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Simplify drawing spline in wxPostScriptDC

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We can produce simpler and more readable PostScript code by doing
the calculations of Bézier curve parameters in the code instead
of delegating this task to the PostScript processor.
This commit is contained in:
Artur Wieczorek 2021-07-04 20:12:45 +02:00
parent 819b11ff89
commit 9b542a965e
1 changed files with 12 additions and 35 deletions
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47
src/generic/dcpsg.cpp
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@ -102,23 +102,6 @@ static const char *wxPostScriptHeaderEllipticArc=
" { fill }{ stroke } ifelse\n" // -> fill or stroke
"} def\n";
static const char *wxPostScriptHeaderSpline = "\
/DrawSplineSection {\n\
/y3 exch def\n\
/x3 exch def\n\
/y2 exch def\n\
/x2 exch def\n\
/y1 exch def\n\
/x1 exch def\n\
/xa x1 x2 x1 sub 0.666667 mul add def\n\
/ya y1 y2 y1 sub 0.666667 mul add def\n\
/xb x3 x2 x3 sub 0.666667 mul add def\n\
/yb y3 y2 y3 sub 0.666667 mul add def\n\
x1 y1 lineto\n\
xa ya xb yb x3 y3 curveto\n\
} def\n\
";
static const char *wxPostScriptHeaderColourImage = "\
% define 'colorimage' if it isn't defined\n\
% ('colortogray' and 'mergeprocs' come from xwd2ps\n\
@ -1468,8 +1451,6 @@ void wxPostScriptDCImpl::DoDrawSpline( const wxPointList *points )
SetPen( m_pen );
// a and b are not used
//double a, b;
double c, d, x1, y1, x3, y3;
wxPoint *p, *q;
@ -1482,16 +1463,8 @@ void wxPostScriptDCImpl::DoDrawSpline( const wxPointList *points )
p = node->GetData();
c = p->x;
d = p->y;
x3 =
#if 0
a =
#endif
(double)(x1 + c) / 2;
y3 =
#if 0
b =
#endif
(double)(y1 + d) / 2;
x3 = (double)(x1 + c) / 2;
y3 = (double)(y1 + d) / 2;
wxString buffer;
buffer.Printf( "newpath\n"
@ -1520,10 +1493,16 @@ void wxPostScriptDCImpl::DoDrawSpline( const wxPointList *points )
x3 = (double)(x2 + c) / 2;
y3 = (double)(y2 + d) / 2;
buffer.Printf( "%f %f %f %f %f %f DrawSplineSection\n",
XLOG2DEV(wxRound(x1)), YLOG2DEV(wxRound(y1)),
XLOG2DEV(wxRound(x2)), YLOG2DEV(wxRound(y2)),
XLOG2DEV(wxRound(x3)), YLOG2DEV(wxRound(y3)) );
// Calculate using degree elevation to a cubic bezier
wxDouble c1x = (x1 + 2 * x2) / 3.0;
wxDouble c1y = (y1 + 2 * y2) / 3.0;
wxDouble c2x = (2 * x2 + x3) / 3.0;
wxDouble c2y = (2 * y2 + y3) / 3.0;
buffer.Printf("%f %f %f %f %f %f curveto\n",
XLOG2DEV(wxRound(c1x)), YLOG2DEV(wxRound(c1y)),
XLOG2DEV(wxRound(c2x)), YLOG2DEV(wxRound(c2y)),
XLOG2DEV(wxRound(x3)), YLOG2DEV(wxRound(y3)));
buffer.Replace( ",", "." );
PsPrint( buffer );
@ -1718,8 +1697,6 @@ bool wxPostScriptDCImpl::StartDoc( const wxString& WXUNUSED(message) )
PsPrint( wxPostScriptHeaderColourImage );
PsPrint( wxPostScriptHeaderReencodeISO1 );
PsPrint( wxPostScriptHeaderReencodeISO2 );
if (wxPostScriptHeaderSpline)
PsPrint( wxPostScriptHeaderSpline );
PsPrint( wxPostScriptHeaderStrSplit );
PsPrint( "%%EndProlog\n" );