From 3dd586b5beb52858f117bf932757435d8b121a09 Mon Sep 17 00:00:00 2001
From: Yorik van Havre <yorik@uncreated.net>
Date: Tue, 13 Sep 2016 20:11:03 -0300
Subject: [PATCH] Draft: small optimizations of Draft's SVG output and fixed
 wrong dash scale

---
 src/Mod/Draft/Draft.py | 41 +++++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/src/Mod/Draft/Draft.py b/src/Mod/Draft/Draft.py
index 51cccd7f6..4370a90d2 100644
--- a/src/Mod/Draft/Draft.py
+++ b/src/Mod/Draft/Draft.py
@@ -1719,6 +1719,7 @@ def getSVG(obj,scale=1,linewidth=0.35,fontsize=12,fillstyle="shape color",direct
     any text). You can also supply an arbitrary projection vector. the
     scale parameter allows to scale linewidths down, so they are resolution-independant.'''
     import Part, DraftGeomUtils
+    pathdata = []
     svg = ""
     linewidth = float(linewidth)/scale
     fontsize = (float(fontsize)/scale)/2
@@ -1726,6 +1727,7 @@ def getSVG(obj,scale=1,linewidth=0.35,fontsize=12,fillstyle="shape color",direct
         linespacing = float(linespacing)/scale
     else:
         linespacing = 0.5
+    #print obj.Label," line spacing ",linespacing,"scale ",scale
     pointratio = .75 # the number of times the dots are smaller than the arrow size
     plane = None
     if direction:
@@ -1745,12 +1747,19 @@ def getSVG(obj,scale=1,linewidth=0.35,fontsize=12,fillstyle="shape color",direct
     def getLineStyle():
         "returns a linestyle"
         p = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Mod/Draft")
+        l = None
         if linestyle == "Dashed":
-            return p.GetString("svgDashedLine","0.09,0.05")
+            l = p.GetString("svgDashedLine","0.09,0.05")
         elif linestyle == "Dashdot":
-            return p.GetString("svgDashdotLine","0.09,0.05,0.02,0.05")
+            l = p.GetString("svgDashdotLine","0.09,0.05,0.02,0.05")
         elif linestyle == "Dotted":
-            return p.GetString("svgDottedLine","0.02,0.02")
+            l = p.GetString("svgDottedLine","0.02,0.02")
+        if l:
+            l = l.split(",")
+            # scale dashes
+            l = ",".join([str(float(d)/scale) for d in l])
+            #print "lstyle ",l
+            return l
         return "none"
 
     def getProj(vec):
@@ -1785,6 +1794,7 @@ def getSVG(obj,scale=1,linewidth=0.35,fontsize=12,fillstyle="shape color",direct
                 w1.fixWire()
                 egroups.append(Part.__sortEdges__(w1.Edges))
         for egroupindex, edges in enumerate(egroups):
+            edata = ""
             vs=() #skipped for the first edge
             for edgeindex,e in enumerate(edges):
                 previousvs = vs
@@ -1795,7 +1805,7 @@ def getSVG(obj,scale=1,linewidth=0.35,fontsize=12,fillstyle="shape color",direct
                         vs.reverse()
                 if edgeindex == 0:
                     v = getProj(vs[0].Point)
-                    svg += 'M '+ str(v.x) +' '+ str(v.y) + ' '
+                    edata += 'M '+ str(v.x) +' '+ str(v.y) + ' '
                 else:
                     if (vs[0].Point-previousvs[-1].Point).Length > 1e-6:
                         raise ValueError('edges not ordered')
@@ -1841,13 +1851,13 @@ def getSVG(obj,scale=1,linewidth=0.35,fontsize=12,fillstyle="shape color",direct
                              == (e.LastParameter > e.FirstParameter)
                     #        == (e.Orientation == "Forward")
                     for v in endpoints:
-                        svg += 'A %s %s %s %s %s %s %s ' % \
+                        edata += 'A %s %s %s %s %s %s %s ' % \
                                 (str(rx),str(ry),str(rot),\
                                 str(int(flag_large_arc)),\
                                 str(int(flag_sweep)),str(v.x),str(v.y))
                 elif DraftGeomUtils.geomType(e) == "Line":
                     v = getProj(vs[-1].Point)
-                    svg += 'L '+ str(v.x) +' '+ str(v.y) + ' '
+                    edata += 'L '+ str(v.x) +' '+ str(v.y) + ' '
                 else:
                     bspline=e.Curve.toBSpline(e.FirstParameter,e.LastParameter)
                     if bspline.Degree > 3 or bspline.isRational():
@@ -1860,21 +1870,28 @@ def getSVG(obj,scale=1,linewidth=0.35,fontsize=12,fillstyle="shape color",direct
                             if bezierseg.Degree>3: #should not happen
                                 raise AssertionError
                             elif bezierseg.Degree==1:
-                                svg +='L '
+                                edata +='L '
                             elif bezierseg.Degree==2:
-                                svg +='Q '
+                                edata +='Q '
                             elif bezierseg.Degree==3:
-                                svg +='C '
+                                edata +='C '
                             for pole in bezierseg.getPoles()[1:]:
                                 v = getProj(pole)
-                                svg += str(v.x) +' '+ str(v.y) + ' '
+                                edata += str(v.x) +' '+ str(v.y) + ' '
                     else:
                         print("Debug: one edge (hash ",e.hashCode(),\
                                 ") has been discretized with parameter 0.1")
                         for linepoint in bspline.discretize(0.1)[1:]:
                             v = getProj(linepoint)
-                            svg += 'L '+ str(v.x) +' '+ str(v.y) + ' '
-            if fill != 'none': svg += 'Z '
+                            edata += 'L '+ str(v.x) +' '+ str(v.y) + ' '
+            if fill != 'none': 
+                edata += 'Z '
+            if edata in pathdata:
+                # do not draw a path on another identical path
+                return ""
+            else:
+                svg += edata
+                pathdata.append(edata)
         svg += '" '
         svg += 'stroke="' + stroke + '" '
         svg += 'stroke-width="' + str(linewidth) + ' px" '