Hi all, what could be the reason that the status of
Magnum::GL::defaultFramebuffer turns into undefined? (when previously complete)
It seems the moment I
frame_buffer->attachRenderbuffer(
Magnum::GL::Framebuffer::BufferAttachment::Depth, *depth_buffer);the defaultframebuffer turns undefined - would anyone have any hunches?
Sorry, it seems it's this line
frame_buffer->attachTexture(
Magnum::GL::Framebuffer::ColorAttachment{ 0 }, *rendertex, 0);
rendertex:
const auto rendertex = std::make_shared<Magnum::GL::Texture2D>();
rendertex->setStorage(1, Magnum::GL::TextureFormat::RGBA8, { render_w, render_h });
rendertex->setWrapping(Magnum::SamplerWrapping::ClampToEdge);It actually seems like the moment I do this
const auto frame_buffer = std::make_shared<Magnum::GL::Framebuffer>(Magnum::Range2Di{ {}, { render_w, render_h } });we get the undefined.
on iOS
Here's the full code:
https://gist.github.com/hsdk123/0e88dada6e5e5f88e23d64fb82481397
https://gist.github.com/hsdk123/0e88dada6e5e5f88e23d64fb82481397
@hsdk123 what do you mean by "undefined"?
amazing
cmake's try_compile doesn't work when i want to link to libraries defined in the project
so when assimp is a cmake subproject, the try_compile check that's there to check for stupidity levels of that library will break the build
actually this kinda makes sense, after all
try_compile() is ran before any of the libraries i could link to are built, so it can't link to them anyway
is this a stockholm syndrome?
it's only useful if you include a source code of yours that uses a header from the library you want to test against
to make sure that the library you're linking against has the required stuff that is exposed thru the headers
kinda similar to the autotools/configure from the days of makefile
yeah yeah that's what i use it for
but wasn't aware of this limitation
the cmake docs says it can be used for compiling the whole project but the text there in the docs is unclear
yeah no, all i need it for is checking assimp's version
this fixes it: mosra/magnum-plugins@f74c851
aha ok
nice trick
@mosra
undefined
Magnum::GL::defaultFramebuffer.checkStatus for both read/draw return undefined
when it was 'complete' right before the new frame buffer creation
:eyes:
huh
i suppose this is because iOS doesn't actually have a default framebuffer?
so at the start, what magnum thinks is a default framebuffer, is some other FB, and checking for its status will return "complete"
then when you create another FB it'll switch to the new one
and when you ask on the default framebuffer again, it'll try to bind framebuffer 0, which doesn't exist, so it'll be undefined
soo i guess the solution is to not even use the
GL::defaultFramebuffer but instead query the real framebuffer ID , GL::Framebuffer::wrap() it and use that instead
query the real framebuffer ID
How would I do this?
if you apply this patch, you should consistently get "undefined" both before and after ... can you try it?
diff --git a/src/Magnum/GL/Implementation/FramebufferState.cpp b/src/Magnum/GL/Implementation/FramebufferState.cpp
index 38f48883c..43dcca79c 100644
--- a/src/Magnum/GL/Implementation/FramebufferState.cpp
+++ b/src/Magnum/GL/Implementation/FramebufferState.cpp
@@ -39,7 +39,7 @@ using namespace Containers::Literals;
constexpr const Range2Di FramebufferState::DisengagedViewport;
-FramebufferState::FramebufferState(Context& context, Containers::StaticArrayView<Implementation::ExtensionCount, const char*> extensions): readBinding{0}, drawBinding{0}, renderbufferBinding{0}, maxDrawBuffers{0}, maxColorAttachments{0}, maxRenderbufferSize{0},
+FramebufferState::FramebufferState(Context& context, Containers::StaticArrayView<Implementation::ExtensionCount, const char*> extensions): readBinding{State::DisengagedBinding}, drawBinding{State::DisengagedBinding}, renderbufferBinding{0}, maxDrawBuffers{0}, maxColorAttachments{0}, maxRenderbufferSize{0},
#if !(defined(MAGNUM_TARGET_WEBGL) && defined(MAGNUM_TARGET_GLES2))
maxSamples{0},
#endifHow would I do this?
this seems to be the way: https://stackoverflow.com/a/9755439 (no, magnum doesn't have such getters on its own)
so at the start, what magnum thinks is a default framebuffer, is some other FB
Just to confirm, so what magnum thinks is a default framebuffer, is still a valid framebuffer, just not the default one?
GL_FRAMEBUFFER_BINDING_OES
What header do I need to include to get this?
ah, oh ...
GL_FRAMEBUFFER_BINDING, then? GL_FRAMEBUFFER_DRAW_BINDING? something along those lines?
what magnum thinks is a default framebuffer, is still a valid framebuffer, just not the default one?
exactly, and the state tracker thinks it's the default one because that's what it usually is on other platforms
@mosra
GL_FRAMEBUFFER_BINDING
Seems we might be moving forward. I now realise that I getGL::Renderer::Error::InvalidOperation errors each time I run SDL2Application::swapBuffers() on ios - any hunches?
so if you ask for error state right before swapBuffers(), it's not there, but after that it is?
Correct
:eyes:
hahah i have no idea
i would need to look into what SDL does there
but ... this used to work, no? few years ago definitely
I think back when it used to work, I didn't create new framebuffer objects
oh so if you don't create that new framebuffer, it doesn't emit an error?
Yup, if I just use the default frame buffer the whole way, it's fine
does anything from here ring a bell? are you using multisampling?
how do you query and wrap the existing framebuffer?
GLint defaultFBO_index;
/*glGetIntegerv(GL_FRAMEBUFFER_BINDING_OES, &defaultFBO);*/
glGetIntegerv(GL_FRAMEBUFFER_BINDING, &defaultFBO_index);
Magnum::Debug{} << "default framebuffer index: " << defaultFBO_index;
const auto viewport = Magnum::GL::defaultFramebuffer.viewport();
_default_frame_buffer = std::make_unique< Magnum::GL::Framebuffer>(
Magnum::GL::Framebuffer::wrap(defaultFBO_index, viewport)
);
not sure what multisampling is
antialiasing
setSampleCount() in Sdl2Application configuration
nope, didn't know that existed
okay
do you have a possibility of running this through the xcode opengl debugger/tracer/profiler? if it still exists there
that should (hopefully) show what GL call this fails on
xcode opengl debugger
Didn't know that existed either - will look it up!
if you do
_default_frame_buffer.bind() before swapBuffers(), does it fix the error?
actually probably
glBindFramebuffer(GL_READ_FRAMEBUFFER, _default_frame_buffer.id()); instead :sweat_smile:
Will try both!
@mosra
Seems both don't work - I've tried using the gpu capture feature in xcode, and I see
on here
https://github.com/libsdl-org/SDL/blob/39302c921445e9f695a72469be17ba041f6f09db/src/video/uikit/SDL_uikitopenglview.m#L319
Seems both don't work - I've tried using the gpu capture feature in xcode, and I see
Attempted present of non-layer backed renderbufferon here
https://github.com/libsdl-org/SDL/blob/39302c921445e9f695a72469be17ba041f6f09db/src/video/uikit/SDL_uikitopenglview.m#L319
Seems what I needed was
glBindRenderbuffer!