Why graph draw FPS changing when resolution changed?
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I draw graph and I use QWT Lib. Also I use OpenGL canvas for QWT plot.
For example :
When I use 1920x1080 window size, FPS is 100,
and when I use 4K window size, FPS is 15.
(FPS values just for example, is slowing)Why that happend ?
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I draw graph and I use QWT Lib. Also I use OpenGL canvas for QWT plot.
For example :
When I use 1920x1080 window size, FPS is 100,
and when I use 4K window size, FPS is 15.
(FPS values just for example, is slowing)Why that happend ?
@Joe-von-Habsburg
I know nothing about OpenGL or QWT. But since 4k resolution is many more pixels than 1920x1080 would you not expect/be unsurprised if the FPS drops? Every graphics game I play has lower FPS as you increase the resolution.... You either reduce the resolution, typically to your 1080p, or buy a better graphics card.... -
@Joe-von-Habsburg
I know nothing about OpenGL or QWT. But since 4k resolution is many more pixels than 1920x1080 would you not expect/be unsurprised if the FPS drops? Every graphics game I play has lower FPS as you increase the resolution.... You either reduce the resolution, typically to your 1080p, or buy a better graphics card....@JonB said in Why graph draw FPS changing when resolution changed?:
Every graphics game I play has lower FPS as you increase the resolution....
I know...
I have a question.
Is there a way to keep the resolution at fullhd even when using a 4K display? -
@JonB said in Why graph draw FPS changing when resolution changed?:
Every graphics game I play has lower FPS as you increase the resolution....
I know...
I have a question.
Is there a way to keep the resolution at fullhd even when using a 4K display?@Joe-von-Habsburg said in Why graph draw FPS changing when resolution changed?:
Is there a way to keep the resolution at fullhd even when using a 4K display?
You could try to render offscreen to an image of 1920x1080 and then display that image on a 4k display.
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@Joe-von-Habsburg said in Why graph draw FPS changing when resolution changed?:
Is there a way to keep the resolution at fullhd even when using a 4K display?
You could try to render offscreen to an image of 1920x1080 and then display that image on a 4k display.
@SimonSchroeder said in Why graph draw FPS changing when resolution changed?:
You could try to render offscreen to an image of 1920x1080 and then display that image on a 4k display.
I don't know how to do this.
After reviewing the code a bit, I identified the root cause of the problem.
My issue is related to the waterfall plot (QwtPlotSpectrogram). This waterfall plot is constantly giving me trouble. -
There might be more performant versions of this (in general OpenGL can render to an offscreen target), but the easiest in the context of Qt would be to use a QPixmap as a QPaintDevice instead of a QWidget. The QPixmap can then displayed in its own widget as an image.
