Merge pull request #254 from guzba/master

path as ref object

README.md

@@ -127,19 +127,20 @@ image.fillText(font.typeset(text, bounds = vec2(180, 180)), vec2(10, 10))
 ### Text spans
 [examples/text_spans.nim](examples/text_spans.nim)
 ```nim
-let font = readFont("tests/fonts/Ubuntu-Regular_1.ttf")
+let typeface = readTypeface("tests/fonts/Ubuntu-Regular_1.ttf")
 
-proc style(font: Font, size: float32, color: ColorRGBA): Font =
+proc newFont(typeface: Typeface, size: float32, color: ColorRGBA): Font =
-  result = font
+  result = newFont(typeface)
   result.size = size
   result.paint.color = color
 
 let spans = @[
-  newSpan("verb [with object] ", font.style(12, rgba(200, 200, 200, 255))),
+  newSpan("verb [with object] ",
-  newSpan("strallow\n", font.style(36, rgba(0, 0, 0, 255))),
+    typeface.newFont(12, rgba(200, 200, 200, 255))),
-  newSpan("\nstral·low\n", font.style(13, rgba(0, 127, 244, 255))),
+  newSpan("strallow\n", typeface.newFont(36, rgba(0, 0, 0, 255))),
+  newSpan("\nstral·low\n", typeface.newFont(13, rgba(0, 127, 244, 255))),
   newSpan("\n1. free (something) from restrictive restrictions \"the regulations are intended to strallow changes in public policy\" ",
-      font.style(14, rgba(80, 80, 80, 255)))
+      typeface.newFont(14, rgba(80, 80, 80, 255)))
 ]
 
 image.fillText(typeset(spans, bounds = vec2(180, 180)), vec2(10, 10))
@@ -265,7 +266,7 @@ image.fillPath(
 ### Image tiled
 [examples/image_tiled.nim](examples/image_tiled.nim)
 ```nim
-var path: Path
+let path = newPath()
 path.polygon(
   vec2(100, 100),
   70,

examples/image_tiled.nim

@@ -3,7 +3,7 @@ import pixie
 let image = newImage(200, 200)
 image.fill(rgba(255, 255, 255, 255))
 
-var path: Path
+let path = newPath()
 path.polygon(
   vec2(100, 100),
   70,

examples/text_spans.nim

@@ -3,19 +3,20 @@ import pixie
 let image = newImage(200, 200)
 image.fill(rgba(255, 255, 255, 255))
 
-let font = readFont("tests/fonts/Ubuntu-Regular_1.ttf")
+let typeface = readTypeface("tests/fonts/Ubuntu-Regular_1.ttf")
 
-proc style(font: Font, size: float32, color: ColorRGBA): Font =
+proc newFont(typeface: Typeface, size: float32, color: ColorRGBA): Font =
-  result = font
+  result = newFont(typeface)
   result.size = size
   result.paint.color = color
 
 let spans = @[
-  newSpan("verb [with object] ", font.style(12, rgba(200, 200, 200, 255))),
+  newSpan("verb [with object] ",
-  newSpan("strallow\n", font.style(36, rgba(0, 0, 0, 255))),
+    typeface.newFont(12, rgba(200, 200, 200, 255))),
-  newSpan("\nstral·low\n", font.style(13, rgba(0, 127, 244, 255))),
+  newSpan("strallow\n", typeface.newFont(36, rgba(0, 0, 0, 255))),
+  newSpan("\nstral·low\n", typeface.newFont(13, rgba(0, 127, 244, 255))),
   newSpan("\n1. free (something) from restrictive restrictions \"the regulations are intended to strallow changes in public policy\" ",
-      font.style(14, rgba(80, 80, 80, 255)))
+      typeface.newFont(14, rgba(80, 80, 80, 255)))
 ]
 
 image.fillText(typeset(spans, bounds = vec2(180, 180)), vec2(10, 10))

src/pixie.nim

@@ -103,7 +103,7 @@ proc fillRect*(
   transform: Vec2 | Mat3 = vec2(0, 0)
 ) =
   ## Fills a rectangle.
-  var path: Path
+  let path = newPath()
   path.rect(rect)
   mask.fillPath(path, transform)
 
@@ -114,7 +114,7 @@ proc strokeRect*(
   strokeWidth = 1.0
 ) =
   ## Strokes a rectangle.
-  var path: Path
+  let path = newPath()
   path.rect(rect)
   mask.strokePath(path, transform, strokeWidth)
 
