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by Daniel Gessel
Thu Jul 09, 2020 3:15 pm
Forum: OpenGLES
Topic: Clarification about glTexSubImage2D on legacy-driver
Replies: 4
Views: 140

Re: Clarification about glTexSubImage2D on legacy-driver

Apple had an extension to allow this, but I don’t think anybody else has ever implemented it.
by Daniel Gessel
Tue Jun 30, 2020 3:40 pm
Forum: OpenGLES
Topic: Tearing in kmscube on Pi4
Replies: 14
Views: 2083

Re: Tearing in kmscube on Pi4

I modeled some kms based page flipping code on kmscube which I cloned from: https://gitlab.freedesktop.org/mesa/kmscube.git and see tearing on my Pi4 at the top of the screen. So I went back to kmscube and modified the beginning of draw_cube_smooth (in cube-smooth.c) to draw a moving vertical red l...
by Daniel Gessel
Mon Mar 09, 2020 11:29 pm
Forum: OpenGLES
Topic: texelFetch does not have enough precision.
Replies: 6
Views: 1090

Re: texelFetch does not have enough precision.

Rumor is the VC6 in the Pi4 has support for f16 at double rate, so it may default to that lower precision unless you specify highp. I haven’t tested with the latest drivers so I’m not sure.
by Daniel Gessel
Sun Mar 01, 2020 9:54 pm
Forum: OpenGLES
Topic: texelFetch does not have enough precision.
Replies: 6
Views: 1090

Re: texelFetch does not have enough precision.

Have you tried specifying highp? Which pi is this on, pi4 or other?
by Daniel Gessel
Thu Feb 20, 2020 1:50 pm
Forum: Graphics programming
Topic: WebGL vs native OpenGL on Pi 4
Replies: 4
Views: 841

Re: WebGL vs native OpenGL on Pi 4

If you end up creating benchmarks, please share the results. OpenGL desktop may be slow compared to OpenGL ES on the desktop, as it’s not a focus for the driver developers, and may not get the nifty features added with GLES 3.1 (e.g. compute shaders) for some time.
by Daniel Gessel
Thu Feb 20, 2020 1:35 pm
Forum: OpenGLES
Topic: Pi4 gbm needs 'sudo' ?
Replies: 3
Views: 581

Re: Pi4 gbm needs 'sudo' ?

It shouldn’t require sudo... have you tried kmscube on your system? I based my GBM/KMS code on the legacy mode setting path and haven’t needed sudo (though I haven’t upgraded to the latest OS update).
by Daniel Gessel
Tue Feb 18, 2020 10:57 am
Forum: OpenGLES
Topic: RP3 GL_LINES Problem
Replies: 14
Views: 1150

Re: RP3 GL_LINES Problem

Instead of glReadPixels, glCopyTexSubImage, of just 1 pixel to a dummy texture, might force the right synchronization on the gpu without the full synchronization with the cpu that glFinish does.
by Daniel Gessel
Tue Feb 18, 2020 2:49 am
Forum: OpenGLES
Topic: RP3 GL_LINES Problem
Replies: 14
Views: 1150

Re: RP3 GL_LINES Problem

Can you try glFinish instead of glFlush, just as a sanity check?
by Daniel Gessel
Mon Feb 10, 2020 2:05 pm
Forum: Graphics programming
Topic: Fast(er) image rendering to screen on a Pi3
Replies: 9
Views: 1634

Re: Fast(er) image rendering to screen on a Pi3

The legacy driver has an implementation of OpenGL ES 2.0 that is hardware accelerated. It is proprietary Broadcom implementation, and doesn’t go through X at all. It renders into overlays so it can get the benefit of page flipping when running its overlays on top of X. From you previous posts, I thi...
by Daniel Gessel
Wed Feb 05, 2020 5:19 pm
Forum: Off topic discussion
Topic: Best example of a bad forum post?
Replies: 87
Views: 7267

Re: Best example of a bad forum post?

It’s definitely elitist, by my definition, to divide the world into “losers” and not. It’s a horrible word, used by horrible people, ultimately identifying the user as deserving to be placed into their own negative category (if I may be so elitist). Fortunately, that is not a word that has been int...
by Daniel Gessel
Wed Feb 05, 2020 4:33 pm
Forum: Off topic discussion
Topic: Best example of a bad forum post?
Replies: 87
Views: 7267

Re: Best example of a bad forum post?

It’s definitely elitist, by my definition, to divide the world into “losers” and not. It’s a horrible word, used by horrible people, ultimately identifying the user as deserving to be placed into their own negative category (if I may be so elitist). Offering advice on how to ask a technical question...
by Daniel Gessel
Wed Feb 05, 2020 3:27 pm
Forum: OpenGLES
Topic: eglInitialize
Replies: 4
Views: 847

Re: eglInitialize

It is set to the default, Legacy. ... Ironically, it works fine now on the Pi 4 :). Hmm, that throws me as I thought the dispmanx stuff didn’t work on Pi4 and maybe Buster was defaulting to fKMS on Pi3... My understanding is we’re all supposed to migrate to KMS, so I started there and don’t have en...
by Daniel Gessel
Wed Feb 05, 2020 1:43 pm
Forum: OpenGLES
Topic: eglInitialize
Replies: 4
Views: 847

Re: eglInitialize

Which driver are you running? Legacy, FKMS or KMS?
by Daniel Gessel
Wed Feb 05, 2020 1:20 pm
Forum: Off topic discussion
Topic: Best example of a bad forum post?
Replies: 87
Views: 7267

Re: Best example of a bad forum post?

