Fast panning

[coastckr]

Hello Rene,

I am trying to draw a very large map with thousands of vectors and pan around it smoothly.
What would be the best / fastest way to do this?
I was thinking of using a CBcmFrameBuffer object, have C2DGraphics draw in it and then use CBcmFrameBuffer)::SetVirtualOffset() for the panning.
However, I am having trouble bridging those and avoiding dma errors.
On the other hand, I assume LVGL would introduce too much overhead, right?

[rsta2]

I think C2DGraphics cannot do this, because it's not quick enough for that purpose. You may have a look at the 32-Bit OpenVG 1.1 support in Circle for RPi 1-3 and Zero (2) in addon/vc4/interface/ or here: https://github.com/rsta2/libgraphics CBcmFrameBuffer::SetVirtualOffset() could also be a solution, but in C2DGraphics it is only used vertically to swap the frame buffers to prevent tearing and flickering. Panning is not supported there. You would have to modify it to use panning. Unfortunately I never used this and cannot say, if this can work.

[coastckr]

Is it true that OpenVG 1.1 does not work in 64-bit mode or with raspi4 in general?
Would a combination of CBcmFrameBuffer::SetVirtualOffset() and CScreenDevice::SetPixel() or CDisplay::SetPixel() work, or should I look into a blit method?

[rsta2]

Is it true that OpenVG 1.1 does not work in 64-bit mode or with raspi4 in general?

Yes.

Would a combination of CBcmFrameBuffer::SetVirtualOffset() and CScreenDevice::SetPixel() or CDisplay::SetPixel() work, or should I look into a blit method?

I guess yes, you could use CScreenDevice::SetPixel() or CBcmFrameBuffer::CBcmFrameBuffer() for drawing and CBcmFrameBuffer::SetVirtualOffset() for panning. But again, I only used CBcmFrameBuffer::SetVirtualOffset() to stop screen tearing and flicking, not for panning.