@@ -125,7 +125,7 @@ proc fillRoundedRect*(
   transform: Vec2 | Mat3 = vec2(0, 0)
 ) =
   ## Fills a rounded rectangle.
-  var path: Path
+  let path = newPath()
   path.roundedRect(rect, nw, ne, se, sw)
   mask.fillPath(path, transform)
 
@@ -136,7 +136,7 @@ proc fillRoundedRect*(
   transform: Vec2 | Mat3 = vec2(0, 0)
 ) =
   ## Fills a rounded rectangle.
-  var path: Path
+  let path = newPath()
   path.roundedRect(rect, radius, radius, radius, radius)
   mask.fillPath(path, transform)
 
@@ -148,7 +148,7 @@ proc strokeRoundedRect*(
   strokeWidth = 1.0
 ) =
   ## Strokes a rounded rectangle.
-  var path: Path
+  let path = newPath()
   path.roundedRect(rect, nw, ne, se, sw)
   mask.strokePath(path, transform, strokeWidth)
 
@@ -160,7 +160,7 @@ proc strokeRoundedRect*(
   strokeWidth = 1.0
 ) =
   ## Strokes a rounded rectangle.
-  var path: Path
+  let path = newPath()
   path.roundedRect(rect, radius, radius, radius, radius)
   mask.strokePath(path, transform, strokeWidth)
 
@@ -171,7 +171,7 @@ proc strokeSegment*(
   strokeWidth = 1.0
 ) =
   ## Strokes a segment (draws a line from segment.at to segment.to).
-  var path: Path
+  let path = newPath()
   path.moveTo(segment.at)
   path.lineTo(segment.to)
   mask.strokePath(path, transform, strokeWidth)
@@ -183,7 +183,7 @@ proc fillEllipse*(
   transform: Vec2 | Mat3 = vec2(0, 0)
 ) =
   ## Fills an ellipse.
-  var path: Path
+  let path = newPath()
   path.ellipse(center, rx, ry)
   mask.fillPath(path, transform)
 
@@ -195,7 +195,7 @@ proc strokeEllipse*(
   strokeWidth = 1.0
 ) =
   ## Strokes an ellipse.
-  var path: Path
+  let path = newPath()
   path.ellipse(center, rx, ry)
   mask.strokePath(path, transform, strokeWidth)
 
@@ -206,7 +206,7 @@ proc fillCircle*(
   transform: Vec2 | Mat3 = vec2(0, 0)
 ) =
   ## Fills a circle.
-  var path: Path
+  let path = newPath()
   path.ellipse(center, radius, radius)
   mask.fillPath(path, transform)
 
@@ -218,7 +218,7 @@ proc strokeCircle*(
   strokeWidth = 1.0
 ) =
   ## Strokes a circle.
-  var path: Path
+  let path = newPath()
   path.ellipse(center, radius, radius)
   mask.fillPath(path, transform, strokeWidth)
 
@@ -230,7 +230,7 @@ proc fillPolygon*(
   transform: Vec2 | Mat3 = vec2(0, 0)
 ) =
   ## Fills a polygon.
-  var path: Path
+  let path = newPath()
   path.polygon(pos, size, sides)
   mask.fillPath(path, transform)
 
@@ -243,6 +243,6 @@ proc strokePolygon*(
   strokeWidth = 1.0
 ) =
   ## Strokes a polygon.
-  var path: Path
+  let path = newPath()
   path.polygon(pos, size, sides)
   mask.strokePath(path, transform, strokeWidth)

src/pixie/contexts.nim

@@ -1,5 +1,5 @@
-import bumpy, chroma, tables, pixie/blends, pixie/common, pixie/fonts,
+import bumpy, chroma, pixie/blends, pixie/common, pixie/fonts, pixie/images,
-    pixie/images, pixie/masks, pixie/paints, pixie/paths, vmath
+    pixie/masks, pixie/paints, pixie/paths, tables, vmath
 
 ## This file provides a Nim version of the Canvas 2D API commonly used on the
 ## web. The goal is to make picking up Pixie easy for developers familiar with
@@ -49,6 +49,7 @@ proc newContext*(image: Image): Context =
   result = Context()
   result.image = image
   result.mat = mat3()
+  result.path = newPath()
   result.globalAlpha = 1
   result.lineWidth = 1
   result.miterLimit = 10
@@ -164,7 +165,7 @@ proc stroke(ctx: Context, image: Image, path: Path) =
     ctx.layer.applyOpacity(ctx.globalAlpha)
     ctx.restore()
 
-proc createFont(ctx: Context): Font =
+proc newFont(ctx: Context): Font =
   if ctx.font == "":
     raise newException(PixieError, "No font has been set on this Context")
 
