add LPE Interpolate

(bzr r6431)

1 files changed, 119 insertions, 0 deletions

diff --git a/src/live_effects/lpe-interpolate.cpp b/src/live_effects/lpe-interpolate.cpp
new file mode 100644
index 000000000..f2ac17ef8
--- /dev/null
+++ b/src/live_effects/lpe-interpolate.cpp
@@ -0,0 +1,119 @@
+#define INKSCAPE_LPE_INTERPOLATE_CPP
+/** \file
+ * LPE boolops implementation
+ */
+/*
+ * Authors:
+ *   Johan Engelen
+ *
+ * Copyright (C) Johan Engelen 2007-2008 <j.b.c.engelen@utwente.nl>
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include "live_effects/lpe-interpolate.h"
+
+#include <2geom/path.h>
+#include <2geom/sbasis-to-bezier.h>
+#include <2geom/d2-sbasis.h>
+#include <2geom/piecewise.h>
+
+#include "sp-path.h"
+#include "display/curve.h"
+
+namespace Inkscape {
+namespace LivePathEffect {
+
+LPEInterpolate::LPEInterpolate(LivePathEffectObject *lpeobject) :
+    Effect(lpeobject),
+    interpolate_path(_("Interpolate trajectory"), _("Path along which intermediate steps are created."), "trajectory", &wr, this, "M0,0 L0,0"),
+    number_of_steps(_("Steps"), _("Determines the number of steps from start to end path."), "steps", &wr, this, 5),
+    spacing(_("Spacing"), _("Determines the spacing between intermediate steps."), "spacing", &wr, this, 1)
+{
+    show_orig_path = true;
+
+    registerParameter( dynamic_cast<Parameter *>(&interpolate_path) );
+    registerParameter( dynamic_cast<Parameter *>(&number_of_steps) );
+
+    number_of_steps.param_make_integer();
+    number_of_steps.param_set_range(2, NR_HUGE);
+}
+
+LPEInterpolate::~LPEInterpolate()
+{
+
+}
+
+/*
+ * interpolate path_in[0] to path_in[1]
+ */
+Geom::PathVector
+LPEInterpolate::doEffect_path (Geom::PathVector const & path_in)
+{
+    if ( (path_in.size() < 2) || (number_of_steps < 2))
+        return path_in;
+
+    std::vector<Geom::Path> path_out;
+
+    Geom::Piecewise<Geom::D2<Geom::SBasis> > pwd2_A = path_in[0].toPwSb();
+    Geom::Piecewise<Geom::D2<Geom::SBasis> > pwd2_B = path_in[1].toPwSb();
+
+    // Transform both paths to (0,0) midpoint, so they can easily be positioned along interpolate_path
+    pwd2_A -= Geom::bounds_exact(pwd2_A).midpoint();
+    pwd2_B -= Geom::bounds_exact(pwd2_B).midpoint();
+
+    // Make sure both paths have the same number of segments and cuts at the same locations
+    pwd2_B.setDomain(pwd2_A.domain());
+    Geom::Piecewise<Geom::D2<Geom::SBasis> > pA = Geom::partition(pwd2_A, pwd2_B.cuts);
+    Geom::Piecewise<Geom::D2<Geom::SBasis> > pB = Geom::partition(pwd2_B, pwd2_A.cuts);
+
+    Geom::Path const &trajectory = interpolate_path.get_pathvector()[0];
+    double trajectory_length = trajectory.size();
+
+    for (int i = 0; i < number_of_steps; ++i) {
+        double fraction = i / (number_of_steps-1);
+
+        Geom::Piecewise<Geom::D2<Geom::SBasis> > pResult = pA*fraction  +  pB*(1-fraction);
+        pResult += trajectory.pointAt((1.-fraction)*trajectory_length);
+
+        Geom::PathVector pathv = Geom::path_from_piecewise(pResult, LPE_CONVERSION_TOLERANCE);
+        path_out.push_back( pathv[0] );
+    }
+
+    return path_out;
+}
+
+void
+LPEInterpolate::resetDefaults(SPItem * item)
+{
+    if (!SP_IS_PATH(item))
+        return;
+
+    SPCurve const *crv = sp_path_get_curve_reference(SP_PATH(item));
+    Geom::PathVector const &pathv = crv->get_pathvector();
+    if ( (pathv.size() < 2) )
+        return;
+
+    Geom::Rect bounds_A = pathv[0].boundsExact();
+    Geom::Rect bounds_B = pathv[1].boundsExact();
+
+    Geom::PathVector traj_pathv;
+    traj_pathv.push_back( Geom::Path() );
+    traj_pathv[0].start( bounds_A.midpoint() );
+    traj_pathv[0].appendNew<Geom::LineSegment>( bounds_B.midpoint() );
+    interpolate_path.set_new_value( traj_pathv, true );
+}
+
+} //namespace LivePathEffect
+} /* namespace Inkscape */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :