From a6163888f3c56123b1db313743c6147ba498732c Mon Sep 17 00:00:00 2001
From: Yuval Adam <yuv.adm@gmail.com>
Date: Fri, 8 Aug 2014 14:42:07 +0300
Subject: Add third_party libs

---
 third_party/windows/fltk-1.1.10/src/fl_arc.cxx | 87 ++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 third_party/windows/fltk-1.1.10/src/fl_arc.cxx

(limited to 'third_party/windows/fltk-1.1.10/src/fl_arc.cxx')

diff --git a/third_party/windows/fltk-1.1.10/src/fl_arc.cxx b/third_party/windows/fltk-1.1.10/src/fl_arc.cxx
new file mode 100644
index 0000000..2ff9ef0
--- /dev/null
+++ b/third_party/windows/fltk-1.1.10/src/fl_arc.cxx
@@ -0,0 +1,87 @@
+//
+// "$Id: fl_arc.cxx 5349 2006-08-23 14:43:07Z matt $"
+//
+// Arc functions for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 1998-2005 by Bill Spitzak and others.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Library General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Library General Public License for more details.
+//
+// You should have received a copy of the GNU Library General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+// USA.
+//
+// Please report all bugs and problems on the following page:
+//
+//     http://www.fltk.org/str.php
+//
+
+// Utility for drawing arcs and circles.  They are added to
+// the current fl_begin/fl_vertex/fl_end path.
+// Incremental math implementation:
+
+#include <FL/fl_draw.H>
+#include <FL/math.h>
+
+// avoid problems with some platforms that don't 
+// implement hypot.
+static double _fl_hypot(double x, double y) {
+  return sqrt(x*x + y*y);
+}
+
+
+void fl_arc(double x, double y, double r, double start, double end) {
+
+  // draw start point accurately:
+  
+  double A = start*(M_PI/180);		// Initial angle (radians)
+  double X =  r*cos(A);			// Initial displacement, (X,Y)
+  double Y = -r*sin(A);			//   from center to initial point
+  fl_vertex(x+X,y+Y);			// Insert initial point
+
+  // Maximum arc length to approximate with chord with error <= 0.125
+  
+  double epsilon; {
+    double r1 = _fl_hypot(fl_transform_dx(r,0), // Horizontal "radius"
+		          fl_transform_dy(r,0));
+    double r2 = _fl_hypot(fl_transform_dx(0,r), // Vertical "radius"
+		          fl_transform_dy(0,r));
+		      
+    if (r1 > r2) r1 = r2;		// r1 = minimum "radius"
+    if (r1 < 2.) r1 = 2.;		// radius for circa 9 chords/circle
+    
+    epsilon = 2*acos(1.0 - 0.125/r1);	// Maximum arc angle
+  }
+  A = end*(M_PI/180) - A;		// Displacement angle (radians)
+  int i = int(ceil(fabs(A)/epsilon));	// Segments in approximation
+  
+  if (i) {
+    epsilon = A/i;			// Arc length for equal-size steps
+    double cos_e = cos(epsilon);	// Rotation coefficients
+    double sin_e = sin(epsilon);
+    do {
+      double Xnew =  cos_e*X + sin_e*Y;
+		Y = -sin_e*X + cos_e*Y;
+      fl_vertex(x + (X=Xnew), y + Y);
+    } while (--i);
+  }
+}
+
+#if 0 // portable version.  X-specific one in fl_vertex.cxx
+void fl_circle(double x,double y,double r) {
+  _fl_arc(x, y, r, r, 0, 360);
+}
+#endif
+
+//
+// End of "$Id: fl_arc.cxx 5349 2006-08-23 14:43:07Z matt $".
+//
-- 
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