@@ -175,7 +176,7 @@ proc createFont(ctx: Context): Font =
   result.size = ctx.fontSize
 
 proc fillText(ctx: Context, image: Image, text: string, at: Vec2) =
-  let font = ctx.createFont()
+  let font = newFont(ctx)
 
   # Canvas positions text relative to the alphabetic baseline by default
   var at = at
@@ -201,7 +202,7 @@ proc fillText(ctx: Context, image: Image, text: string, at: Vec2) =
     ctx.restore()
 
 proc strokeText(ctx: Context, image: Image, text: string, at: Vec2) =
-  let font = ctx.createFont()
+  let font = newFont(ctx)
 
   # Canvas positions text relative to the alphabetic baseline by default
   var at = at
@@ -233,7 +234,7 @@ proc strokeText(ctx: Context, image: Image, text: string, at: Vec2) =
 
 proc beginPath*(ctx: Context) {.inline.} =
   ## Starts a new path by emptying the list of sub-paths.
-  ctx.path = Path()
+  ctx.path = newPath()
 
 proc moveTo*(ctx: Context, v: Vec2) {.inline.} =
   ## Begins a new sub-path at the point (x, y).
@@ -355,7 +356,7 @@ proc stroke*(ctx: Context) {.inline.} =
 
 proc clearRect*(ctx: Context, rect: Rect) =
   ## Erases the pixels in a rectangular area.
-  var path: Path
+  let path = newPath()
   path.rect(rect)
   if ctx.layer != nil:
     ctx.layer.fillPath(
@@ -376,7 +377,7 @@ proc clearRect*(ctx: Context, x, y, width, height: float32) {.inline.} =
 
 proc fillRect*(ctx: Context, rect: Rect) =
   ## Draws a rectangle that is filled according to the current fillStyle.
-  var path: Path
+  let path = newPath()
   path.rect(rect)
   ctx.fill(path)
 
@@ -387,7 +388,7 @@ proc fillRect*(ctx: Context, x, y, width, height: float32) {.inline.} =
 proc strokeRect*(ctx: Context, rect: Rect) =
   ## Draws a rectangle that is stroked (outlined) according to the current
   ## strokeStyle and other context settings.
-  var path: Path
+  let path = newPath()
   path.rect(rect)
   ctx.stroke(path)
 
@@ -434,7 +435,7 @@ proc measureText*(ctx: Context, text: string): TextMetrics =
   ## Returns a TextMetrics object that contains information about the measured
   ## text (such as its width, for example).
   let
-    font = ctx.createFont()
+    font = newFont(ctx)
     bounds = typeset(font, text).computeBounds()
   result.width = bounds.x
 
@@ -520,7 +521,7 @@ proc polygon*(ctx: Context, pos: Vec2, size: float32, sides: int) {.inline.} =
 
 proc fillRoundedRect*(ctx: Context, rect: Rect, nw, ne, se, sw: float32) =
   ## Draws a rounded rectangle that is filled according to the current fillStyle.
-  var path: Path
+  let path = newPath()
   path.roundedRect(rect, nw, ne, se, sw)
   ctx.fill(path)
 
@@ -531,7 +532,7 @@ proc fillRoundedRect*(ctx: Context, rect: Rect, radius: float32) {.inline.} =
 proc strokeRoundedRect*(ctx: Context, rect: Rect, nw, ne, se, sw: float32) =
   ## Draws a rounded rectangle that is stroked (outlined) according to the
   ## current strokeStyle and other context settings.
-  var path: Path
+  let path = newPath()
   path.roundedRect(rect, nw, ne, se, sw)
   ctx.stroke(path)
 
@@ -543,61 +544,61 @@ proc strokeRoundedRect*(ctx: Context, rect: Rect, radius: float32) {.inline.} =
 proc strokeSegment*(ctx: Context, segment: Segment) =
   ## Strokes a segment (draws a line from segment.at to segment.to) according
   ## to the current strokeStyle and other context settings.
-  var path: Path
+  let path = newPath()
   path.moveTo(segment.at)
   path.lineTo(segment.to)
   ctx.stroke(path)
 
 proc fillEllipse*(ctx: Context, center: Vec2, rx, ry: float32) =
   ## Draws an ellipse that is filled according to the current fillStyle.
-  var path: Path
+  let path = newPath()
   path.ellipse(center, rx, ry)
   ctx.fill(path)
 
