Release 0.61.08

[synfig.git] / synfig-core / tags / stable / src / modules / mod_gradient / curvegradient.cpp

diff --git a/synfig-core/tags/stable/src/modules/mod_gradient/curvegradient.cpp b/synfig-core/tags/stable/src/modules/mod_gradient/curvegradient.cpp
index 9ae4af2..2fb682f 100644 (file)
--- a/synfig-core/tags/stable/src/modules/mod_gradient/curvegradient.cpp
+++ b/synfig-core/tags/stable/src/modules/mod_gradient/curvegradient.cpp
@@ -6,6 +6,7 @@
 **
 **     \legal
 **     Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
+**     Copyright (c) 2007 Chris Moore
 **
 **     This package is free software; you can redistribute it and/or
 **     modify it under the terms of the GNU General Public License as
@@ -72,7 +73,7 @@ inline float calculate_distance(const synfig::BLinePoint& a,const synfig::BLineP
 #endif
 }
 
-inline float calculate_distance(const std::vector<synfig::BLinePoint>& bline)
+inline float calculate_distance(const std::vector<synfig::BLinePoint>& bline, bool bline_loop)
 {
        std::vector<synfig::BLinePoint>::const_iterator iter,next,ret;
        std::vector<synfig::BLinePoint>::const_iterator end(bline.end());
@@ -83,10 +84,10 @@ inline float calculate_distance(const std::vector<synfig::BLinePoint>& bline)
 
        next=bline.begin();
 
-       //if(loop)
-       //      iter=--bline.end();
-       //else
-       iter=next++;
+       if(bline_loop)
+               iter=--bline.end();
+       else
+               iter=next++;
 
        for(;next!=end;iter=next++)
        {
@@ -197,7 +198,7 @@ find_closest(bool fast, const std::vector<synfig::BLinePoint>& bline,const Point
 inline void
 CurveGradient::sync()
 {
-       curve_length_=calculate_distance(bline);
+       curve_length_=calculate_distance(bline, bline_loop);
 }
 
 
@@ -237,6 +238,7 @@ CurveGradient::color_func(const Point &point_, int quality, float supersample)co
        Real dist;
 
        float perp_dist;
+       bool edge_case = false;
 
        if(bline.size()==0)
                return Color::alpha();
@@ -260,7 +262,7 @@ CurveGradient::color_func(const Point &point_, int quality, float supersample)co
                        next=find_closest(fast,bline,point,t,bline_loop,&perp_dist);
                        perp_dist/=curve_length_;
                }
-               else
+               else                                    // not perpendicular
                {
                        next=find_closest(fast,bline,point,t,bline_loop);
                }
@@ -285,27 +287,51 @@ CurveGradient::color_func(const Point &point_, int quality, float supersample)co
                  else if(quality<=2)search_iterations=10;
                  else if(quality<=4)search_iterations=8;
                */
-               if(!perpendicular)
+               if(perpendicular)
+               {
+                       if(quality>7)
+                               search_iterations=4;
+               }
+               else                                    // not perpendicular
                {
                        if(quality<=6)search_iterations=7;
                        else if(quality<=7)search_iterations=6;
                        else if(quality<=8)search_iterations=5;
                        else search_iterations=4;
                }
-               else
-               {
-                       if(quality>7)
-                               search_iterations=4;
-               }
 
                // Figure out the closest point on the curve
                if (fast)
                        t = curve.find_closest(fast, point,search_iterations);
 
-
                // Calculate our values
-               p1=curve(t);
-               tangent=deriv(t).norm();
+               p1=curve(t);                     // the closest point on the curve
+               tangent=deriv(t).norm(); // the unit tangent at that point
+
+               // if the point we're nearest to is at either end of the
+               // bline, our distance from the curve is the distance from the
+               // point on the curve.  we need to know which side of the
+               // curve we're on, so find the average of the two tangents at
+               // this point
+               if (t<0.00001 || t>0.99999)
+               {
+                       if (t<0.5)
+                       {
+                               if (iter->get_split_tangent_flag())
+                               {
+                                       tangent=(iter->get_tangent1().norm()+tangent).norm();
+                                       edge_case=true;
+                               }
+                       }
+                       else
+                       {
+                               if (next->get_split_tangent_flag())
+                               {
+                                       tangent=(next->get_tangent2().norm()+tangent).norm();
+                                       edge_case=true;
+                               }
+                       }
+               }
 
                if(perpendicular)
                {
@@ -313,23 +339,12 @@ CurveGradient::color_func(const Point &point_, int quality, float supersample)co
                        p1-=tangent*perp_dist;
                        tangent=-tangent.perp();
                }
-               else
-               {
+               else                                    // not perpendicular
+                       // the width of the bline at the closest point on the curve
                        thickness=(next->get_width()-iter->get_width())*t+iter->get_width();
-               }
-               //}
        }
 
-       if(!perpendicular)
-       {
-               diff=tangent.perp()*thickness*width;
-               p1-=diff*0.5;
-               const Real mag(diff.inv_mag());
-               supersample=supersample*mag;
-               diff*=mag*mag;
-               dist=((point_-offset)*diff-p1*diff);
-       }
-       else
+       if(perpendicular)
        {
                if(quality>7)
                {
@@ -350,6 +365,23 @@ CurveGradient::color_func(const Point &point_, int quality, float supersample)co
                        dist=((point_-offset)*diff-p1*diff);
                }
        }
+       else                                            // not perpendicular
+       {
+               if (edge_case)
+               {
+                       diff=(p1-(point_-offset));
+                       if(diff*tangent.perp()<0) diff=-diff;
+                       diff=diff.norm()*thickness*width;
+               }
+               else
+                       diff=tangent.perp()*thickness*width;
+
+               p1-=diff*0.5;
+               const Real mag(diff.inv_mag());
+               supersample=supersample*mag;
+               diff*=mag*mag;
+               dist=((point_-offset)*diff-p1*diff);
+       }
 
        if(loop)
                dist-=floor(dist);
@@ -386,7 +418,7 @@ CurveGradient::color_func(const Point &point_, int quality, float supersample)co
 }
 
 float
-CurveGradient::calc_supersample(const synfig::Point &x, float pw,float ph)const
+CurveGradient::calc_supersample(const synfig::Point &/*x*/, float pw,float /*ph*/)const
 {
        return pw;
 }