Issue-16 Fix 90 degree bug in find findPoint

Actually very similar to issue-11, but I just didn't solve it 100%

README.md

@@ -10,7 +10,11 @@ The truth is radii, internal radii in particular can be a real pain to add in op
 
 ## Documentation
 
-[Here is an overview of the library's features](https://kurthutten.com/blog/round-anything-a-pragmatic-approach-to-openscad-design/).
+See an overview of the library in [video form](https://www.youtube.com/watch?v=laxv2wFKq8Q)
+<a href="https://www.youtube.com/watch?v=laxv2wFKq8Q"><img src="https://i.ytimg.com/vi/laxv2wFKq8Q/sddefault.jpg" width="100%" align="left"></a>
+
+
+[Written overview](https://kurthutten.com/blog/round-anything-a-pragmatic-approach-to-openscad-design/).
 
 [Full documentation of the API is here](https://kurthutten.com/blog/round-anything-api/).
 

polyround.scad

@@ -29,6 +29,11 @@ let(
   points[listWrap(i+1,lp)],
 ],thick=offset,mode=isCWorCCW)];
 
+function reverseList(list) = [ for(i=[len(list) - 1:-1:0]) list[i] ];
+
+// Apply `reverseList` to the array of vertex indices for an array of faces
+function invertFaces(faces) = [ for(f=faces) reverseList(f) ];
+
 function makeCurvedPartOfPolyHedron(radiiPoints,r,fn,minR=0.01)=
 // this is a private function that I'm not expecting library users to use directly
 // radiiPoints= serise of x, y, r points
@@ -129,7 +134,7 @@ function extrudePolygonWithRadius(radiiPoints,h=5,r1=1,r2=1,fn=4)=
 let(
   // top is the top curved part of the extrude
   top=makeCurvedPartOfPolyHedron(radiiPoints,r1,fn),
-  topRadiusPoints=translate3Dcoords(top[0],[0,0,h-r1]),
+  topRadiusPoints=translate3Dcoords(top[0],[0,0,h-abs(r1)]),
   singeLayerLength=top[2],
   topRadiusFaces=top[1],
   radiusPointsLength=len(topRadiusPoints), // is the same length as bottomRadiusPoints
@@ -152,7 +157,7 @@ let(
   topCapFace=[for(i=[0:singeLayerLength-1])radiusPointsLength-singeLayerLength+i],
   bottomCapFace=[for(i=[0:singeLayerLength-1])radiusPointsLength*2-singeLayerLength+i],
   finalPolyhedronPoints=concat(topRadiusPoints,bottomRadiusPoints),
-  finalPolyhedronFaces=concat(topRadiusFaces,bottomRadiusFaces, sideFaces, [topCapFace], [bottomCapFace])
+  finalPolyhedronFaces=concat(topRadiusFaces,invertFaces(bottomRadiusFaces),invertFaces(sideFaces),[topCapFace],invertFaces([bottomCapFace]))
 )
 [
   finalPolyhedronPoints,
@@ -160,7 +165,11 @@ let(
 ];
 
 module polyRoundExtrude(radiiPoints,length=5,r1=1,r2=1,fn=10,convexity=10) {
-  polyhedronPointsNFaces=extrudePolygonWithRadius(radiiPoints,length,r1,r2,fn);
+  orderedRadiiPoints = CWorCCW(radiiPoints) == 1
+    ? reverseList(radiiPoints)
+    : radiiPoints;
+
+  polyhedronPointsNFaces=extrudePolygonWithRadius(orderedRadiiPoints,length,r1,r2,fn);
   polyhedron(points=polyhedronPointsNFaces[0], faces=polyhedronPointsNFaces[1], convexity=convexity);
 }
 
@@ -327,14 +336,22 @@ function parallelFollow(rp,thick=4,minR=1,mode=1)=
   )
 	concat(cen,outR);
 
+function is90or270(ang)=ang==90?1:ang==270?1:0;
+
 function findPoint(ang1,refpoint1,ang2,refpoint2,r=0)=
+// finds the intersection of two lines given two angles and points on those lines
   let(
+    overrideX=is90or270(ang1)?
+      refpoint1.x:
+      is90or270(ang2)?
+      refpoint2.x:
+      0,
     m1=tan(ang1),
     c1=refpoint1.y-m1*refpoint1.x,
 	  m2=tan(ang2),
     c2=refpoint2.y-m2*refpoint2.x,
-    outputX=(c2-c1)/(m1-m2),
-    outputY=m1*outputX+c1
+    outputX=overrideX?overrideX:(c2-c1)/(m1-m2),
+    outputY=is90or270(ang1)?m2*outputX+c2:m1*outputX+c1
   )
 	[outputX,outputY,r];
 