 proc strokeEllipse*(ctx: Context, center: Vec2, rx, ry: float32) =
   ## Draws an ellipse that is stroked (outlined) according to the current
   ## strokeStyle and other context settings.
-  var path: Path
+  let path = newPath()
   path.ellipse(center, rx, ry)
   ctx.stroke(path)
 
 proc fillCircle*(ctx: Context, circle: Circle) =
   ## Draws a circle that is filled according to the current fillStyle
-  var path: Path
+  let path = newPath()
   path.circle(circle.pos, circle.radius)
   ctx.fill(path)
 
 proc fillCircle*(ctx: Context, center: Vec2, radius: float32) =
   ## Draws a circle that is filled according to the current fillStyle.
-  var path: Path
+  let path = newPath()
   path.ellipse(center, radius, radius)
   ctx.fill(path)
 
 proc strokeCircle*(ctx: Context, circle: Circle) =
   ## Draws a circle that is stroked (outlined) according to the current
   ## strokeStyle and other context settings.
-  var path: Path
+  let path = newPath()
   path.circle(circle.pos, circle.radius)
   ctx.stroke(path)
 
 proc strokeCircle*(ctx: Context, center: Vec2, radius: float32) =
   ## Draws a circle that is stroked (outlined) according to the current
   ## strokeStyle and other context settings.
-  var path: Path
+  let path = newPath()
   path.ellipse(center, radius, radius)
   ctx.stroke(path)
 
 proc fillPolygon*(ctx: Context, pos: Vec2, size: float32, sides: int) =
   ## Draws an n-sided regular polygon at (x, y) of size that is filled according
   ## to the current fillStyle.
-  var path: Path
+  let path = newPath()
   path.polygon(pos, size, sides)
   ctx.fill(path)
 
 proc strokePolygon*(ctx: Context, pos: Vec2, size: float32, sides: int) =
   ## Draws an n-sided regular polygon at (x, y) of size that is stroked
   ## (outlined) according to the current strokeStyle and other context settings.
-  var path: Path
+  let path = newPath()
   path.polygon(pos, size, sides)
   ctx.stroke(path)
 
@@ -610,7 +611,7 @@ proc drawImage*(ctx: Context, image: Image, dx, dy, dWidth, dHeight: float32) =
     ))
     savedStyle = ctx.fillStyle
   ctx.fillStyle = Paint(kind: pkImage, image: image, imageMat: imageMat)
-  var path: Path
+  let path = newPath()
   path.rect(rect(dx, dy, dWidth, dHeight))
   ctx.fill(path)
   ctx.fillStyle = savedStyle

src/pixie/fileformats/svg.nim

@@ -376,7 +376,7 @@ proc draw(img: Image, node: XmlNode, ctxStack: var seq[Ctx]) =
       x2 = parseFloat(node.attrOrDefault("x2", "0"))
       y2 = parseFloat(node.attrOrDefault("y2", "0"))
 
-    var path: Path
+    let path = newPath()
     path.moveTo(x1, y1)
     path.lineTo(x2, y2)
 
@@ -405,7 +405,7 @@ proc draw(img: Image, node: XmlNode, ctxStack: var seq[Ctx]) =
     if vecs.len == 0:
       failInvalid()
 
-    var path: Path
+    let path = newPath()
     path.moveTo(vecs[0])
     for i in 1 ..< vecs.len:
       path.lineTo(vecs[i])
@@ -434,7 +434,7 @@ proc draw(img: Image, node: XmlNode, ctxStack: var seq[Ctx]) =
       rx = max(parseFloat(node.attrOrDefault("rx", "0")), 0)
       ry = max(parseFloat(node.attrOrDefault("ry", "0")), 0)
 
-    var path: Path
+    let path = newPath()
     if rx > 0 or ry > 0:
       if rx == 0:
         rx = ry
@@ -473,7 +473,7 @@ proc draw(img: Image, node: XmlNode, ctxStack: var seq[Ctx]) =
       rx = parseFloat(node.attrOrDefault("rx", "0"))
       ry = parseFloat(node.attrOrDefault("ry", "0"))
 
-    var path: Path
+    let path = newPath()
     path.ellipse(cx, cy, rx, ry)
 
     img.fill(ctx, path)

src/pixie/fontformats/opentype.nim

@@ -1229,6 +1229,9 @@ proc parseGlyph(opentype: OpenType, glyphId: uint16): Path
 proc parseGlyphPath(buf: string, offset, numberOfContours: int): Path =
   if numberOfContours < 0:
     raise newException(PixieError, "Glyph numberOfContours must be >= 0")
+
+  result = newPath()
+
   if numberOfContours == 0:
     return
 
