch.
We want to scale with multiplied alpha, but we don't want to multiply
with alpha again on top of it.

Fixes #4983, hopefully.
2017-10-19 19:01:33 +02:00
James Ross-Gowan d9e3bad500 vo_gpu: add rgba16hf to the list of FBO formats
This should be functionally identical to rgba16f, since the formats only
differ in their representation on the CPU, but it could be useful for RA
backends that don't expose rgba16f, like Vulkan. It's definitely useful
for the WIP D3D11 backend.
2017-10-18 23:55:13 +11:00
wm4 c90f76d322 vo_gpu: fix video sometimes not being rerendered on equalizer change
With video paused, changing the brightness controls (or similar) would
sometimes not rerender the video frame. So the OSD would redraw, but the
video wouldn't change. This is caused by output caching, and a redraw
request is free to return the cached frame. Change it such to invalidate
the cached frame if any of the options or the equalizer change.

In theory, gl_video_reset_surfaces() could be called if the equalizer
changes - this would apparently force interpolatzion to redraw all
frames. But this looks kind of crappy when changing the equalizer during
playback. It'll "eventually" use the correct settings anyway, and when
paused interpolation is off.
2017-10-17 09:07:35 +02:00
Niklas Haas eb69e73eb4 vo_gpu: enable 3DLUTs in dumb mode
Unless FBOs are unsupported, this works. In particular, it's required to
get ICC profiles working in voluntary dumb mode. So instead of
blanket-disabling it, only disable it in the !have_fbo false case.
2017-09-30 19:03:34 +02:00
Niklas Haas 07fa5c8a8f vo_gpu: fix --opengl-gamma redirect
It still pointed at --gpu-gamma, but we decided on --gamma-factor
instead.
2017-09-28 17:21:56 +02:00
Niklas Haas 791b9c4024 vo_gpu: set the correct number of vertex attribs
This was always set to the length of the VAO, but it should have been
set to the number of vertex attribs actually in use for this frame. No
idea how that managed to survive the test framework on nvidia/linux, but
ANGLE caught it.
2017-09-28 12:50:45 +02:00
Niklas Haas 67fd5882b8
vo_gpu: make the vertex attribs dynamic
This has several advantages:

1. no more redundant texcoords when we don't need them
2. no more arbitrary limit on how many textures we can bind
3. (that extends to user shaders as well)
4. no more arbitrary limits on tscale radius

To realize this, the VAO was moved from a hacky stateful approach
(gl_sc_set_vertex_attribs) - which always bothered me since it was
required for compute shaders as well even though they ignored it - to be
a proper parameter of gl_sc_dispatch_draw, and internally plumbed into
gl_sc_generate, which will make a (properly mangled) deep copy into
params.vertex_attribs.
2017-09-28 01:54:38 +02:00
Niklas Haas 002a0ce232 vo_gpu: kill some static arrays
This gets rid of the hard-coded limits on the number of hooks, textures
and hook points.
2017-09-28 01:54:33 +02:00
Niklas Haas 47af509e1f vo_gpu: attempt to avoid UBOs for dynamic variables
This makes the radeon driver shut up about frequently updating
STATIC_DRAW UBOs (--opengl-debug), and also reduces the amount of
synchronization necessary for vulkan uniform buffers.

Also add some extra debugging/tracing code paths. I went with a
flags-based approach in case we ever want to extend this.
2017-09-26 17:25:35 +02:00
Niklas Haas b0ba193b66 vo_gpu: handle texture initialization errors gracefully
Tested by making the ra_tex_resize function always fail (apart from the
initial FBO check). This required a few changes:

1. reset shaders on failed dispatch
2. reset cleanup binds on failed dispatch
3. fall back to initializing the struct image to 1x1 on failure
4. handle output_fbo_valid gracefully
2017-09-23 09:58:27 +02:00
Niklas Haas f3ec494613 vo_gpu: reduce the --alpha=blend-tiles checkerboard intensity
This was sort of grating by default and made it really hard to actually
read e.g. text on top of a transparent background. I decided to approach
the problem from both directions, making the whites darker and the grays
lighter. This brings it closer to the dynamic range of e.g. the
wikipedia transparent svg preview.
2017-09-22 21:14:27 +02:00
Niklas Haas e3288c4597 vo_gpu: simplify compute shader coordinate calculation
Since the removal of FBOTEX_FUZZY, this can be made slightly simpler.
2017-09-22 17:22:53 +02:00
Niklas Haas 62ddc85d17 vo_gpu: simplify structs / names
Due to the plethora of historical baggage from different eras getting
confusing, I decided to simplify and unify the struct organization and
naming scheme.

