X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fline-geometry.cpp;h=2e528f3afe5b555e64c459f02ef58e5d76a16836;hb=c559a44911579b77710f6698f1a064195da7c292;hp=5d8eca8a12197f2138f4dbdca8b215dd15b6296d;hpb=492de225e9b11f35d98b6b75efa58e115ee688fa;p=inkscape.git

diff --git a/src/line-geometry.cpp b/src/line-geometry.cpp
index 5d8eca8a1..2e528f3af 100644
--- a/src/line-geometry.cpp
+++ b/src/line-geometry.cpp
@@ -13,11 +13,11 @@
 
 #include "line-geometry.h"
 #include "inkscape.h"
+#include "desktop.h"
 #include "desktop-style.h"
 #include "desktop-handles.h"
 #include "display/sp-canvas.h"
 #include "display/sodipodi-ctrl.h"
-//#include "display/curve.cpp"
 
 namespace Box3D {
 
@@ -26,14 +26,14 @@ namespace Box3D {
  * of the segment. Otherwise interpret it as the direction of the line.
  * FIXME: Think of a better way to distinguish between the two constructors of lines.
  */
-Line::Line(NR::Point const &start, NR::Point const &vec, bool is_endpoint) {
+Line::Line(Geom::Point const &start, Geom::Point const &vec, bool is_endpoint) {
     pt = start;
     if (is_endpoint)
         v_dir = vec - start;
     else
     	v_dir = vec;
     normal = v_dir.ccw();
-    d0 = NR::dot(normal, pt);
+    d0 = Geom::dot(normal, pt);
 }
 
 Line::Line(Line const &line) {
@@ -52,38 +52,38 @@ Line &Line::operator=(Line const &line) {
     return *this;
 }
 
-NR::Maybe<NR::Point> Line::intersect(Line const &line) {
-    NR::Coord denom = NR::dot(v_dir, line.normal);
-    NR::Maybe<NR::Point> no_point = NR::Nothing();
+boost::optional<Geom::Point> Line::intersect(Line const &line) {
+    Geom::Coord denom = Geom::dot(v_dir, line.normal);
+    boost::optional<Geom::Point> no_point;
     if (fabs(denom) < 1e-6)
         return no_point;
 
-    NR::Coord lambda = (line.d0 - NR::dot(pt, line.normal)) / denom;
+    Geom::Coord lambda = (line.d0 - Geom::dot(pt, line.normal)) / denom;
     return pt + lambda * v_dir;
 }
 
-void Line::set_direction(NR::Point const &dir)
+void Line::set_direction(Geom::Point const &dir)
 {
     v_dir = dir;
     normal = v_dir.ccw();
-    d0 = NR::dot(normal, pt);
+    d0 = Geom::dot(normal, pt);
 }
 
-NR::Point Line::closest_to(NR::Point const &pt)
+Geom::Point Line::closest_to(Geom::Point const &pt)
 {
 	/* return the intersection of this line with a perpendicular line passing through pt */ 
-    NR::Maybe<NR::Point> result = this->intersect(Line(pt, (this->v_dir).ccw(), false));
-    g_return_val_if_fail (result, NR::Point (0.0, 0.0));
+    boost::optional<Geom::Point> result = this->intersect(Line(pt, (this->v_dir).ccw(), false));
+    g_return_val_if_fail (result, Geom::Point (0.0, 0.0));
     return *result;
 }
 
-double Line::lambda (NR::Point const pt)
+double Line::lambda (Geom::Point const pt)
 {
-    double sign = (NR::dot (pt - this->pt, this->v_dir) > 0) ? 1.0 : -1.0;
-    double lambda = sign * NR::L2 (pt - this->pt);
+    double sign = (Geom::dot (pt - this->pt, this->v_dir) > 0) ? 1.0 : -1.0;
+    double lambda = sign * Geom::L2 (pt - this->pt);
     // FIXME: It may speed things up (but how much?) if we assume that
     //        pt lies on the line and thus skip the following test
-    NR::Point test = point_from_lambda (lambda);
+    Geom::Point test = point_from_lambda (lambda);
     if (!pts_coincide (pt, test)) {
         g_warning ("Point does not lie on line.\n");
         return 0;
@@ -91,13 +91,8 @@ 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)
+std::pair<double, double> coordinates (Geom::Point const &v1, Geom::Point const &v2, Geom::Point const &w)
 {
     double det = determinant (v1, v2);;
     if (fabs (det) < epsilon) {
@@ -111,25 +106,25 @@ std::pair<double, double> coordinates (NR::Point const &v1, NR::Point const &v2,
 }
 
 /* whether w lies inside the sector spanned by v1 and v2 */
-bool lies_in_sector (NR::Point const &v1, NR::Point const &v2, NR::Point const &w)
+bool lies_in_sector (Geom::Point const &v1, Geom::Point const &v2, Geom::Point const &w)
 {
     std::pair<double, double> coords = coordinates (v1, v2, w);
     if (coords.first == HUGE_VAL) {
         // catch the case that the vectors are not linearly independent
         // FIXME: Can we assume that it's safe to return true if the vectors point in different directions?
-        return (NR::dot (v1, v2) < 0);
+        return (Geom::dot (v1, v2) < 0);
     }
     return (coords.first >= 0 and coords.second >= 0);
 }
 
-bool lies_in_quadrangle (NR::Point const &A, NR::Point const &B, NR::Point const &C, NR::Point const &D, NR::Point const &pt)
+bool lies_in_quadrangle (Geom::Point const &A, Geom::Point const &B, Geom::Point const &C, Geom::Point const &D, Geom::Point const &pt)
 {
     return (lies_in_sector (D - A, B - A, pt - A) && lies_in_sector (D - C, B - C, pt - C));
 }
 