@@ -1357,6 +1360,8 @@ proc parseGlyphPath(buf: string, offset, numberOfContours: int): Path =
     result.closePath()
 
 proc parseCompositeGlyph(opentype: OpenType, offset: int): Path =
+  result = newPath()
+
   var
     i = offset
     moreComponents = true
@@ -1458,7 +1463,7 @@ proc parseGlyph(opentype: OpenType, glyphId: uint16): Path =
   if glyphId.int + 1 < opentype.glyf.offsets.len and
     glyphOffset == opentype.glyf.offsets[glyphId + 1]:
     # Empty glyph
-    return
+    return Path()
 
   var i = glyphOffset.int
   opentype.buf.eofCheck(i + 10)

src/pixie/fonts.nim

@@ -1,5 +1,6 @@
-import bumpy, chroma, common, os, pixie/fontformats/opentype, pixie/fontformats/svgfont,
+import bumpy, chroma, common, os, pixie/fontformats/opentype,
-    pixie/images, pixie/masks, pixie/paints, pixie/paths, strutils, unicode, vmath
+    pixie/fontformats/svgfont, pixie/images, pixie/masks, pixie/paints,
+    pixie/paths, strutils, unicode, vmath
 
 const
   AutoLineHeight* = -1.float32 ## Use default line height for the font size
@@ -93,11 +94,12 @@ proc strikeoutThickness(typeface: Typeface): float32 {.inline.} =
 
 proc getGlyphPath*(typeface: Typeface, rune: Rune): Path {.inline.} =
   ## The glyph path for the rune.
+  result = newPath()
   if rune.uint32 > SP.uint32: # Empty paths for control runes (not tofu)
     if typeface.opentype != nil:
-      result = typeface.opentype.getGlyphPath(rune)
+      result.addPath(typeface.opentype.getGlyphPath(rune))
     else:
-      result = typeface.svgFont.getGlyphPath(rune)
+      result.addPath(typeface.svgFont.getGlyphPath(rune))
 
 proc getAdvance*(typeface: Typeface, rune: Rune): float32 {.inline.} =
   ## The advance for the rune in pixels.

src/pixie/paths.nim

@@ -28,7 +28,7 @@ type
     kind: PathCommandKind
     numbers: seq[float32]
 
-  Path* = object
+  Path* = ref object
     ## Used to hold paths and create paths.
     commands: seq[PathCommand]
     start, at: Vec2 # Maintained by moveTo, lineTo, etc. Used by arcTo.
@@ -46,6 +46,10 @@ const
 when defined(release):
   {.push checks: off.}
 
+proc newPath*(): Path =
+  ## Create a new Path.
+  Path()
+
 proc pixelScale(transform: Vec2 | Mat3): float32 =
   ## What is the largest scale factor of this transform?
   when type(transform) is Vec2:
@@ -104,6 +108,7 @@ proc `$`*(path: Path): string =
 
 proc parsePath*(path: string): Path =
   ## Converts a SVG style path string into seq of commands.
+  result = newPath()
 
   if path.len == 0:
     return
@@ -123,7 +128,7 @@ proc parsePath*(path: string): Path =
     numberStart = 0
     hitDecimal = false
 
-  proc finishCommand(result: var Path) =
+  proc finishCommand(result: Path) =
     finishNumber()
 
     if armed: # The first finishCommand() arms
@@ -247,7 +252,7 @@ proc parsePath*(path: string): Path =
 
   finishCommand(result)
 
-proc transform*(path: var Path, mat: Mat3) =
+proc transform*(path: Path, mat: Mat3) =
   ## Apply a matrix transform to a path.
   if mat == mat3():
     return
@@ -312,39 +317,39 @@ proc transform*(path: var Path, mat: Mat3) =
       command.numbers[5] = to.x
       command.numbers[6] = to.y
 
-proc addPath*(path: var Path, other: Path) =
+proc addPath*(path: Path, other: Path) =
   ## Adds a path to the current path.
   path.commands.add(other.commands)
 
-proc closePath*(path: var Path) =
+proc closePath*(path: Path) =
   ## Attempts to add a straight line from the current point to the start of
   ## the current sub-path. If the shape has already been closed or has only
   ## one point, this function does nothing.
   path.commands.add(PathCommand(kind: Close))
   path.at = path.start
 
-proc moveTo*(path: var Path, x, y: float32) =
+proc moveTo*(path: Path, x, y: float32) =
   ## Begins a new sub-path at the point (x, y).
   path.commands.add(PathCommand(kind: Move, numbers: @[x, y]))
   path.start = vec2(x, y)
   path.at = path.start
 