@@ -374,13 +391,23 @@ function beamChain(radiiPoints,offset1=0,offset2,mode=0,minR=0,startAngle,endAng
             getAngle(radiiPoints[Lrp-1],radiiPoints[Lrp-2])+endAngle:
             endAngle,
     OffLn1=[for(i=[0:Lrp3]) offset1==0?radiiPoints[i+1]:parallelFollow([radiiPoints[i],radiiPoints[i+1],radiiPoints[i+2]],offset1,minR,mode=CWorCCW1)],
-    OffLn2=[for(i=[0:Lrp3]) offset2==0?radiiPoints[i+1]:parallelFollow([radiiPoints[i],radiiPoints[i+1],radiiPoints[i+2]],offset2b,minR,mode=CWorCCW2)],  
+    OffLn2=[for(i=[0:Lrp3]) offset2==0?radiiPoints[i+1]:parallelFollow([radiiPoints[i],radiiPoints[i+1],radiiPoints[i+2]],offset2b,minR,mode=CWorCCW2)],
+
     Rp1=abs(radiiPoints[0].z),
     Rp2=abs(radiiPoints[Lrp-1].z),
-    endP1a=findPoint(getAngle(radiiPoints[0],radiiPoints[1]),         OffLn1[0],              startAngle,radiiPoints[0],     Rp1),
-    endP1b=findPoint(getAngle(radiiPoints[Lrp-1],radiiPoints[Lrp-2]), OffLn1[len(OffLn1)-1],  endAngle,radiiPoints[Lrp-1], Rp2),
-    endP2a=findPoint(getAngle(radiiPoints[0],radiiPoints[1]),         OffLn2[0],              startAngle,radiiPoints[0],     Rp1),
-    endP2b=findPoint(getAngle(radiiPoints[Lrp-1],radiiPoints[Lrp-2]), OffLn2[len(OffLn1)-1],  endAngle,radiiPoints[Lrp-1], Rp2),
+    
+    endP1aAngle = getAngle(radiiPoints[0],radiiPoints[1]),
+    endP1a=findPoint(endP1aAngle,         OffLn1[0],              startAngle,radiiPoints[0],     Rp1),
+
+    endP1bAngle = getAngle(radiiPoints[Lrp-1],radiiPoints[Lrp-2]),
+    endP1b=findPoint(endP1bAngle, OffLn1[len(OffLn1)-1],  endAngle,radiiPoints[Lrp-1], Rp2),
+
+    endP2aAngle = getAngle(radiiPoints[0],radiiPoints[1]),
+    endP2a=findPoint(endP2aAngle,         OffLn2[0],              startAngle,radiiPoints[0],     Rp1),
+
+    endP2bAngle = getAngle(radiiPoints[Lrp-1],radiiPoints[Lrp-2]),
+    endP2b=findPoint(endP2bAngle, OffLn2[len(OffLn1)-1],  endAngle,radiiPoints[Lrp-1], Rp2),
+
     absEnda=getAngle(endP1a,endP2a),
     absEndb=getAngle(endP1b,endP2b),
     negRP1a=[cos(absEnda)*radiiPoints[0].z*10+endP1a.x,        sin(absEnda)*radiiPoints[0].z*10+endP1a.y,       0.0],
@@ -432,22 +459,23 @@ function CentreN2PointsArc(p1,p2,cen,mode=0,fn)=
   mode==3, plotted counter clockwise
   */
 	let(
-    CWorCCW=CWorCCW([cen,p1,p2]),//determine the direction of rotation
+    isCWorCCW=CWorCCW([cen,p1,p2]),//determine the direction of rotation
     //determine the arc angle depending on the mode
     p1p2Angle=cosineRuleAngle(p2,cen,p1),
     arcAngle=
       mode==0?p1p2Angle:
       mode==1?p1p2Angle-360:
-      mode==2&&CWorCCW==-1?p1p2Angle:
-      mode==2&&CWorCCW== 1?p1p2Angle-360:
-      mode==3&&CWorCCW== 1?p1p2Angle:
-      mode==3&&CWorCCW==-1?p1p2Angle-360:
-      cosineRuleAngle(p2,cen,p1)
-    ,
+      mode==2&&isCWorCCW==-1?p1p2Angle:
+      mode==2&&isCWorCCW== 1?p1p2Angle-360:
+      mode==3&&isCWorCCW== 1?p1p2Angle:
+      mode==3&&isCWorCCW==-1?p1p2Angle-360:
+      cosineRuleAngle(p2,cen,p1),
     r=pointDist(p1,cen),//determine the radius
 	  p1Angle=getAngle(cen,p1) //angle of line 1
   )
-  [for(i=[0:fn]) [cos(p1Angle+(arcAngle/fn)*i*CWorCCW)*r+cen[0],sin(p1Angle+(arcAngle/fn)*i*CWorCCW)*r+cen[1]]];
+  [for(i=[0:fn])
+  let(angleIncrement=(arcAngle/fn)*i*isCWorCCW)
+  [cos(p1Angle+angleIncrement)*r+cen.x,sin(p1Angle+angleIncrement)*r+cen.y]];
 
