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/perspective-line.cpp | 63 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 src/perspective-line.cpp

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

diff --git a/src/perspective-line.cpp b/src/perspective-line.cpp
new file mode 100644
index 000000000..b2e4d2340
--- /dev/null
+++ b/src/perspective-line.cpp
@@ -0,0 +1,63 @@
+#define __PERSPECTIVE_LINE_C__
+
+/*
+ * Perspective line for 3D perspectives
+ *
+ * Authors:
+ *   Maximilian Albert <Anhalter42@gmx.de>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include "perspective-line.h"
+
+namespace Box3D {
+
+PerspectiveLine::PerspectiveLine (NR::Point const &pt, PerspDir const axis, Perspective3D *perspective) :
+        Line (pt, *(perspective->get_vanishing_point(axis)), true)
+{
+    g_assert (perspective != NULL);
+
+    if (perspective->get_vanishing_point(axis)->state == VP_INFINITE) {
+        this->set_direction(perspective->get_vanishing_point(axis)->v_dir);
+    }
+    this->vp_dir = axis;
+    this->persp  = perspective;
+}
+
+// This function makes sure not to return NR::Nothing()
+// FIXME: How to gracefully handle parallel lines?
+NR::Maybe<NR::Point> PerspectiveLine::intersect (Line const &line)
+{
+    NR::Maybe<NR::Point> pt = this->Line::intersect(line);
+    if (!pt) {
+        Box3D::VanishingPoint vp = *(persp->get_vanishing_point(vp_dir));
+        if (vp.state == VP_INFINITE) {
+            pt = vp;
+        } else {
+            pt = NR::Point (0.0, 0.0); // FIXME: Better solution needed
+        }
+    }
+    return pt; 
+}
+
+// FIXME: Do we really need two intersection methods?
+NR::Point PerspectiveLine::meet(Line const &line)
+{
+    return *intersect(line); // works since intersect() does not return NR::Nothing()
+}
+
+} // 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 :
-- 
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