-proc moveTo*(path: var Path, v: Vec2) {.inline.} =
+proc moveTo*(path: Path, v: Vec2) {.inline.} =
   ## Begins a new sub-path at the point (x, y).
   path.moveTo(v.x, v.y)
 
-proc lineTo*(path: var Path, x, y: float32) =
+proc lineTo*(path: Path, x, y: float32) =
   ## Adds a straight line to the current sub-path by connecting the sub-path's
   ## last point to the specified (x, y) coordinates.
   path.commands.add(PathCommand(kind: Line, numbers: @[x, y]))
   path.at = vec2(x, y)
 
-proc lineTo*(path: var Path, v: Vec2) {.inline.} =
+proc lineTo*(path: Path, v: Vec2) {.inline.} =
   ## Adds a straight line to the current sub-path by connecting the sub-path's
   ## last point to the specified (x, y) coordinates.
   path.lineTo(v.x, v.y)
 
-proc bezierCurveTo*(path: var Path, x1, y1, x2, y2, x3, y3: float32) =
+proc bezierCurveTo*(path: Path, x1, y1, x2, y2, x3, y3: float32) =
   ## Adds a cubic Bézier curve to the current sub-path. It requires three
   ## points: the first two are control points and the third one is the end
   ## point. The starting point is the latest point in the current path,
@@ -355,14 +360,14 @@ proc bezierCurveTo*(path: var Path, x1, y1, x2, y2, x3, y3: float32) =
   ))
   path.at = vec2(x3, y3)
 
-proc bezierCurveTo*(path: var Path, ctrl1, ctrl2, to: Vec2) {.inline.} =
+proc bezierCurveTo*(path: Path, ctrl1, ctrl2, to: Vec2) {.inline.} =
   ## Adds a cubic Bézier curve to the current sub-path. It requires three
   ## points: the first two are control points and the third one is the end
   ## point. The starting point is the latest point in the current path,
   ## which can be changed using moveTo() before creating the Bézier curve.
   path.bezierCurveTo(ctrl1.x, ctrl1.y, ctrl2.x, ctrl2.y, to.x, to.y)
 
-proc quadraticCurveTo*(path: var Path, x1, y1, x2, y2: float32) =
+proc quadraticCurveTo*(path: Path, x1, y1, x2, y2: float32) =
   ## Adds a quadratic Bézier curve to the current sub-path. It requires two
   ## points: the first one is a control point and the second one is the end
   ## point. The starting point is the latest point in the current path,
@@ -374,7 +379,7 @@ proc quadraticCurveTo*(path: var Path, x1, y1, x2, y2: float32) =
   ))
   path.at = vec2(x2, y2)
 
-proc quadraticCurveTo*(path: var Path, ctrl, to: Vec2) {.inline.} =
+proc quadraticCurveTo*(path: Path, ctrl, to: Vec2) {.inline.} =
   ## Adds a quadratic Bézier curve to the current sub-path. It requires two
   ## points: the first one is a control point and the second one is the end
   ## point. The starting point is the latest point in the current path,
@@ -383,7 +388,7 @@ proc quadraticCurveTo*(path: var Path, ctrl, to: Vec2) {.inline.} =
   path.quadraticCurveTo(ctrl.x, ctrl.y, to.x, to.y)
 
 proc ellipticalArcTo*(
-  path: var Path,
+  path: Path,
   rx, ry: float32,
   xAxisRotation: float32,
   largeArcFlag, sweepFlag: bool,
@@ -399,7 +404,7 @@ proc ellipticalArcTo*(
   ))
   path.at = vec2(x, y)
 
-proc arc*(path: var Path, x, y, r, a0, a1: float32, ccw: bool) =
+proc arc*(path: Path, x, y, r, a0, a1: float32, ccw: bool) =
   ## Adds a circular arc to the current sub-path.
   if r == 0: # When radius is zero, do nothing.
     return
@@ -436,11 +441,11 @@ proc arc*(path: var Path, x, y, r, a0, a1: float32, ccw: bool) =
     path.at.y = y + r * sin(a1)
     path.ellipticalArcTo(r, r, 0, angle >= PI, cw, path.at.x, path.at.y)
 
-proc arc*(path: var Path, pos: Vec2, r: float32, a: Vec2, ccw: bool = false) =
+proc arc*(path: Path, pos: Vec2, r: float32, a: Vec2, ccw: bool = false) =
   ## Adds a circular arc to the current sub-path.
   path.arc(pos.x, pos.y, r, a.x, a.y, ccw)
 