 function translateRadiiPoints(radiiPoints,tran=[0,0],rot=0)=
 	[for(i=radiiPoints) 
@@ -539,7 +567,7 @@ function mirrorPoints(radiiPoints,rot=0,endAttenuation=[0,0])= //mirrors a list
   concat(radiiPoints,temp2);
 
 function processRadiiPoints(rp)=
-  [for(i=[0:len(rp)-1]) 
+  [for(i=[0:len(rp)-1])
     processRadiiPoints2(rp,i)
   ];
 
@@ -663,9 +691,9 @@ function getAngle(p1,p2)=p1==p2?0:invtan(p2[0]-p1[0],p2[1]-p1[1]);
 function getMidpoint(p1,p2)=[(p1[0]+p2[0])/2,(p1[1]+p2[1])/2]; //returns the midpoint of two points
 function pointDist(p1,p2)=sqrt(abs(sq(p1[0]-p2[0])+sq(p1[1]-p2[1]))); //returns the distance between two points
 function isColinear(p1,p2,p3)=getGradient(p1,p2)==getGradient(p2,p3)?1:0;//return 1 if 3 points are colinear
-module polyline(p) {
+module polyline(p, width=0.3) {
   for(i=[0:max(0,len(p)-1)]){
-    line(p[i],p[listWrap(i+1,len(p) )]);
+    color([i*1/len(p),1-i*1/len(p),0,0.5])line(p[i],p[listWrap(i+1,len(p) )],width);
   }
 } // polyline plotter
 module line(p1, p2 ,width=0.3) { // single line plotter

roundAnythingExamples.scad

@@ -1,6 +1,7 @@
 include <polyround.scad>
 
 basicPolyRoundExample();
+// polyLineExample();
 // parametricPolyRoundExample();
 // experimentalParametricPolyRoundExample();
 // conflicResolutionExample();
@@ -9,15 +10,27 @@ basicPolyRoundExample();
 // beamChainExample();
 // mirrorPointsExample();
 // radiusExtrudeExample();
-// radiusExtrudePolygon();
 // polyRoundExtrudeExample();
 
+
+// testing 
+// testGeometries();
+
 module basicPolyRoundExample(){
+  // polyLine is a dev helper. Aim is to show the points of the polygon and their order before
+  // you're ready to move on to polyRound and a polygon
   radiiPoints=[[-4,0,1],[5,3,1.5],[0,7,0.1],[8,7,10],[20,20,0.8],[10,0,10]];
   polygon(polyRound(radiiPoints,30));
   %translate([0,0,0.3])polygon(getpoints(radiiPoints));//transparent copy of the polgon without rounding
 }
 
+module polyLineExample() {
+  radiiPoints=[[-4,0,1],[5,3,1.5],[0,7,0.1],[8,7,10],[20,20,0.8],[10,0,10]];
+  polyline(polyRound(radiiPoints,3), 0.05);
+  translate([0,10,0])
+  polyline(radiiPoints, 0.05);
+}
+
 module parametricPolyRoundExample() {
   //Example of how a parametric part might be designed with this tool 
   width=20;       height=25;
@@ -67,7 +80,7 @@ module experimentalParametricPolyRoundExample() {
 
 module conflicResolutionExample(){
   //example of radii conflict handling and debuging feature
-  function makeRadiiPoints(r1, r2)=[[0,0,0],[0,20,r1],[20,20,r1],[20,0,0]];
+  function makeRadiiPoints(r1, r2)=[[0,0,0],[0,20,r1],[20,20,r2],[20,0,0]];
 
