Infrastructure to set direction of infinite VPs (now adjustable by some shortcuts; this may be removed later on)

(bzr r3657)

8 files changed, 91 insertions, 5 deletions

diff --git a/src/box3d-context.cpp b/src/box3d-context.cpp
index 8b8b1ca99..2abf0112f 100644
--- a/src/box3d-context.cpp
+++ b/src/box3d-context.cpp
@@ -451,6 +451,36 @@ static gint sp_3dbox_context_root_handler(SPEventContext *event_context, GdkEven
                 ret = TRUE;
             break;
 
+        case GDK_bracketright:
+            inkscape_active_document()->current_perspective->rotate (Box3D::X, -10);
+            ret = true;
+            break;
+
+        case GDK_bracketleft:
+            inkscape_active_document()->current_perspective->rotate (Box3D::X, 10);
+            ret = true;
+            break;
+
+        case GDK_parenright:
+            inkscape_active_document()->current_perspective->rotate (Box3D::Y, -10);
+            ret = true;
+            break;
+
+        case GDK_parenleft:
+            inkscape_active_document()->current_perspective->rotate (Box3D::Y, 10);
+            ret = true;
+            break;
+
+        case GDK_braceright:
+            inkscape_active_document()->current_perspective->rotate (Box3D::Z, -10);
+            ret = true;
+            break;
+
+        case GDK_braceleft:
+            inkscape_active_document()->current_perspective->rotate (Box3D::Z, 10);
+            ret = true;
+            break;
+
         case GDK_I:
             Box3D::Perspective3D::print_debugging_info();
             ret = true;
diff --git a/src/box3d.cpp b/src/box3d.cpp
index 5e67f46ab..1942ea3d6 100644
--- a/src/box3d.cpp
+++ b/src/box3d.cpp
@@ -799,6 +799,23 @@ sp_3dbox_link_to_existing_paths (SP3DBox *box, Inkscape::XML::Node *repr) {
 }
 
 void
+sp_3dbox_reshape_after_VP_rotation (SP3DBox *box, Box3D::Axis axis)
+{
+    Box3D::Perspective3D *persp = inkscape_active_document()->get_persp_of_box (box);
+    Box3D::VanishingPoint *vp = persp->get_vanishing_point (axis);
+
+    guint c1 = (axis == Box3D::Z) ? 1 : sp_3dbox_get_front_corner_id (box); // hack
+    guint c2 = c1 ^ axis;
+    NR::Point v = box->corners[c1] - box->corners[c2];
+    double dist = NR::L2 (v) * ((NR::dot (v, vp->v_dir) < 0) ? 1 : -1); // "directed" distance
+
+    Box3D::PerspectiveLine pline (box->corners[c1], axis, persp);
+    NR::Point pt = pline.point_from_lambda (dist);
+
+    sp_3dbox_move_corner_in_Z_direction (box, c2, pt, axis == Box3D::Z);
+}
+
+void
 sp_3dbox_move_corner_in_XY_plane (SP3DBox *box, guint id, NR::Point pt, Box3D::Axis axes)
 {
     Box3D::Perspective3D * persp = SP_OBJECT_DOCUMENT (G_OBJECT (box))->get_persp_of_box (box);
diff --git a/src/box3d.h b/src/box3d.h
index 3d52c96d1..1e567ded9 100644
--- a/src/box3d.h
+++ b/src/box3d.h
@@ -77,6 +77,7 @@ void sp_3dbox_update_curves (SP3DBox *box);
 void sp_3dbox_link_to_existing_paths (SP3DBox *box, Inkscape::XML::Node *repr);
 void sp_3dbox_set_ratios (SP3DBox *box, Box3D::Axis axes = Box3D::XYZ);
 void sp_3dbox_switch_front_face (SP3DBox *box, Box3D::Axis axis);
+void sp_3dbox_reshape_after_VP_rotation (SP3DBox *box, Box3D::Axis axis);
 void sp_3dbox_move_corner_in_XY_plane (SP3DBox *box, guint id, NR::Point pt, Box3D::Axis axes = Box3D::XY);
 void sp_3dbox_move_corner_in_Z_direction (SP3DBox *box, guint id, NR::Point pt, bool constrained = true);
 void sp_3dbox_reshape_after_VP_toggling (SP3DBox *box, Box3D::Axis axis);
diff --git a/src/line-geometry.cpp b/src/line-geometry.cpp
index 7b6ba0449..872e9ed6b 100644
--- a/src/line-geometry.cpp
+++ b/src/line-geometry.cpp
@@ -91,11 +91,6 @@ double Line::lambda (NR::Point const pt)
     return lambda;
 }
 