-proc arcTo*(path: var Path, x1, y1, x2, y2, r: float32) =
+proc arcTo*(path: Path, x1, y1, x2, y2, r: float32) =
   ## Adds a circular arc using the given control points and radius.
   ## Commonly used for making rounded corners.
   if r < 0: # When radius is negative, error.
@@ -481,11 +486,11 @@ proc arcTo*(path: var Path, x1, y1, x2, y2, r: float32) =
     path.at.y = y1 + t21 * y21
     path.ellipticalArcTo(r, r, 0, false, y01 * x20 > x01 * y20, path.at.x, path.at.y)
 
-proc arcTo*(path: var Path, a, b: Vec2, r: float32) =
+proc arcTo*(path: Path, a, b: Vec2, r: float32) =
   ## Adds a circular arc using the given control points and radius.
   path.arcTo(a.x, a.y, b.x, b.y, r)
 
-proc rect*(path: var Path, x, y, w, h: float32, clockwise = true) =
+proc rect*(path: Path, x, y, w, h: float32, clockwise = true) =
   ## Adds a rectangle.
   ## Clockwise param can be used to subtract a rect from a path when using
   ## even-odd winding rule.
@@ -502,13 +507,13 @@ proc rect*(path: var Path, x, y, w, h: float32, clockwise = true) =
     path.lineTo(x + w, y)
     path.closePath()
 
-proc rect*(path: var Path, pos: Vec2, wh: Vec2, clockwise = true) {.inline.} =
+proc rect*(path: Path, pos: Vec2, wh: Vec2, clockwise = true) {.inline.} =
   ## Adds a rectangle.
   ## Clockwise param can be used to subtract a rect from a path when using
   ## even-odd winding rule.
   path.rect(pos.x, pos.y, wh.x, wh.y, clockwise)
 
-proc rect*(path: var Path, rect: Rect, clockwise = true) {.inline.} =
+proc rect*(path: Path, rect: Rect, clockwise = true) {.inline.} =
   ## Adds a rectangle.
   ## Clockwise param can be used to subtract a rect from a path when using
   ## even-odd winding rule.
@@ -519,7 +524,7 @@ const splineCircleK = 4.0 * (-1.0 + sqrt(2.0)) / 3
   ## https://dl3.pushbulletusercontent.com/a3fLVC8boTzRoxevD1OgCzRzERB9z2EZ/unknown.png
 
 proc roundedRect*(
-  path: var Path, x, y, w, h, nw, ne, se, sw: float32, clockwise = true
+  path: Path, x, y, w, h, nw, ne, se, sw: float32, clockwise = true
 ) =
   ## Adds a rounded rectangle.
   ## Clockwise param can be used to subtract a rect from a path when using
@@ -586,7 +591,7 @@ proc roundedRect*(
   path.closePath()
 
 proc roundedRect*(
-  path: var Path, pos, wh: Vec2, nw, ne, se, sw: float32, clockwise = true
+  path: Path, pos, wh: Vec2, nw, ne, se, sw: float32, clockwise = true
 ) {.inline.} =
   ## Adds a rounded rectangle.
   ## Clockwise param can be used to subtract a rect from a path when using
@@ -594,14 +599,14 @@ proc roundedRect*(
   path.roundedRect(pos.x, pos.y, wh.x, wh.y, nw, ne, se, sw, clockwise)
 
 proc roundedRect*(
-  path: var Path, rect: Rect, nw, ne, se, sw: float32, clockwise = true
+  path: Path, rect: Rect, nw, ne, se, sw: float32, clockwise = true
 ) {.inline.} =
   ## Adds a rounded rectangle.
   ## Clockwise param can be used to subtract a rect from a path when using
   ## even-odd winding rule.
   path.roundedRect(rect.x, rect.y, rect.w, rect.h, nw, ne, se, sw, clockwise)
 
-proc ellipse*(path: var Path, cx, cy, rx, ry: float32) =
+proc ellipse*(path: Path, cx, cy, rx, ry: float32) =
   ## Adds a ellipse.
   let
     magicX = splineCircleK * rx
@@ -614,23 +619,23 @@ proc ellipse*(path: var Path, cx, cy, rx, ry: float32) =
   path.bezierCurveTo(cx + magicX, cy - ry, cx + rx, cy - magicY, cx + rx, cy)
   path.closePath()
 
-proc ellipse*(path: var Path, center: Vec2, rx, ry: float32) {.inline.} =
+proc ellipse*(path: Path, center: Vec2, rx, ry: float32) {.inline.} =
   ## Adds a ellipse.
   path.ellipse(center.x, center.y, rx, ry)
 
