From cf233ff5bbc68bd598ef4b81c7b4063548f2eff9 Mon Sep 17 00:00:00 2001
From: Maximilian Albert <maximilian.albert@gmail.com>
Date: Thu, 21 Jun 2007 13:01:57 +0000
Subject: First (very limited) version of the 3D box tool; allows for drawing
 of new boxes in a fixed perspective without any live interaction.

(bzr r3084)
---
 src/line-geometry.cpp | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 src/line-geometry.cpp

(limited to 'src/line-geometry.cpp')

diff --git a/src/line-geometry.cpp b/src/line-geometry.cpp
new file mode 100644
index 000000000..d36b1b63d
--- /dev/null
+++ b/src/line-geometry.cpp
@@ -0,0 +1,112 @@
+#define __LINE_GEOMETRY_C__
+
+/*
+ * Routines for dealing with lines (intersections, etc.)
+ *
+ * Authors:
+ *   Maximilian Albert <Anhalter42@gmx.de>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include "line-geometry.h"
+#include "inkscape.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 {
+
+/** 
+ * Draw a line beginning at 'start'. If is_endpoint is true, use 'vec' as the endpoint
+ * 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) {
+    pt = start;
+    if (is_endpoint)
+        v_dir = vec - start;
+    else
+    	v_dir = vec;
+    normal = v_dir.ccw();
+    d0 = NR::dot(normal, pt);
+}
+
+Line::Line(Line const &line) {
+    pt = line.pt;
+    v_dir = line.v_dir;
+    normal = line.normal;
+    d0 = line.d0;
+}
+
+Line &Line::operator=(Line const &line) {
+    pt = line.pt;
+    v_dir = line.v_dir;
+    normal = line.normal;
+    d0 = line.d0;
+
+    return *this;
+}
+
+NR::Maybe<NR::Point> Line::intersect(Line const &line) {
+    NR::Coord denom = NR::dot(v_dir, line.normal);
+    g_return_val_if_fail(fabs(denom) > 1e-6, NR::Nothing());
+
+    NR::Coord lambda = (line.d0 - NR::dot(pt, line.normal)) / denom;
+    return pt + lambda * v_dir;
+}
+
+void Line::set_direction(NR::Point const &dir)
+{
+    v_dir = dir;
+    normal = v_dir.ccw();
+    d0 = NR::dot(normal, pt);
+}
+
+NR::Point Line::closest_to(NR::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));
+    return *result;
+}
+
+void create_canvas_point(NR::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,
+                          "size", size,
+                          "filled", 1,
+                          "fill_color", rgba,
+                          "stroked", 1,
+                          "stroke_color", 0x000000ff,
+                          NULL);
+    SP_CTRL(canvas_pt)->moveto(pos);
+}
+
+void create_canvas_line(NR::Point const &p1, NR::Point const &p2, guint32 rgba)
+{
+    SPDesktop *desktop = inkscape_active_desktop();
+    SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(desktop),
+                                                            SP_TYPE_CTRLLINE, NULL);
+    sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
+    sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
+    sp_canvas_item_show (line);
+}
+
+} // namespace Box3D 
+ 
+/*
+  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:encoding=utf-8:textwidth=99 :
-- 
cgit v1.2.3