New LPE: Perspective paths

(bzr r5310)

1 files changed, 148 insertions, 0 deletions

diff --git a/src/live_effects/lpe-perspective_path.cpp b/src/live_effects/lpe-perspective_path.cpp
new file mode 100644
index 000000000..923a4baa4
--- /dev/null
+++ b/src/live_effects/lpe-perspective_path.cpp
@@ -0,0 +1,148 @@
+#define INKSCAPE_LPE_PERSPECTIVE_PATH_CPP
+/** \file
+ * LPE <perspective_path> implementation, used as an example for a base starting class
+ * when implementing new LivePathEffects.
+ *
+ * In vi, three global search-and-replaces will let you rename everything
+ * in this and the .h file:
+ *
+ *   :%s/PERSPECTIVE_PATH/YOURNAME/g
+ *   :%s/PerspectivePath/Yourname/g
+ *   :%s/perspective_path/yourname/g
+ */
+/*
+ * Authors:
+ *   Johan Engelen
+ *   Maximilian Albert
+ *
+ * Copyright (C) Johan Engelen 2007 <j.b.c.engelen@utwente.nl>
+ * Copyright (C) Maximilian Albert 2008 <maximilian.albert@gmail.com>
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include "persp3d.h"
+//#include "transf_mat_3x4.h"
+#include "document.h"
+
+#include "live_effects/lpe-perspective_path.h"
+#include "display/curve.h"
+#include <libnr/n-art-bpath.h>
+
+#include "inkscape.h"
+
+// You might need to include other 2geom files. You can add them here:
+#include <2geom/path.h>
+
+namespace Inkscape {
+namespace LivePathEffect {
+
+LPEPerspectivePath::LPEPerspectivePath(LivePathEffectObject *lpeobject) :
+    Effect(lpeobject),
+    // initialise your parameters here:
+    scalex(_("Scale x"), _("Scale factor in x direction"), "scalex", &wr, this, 1.0),
+    scaley(_("Scale y"), _("Scale factor in y direction"), "scaley", &wr, this, 1.0),
+    offsetx(_("Offset x"), _("Offset in x direction"), "offsetx", &wr, this, 0.0),
+    offsety(_("Offset y"), _("Offset in y direction"), "offsety", &wr, this, 0.0),
+    uses_plane_xy(_("Uses XY plane?"), _("If true, put the path on the left side of an imaginary box, otherwise on the right side"), "uses_plane_xy", &wr, this, true)
+{
+    // register all your parameters here, so Inkscape knows which parameters this effect has:
+    registerParameter( dynamic_cast<Parameter *>(&scalex) );
+    registerParameter( dynamic_cast<Parameter *>(&scaley) );
+    registerParameter( dynamic_cast<Parameter *>(&offsetx) );
+    registerParameter( dynamic_cast<Parameter *>(&offsety) );
+    registerParameter( dynamic_cast<Parameter *>(&uses_plane_xy) );
+
+    Persp3D *persp = persp3d_document_first_persp(inkscape_active_document());
+
+    Proj::TransfMat3x4 pmat = persp->tmat;
+
+    pmat.copy_tmat(tmat);
+}
+
+LPEPerspectivePath::~LPEPerspectivePath()
+{
+
+}
+
+Geom::Piecewise<Geom::D2<Geom::SBasis> >
+LPEPerspectivePath::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > & pwd2_in)
+{
+    using namespace Geom;
+
+    Piecewise<D2<SBasis> > path_a_pw = pwd2_in;
+
+    // FIXME: the minus sign is there because the SVG coordinate system goes down;
+    //        remove this once we have unified coordinate systems
+    path_a_pw = path_a_pw + Geom::Point(offsetx, -offsety);
+
+    D2<Piecewise<SBasis> > B = make_cuts_independant(path_a_pw);
+    Piecewise<SBasis> preimage[4];
+
+    Geom::Interval bounds_X = bounds_fast(pwd2_in)[0];
+    Geom::Interval bounds_Y = bounds_fast(pwd2_in)[1];
+
+    Geom::Point orig = Geom::Point(uses_plane_xy ? bounds_X.max() : bounds_X.min(),
+                                   bounds_Y.middle());
+    //Geom::Point orig = Geom::Point(bounds_X.min(), bounds_Y.middle());
+    //orig = Geom::Point(orig[X], sp_document_height(inkscape_active_document()) - orig[Y]);
+
+    double offset = uses_plane_xy ? bounds_X.extent() : 0.0;
+
+    /**
+    g_print ("Orig: (%8.2f, %8.2f)\n", orig[X], orig[Y]);
+
+    g_print ("B[1] - orig[1]: %8.2f\n", (B[1] - orig[1])[0].valueAt(0));
+    g_print ("B[0] - orig[0]: %8.2f\n", (B[0] - orig[0])[0].valueAt(0));
+    **/
+
+    if (uses_plane_xy) {
+        preimage[0] =  (-B[0] + orig[0]) * scalex / 200.0;
+        preimage[1] =  ( B[1] - orig[1]) * scaley / 400.0;
+        preimage[2] =  B[0] - B[0]; // hack!
+    } else {
+        preimage[0] =  B[0] - B[0]; // hack!
+        preimage[1] =  (B[1] - orig[1]) * scaley / 400.0;
+        preimage[2] =  (B[0] - orig[0]) * scalex / 200.0;
+    }
+
+    /* set perspective origin to first point of path */
+    tmat[0][3] = orig[0];
+    tmat[1][3] = orig[1];
+
+    /**
+    g_print ("preimage[1]: %8.2f\n", preimage[1][0].valueAt(0));
+    g_print ("preimage[2]: %8.2f\n", preimage[2][0].valueAt(0));
+    **/
+
+    Piecewise<SBasis> res[3];
+    for (int j = 0; j < 3; ++j) {
+        res[j] =
+              preimage[0] * tmat[j][0]
+            + preimage[1] * tmat[j][1]
+            + preimage[2] * tmat[j][2]
+            +               tmat[j][3];
+    }
+    D2<Piecewise<SBasis> > result(divide(res[0],res[2], 3), 
+                                  divide(res[1],res[2], 3));
+
+    Piecewise<D2<SBasis> > output = sectionize(result);
+
+    return output;
+}
+
+/* ######################## */
+
+} //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 :