Structs that got renamed:

1. fbodst     -> ra_fbo  (and moved to gpu/context.h)
2. fbotex     -> removed (redundant after 2af2fa7a)
3. fbosurface -> surface
4. img_tex    -> image

In addition to these structs being renamed, all of the names have been
made consistent. The new scheme is as follows:

struct image img;
struct ra_tex *tex;
struct ra_fbo fbo;

This also affects derived names, e.g. indirect_fbo -> indirect_tex.
Notably also, finish_pass_fbo -> finish_pass_tex and finish_pass_direct
-> finish_pass_fbo.

The new equivalent of fbotex_change() is called ra_tex_resize().

This commit (should) contain no logic changes, just renaming a bunch of
crap.
2017-09-22 16:58:55 +02:00
Niklas Haas 2af2fa7a27 vo_gpu: kill off FBOTEX_FUZZY
I've observed the garbage pixels in more scenarios. They also were never
really needed to begin with, originally being a discovered work-around
for bug that we fixed since then anyway. Doesn't really seem to even
help resizing, since the OpenGL drivers are all smart enough to pool
resources internally anyway.

Fixes #1814
2017-09-22 16:33:25 +02:00
wm4 fba927de41 options: properly handle deprecated options with CLI actions
We want e.g. --opengl-shaders-append=foo to resolve to the new option,
all while printing an option name. --opengl-shader is a similar case.
These options are special, because they apply "actions" on actual
options by specifying a suffix. So the alias/deprecation handling has to
be part of resolving the actual option from prefix and suffix.
2017-09-22 11:31:03 +02:00
Niklas Haas b940691784 vo_gpu: drop the RA_CAP_NESTED_ARRAY req from EWA compute
Almost as fast as the old code, but more general. Notably, glslang
doesn't support nested arrays.

(cf. https://github.com/KhronosGroup/glslang/issues/1057)

Also much cleaner code-wise, so I think I'll keep it even if glslang
implements array_of_arrays.
2017-09-21 15:15:59 +02:00
Niklas Haas db0fb3c48b
vo_gpu: fix gamma scale
This never really made sense since the BT.1886 changes. It should get
*brighter* for bright rooms, not darker for dark rooms. Picked some new
values that seemed reasonable-ish.
2017-09-21 15:01:26 +02:00
Niklas Haas e92effb14f vo_gpu: describe the plane merging pass
This can get left unknown if something hooks NATIVE
2017-09-21 15:01:22 +02:00
Niklas Haas 65979986a9 vo_opengl: refactor into vo_gpu
This is done in several steps:

1. refactor MPGLContext -> struct ra_ctx
2. move GL-specific stuff in vo_opengl into opengl/context.c
3. generalize context creation to support other APIs, and add --gpu-api
4. rename all of the --opengl- options that are no longer opengl-specific
5. move all of the stuff from opengl/* that isn't GL-specific into gpu/
   (note: opengl/gl_utils.h became opengl/utils.h)
6. rename vo_opengl to vo_gpu
7. to handle window screenshots, the short-term approach was to just add
   it to ra_swchain_fns. Long term (and for vulkan) this has to be moved to
   ra itself (and vo_gpu altered to compensate), but this was a stop-gap
   measure to prevent this commit from getting too big
8. move ra->fns->flush to ra_gl_ctx instead
9. some other minor changes that I've probably already forgotten

Note: This is one half of a major refactor, the other half of which is
provided by rossy's following commit. This commit enables support for
all linux platforms, while his version enables support for all non-linux
platforms.

Note 2: vo_opengl_cb.c also re-uses ra_gl_ctx so it benefits from the
--opengl- options like --opengl-early-flush, --opengl-finish etc. Should
be a strict superset of the old functionality.

Disclaimer: Since I have no way of compiling mpv on all platforms, some
of these ports were done blindly. Specifically, the blind ports included
context_mali_fbdev.c and context_rpi.c. Since they're both based on
egl_helpers, the port should have gone smoothly without any major
changes required. But if somebody complains about a compile error on
those platforms (assuming anybody actually uses them), you know where to
complain.
2017-09-21 15:00:55 +02:00