partial: 0.1.55.jcn

diff --git a/lily/bezier.cc b/lily/bezier.cc
new file mode 100644 (file)
index 0000000..8c94e4e
--- /dev/null
+++ b/lily/bezier.cc
@@ -0,0 +1,120 @@
+/*
+  bezier.cc -- implement Bezier and Bezier_bow
+
+  source file of the GNU LilyPond music typesetter
+
+  (c) 1998 Jan Nieuwenhuizen <jan@digicash.com>
+*/
+
+#include <math.h>
+#include "bezier.hh"
+#include "dimen.hh"
+#include "paper-def.hh"
+
+Bezier::Bezier (int steps_i)
+{
+  steps_i_ = steps_i;
+  curve_ = new Point [steps_i_ + 1];
+}
+
+Bezier::~Bezier ()
+{
+  delete[] curve_;
+}
+
+//from GNU gs3.33: ega.c
+void
+Bezier::calc (Point control[4])
+{       
+  Real dt = 1.0 / steps_i_;
+  Real cx = 3.0 * (control[1].x - control[0].x);
+  Real bx = 3.0 * (control[2].x - control[1].x) - cx;
+  Real ax = control[3].x - (control[0].x + cx + bx);
+  Real cy = 3.0 * (control[1].y - control[0].y);
+  Real by = 3.0 * (control[2].y - control[1].y) - cy; 
+  Real ay = control[3].y - (control[0].y + cy + by);
+  Real t = 0.0;
+  int i = 0;
+  while ( t <= 1.0 )
+    {    
+      curve_[i].x = ((ax * t + bx) * t + cx) * t + control[0].x;
+      curve_[i++].y = ((ay * t + by) * t + cy) * t + control[0].y;
+      t += dt;
+    }
+}
+
+Real
+Bezier::y (Real x)
+{
+  if (x <= curve_[0].x)
+    return curve_[0].y;
+  for (int i = 1; i < steps_i_; i++ )
+    {
+      if (x < curve_[i].x)
+       {
+         Real lin = (x - curve_[i-1].x) / (curve_[i].x - curve_[i-1].x);
+         return curve_[i-1].y + lin * (curve_[i].y - curve_[i-1].y);
+        }
+    }
+  return curve_[steps_i_-1].y;
+}
+
+
+Bezier_bow::Bezier_bow (Paper_def* paper_l)
+  : Bezier(10)
+{
+  paper_l_ = paper_l;
+}
+
+
+/* 
+  from feta-sleur.ly
+
+       slurheightlimit#:=staffsize#/2;
+       sluralpha:=slurheightlimit#*pi/2;
+       % slurratio:=1/3;
+       slurratio:=0.3333;
+       slurbeta:=3/4*pi*slurratio/sluralpha;
+
+        b#:=length(dx#,dy#);
+        % ugh: huh? 2/5
+        indent#:=2/5*sluralpha*atan(slurbeta*b#);
+        height:=(indent+h)*d;
+        z1=(0,0);
+        z2=(b,0);
+        z3=(indent,height);
+        z4=(b-indent,height);
+
+       boogje:=boogje rotated angle(dxs,dys);
+*/
+
+void
+Bezier_bow::calc (Real dx, Real dy, Real h, Real d)
+{
+  // ugh
+  Real pi = M_PI;
+  // ugh
+  Real staffsize_f = paper_l_->get_var ("barsize");
+  Real height_limit = staffsize_f;
+  Real alpha = height_limit * pi / 2.0;
+  Real ratio = 1.0/3.0;
+  Real beta = 3.0/4.0 * pi * ratio/alpha;
+
+  Real b = sqrt (dx * dx + dy * dy);
+  Real indent = 2.0/5.0 * alpha * atan (beta * b);
+  // ugh, ugly height hack, see lily-ps-defs.tex
+  Real height = (indent + h) * d;
+ 
+  Point control[4] = {0, 0, indent, height, b - indent, height, b, 0 };
+ 
+  Real phi = dx ? atan (dy/dx) : sign (dy) * pi / 2.0;
+  Real sphi = sin (phi);
+  Real cphi = cos (phi);
+  for (int i = 1; i < 4; i++)
+    {
+      control[i].x = cphi * control[i].x - sphi * control[i].y;
+      control[i].y = sphi * control[i].x + cphi * control[i].y;
+    }
+  Bezier::calc (control);
+}
+

diff --git a/lily/include/bezier.hh b/lily/include/bezier.hh
new file mode 100644 (file)
index 0000000..69a24d5
--- /dev/null
+++ b/lily/include/bezier.hh
@@ -0,0 +1,61 @@
+/*
+  bezier.hh -- declare Bezier and Bezier_bow
+
+  (c) 1998 Jan Nieuwenhuizen <jan@digicash.com>
+*/
+
+#ifndef BEZIER_HH
+#define BEZIER_HH
+
+#include "lily-proto.hh"
+#include "real.hh"
+
+/**
+ Handy (x,y) of reals for Bezier  
+ */
+struct Point
+{
+  Real x;
+  Real y;
+};
+
+/**
+  Simple bezier curve
+ */
+class Bezier
+{
+public:
+  Bezier (int steps_i);
+  virtual ~Bezier ();
+
+  /**
+  Calculate bezier curve into Point (x,y) array.
+  */
+  void calc (Point control[4]);
+
+  /**
+  Return y that goes with x by interpolation.
+  */
+  Real y (Real x);
+
+  int steps_i_;
+  Point* curve_;
+};
+
+/**
+  Implement bow specific bezier curve
+ */
+class Bezier_bow : public Bezier
+{
+public:
+  Bezier_bow (Paper_def* paper_l);
+
+  /**
+   Calculate bezier curve for bow from bow parameters.
+   */
+  void calc (Real dx, Real dy, Real h, Real d);
+  Paper_def* paper_l_;
+};
+
+
+#endif // BEZIER_HH