Fix buffer bugs

lionterest · Aug 13, 2021 · 44936d3 · 44936d3
1 parent 8d15638
commit 44936d3
Show file tree

Hide file tree

Showing 3 changed files with 20 additions and 7 deletions.
diff --git a/algorithm/buffer/buffer.go b/algorithm/buffer/buffer.go
@@ -1,3 +1,4 @@
+// Package buffer define geomtry matrix conversion.
 package buffer
 
 import (
@@ -107,6 +108,7 @@ func (eb *ComputerBuffer) isLineOffsetEmpty(distance float64) bool {
 }
 func (eb *ComputerBuffer) addPolygon(p matrix.PolygonMatrix) {
  offsetDistance := eb.distance
+
  offsetSide := calc.SideLeft
  if eb.distance < 0.0 {
  offsetDistance = -eb.distance
@@ -162,8 +164,7 @@ func (eb *ComputerBuffer) AddRingBothSides(ring matrix.LineMatrix, distance floa
 // addRingSide Adds an offset curve for one side of a ring.
 // The side and left and right topological location arguments
 // are provided as if the ring is oriented CW.
-// (If the ring is in the opposite orientation,
-// this is detected and
+// (If the ring is in the opposite orientation,this is detected and
 // the left and right locations are interchanged and the side is flipped.)
 func (eb *ComputerBuffer) addRingSide(ring matrix.LineMatrix, offsetDistance float64, side, cwLeftLoc, cwRightLoc int) {
  // don't bother adding ring if it is "flat" and will disappear in the output
@@ -173,17 +174,17 @@ func (eb *ComputerBuffer) addRingSide(ring matrix.LineMatrix, offsetDistance flo
 
  leftLoc := cwLeftLoc
  rightLoc := cwRightLoc
+
+ // add test ccw
  isCCW := measure.IsCCW(matrix.LineMatrix(ring))
- if len(ring) >= calc.MinRingSize && isCCW {
+ if len(ring) >= calc.MinRingSize && !isCCW {
  leftLoc = cwRightLoc
  rightLoc = cwLeftLoc
  if side == calc.SideLeft {
  side = calc.SideRight
- }
- if side == calc.SideRight {
+ } else if side == calc.SideRight {
  side = calc.SideLeft
  }
-
  }
  eb.RingCurve(matrix.LineMatrix(ring), offsetDistance, side, leftLoc, rightLoc)
 

diff --git a/algorithm/buffer/buffer_test.go b/algorithm/buffer/buffer_test.go
@@ -82,10 +82,21 @@ func TestBuffer(t *testing.T) {
  {122.99325784324384, 41.118723147333654}},
  },
  },
+ {name: "poly buffer", args: args{
+ geom: matrix.PolygonMatrix{{{100, 100}, {200, 100}, {200, 200}, {100, 200}, {100, 100}}},
+ distance: 50,
+ quadsegs: 4,
+ }, want: matrix.PolygonMatrix{
+ {{50, 100}, {53.80602337443563, 80.86582838174559}, {64.64466094067251, 64.64466094067274}, {80.86582838174527, 53.80602337443576}, {100, 50}, {200, 50},
+ {219.1341716182545, 53.80602337443566}, {235.35533905932738, 64.64466094067262}, {246.19397662556435, 80.86582838174552}, {250, 100}, {250, 200},
+ {246.19397662556435, 219.1341716182545}, {235.35533905932738, 235.35533905932738}, {219.1341716182545, 246.19397662556435}, {200, 250}, {100, 250},
+ {80.86582838174552, 246.19397662556435}, {64.64466094067262, 235.35533905932738}, {53.80602337443566, 219.1341716182545}, {50, 200}, {50, 100}},
+ },
+ },
  }
  for _, tt := range tests {
  t.Run(tt.name, func(t *testing.T) {
- if got := Buffer(tt.args.geom, tt.args.distance, tt.args.quadsegs); !got.EqualsExact(tt.want, 0.000001) {
+ if got := Buffer(tt.args.geom, tt.args.distance, tt.args.quadsegs); got == nil || !got.EqualsExact(tt.want, 0.000001) {
  t.Errorf("Buffer() = %v,\n want %v", got, tt.want)
  }
  })

diff --git a/algorithm/buffer/simplify/douglas_peucker_line_simplifier.go b/algorithm/buffer/simplify/douglas_peucker_line_simplifier.go
@@ -1,3 +1,4 @@
+// Package simplify define Douglas Peucker and Topology Preserving simplify.
 package simplify
 
 import (