   // the squre shape being 20 wide, two radii of 10 both fit into the shape (just)
   translate([-25,0,0])polygon(polyRound(makeRadiiPoints(10,10),50));
@@ -79,7 +92,7 @@ module conflicResolutionExample(){
   translate([25,0,0])polygon(polyRound(makeRadiiPoints(10,40),50));
 
   //mode 2 = no radii limiting
-  translate([50,0,0])polygon(polyRound(makeRadiiPoints(15,20),50,mode=2));
+  translate([50,0,0])polygon(polyRound(makeRadiiPoints(12,20),50,mode=2));
 }
 
 module translateRadiiPointsExample() {
@@ -113,8 +126,8 @@ module translateRadiiPointsExample() {
 
 module 2dShellExample(){
   radiiPoints=[[-4,0,1],[5,3,1.5],[0,7,0.1],[8,7,10],[20,20,0.8],[10,0,10]];
-  shell2d(-0.5)polygon(polyRound(radiiPoints,30));
-  translate([0,-10,0])shell2d(-0.5){
+  linear_extrude(1)shell2d(-0.5)polygon(polyRound(radiiPoints,30));
+  translate([0,-10,0])linear_extrude(1)shell2d(-0.5){
     polygon(polyRound(radiiPoints,30));
     translate([8,8])gridpattern(memberW = 0.3, sqW = 1, iter = 17, r = 0.2);
   }
@@ -124,43 +137,43 @@ module beamChainExample(){
   function beamPoints(r1,r2,rStart=0,rEnd=0)=[[0,0,rStart],[2,8,0],[5,4,r1],[15,10,r2],[17,2,rEnd]];
 
   // chained lines by themselves
-  translate(){
+  translate([0,0,0]){
     radiiPoints=beamPoints(0,0);
-    for(i=[0: len(radiiPoints)]){color("red")translate([radiiPoints[i].x,radiiPoints[i].y,0])cylinder(d=0.2, h=1);}
-    polygon(polyRound(beamChain(radiiPoints,offset1=0.02, offset2=-0.02),20));
+    for(i=[0: len(radiiPoints)-1]){color("red")translate([radiiPoints[i].x,radiiPoints[i].y,0])cylinder(d=0.2, h=1);}
+    linear_extrude(1)polygon(polyRound(beamChain(radiiPoints,offset1=0.02, offset2=-0.02),20));
   }
   
 
   // Add some radii to the line transitions
   translate([0,-7,0]){
     radiiPoints=beamPoints(2,1);
-    for(i=[0: len(ex3)]){color("red")translate([radiiPoints[i].x,radiiPoints[i].y,0])cylinder(d=0.2, h=1);}
-    polygon(polyRound(beamChain(radiiPoints,offset1=0.02, offset2=-0.02),20));
+    for(i=[0: len(radiiPoints)-1]){color("red")translate([radiiPoints[i].x,radiiPoints[i].y,0])cylinder(d=0.2, h=1);}
+    linear_extrude(1)polygon(polyRound(beamChain(radiiPoints,offset1=0.02, offset2=-0.02),20));
   }
   
   // Give make the lines beams with some thickness
   translate([0,-7*2,0]){
     radiiPoints=beamPoints(2,1);
-    polygon(polyRound(beamChain(radiiPoints,offset1=0.5, offset2=-0.5),20));
+    linear_extrude(1)polygon(polyRound(beamChain(radiiPoints,offset1=0.5, offset2=-0.5),20));
   }
 
   // Add an angle to the start of the beam
   translate([0,-7*3,0]){
     radiiPoints=beamPoints(2,1);
-    polygon(polyRound(beamChain(radiiPoints,offset1=0.5, offset2=-0.5, startAngle=45),20));
+    linear_extrude(1)polygon(polyRound(beamChain(radiiPoints,offset1=0.5, offset2=-0.5, startAngle=45),20));
   }
 