how to ask good questions :- http://www.catb.org/esr/faqs/smart-questions.html Now that should be a sticky somewhere on here. Absolutely disagree. I detest the elitist and arrogant tone used in that. It comes from a perspective of those who don't want to 'waste time' answering questions unless peop...
by Daniel Gessel
Tue Feb 04, 2020 4:26 pm
Forum: General discussion
Topic: Future of raspberry pi - software related
Replies: 382
Views: 36755

Re: Future of raspberry pi - software related

They've still got the basics wrong in this thing. Take their bool, for example: you have two valid values in a bool, true and false. They're using 32 bits for them, which gives them a few more values that can be expressed in a bool than simply those two, and as it's now a typedef -- not even an enu...
by Daniel Gessel
Tue Feb 04, 2020 3:12 am
Forum: Beginners
Topic: GIMP with hardware acceleration with Raspberry Pi 4B
Replies: 2
Views: 576

Re: GIMP with hardware acceleration with Raspberry Pi 4B

VC4CL may not be.complete enough for GIMP. It also doesn’t run on Pi4, only earlier versions of the Pi. The author of VC4CL frequents these boards. This is the main VC4CL thread:

https://www.raspberrypi.org/forums/view ... 7&t=194952
by Daniel Gessel
Mon Feb 03, 2020 3:49 pm
Forum: General discussion
Topic: Future of raspberry pi - software related
Replies: 382
Views: 36755

Re: Future of raspberry pi - software related

I’m not sure exactly how I’d implement a threaded compacting garbage collector without being able to look at bits in a pointer. Looking at a pointer in the context of that sort of thing is fine, because it's one, smallish piece of code that's buried in a system library, and can be altered without r...
by Daniel Gessel
Mon Feb 03, 2020 3:03 pm
Forum: General discussion
Topic: Future of raspberry pi - software related
Replies: 382
Views: 36755

Re: Future of raspberry pi - software related

And I'm sorry, but there's just *zero* justification for encoding addresses into integer datatypes -- even 64b ones. None. We've been there, done that, and struggled for well over a decade fixing the mess it caused when int remained 32b, but void * turned 64b (which could arguably have been solved ...
by Daniel Gessel
Mon Feb 03, 2020 2:37 pm
Forum: General discussion
Topic: Future of raspberry pi - software related
Replies: 382
Views: 36755

Re: Future of raspberry pi - software related

See this new blog about comming software realted to rasp pi4/VC6 : https://www.raspberrypi.org/blog/vulkan-raspberry-pi-first-triangle/ -> Raspberry Pi 4 Model B is now OpenGL ES 3.1 certified. -> Eben Upton says first beta vulcan will take about half a year. mic_s . Nice! I looked at that post bef...
by Daniel Gessel
Mon Feb 03, 2020 1:19 pm
Forum: General discussion
Topic: Future of raspberry pi - software related
Replies: 382
Views: 36755

Re: Future of raspberry pi - software related

See this new blog about comming software realted to rasp pi4/VC6 : https://www.raspberrypi.org/blog/vulkan-raspberry-pi-first-triangle/ -> Raspberry Pi 4 Model B is now OpenGL ES 3.1 certified. -> Eben Upton says first beta vulcan will take about half a year. mic_s . Nice! I looked at that post bef...
by Daniel Gessel
Sun Feb 02, 2020 6:19 pm
Forum: General discussion
Topic: clusters of rpi4 with clusterHAT holding 4 pi zero ?
Replies: 22
Views: 1661

Re: clusters of rpi4 with clusterHAT holding 4 pi zero ?

I’m thinking of GPUs like: https://en.wikipedia.org/wiki/List_of_AMD_graphics_processing_units#Radeon_RX_5000_series However, this is far off topic for both the original post and the RPi boards generally. I believe the Pi4’s 4 cores with SIMD provide a theoretical 24 Gflops and the GPU another 32. E...
by Daniel Gessel
Sun Feb 02, 2020 2:53 pm
Forum: General discussion
Topic: clusters of rpi4 with clusterHAT holding 4 pi zero ?
Replies: 22
Views: 1661

Re: clusters of rpi4 with clusterHAT holding 4 pi zero ?

A modern $500 GPU hits 10’s of teraflops. The Pi4 is less than 100 Gflops. So the GPU is at least 100 times faster by this metric (which the OP mentioned at least once). You get at least 10 times more for your money by building around GPUs, which is how modern supercomputers seem to be getting built...
by Daniel Gessel
Sun Feb 02, 2020 1:26 pm
Forum: General discussion
Topic: Future of raspberry pi - software related
Replies: 382
Views: 36755

Re: Future of raspberry pi - software related

Kmscube works on Pi4
by Daniel Gessel
Sat Feb 01, 2020 8:59 am
Forum: General discussion
Topic: Future of raspberry pi - software related
Replies: 382
Views: 36755

Re: Future of raspberry pi - software related

Considering how "niche" 3D is in the education context I'm surprised they've put as much resource into openGLES, though I guess originally it came pretty much for free in the existing firmware on the earlier PIs. Hopefully, then, this represents a change and we’ll get some extra attention for 3D gr...
by Daniel Gessel
Sat Feb 01, 2020 12:39 am
Forum: General discussion
Topic: clusters of rpi4 with clusterHAT holding 4 pi zero ?
Replies: 22
Views: 1661

Re: clusters of rpi4 with clusterHAT holding 4 pi zero ?

I’d recommend focusing on the education first, learning how to write simulations of black holes and other stuff you’re interested in. A pile of pi zeros won’t be able to work well together and your education will get you access to the computing power you need. In the meantime, you could start to lea...

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