-static double pos_angle (NR::Point v, NR::Point w)
+static double pos_angle (Geom::Point v, Geom::Point w)
 {
-    return fabs (NR::atan2 (v) - NR::atan2 (w));
+    return fabs (Geom::atan2 (v) - Geom::atan2 (w));
 }
 
 /*
@@ -137,16 +132,16 @@ static double pos_angle (NR::Point v, NR::Point w)
  * starting at pt and going into direction dir.
  * If none of the sides is hit, it returns a pair containing two identical points.
  */
-std::pair<NR::Point, NR::Point>
-side_of_intersection (NR::Point const &A, NR::Point const &B, NR::Point const &C, NR::Point const &D,
-                      NR::Point const &pt, NR::Point const &dir)
+std::pair<Geom::Point, Geom::Point>
+side_of_intersection (Geom::Point const &A, Geom::Point const &B, Geom::Point const &C, Geom::Point const &D,
+                      Geom::Point const &pt, Geom::Point const &dir)
 {
-    NR::Point dir_A (A - pt);
-    NR::Point dir_B (B - pt);
-    NR::Point dir_C (C - pt);
-    NR::Point dir_D (D - pt);
+    Geom::Point dir_A (A - pt);
+    Geom::Point dir_B (B - pt);
+    Geom::Point dir_C (C - pt);
+    Geom::Point dir_D (D - pt);
 
-    std::pair<NR::Point, NR::Point> result;
+    std::pair<Geom::Point, Geom::Point> result;
     double angle = -1;
     double tmp_angle;
 
@@ -183,58 +178,24 @@ side_of_intersection (NR::Point const &A, NR::Point const &B, NR::Point const &C
     }
 }
 
-double cross_ratio (NR::Point const &A, NR::Point const &B, NR::Point const &C, NR::Point const &D)
-{
-    Line line (A, D);
-    double lambda_A = line.lambda (A);
-    double lambda_B = line.lambda (B);
-    double lambda_C = line.lambda (C);
-    double lambda_D = line.lambda (D);
-
-    if (fabs (lambda_D - lambda_A) < epsilon || fabs (lambda_C - lambda_B) < epsilon) {
-        // FIXME: What should we return if the cross ratio can't be computed?
-        return 0;
-        //return NR_HUGE;
-    }
-    return (((lambda_C - lambda_A) / (lambda_D - lambda_A)) * ((lambda_D - lambda_B) / (lambda_C - lambda_B)));
-}
-
-double cross_ratio (VanishingPoint const &V, NR::Point const &B, NR::Point const &C, NR::Point const &D)
+boost::optional<Geom::Point> Line::intersection_with_viewbox (SPDesktop *desktop)
 {
-    if (V.is_finite()) {
-        return cross_ratio (V.get_pos(), B, C, D);
-    } else {
-        Line line (B, D);
-        double lambda_B = line.lambda (B);
-        double lambda_C = line.lambda (C);
-        double lambda_D = line.lambda (D);
-
-        if (fabs (lambda_C - lambda_B) < epsilon) {
-            // FIXME: What should we return if the cross ratio can't be computed?
-            return 0;
-            //return NR_HUGE;
-        }
-        return (lambda_D - lambda_B) / (lambda_C - lambda_B);
+    Geom::Rect vb = desktop->get_display_area();
+    /* remaining viewbox corners */
+    Geom::Point ul (vb.min()[Geom::X], vb.max()[Geom::Y]);
+    Geom::Point lr (vb.max()[Geom::X], vb.min()[Geom::Y]);
+
+    std::pair <Geom::Point, Geom::Point> e = side_of_intersection (vb.min(), lr, vb.max(), ul, this->pt, this->v_dir);
+    if (e.first == e.second) {
+        // perspective line lies outside the canvas
+        return boost::optional<Geom::Point>();
     }
-}
-
-NR::Point fourth_pt_with_given_cross_ratio (NR::Point const &A, NR::Point const &C, NR::Point const &D, double gamma)
-{
-    Line line (A, D);
-    double lambda_A = line.lambda (A);
-    double lambda_C = line.lambda (C);
-    double lambda_D = line.lambda (D);
 
-    double beta = (lambda_C - lambda_A) / (lambda_D - lambda_A);
-    if (fabs (beta - gamma) < epsilon) {
-        // FIXME: How to handle the case when the point can't be computed?
-        // g_warning ("Cannot compute point with given cross ratio.\n");
-        return NR::Point (0.0, 0.0);
-    }
-    return line.point_from_lambda ((beta * lambda_D - gamma * lambda_C) / (beta - gamma));
+    Line line (e.first, e.second);
+    return this->intersect (line);
 }
 
-void create_canvas_point(NR::Point const &pos, double size, guint32 rgba)
+void create_canvas_point(Geom::Point const &pos, double size, guint32 rgba)
 {
     SPDesktop *desktop = inkscape_active_desktop();
     SPCanvasItem * canvas_pt = sp_canvas_item_new(sp_desktop_controls(desktop), SP_TYPE_CTRL,
@@ -247,7 +208,7 @@ void create_canvas_point(NR::Point const &pos, double size, guint32 rgba)
     SP_CTRL(canvas_pt)->moveto(pos);
 }
 
-void create_canvas_line(NR::Point const &p1, NR::Point const &p2, guint32 rgba)
+void create_canvas_line(Geom::Point const &p1, Geom::Point const &p2, guint32 rgba)
 {
     SPDesktop *desktop = inkscape_active_desktop();
     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(desktop),
@@ -268,4 +229,4 @@ void create_canvas_line(NR::Point const &p1, NR::Point const &p2, guint32 rgba)
   fill-column:99
   End:
 */
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :