Merge commit '4773cc1128f60e83ba5721fe1ad3497b15078361'

1 files changed, 335 insertions, 0 deletions

diff --git a/tkblt/generic/tkbltGrMisc.C b/tkblt/generic/tkbltGrMisc.C
new file mode 100644
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--- /dev/null
+++ b/tkblt/generic/tkbltGrMisc.C
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+/*
+ * Smithsonian Astrophysical Observatory, Cambridge, MA, USA
+ * This code has been modified under the terms listed below and is made
+ * available under the same terms.
+ */
+
+/*
+ *	Copyright 1993-2004 George A Howlett.
+ *
+ *	Permission is hereby granted, free of charge, to any person obtaining
+ *	a copy of this software and associated documentation files (the
+ *	"Software"), to deal in the Software without restriction, including
+ *	without limitation the rights to use, copy, modify, merge, publish,
+ *	distribute, sublicense, and/or sell copies of the Software, and to
+ *	permit persons to whom the Software is furnished to do so, subject to
+ *	the following conditions:
+ *
+ *	The above copyright notice and this permission notice shall be
+ *	included in all copies or substantial portions of the Software.
+ *
+ *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *	EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *	MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *	NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *	LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *	OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *	WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <limits.h>
+#include <float.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <cmath>
+
+#include <tk.h>
+#include <tkInt.h>
+
+#include "tkbltGraph.h"
+#include "tkbltGrMisc.h"
+
+using namespace Blt;
+
+char* Blt::dupstr(const char* str)
+{
+  char* copy =NULL;
+  if (str) {
+    copy=new char[strlen(str)+1];
+    strcpy(copy,str);
+  }
+
+  return copy;
+}
+
+int Blt::pointInPolygon(Point2d *s, Point2d *points, int nPoints)
+{
+  int count = 0;
+  for (Point2d *p=points, *q=p+1, *qend=p + nPoints; q < qend; p++, q++) {
+    if (((p->y <= s->y) && (s->y < q->y)) || 
+	((q->y <= s->y) && (s->y < p->y))) {
+      double b;
+
+      b = (q->x - p->x) * (s->y - p->y) / (q->y - p->y) + p->x;
+      if (s->x < b) {
+	count++;	/* Count the number of intersections. */
+      }
+    }
+  }
+  return (count & 0x01);
+}
+
+static int ClipTest (double ds, double dr, double *t1, double *t2)
+{
+  double t;
+
+  if (ds < 0.0) {
+    t = dr / ds;
+    if (t > *t2) {
+      return 0;
+    } 
+    if (t > *t1) {
+      *t1 = t;
+    }
+  } else if (ds > 0.0) {
+    t = dr / ds;
+    if (t < *t1) {
+      return 0;
+    } 
+    if (t < *t2) {
+      *t2 = t;
+    }
+  } else {
+    /* d = 0, so line is parallel to this clipping edge */
+    if (dr < 0.0) {		/* Line is outside clipping edge */
+      return 0;
+    }
+  }
+  return 1;
+}
+
+/*
+ *---------------------------------------------------------------------------
+ *	Clips the given line segment to a rectangular region.  The coordinates
+ *	of the clipped line segment are returned.  The original coordinates
+ *	are overwritten.
+ *
+ *	Reference: 
+ *	  Liang, Y-D., and B. Barsky, A new concept and method for
+ *	  Line Clipping, ACM, TOG,3(1), 1984, pp.1-22.
+ *---------------------------------------------------------------------------
+ */
+int Blt::lineRectClip(Region2d* regionPtr, Point2d *p, Point2d *q)
+{
+  double t1, t2;
+  double dx, dy;
+
+  t1 = 0.0, t2 = 1.0;
+  dx = q->x - p->x;
+  if ((ClipTest (-dx, p->x - regionPtr->left, &t1, &t2)) &&
+      (ClipTest (dx, regionPtr->right - p->x, &t1, &t2))) {
+    dy = q->y - p->y;
+    if ((ClipTest (-dy, p->y - regionPtr->top, &t1, &t2)) && 
+	(ClipTest (dy, regionPtr->bottom - p->y, &t1, &t2))) {
+      if (t2 < 1.0) {
+	q->x = p->x + t2 * dx;
+	q->y = p->y + t2 * dy;
+      }
+      if (t1 > 0.0) {
+	p->x += t1 * dx;
+	p->y += t1 * dy;
+      }
+      return 1;
+    }
+  }
+  return 0;
+}
+
+/*
+ *---------------------------------------------------------------------------
+ *	Clips the given polygon to a rectangular region.  The resulting
+ *	polygon is returned. Note that the resulting polyon may be complex,
+ *	connected by zero width/height segments.  The drawing routine (such as
+ *	XFillPolygon) will not draw a connecting segment.
+ *
+ *	Reference:  
+ *	  Liang Y. D. and Brian A. Barsky, "Analysis and Algorithm for
+ *	  Polygon Clipping", Communications of ACM, Vol. 26,
+ *	  p.868-877, 1983
+ *---------------------------------------------------------------------------
+ */
+#define AddVertex(vx, vy)	    r->x=(vx), r->y=(vy), r++, count++ 
+#define LastVertex(vx, vy)	    r->x=(vx), r->y=(vy), count++ 
+
+int Blt::polyRectClip(Region2d *regionPtr, Point2d *points, int nPoints,
+		      Point2d *clipPts)
+{
+  Point2d* r = clipPts;
+  // Counts # of vertices in output polygon.
+  int count = 0;
+
+  points[nPoints] = points[0];
+  for (Point2d *p=points, *q=p+1, *pend=p+nPoints; p<pend; p++, q++) {
+    double dx, dy;
+    double tin1, tin2, tinx, tiny;
+    double xin, yin, xout, yout;
+
+    dx = q->x - p->x;	/* X-direction */
+    dy = q->y - p->y;	/* Y-direction */
+
+    if (fabs(dx) < FLT_EPSILON)
+      dx = (p->x > regionPtr->left) ? -FLT_EPSILON : FLT_EPSILON ;
+
+    if (fabs(dy) < FLT_EPSILON)
+      dy = (p->y > regionPtr->top) ? -FLT_EPSILON : FLT_EPSILON ;
+
+    if (dx > 0.0) {		/* Left */
+      xin = regionPtr->left;
+      xout = regionPtr->right + 1.0;
+    }
+    else {		/* Right */
+      xin = regionPtr->right + 1.0;
+      xout = regionPtr->left;
+    }
+    if (dy > 0.0) {		/* Top */
+      yin = regionPtr->top;
+      yout = regionPtr->bottom + 1.0;
+    }
+    else {		/* Bottom */
+      yin = regionPtr->bottom + 1.0;
+      yout = regionPtr->top;
+    }
+	
+    tinx = (xin - p->x) / dx;
+    tiny = (yin - p->y) / dy;
+	
+    if (tinx < tiny) {	/* Hits x first */
+      tin1 = tinx;
+      tin2 = tiny;
+    }
+    else {		/* Hits y first */
+      tin1 = tiny;
+      tin2 = tinx;
+    }
+	
+    if (tin1 <= 1.0) {
+      if (tin1 > 0.0) {
+	AddVertex(xin, yin);
+      }
+      if (tin2 <= 1.0) {
+	double toutx = (xout - p->x) / dx;
+	double touty = (yout - p->y) / dy;
+	double tout1 = MIN(toutx, touty);
+		
+	if ((tin2 > 0.0) || (tout1 > 0.0)) {
+	  if (tin2 <= tout1) {
+	    if (tin2 > 0.0) {
+	      if (tinx > tiny) {
+		AddVertex(xin, p->y + tinx * dy);
+	      } else {
+		AddVertex(p->x + tiny * dx, yin);
+	      }
+	    }
+	    if (tout1 < 1.0) {
+	      if (toutx < touty) {
+		AddVertex(xout, p->y + toutx * dy);
+	      } else {
+		AddVertex(p->x + touty * dx, yout);
+	      }
+	    } else {
+	      AddVertex(q->x, q->y);
+	    }
+	  } else {
+	    if (tinx > tiny) {
+	      AddVertex(xin, yout);
+	    } else {
+	      AddVertex(xout, yin);
+	    }
+
+	  }
+	}
+      }
+    }
+  }
+  if (count > 0) {
+    LastVertex(clipPts[0].x, clipPts[0].y);
+  }
+  return count;
+}
+
+/*
+ *---------------------------------------------------------------------------
+ *	Computes the projection of a point on a line.  The line (given by two
+ *	points), is assumed the be infinite.
+ *
+ *	Compute the slope (angle) of the line and rotate it 90 degrees.  Using
+ *	the slope-intercept method (we know the second line from the sample
+ *	test point and the computed slope), then find the intersection of both
+ *	lines. This will be the projection of the sample point on the first
+ *	line.
+ *---------------------------------------------------------------------------
+ */
+Point2d Blt::getProjection(int x, int y, Point2d *p, Point2d *q)
+{
+  double dx = p->x - q->x;
+  double dy = p->y - q->y;
+
+  /* Test for horizontal and vertical lines */
+  Point2d t;
+  if (fabs(dx) < DBL_EPSILON) {
+    t.x = p->x;
+    t.y = (double)y;
+  }
+  else if (fabs(dy) < DBL_EPSILON) {
+    t.x = (double)x;
+    t.y = p->y;
+  }
+  else {
+    /* Compute the slope and intercept of PQ. */
+    double m1 = (dy / dx);
+    double b1 = p->y - (p->x * m1);
+
+    /* 
+     * Compute the slope and intercept of a second line segment: one that
+     * intersects through sample X-Y coordinate with a slope perpendicular
+     * to original line.
+     */
+
+    /* Find midpoint of PQ. */
+    double midX = (p->x + q->x) * 0.5;
+    double midY = (p->y + q->y) * 0.5;
+
+    /* Rotate the line 90 degrees */
+    double ax = midX - (0.5 * dy);
+    double ay = midY - (0.5 * -dx);
+    double bx = midX + (0.5 * dy);
+    double by = midY + (0.5 * -dx);
+
+    double m2 = (ay - by) / (ax - bx);
+    double b2 = y - (x * m2);
+
+    /*
+     * Given the equations of two lines which contain the same point,
+     *
+     *    y = m1 * x + b1
+     *    y = m2 * x + b2
+     *
+     * solve for the intersection.
+     *
+     *    x = (b2 - b1) / (m1 - m2)
+     *    y = m1 * x + b1
+     *
+     */
+
+    t.x = (b2 - b1) / (m1 - m2);
+    t.y = m1 * t.x + b1;
+  }
+
+  return t;
+}
+
+Graph* Blt::getGraphFromWindowData(Tk_Window tkwin)
+{
+  while (tkwin) {
+    TkWindow* winPtr = (TkWindow*)tkwin;
+    if (winPtr->instanceData != NULL) {
+      Graph* graphPtr = (Graph*)winPtr->instanceData;
+      if (graphPtr)
+	return graphPtr;
+    }
+    tkwin = Tk_Parent(tkwin);
+  }
+  return NULL;
+}
+