Include a stripped-down version of FLTK in tree and add a USE_INCLUDED_FLTK option to build against it.
git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4603 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/common/fltk/src/fl_arc.cxx b/common/fltk/src/fl_arc.cxx
new file mode 100644
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+++ b/common/fltk/src/fl_arc.cxx
@@ -0,0 +1,91 @@
+//
+// "$Id: fl_arc.cxx 7903 2010-11-28 21:06:39Z matt $"
+//
+// Arc functions for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 1998-2010 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
+//
+
+/**
+ \file fl_arc.cxx
+ \brief Utility functions for drawing arcs and circles.
+*/
+
+// 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_Graphics_Driver::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 7903 2010-11-28 21:06:39Z matt $".
+//