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TAChart: Fix drawing of line series with number of points above 1000000

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git-svn-id: trunk@40043 -
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ask 2013-01-30 03:26:23 +00:00
parent f58b1e6120
commit c04513ee75
1 changed files with 10 additions and 4 deletions
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14
components/tachart/taseries.pas
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@ -405,19 +405,25 @@ var
// Drawing long polylines with wide pen is very inefficient on Windows and GTK.
// On Windows it is so bad that trying to draw polyline with 50000 points
// will cause hard freeze of entire OS. (!)
// Also, Windows refuses to draw any polyline with number of points
// above approximately one million.
// So, split long polylines into segments.
function PolylineIsTooLong: Boolean; inline;
const
// There is a trade-off between the call overhead for short serment and
// the above-mentioned inefficiency for long ones.
// This value was selected by some experiments as "optimal enough" for
// First value was selected by some experiments as "optimal enough" for
// both affected platforms.
MAX_LENGTH = 50;
MAX_LENGTH: array [Boolean] of Integer = (50000, 1000000);
begin
{$IF defined(WIN32) or defined(GTK2)}
{$IF defined(WIN32)}
Result :=
(breakCount > 0) and
(pointCount - breaks[breakCount - 1] > MAX_LENGTH[LinePen.Width = 1]);
{$ELSEIF defined(GTK2)}
Result :=
(LinePen.Width > 1) and (breakCount > 0) and
(pointCount - breaks[breakCount - 1] > MAX_LENGTH);
(pointCount - breaks[breakCount - 1] > MAX_LENGTH[false]);
{$ELSE}
Result := false;
{$ENDIF}