speed of qt terminal

[Tatsuro M. <tma...@ya...>]

In octave-maintainers ML, the tread "gnuplot graphics toolkit bugs" is open.
http://octave.1599824.n4.nabble.com/gnuplot-graphics-toolkit-bugs-td4671157.html


In the discussion there is a statement.(by Daniel J Sebald)

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>    It is now the fastest and most full-featured interactive terminal option. (for qt) 

except the speed.  Perhaps there is some hardware in which Qt can use, 
say, OpenGL directly, but on my system that isn't the case.  Qt terminal 
is drastically slower. 
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I have built windows version of gnuplot 5.0 and 5.1 with qt terminal.
For my PC "all.dem" speed of windows, wxt, qt terminals, the qt terminal is fastest.

Qt development toolkits (Qt 5.3) for gnuplot for windows build are prepared from source
with configure option "-no-opengl".

To my understanding, gnuplot does not use opengl. Am I right?

In other places Daniel state
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For example, qt terminal uses QPixmap 

http://doc.qt.io/qt-5/qpixmap.html

which is a feature of Qt to handle display of images.  However, this is 
at a very high level in which image elements are treated individually, 
not as a whole image.  Consequently, the user will find that the Qt 
terminal can be rather slow for large data sets.  x11 is very low level, 
so is much faster.  Yet, wxt is fast as well.
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This thread is made from just curiosity.

Tatsuro