context line dashes

src/pixie/context.nim

@@ -17,6 +17,7 @@ type
     font*: Font
     textAlign*: HAlignMode
     path: Path
+    lineDash: seq[float32]
     mat: Mat3
     mask: Mask
     layer: Image
@@ -30,6 +31,7 @@ type
     lineJoin: LineJoin
     font: Font
     textAlign: HAlignMode
+    lineDash: seq[float32]
     mat: Mat3
     mask: Mask
     layer: Image
@@ -60,6 +62,7 @@ proc state(ctx: Context): ContextState =
   result.lineJoin = ctx.lineJoin
   result.font = ctx.font
   result.textAlign = ctx.textAlign
+  result.lineDash = ctx.lineDash
   result.mat = ctx.mat
   result.mask = if ctx.mask != nil: ctx.mask.copy() else: nil
 
@@ -94,6 +97,7 @@ proc restore*(ctx: Context) =
   ctx.lineJoin = state.lineJoin
   ctx.font = state.font
   ctx.textAlign = state.textAlign
+  ctx.lineDash = state.lineDash
   ctx.mat = state.mat
   ctx.mask = state.mask
   ctx.layer = state.layer
@@ -124,7 +128,8 @@ proc stroke(ctx: Context, image: Image, path: Path) {.inline.} =
     ctx.lineWidth,
     ctx.lineCap,
     ctx.lineJoin,
-    ctx.miterLimit
+    ctx.miterLimit,
+    ctx.lineDash
   )
 
 proc fillText(ctx: Context, image: Image, text: string, at: Vec2) {.inline.} =
@@ -162,7 +167,8 @@ proc strokeText(ctx: Context, image: Image, text: string, at: Vec2) {.inline.} =
     hAlign = ctx.textAlign,
     lineCap = ctx.lineCap,
     lineJoin = ctx.lineJoin,
-    miterLimit = ctx.miterLimit
+    miterLimit = ctx.miterLimit,
+    dashes = ctx.lineDash
   )
 
 proc beginPath*(ctx: Context) {.inline.} =
@@ -375,6 +381,12 @@ proc measureText*(ctx: Context, text: string): TextMetrics =
   let bounds = typeset(ctx.font, text).computeBounds()
   result.width = bounds.x
 
+proc getLineDash*(ctx: Context): seq[float32] {.inline.} =
+  ctx.lineDash
+
+proc setLineDash*(ctx: Context, lineDash: seq[float32]) {.inline.} =
+  ctx.lineDash = lineDash
+
 proc getTransform*(ctx: Context): Mat3 {.inline.} =
   ## Retrieves the current transform matrix being applied to the context.
   ctx.mat

src/pixie/fonts.nim

@@ -443,7 +443,8 @@ proc strokeText*(
   strokeWidth = 1.0,
   lineCap = lcButt,
   lineJoin = ljMiter,
-  miterLimit = defaultMiterLimit
+  miterLimit = defaultMiterLimit,
+  dashes: seq[float32] = @[]
 ) =
   ## Strokes the text arrangement.
   for spanIndex, (start, stop) in arrangement.spans:
@@ -456,10 +457,25 @@ proc strokeText*(
       )
       when type(target) is Image:
         target.strokePath(
-          path, font.paint, transform, strokeWidth, lineCap, lineJoin
+          path,
+          font.paint,
+          transform,
+          strokeWidth,
+          lineCap,
+          lineJoin,
+          miterLimit,
+          dashes
         )
       else: # target is Mask
-        target.strokePath(path, transform, strokeWidth, lineCap, lineJoin)
+        target.strokePath(
+          path,
+          transform,
+          strokeWidth,
+          lineCap,
+          lineJoin,
+          miterLimit,
+          dashes
+        )
 
 proc strokeText*(
   target: Image | Mask,
@@ -472,7 +488,8 @@ proc strokeText*(
   vAlign = vaTop,
   lineCap = lcButt,
   lineJoin = ljMiter,
-  miterLimit = defaultMiterLimit
+  miterLimit = defaultMiterLimit,
+  dashes: seq[float32] = @[]
 ) {.inline.} =
   ## Typesets and strokes the text. Optional parameters:
   ## transform: translation or matrix to apply
@@ -487,5 +504,7 @@ proc strokeText*(
     transform,
     strokeWidth,
     lineCap,
-    lineJoin
+    lineJoin,
+    miterLimit,
+    dashes
   )

src/pixie/paths.nim

@@ -1432,7 +1432,7 @@ proc strokeShapes(
       if dashes.len > 0:
         var dashes = dashes
         if dashes.len mod 2 != 0:
-          dashes.add(dashes[^1])
+          dashes.add(dashes)
         var distance = dist(prevPos, pos)
         let dir = dir(pos, prevPos)
         var currPos = prevPos
@@ -1549,7 +1549,7 @@ proc strokePath*(
   lineCap = lcButt,
   lineJoin = ljMiter,
   miterLimit = defaultMiterLimit,
-  dashes: seq[float32] = @[],
+  dashes: seq[float32] = @[]
 ) =
   ## Strokes a path.
   var strokeShapes = strokeShapes(

tests/test_context.nim

@@ -490,3 +490,28 @@ block:
 
   let metrics = ctx.measureText("Hello world")
   doAssert metrics.width == 61
+
+block:
+  let
+    image = newImage(300, 150)
+    ctx = newContext(image)
+
+  var y = 15.float32
+
+  proc drawDashedLine(pattern: seq[float32]) =
+    ctx.beginPath();
+    ctx.setLineDash(pattern);
+    ctx.moveTo(0, y);
+    ctx.lineTo(300, y);
+    ctx.stroke();
+    y += 20;
+
+  drawDashedLine(@[]);
+  drawDashedLine(@[1.float32, 1]);
+  drawDashedLine(@[10.float32, 10]);
+  drawDashedLine(@[20.float32, 5]);
+  drawDashedLine(@[15.float32, 3, 3, 3]);
+  drawDashedLine(@[20.float32, 3, 3, 3, 3, 3, 3, 3]);
+  drawDashedLine(@[12.float32, 3, 3]);
+
+  image.writeFile("tests/images/context/setLineDash_1.png")