line dash bugfix, implemented getLineDash, added a test

README.md

@@ -107,7 +107,9 @@ These features *should* work just like their HTML5 counterparts, but there are l
 - lineWidth
 - lineEnd (square, butt, round)
 - lineJoin (bevel, miter, round)
+- miterLimit
 - lineDash
+- getLineDash
 - global alpha
 - drawImage
 - getImageData
@@ -115,7 +117,6 @@ These features *should* work just like their HTML5 counterparts, but there are l
 - clearRect
 - shadowColor
 - shadowOffset(X/Y)
-- miterLimit
 - shadowBlur
 
 # Missing features
@@ -123,7 +124,6 @@ These features *should* work just like their HTML5 counterparts, but there are l
 - globalCompositeOperation
 - lineDashOffset
 - textBaseline
-- getLineDash
 - isPointInPath
 - isPointInStroke
 - strokeText

canvas.go

@@ -682,6 +682,13 @@ func (cv *Canvas) SetLineDash(dash []float64) {
 	cv.state.lineDashOffset = 0
 }
 
+// GetLineDash gets the line dash style
+func (cv *Canvas) GetLineDash() []float64 {
+	result := make([]float64, len(cv.state.lineDash))
+	copy(result, cv.state.lineDash)
+	return result
+}
+
 // SetMiterLimit sets the limit for how far a miter line join can be extend.
 // The fallback is a bevel join
 func (cv *Canvas) SetMiterLimit(limit float64) {

canvas_test.go

@@ -206,3 +206,31 @@ func TestMiterLimit(t *testing.T) {
 		cv.Stroke()
 	})
 }
+
+func TestLineDash(t *testing.T) {
+	run(t, func(cv *canvas.Canvas) {
+		cv.SetStrokeStyle("#0F0")
+		cv.SetLineWidth(2.5)
+		cv.SetLineDash([]float64{4, 6, 8})
+		cv.BeginPath()
+		cv.MoveTo(20, 20)
+		cv.LineTo(80, 20)
+		cv.LineTo(80, 80)
+		cv.LineTo(50, 80)
+		cv.LineTo(50, 50)
+		cv.LineTo(20, 50)
+		cv.ClosePath()
+		cv.MoveTo(30, 30)
+		cv.LineTo(70, 30)
+		cv.LineTo(70, 70)
+		cv.LineTo(60, 70)
+		cv.LineTo(60, 40)
+		cv.LineTo(30, 40)
+		cv.ClosePath()
+		cv.Stroke()
+		ld := cv.GetLineDash()
+		if ld[0] != 4 || ld[1] != 6 || ld[2] != 8 || ld[3] != 4 || ld[4] != 6 || ld[5] != 8 {
+			t.Fail()
+		}
+	})
+}

paths.go

@@ -19,6 +19,7 @@ const (
 	pathAttach
 	pathIsRect
 	pathIsConvex
+	pathExplicitMove
 )
 
 // BeginPath clears the current path and starts a new one
@@ -43,8 +44,8 @@ func (cv *Canvas) MoveTo(x, y float64) {
 	if len(cv.linePath) > 0 && isSamePoint(cv.linePath[len(cv.linePath)-1].tf, tf, 0.1) {
 		return
 	}
-	cv.linePath = append(cv.linePath, pathPoint{pos: vec{x, y}, tf: tf, flags: pathMove})
-	cv.polyPath = append(cv.polyPath, pathPoint{pos: vec{x, y}, tf: tf, flags: pathMove})
+	cv.linePath = append(cv.linePath, pathPoint{pos: vec{x, y}, tf: tf, flags: pathMove | pathExplicitMove})
+	cv.polyPath = append(cv.polyPath, pathPoint{pos: vec{x, y}, tf: tf, flags: pathMove | pathExplicitMove})
 }
 
 // LineTo adds a line to the end of the path
@@ -273,17 +274,24 @@ func (cv *Canvas) ClosePath() {
 	if isSamePoint(cv.linePath[len(cv.linePath)-1].tf, cv.linePath[0].tf, 0.1) {
 		return
 	}
-	closeIdx := 0
+	lineCloseIdx := 0
 	for i := len(cv.linePath) - 1; i >= 0; i-- {
-		if cv.linePath[i].flags&pathMove != 0 {
-			closeIdx = i
+		if cv.linePath[i].flags&pathExplicitMove != 0 {
+			lineCloseIdx = i
 			break
 		}
 	}
-	cv.LineTo(cv.linePath[closeIdx].pos[0], cv.linePath[closeIdx].pos[1])
-	cv.linePath[len(cv.linePath)-1].next = cv.linePath[closeIdx].next
+	polyCloseIdx := 0
+	for i := len(cv.polyPath) - 1; i >= 0; i-- {
+		if cv.polyPath[i].flags&pathExplicitMove != 0 {
+			polyCloseIdx = i
+			break
+		}
+	}
+	cv.LineTo(cv.linePath[lineCloseIdx].pos[0], cv.linePath[lineCloseIdx].pos[1])
+	cv.linePath[len(cv.linePath)-1].next = cv.linePath[lineCloseIdx].next
 	cv.linePath[len(cv.linePath)-1].flags |= pathAttach
-	cv.polyPath[len(cv.polyPath)-1].next = cv.polyPath[closeIdx].next
+	cv.polyPath[len(cv.polyPath)-1].next = cv.polyPath[polyCloseIdx].next
 }
 
 // Stroke uses the current StrokeStyle to draw the path