Go to advanced search

by cnlohr
Tue Nov 06, 2018 5:16 am
Forum: Advanced users
Topic: Accurate timing for real time control
Replies: 27
Views: 51973

Re: Accurate timing for real time control

Do we have _any_ shot at getting this for the Pi3? There is _SO MUCH_ that could be done if we could totally disable interrupts for brief periods of time to bang something out a GPIO with high detail. I am wracking around but even after fixing the peripheral offsets, the timing still goes out by a m...
by cnlohr
Thu Nov 01, 2018 4:41 pm
Forum: Beginners
Topic: Installing a 3.5 inch Waveshare LCD with Raspberry Pi3
Replies: 54
Views: 68343

Re: Installing a 3.5 inch Waveshare LCD with Raspberry Pi3

I know I'm late to the thread here, and a little off topic, but I am trying to get this display working with nonstandard software, so I really need the SPI spec for the display controller. Does anyone know what the actual display controller for this display is?
by cnlohr
Sat Jun 23, 2018 3:57 am
Forum: OpenGLES
Topic: Example using vc4-fkms-v3d? OpenGLES with X11?
Replies: 1
Views: 5541

Example using vc4-fkms-v3d? OpenGLES with X11?

I have spent a few hours rifling around the internet and trying to run example code from all sorts of pedigrees from the past to try to get accelerated graphics running on the Pi in X11. It seems that historically, there had been some projects that had to do some very unusual things to get it runnin...
by cnlohr
Wed Jun 20, 2018 5:00 am
Forum: OpenGLES
Topic: glDrawElements abysmally slow
Replies: 10
Views: 6983

Re: glDrawElements abysmally slow

@jpgygax68 - just tried. Each with a unique VBO. Actually, results are _slightly_ worse than re-using VBOs. ~33-40us each draw call, no matter what.

Can anyone else please try to see if this is an issue under all raspi 3D stuff?
by cnlohr
Sun Jun 17, 2018 8:45 pm
Forum: OpenGLES
Topic: glDrawElements abysmally slow
Replies: 10
Views: 6983

Re: glDrawElements abysmally slow

Code: Select all

gpu_mem=256
Here is my full config: https://gist.github.com/cnlohr/152d4b7f ... nt-2621338

Still very curious what your performance is like. I'm hoping I'm not chasing against something systemic.
by cnlohr
Sun Jun 17, 2018 4:57 pm
Forum: OpenGLES
Topic: glDrawElements abysmally slow
Replies: 10
Views: 6983

Re: glDrawElements abysmally slow

@PeterO: But BOTH GLES1 and GLES2 are very slow, both types of draw calls in GLES1 and GLES2 are about the same speed (30+us per call!). I know that additional draw calls are not preferred, and I do batch a fair bit but in practice, most things expect to make a few hundred, maybe 1 or 2 thousand cal...
by cnlohr
Sun Jun 17, 2018 4:16 am
Forum: OpenGLES
Topic: glDrawElements abysmally slow
Replies: 10
Views: 6983

Re: glDrawElements abysmally slow

@PeterO - Is there any way you would share with me example code of something you have that can make a lot of draw calls quickly?
by cnlohr
Sat Jun 16, 2018 5:03 pm
Forum: OpenGLES
Topic: glDrawElements abysmally slow
Replies: 10
Views: 6983

Re: glDrawElements abysmally slow

Thank you for the response! Here is the modified triangle.c. It obtains 10FPS, regardless of resolution, etc. https://gist.github.com/cnlohr/9d63c4034ee01abbe584f209beb629ba If you did want to see my code, as-is... https://github.com/cnlohr/spreadgine - most of the pertinent code is in src/spreadgin...
by cnlohr
Sat Jun 16, 2018 7:16 am
Forum: OpenGLES
Topic: glDrawElements abysmally slow
Replies: 10
Views: 6983

glDrawElements abysmally slow

I have just come across a problem that looks a lot like this right now, and it would be very inconvenient to use X11. I am wondering if you guys are loading "vc4-fkms-v3d" or "vc4-kms-v3d" in your conifg. If I do, I can't seem to use EGL without X11. So, I'm right now living with both of those comme...
by cnlohr
Sat Jun 16, 2018 5:03 am
Forum: Graphics programming
Topic: Increasing GLES2 max window size when operating in framebuffer
Replies: 0
Views: 613

Increasing GLES2 max window size when operating in framebuffer

I've got the pi running my vive pretty well, however, there doesn't seem to be much anything I can do to get the output buffer all the way to 2160 pixels. The engine I'm working with doesn't want two separate window contexts. Currently, I have to settle for 56 dead pixels on both sides of the screen...
by cnlohr
Sat Jun 16, 2018 1:09 am
Forum: Advanced users
Topic: Converting modelines for hdmi_timings [SOLVED]
Replies: 1
Views: 449

Re: Converting modelines for hdmi_timings

It seems that my guesses were correct. Not sure what is up with the pi, but when operating like this if you aren't writing to the framebuffer, or screen, it won't update. Only a small portion of the screen will be displayed. It seemed it worked with the vive the whole time. For more information, inc...
by cnlohr
Thu Jun 14, 2018 2:43 am
Forum: Advanced users
Topic: STICKY: HOWTO: Create Custom HDMI modes
Replies: 205
Views: 317866

Re: STICKY: HOWTO: Create Custom HDMI modes

Does anyone know what the new maximum pixel clock is for the 3B+'s? Based on many other posts, it's definitely not 140 MHz anymore. But, I am trying to find out if it can get up to the 297 for the Vive. If not it certainly can come close. EDIT: Apparently it's right at the edge, and requires overclo...
by cnlohr
Wed Jun 13, 2018 2:58 am
Forum: Advanced users
Topic: Converting modelines for hdmi_timings [SOLVED]
Replies: 1
Views: 449

Converting modelines for hdmi_timings [SOLVED]

It seems that there have been rumors of folks using the raspi's past the 150 MHz pixel clock limit without any issues. I really want to get the HTC Vive working on a raspberry pi so I can dump Orange Pi and their awful GPU support. So I am here again, this time with a brand new Pi Model 3 B+. Unfort...
by cnlohr
Fri Feb 12, 2016 10:41 pm
Forum: Official Foundation Display
Topic: Rotating screen by command after boot
Replies: 2
Views: 418

Rotating screen by command after boot

I've googled this for a while, and can't find anyone who has any inkling about how to change the screen rotation/resolution after boot, i.e. changing display_rotate=# after boot. I'm aware of tvservice, but it doesn't seem to be able to change or look at screen rotation. This is unfortunately needed...

Go to advanced search