-inline static double determinant (NR::Point const &a, NR::Point const &b)
-{
-    return (a[NR::X] * b[NR::Y] - a[NR::Y] * b[NR::X]);
-}
-
 /* The coordinates of w with respect to the basis {v1, v2} */
 std::pair<double, double> coordinates (NR::Point const &v1, NR::Point const &v2, NR::Point const &w)
 {
diff --git a/src/line-geometry.h b/src/line-geometry.h
index fc8f157e9..e678c4031 100644
--- a/src/line-geometry.h
+++ b/src/line-geometry.h
@@ -55,6 +55,10 @@ protected:
     NR::Coord d0;
 };
 
+inline double determinant (NR::Point const &a, NR::Point const &b)
+{
+    return (a[NR::X] * b[NR::Y] - a[NR::Y] * b[NR::X]);
+}
 std::pair<double, double> coordinates (NR::Point const &v1, NR::Point const &v2, NR::Point const &w);
 bool lies_in_sector (NR::Point const &v1, NR::Point const &v2, NR::Point const &w);
 bool lies_in_quadrangle (NR::Point const &A, NR::Point const &B, NR::Point const &C, NR::Point const &D, NR::Point const &pt);
diff --git a/src/perspective3d.cpp b/src/perspective3d.cpp
index 8b1b3863d..9321af356 100644
--- a/src/perspective3d.cpp
+++ b/src/perspective3d.cpp
@@ -180,6 +180,41 @@ Perspective3D::set_vanishing_point (Box3D::Axis const dir, VanishingPoint const
     }
 }
 
+void
+Perspective3D::set_infinite_direction (Box3D::Axis axis, NR::Point const dir)
+{
+    Box3D::Axis axis1 = Box3D::get_remaining_axes (axis).first;
+    Box3D::Axis axis2 = Box3D::get_remaining_axes (axis).second;
+    Box3D::VanishingPoint *vp1 = get_vanishing_point (axis1);
+    Box3D::VanishingPoint *vp2 = get_vanishing_point (axis2);
+    if (fabs (Box3D::determinant (vp1->v_dir, dir)) < Box3D::epsilon ||
+        fabs (Box3D::determinant (vp2->v_dir, dir)) < Box3D::epsilon) {
+        // This is an ad-hoc correction; we should fix this more thoroughly
+        double a = NR::atan2 (dir) + 0.01;
+        this->set_infinite_direction (axis, NR::Point (cos (a), sin (a))); // we call this function again in case there is another conflict (which is unlikely, but possible)
+        return;
+    }
+
+    get_vanishing_point (axis)->set_infinite_direction (dir);
+}
+
+void
+Perspective3D::rotate (Box3D::Axis const axis, double const angle)
+{
+    Box3D::VanishingPoint *vp = get_vanishing_point (axis);
+    if (!vp->is_finite()) {
+        double a = NR::atan2 (vp->v_dir) * 180/M_PI;
+        a += angle;
+        a *= M_PI/180;
+        this->set_infinite_direction (axis, NR::Point (cos (a), sin (a)));
+        for (GSList *i = this->boxes; i != NULL; i = i->next) {
+            sp_3dbox_reshape_after_VP_rotation (SP_3DBOX (i->data), axis);
+            sp_3dbox_set_z_orders_later_on (SP_3DBOX (i->data));
+        }
+        update_box_reprs();
+    }
+}
+
 Axis
 Perspective3D::get_axis_of_VP (VanishingPoint *vp)
 {
diff --git a/src/perspective3d.h b/src/perspective3d.h
index 8c63cf42e..a431e1f99 100644
--- a/src/perspective3d.h
+++ b/src/perspective3d.h
@@ -35,6 +35,8 @@ public:
     Axis get_axis_of_VP (VanishingPoint *vp);
     void set_vanishing_point (Box3D::Axis const dir, VanishingPoint const &pt);
     void set_vanishing_point (Box3D::Axis const dir, gdouble pt_x, gdouble pt_y, gdouble dir_x, gdouble dir_y, VPState st);
+    void set_infinite_direction (Box3D::Axis axis, NR::Point const dir);
+    void rotate (Box3D::Axis const dir, double const angle);
     void add_box (SP3DBox *box);
     void remove_box (const SP3DBox *box);
     bool has_box (const SP3DBox *box) const;
diff --git a/src/vanishing-point.h b/src/vanishing-point.h
index 7d53fa89d..428bb49ad 100644
--- a/src/vanishing-point.h
+++ b/src/vanishing-point.h
@@ -59,6 +59,8 @@ public:
                                                (*this)[NR::Y] = pt[NR::Y]; }
     inline void set_pos(const double pt_x, const double pt_y) { (*this)[NR::X] = pt_x;
                                                                 (*this)[NR::Y] = pt_y; }
+    inline void set_infinite_direction (const NR::Point dir) { v_dir = dir; }
+    inline void set_infinite_direction (const double dir_x, const double dir_y) { v_dir = NR::Point (dir_x, dir_y); }
 
     bool is_finite() const;
     VPState toggle_parallel();