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https://github.com/epasveer/seer.git
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tiresiasfromthebai
9ef82fb898
In scatter mode a two-array (X/Y) plot rebuilt the table and chart once per property setter (data, offset, stride) and restyled every marker four times, so a ~4000-point phase portrait froze for ~0.8s per refresh. - SeerArrayWidget: add a BulkUpdate RAII guard that defers create() until a burst of setters completes, so a refresh does one rebuild, not several. - redecorateScatterSeries: drop the two redundant transparent passes; after addSeries() the series holds the theme pen/brush, so setPen(NoPen)/ setBrush() are already real transitions and either re-pushes both to the markers. ~800ms -> ~200ms per refresh at 4000 points; line/spline and marker appearance unchanged. Add tests/helloscatter, a 4000-point two-array phase portrait with a breakpoint loop, to reproduce the slow refresh.
50 lines
1.1 KiB
C++
50 lines
1.1 KiB
C++
#include <cstdio>
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#define NPOINTS 4000
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double pos[NPOINTS];
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double vel[NPOINTS];
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//
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// Fill pos/vel with the trajectory of a damped harmonic oscillator
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// (semi-implicit Euler integration).
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//
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void integrate (double damping) {
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double x = 1.0;
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double v = 0.0;
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double w = 1.0;
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double dt = 0.005;
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for (int i=0; i<NPOINTS; i++) {
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v += (-w*w*x - damping*v) * dt;
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x += v * dt;
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pos[i] = x;
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vel[i] = v;
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}
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}
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//
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// Exercises the Array Visualizer with a large two-array scatter plot.
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//
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// Open the Array Visualizer, enter 'pos' as array A and 'vel' as array B,
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// length 4000, select B's axis as 'Y', scatter mode, and check 'Auto'.
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// Then set a breakpoint on the printf below and 'Continue' a few times:
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// each stop recomputes the trajectory with a different damping and
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// refreshes the 4000-point phase portrait.
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//
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int main (void) {
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for (int run=0; run<10; run++) {
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double damping = 0.05 + 0.05*run;
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integrate(damping);
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printf("run %d: damping=%.2f pos[end]=%f\n", run, damping, pos[NPOINTS-1]);
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}
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return 0;
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}
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