ultimatepp/uppsrc/Painter/Approximate.cpp
cxl 8ebdcbb0d5 uppsrc: NAMESPACE_UPP / END_UPP_NAMESPACE removed
git-svn-id: svn://ultimatepp.org/upp/trunk@10186 f0d560ea-af0d-0410-9eb7-867de7ffcac7
2016-08-26 17:15:30 +00:00

73 lines
2 KiB
C++

#include "Painter.h"
namespace Upp {
static void sQuadratic(LinearPathConsumer& t, const Pointf& p1, const Pointf& p2, const Pointf& p3,
double qt, int lvl)
{
if(lvl < 16) {
PAINTER_TIMING("Quadratic approximation");
Pointf d = p3 - p1;
double q = Squared(d);
if(q > 1e-30) {
Pointf pd = p2 - p1;
double u = (pd.x * d.x + pd.y * d.y) / q;
if(u <= 0 || u >= 1 || SquaredDistance(u * d, pd) > qt) {
Pointf p12 = Mid(p1, p2);
Pointf p23 = Mid(p2, p3);
Pointf div = Mid(p12, p23);
sQuadratic(t, p1, p12, div, qt, lvl + 1);
sQuadratic(t, div, p23, p3, qt, lvl + 1);
return;
}
}
}
t.Line(p3);
}
void ApproximateQuadratic(LinearPathConsumer& t, const Pointf& p1, const Pointf& p2, const Pointf& p3,
double tolerance)
{
sQuadratic(t, p1, p2, p3, tolerance * tolerance, 0);
// t.Line(p3);
}
static void sCubic(LinearPathConsumer& t,
const Pointf& p1, const Pointf& p2, const Pointf& p3, const Pointf& p4,
double qt, int lvl)
{
if(lvl < 16) {
PAINTER_TIMING("Cubic approximation");
Pointf d = p4 - p1;
double q = d.x * d.x + d.y * d.y;
if(q >= 1e-30) {
Pointf d2 = p2 - p1;
Pointf d3 = p3 - p1;
double u1 = (d2.x * d.x + d2.y * d.y) / q;
double u2 = (d3.x * d.x + d3.y * d.y) / q;
if(u1 <= 0 || u1 >= 1 || u2 <= 0 || u2 >= 1 ||
SquaredDistance(u1 * d, d2) > qt || SquaredDistance(u2 * d, d3) > qt) {
Pointf p12 = Mid(p1, p2);
Pointf p23 = Mid(p2, p3);
Pointf p34 = Mid(p3, p4);
Pointf p123 = Mid(p12, p23);
Pointf p234 = Mid(p23, p34);
Pointf div = Mid(p123, p234);
sCubic(t, p1, p12, p123, div, qt, lvl + 1);
sCubic(t, div, p234, p34, p4, qt, lvl + 1);
return;
}
}
}
t.Line(p4);
}
void ApproximateCubic(LinearPathConsumer& t,
const Pointf& p1, const Pointf& p2, const Pointf& p3, const Pointf& p4,
double tolerance)
{
sCubic(t, p1, p2, p3, p4, tolerance * tolerance, 0);
t.Line(p4);
}
}