   // Put a negative radius at the start for transationing to a flat surface
   translate([0,-7*4,0]){
     radiiPoints=beamPoints(2,1,rStart=-0.7);
-    polygon(polyRound(beamChain(radiiPoints,offset1=0.5, offset2=-0.5, startAngle=45),20));
+    linear_extrude(1)polygon(polyRound(beamChain(radiiPoints,offset1=0.5, offset2=-0.5, startAngle=45),20));
   }
 
   // Define more points for a polygon to be atteched to the end of the beam chain
   clipP=[[16,1.2,0],[16,0,0],[16.5,0,0],[16.5,1,0.2],[17.5,1,0.2],[17.5,0,0],[18,0,0],[18,1.2,0]];
   translate([-15,-7*5+3,0]){
     for(i=[0:len(clipP)-1]){color("red")translate([clipP[i].x,clipP[i].y,0])cylinder(d=0.2, h=1);}
-    polygon(polyRound(clipP,20));
+    linear_extrude(1)polygon(polyRound(clipP,20));
   }
 
   // Attached to the end of the beam chain by dividing the beam paths in forward and return and
@@ -170,7 +183,7 @@ module beamChainExample(){
     forwardPath=beamChain(radiiPoints,offset1=0.5,startAngle=-15,mode=2);
     returnPath=revList(beamChain(radiiPoints,offset1=-0.5,startAngle=-15,mode=2));
     entirePath=concat(forwardPath,clipP,returnPath);
-    polygon(polyRound(entirePath,20));
+    linear_extrude(1)polygon(polyRound(entirePath,20));
   }
 
   // Add transitioning radii into the end polygong
@@ -179,12 +192,13 @@ module beamChainExample(){
     forwardPath=beamChain(radiiPoints,offset1=0.5,startAngle=-15,mode=2);
     returnPath=revList(beamChain(radiiPoints,offset1=-0.5,startAngle=-15,mode=2));
     entirePath=concat(forwardPath,clipP,returnPath);
-    polygon(polyRound(entirePath,20));
+    linear_extrude(1)polygon(polyRound(entirePath,20));
   }
 
   // Define multiple shells from the the one set of points
   translate([0,-7*9,0]){
-    for(i=[0:2]){polygon(polyRound(beamChain(ex3,offset1=-1+i*0.4, offset2=-1+i*0.4+0.25),20));}
+    radiiPoints=beamPoints(2,1,rEnd=3);
+    for(i=[0:2]){linear_extrude(1)polygon(polyRound(beamChain(radiiPoints,offset1=-1+i*0.4, offset2=-1+i*0.4+0.25),20));}
   }
 }
 
@@ -215,3 +229,41 @@ module gridpattern(memberW = 4, sqW = 12, iter = 5, r = 3){
 		}
 	}
 }
+
+
+module testGeometries() {
+  // Check these shapes preview (plus "thrown together") and render correctly with each PR
+  points = [
+    [0, 10, 5],
+    [10, 0, 5],
+    [0, -10, 5],
+    [-10, 0, 5],
+  ];
+  reversedPoints = [
+    [-10, 0, 5],
+    [0, -10, 5],
+    [10, 0, 5],
+    [0, 10, 5],
+  ];
+  polyRoundExtrudeTestShape(points);
+  translate([0,20,0])polyRoundExtrudeTestShape(reversedPoints);
+
+  // Bug report submitted by @lopisan in issue #16, similar to #11, geometry breaks with 90 degree angles
+  didBreakWhen0=0;
+  issue16pointsa=[[0, 0, 0], [0+didBreakWhen0, 10, 0], [10, 10+didBreakWhen0, 0]];
+  translate([20,0,0])linear_extrude(1)polygon(polyRound( beamChain(issue16pointsa, offset1=1, offset2=-1), 30));
+  
+  didBreakWhen0b=1e-6;
+  issue16pointsb=[[0, 0, 0], [0+didBreakWhen0b, 10, 0], [10, 10+didBreakWhen0b, 0]];
+  translate([20,15,0])linear_extrude(1)polygon(polyRound( beamChain(issue16pointsb, offset1=1, offset2=-1), 30));
+
+}
+
+module polyRoundExtrudeTestShape(points) {
+  // make sure no faces are inverted
+  difference() {
+    translate([0, 0, -2.5]) polyRoundExtrude(points,r1=-1,r2=1);
+    sphere(d=9);
+    translate([0,0,7])sphere(d=9);
+  }
+}