From ecbf30e5712c35a65ff6932b9f22e23c7db5d3e4 Mon Sep 17 00:00:00 2001
From: acspike <acspike@users.sourceforge.net>
Date: Thu, 23 Nov 2006 01:50:31 +0000
Subject: [PATCH] PATCH: [ 1601240 ] cubicsuperpath.py: arc conversion

---
 share/extensions/cubicsuperpath.py | 101 ++++++++++++++++++++++++++---
 1 file changed, 93 insertions(+), 8 deletions(-)

diff --git a/share/extensions/cubicsuperpath.py b/share/extensions/cubicsuperpath.py
index 0f34ec841..cc59905ab 100755
--- a/share/extensions/cubicsuperpath.py
+++ b/share/extensions/cubicsuperpath.py
@@ -20,7 +20,81 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 """
 import simplepath 
+from math import *
 
+def matprod(mlist):
+    prod=mlist[0]
+    for m in mlist[1:]:
+        a00=prod[0][0]*m[0][0]+prod[0][1]*m[1][0]
+        a01=prod[0][0]*m[0][1]+prod[0][1]*m[1][1]
+        a10=prod[1][0]*m[0][0]+prod[1][1]*m[1][0]
+        a11=prod[1][0]*m[0][1]+prod[1][1]*m[1][1]
+        prod=[[a00,a01],[a10,a11]]
+    return prod
+def rotmat(teta):
+    return [[cos(teta),-sin(teta)],[sin(teta),cos(teta)]]
+def applymat(mat, pt):
+    x=mat[0][0]*pt[0]+mat[0][1]*pt[1]
+    y=mat[1][0]*pt[0]+mat[1][1]*pt[1]
+    pt[0]=x
+    pt[1]=y
+def norm(pt):
+    return sqrt(pt[0]*pt[0]+pt[1]*pt[1])
+
+def ArcToPath(p1,params):
+    A=p1[:]
+    rx,ry,teta,longflag,sweepflag,x2,y2=params[:]
+    B=[x2,y2]
+    if rx==0 or ry==0:
+        return([[A,A,A],[B,B,B]])
+    mat=matprod((rotmat(teta),[[1/rx,0],[0,1/ry]],rotmat(-teta)))
+    applymat(mat, A)
+    applymat(mat, B)
+    k=[-(B[1]-A[1]),B[0]-A[0]]
+    d=k[0]*k[0]+k[1]*k[1]
+    k[0]/=sqrt(d)
+    k[1]/=sqrt(d)
+    d=sqrt(max(0,1-d/4))
+    if longflag==sweepflag:
+        d*=-1
+    O=[(B[0]+A[0])/2+d*k[0],(B[1]+A[1])/2+d*k[1]]
+    OA=[A[0]-O[0],A[1]-O[1]]
+    OB=[B[0]-O[0],B[1]-O[1]]
+    start=acos(OA[0]/norm(OA))
+    if OA[1]<0:
+        start*=-1
+    end=acos(OB[0]/norm(OB))
+    if OB[1]<0:
+        end*=-1
+
+    if sweepflag and start>end:
+        end +=2*pi
+    if (not sweepflag) and start<end:
+        end -=2*pi
+
+    NbSectors=int(abs(start-end)*2/pi)+1
+    dTeta=(end-start)/NbSectors
+    #v=dTeta*2/pi*0.552
+    v=dTeta*2/pi*4*(sqrt(2)-1)/3
+    #if not sweepflag:
+    #	v*=-1
+    p=[]
+    for i in range(0,NbSectors+1,1):
+        angle=start+i*dTeta
+        v1=[O[0]+cos(angle)-(-v)*sin(angle),O[1]+sin(angle)+(-v)*cos(angle)]
+        pt=[O[0]+cos(angle)                ,O[1]+sin(angle)                ]
+        v2=[O[0]+cos(angle)-  v *sin(angle),O[1]+sin(angle)+  v *cos(angle)]
+        p.append([v1,pt,v2])
+    p[ 0][0]=p[ 0][1][:]
+    p[-1][2]=p[-1][1][:]
+
+    mat=matprod((rotmat(teta),[[rx,0],[0,ry]],rotmat(-teta)))
+    for pts in p:
+        applymat(mat, pts[0])
+        applymat(mat, pts[1])
+        applymat(mat, pts[2])
+    return(p)
+    
 def CubicSuperPath(simplepath):
     csp = []
     subpath = -1
@@ -46,15 +120,26 @@ def CubicSuperPath(simplepath):
             last = params[-2:]
             lastctrl = params[2:4]
         elif cmd == 'Q':
-            #TODO: convert to cubic
-            csp[subpath].append([lastctrl[:],last[:],last[:]])
-            last = params[-2:]
-            lastctrl = params[-2:]
+            q0=last[:]
+            q1=params[0:1]
+            q2=params[2:3]
+            x0=    q0[0]
+            x1=1/3*q0[0]+2/3*q1[0]
+            x2=          2/3*q1[0]+1/3*q2[0]
+            x3=                        q2[0]
+            y0=    q0[1]
+            y1=1/3*q0[1]+2/3*q1[1]
+            y2=          2/3*q1[1]+1/3*q2[1]
+            y3=                        q2[1]
+            csp[subpath].append([lastctrl[:][x0,y0][x1,y1]])
+            last = [x3,y3]
+            lastctrl = [x2,y2]
         elif cmd == 'A':
-            #TODO: convert to cubics
-            csp[subpath].append([lastctrl[:],last[:],last[:]])
-            last = params[-2:]
-            lastctrl = params[-2:]
+            arcp=ArcToPath(last[:],params[:])
+            arcp[ 0][0]=lastctrl[:]
+            last=arcp[-1][1]
+            lastctrl = arcp[-1][0]
+            csp[subpath]+=arcp[:-1]
         elif cmd == 'Z':
             csp[subpath].append([lastctrl[:],last[:],last[:]])
             last = subpathstart[:]
-- 
2.30.2