-proc circle*(path: var Path, cx, cy, r: float32) {.inline.} =
+proc circle*(path: Path, cx, cy, r: float32) {.inline.} =
   ## Adds a circle.
   path.ellipse(cx, cy, r, r)
 
-proc circle*(path: var Path, center: Vec2, r: float32) {.inline.} =
+proc circle*(path: Path, center: Vec2, r: float32) {.inline.} =
   ## Adds a circle.
   path.ellipse(center.x, center.y, r, r)
 
-proc circle*(path: var Path, circle: Circle) {.inline.} =
+proc circle*(path: Path, circle: Circle) {.inline.} =
   ## Adds a circle.
   path.ellipse(circle.pos.x, circle.pos.y, circle.radius, circle.radius)
 
-proc polygon*(path: var Path, x, y, size: float32, sides: int) =
+proc polygon*(path: Path, x, y, size: float32, sides: int) =
   ## Adds an n-sided regular polygon at (x, y) with the parameter size.
   path.moveTo(x + size * cos(0.0), y + size * sin(0.0))
   for side in 0 .. sides:
@@ -639,7 +644,7 @@ proc polygon*(path: var Path, x, y, size: float32, sides: int) =
       y + size * sin(side.float32 * 2.0 * PI / sides.float32)
     )
 
-proc polygon*(path: var Path, pos: Vec2, size: float32, sides: int) {.inline.} =
+proc polygon*(path: Path, pos: Vec2, size: float32, sides: int) {.inline.} =
   ## Adds a n-sided regular polygon at (x, y) with the parameter size.
   path.polygon(pos.x, pos.y, size, sides)
 
@@ -1611,7 +1616,7 @@ proc strokeShapes(
     miterAngleLimit = miterLimitToAngle(miterLimit)
 
   proc makeCircle(at: Vec2): seq[Vec2] =
-    var path: Path
+    let path = newPath()
     path.ellipse(at, halfStroke, halfStroke)
     path.commandsToShapes()[0]
 

tests/test_contexts.nim

@@ -51,7 +51,7 @@ block:
 block:
   let ctx = newContext(newImage(300, 150))
 
-  var region: Path
+  let region = newPath()
   region.moveTo(30, 90)
   region.lineTo(110, 20)
   region.lineTo(240, 130)
@@ -438,7 +438,7 @@ block:
 block:
   let ctx = newContext(newImage(300, 150))
 
-  var region: Path
+  let region = newPath()
   region.rect(80, 10, 20, 130)
   region.rect(40, 50, 100, 50)
   ctx.clip(region, wrEvenOdd)
@@ -453,9 +453,9 @@ block:
 
   let ctx = newContext(image)
 
-  var circlePath: Path
+  var circlePath = newPath()
   circlePath.circle(150, 75, 75)
-  var squarePath: Path
+  var squarePath = newPath()
   squarePath.rect(85, 10, 130, 130)
 
   ctx.clip(circlePath)
@@ -476,7 +476,7 @@ block:
 
   ctx.saveLayer()
 
-  var circlePath: Path
+  var circlePath = newPath()
   circlePath.circle(150, 75, 75)
 
   ctx.clip(circlePath)

tests/test_images.nim

@@ -144,7 +144,7 @@ block: # Test conversion between image and mask
     originalImage = newImage(100, 100)
     originalMask = newMask(100, 100)
 
-  var p: Path
+  let p = newPath()
   p.rect(10, 10, 80, 80)
 
   originalImage.fillPath(p, rgba(255, 0, 0, 255))
@@ -157,7 +157,7 @@ block: # Test conversion between image and mask
   doAssert newImage(newMask(originalImage)).data == newImage(originalMask).data
 
 block:
-  var p: Path
+  let p = newPath()
   p.roundedRect(10, 10, 80, 80, 10, 10, 10, 10)
 
   let image = newImage(100, 100)

tests/test_masks.nim

@@ -21,7 +21,7 @@ block:
     y = 10.0
     h = 80.0
     w = 80.0
-  var path: Path
+  let path = newPath()
   path.moveTo(x + r, y)
 #   path.arcTo(x + w, y, x + w, y + h, r)
 #   path.arcTo(x + w, y + h, x, y + h, r)
@@ -40,7 +40,7 @@ block:
   let image = newImage(100, 100)
   image.fill(rgba(255, 100, 100, 255))
 
-  var path: Path
+  let path = newPath()
   path.ellipse(image.width / 2, image.height / 2, 25, 25)
 
   let mask = newMask(image.width, image.height)
@@ -53,7 +53,7 @@ block:
   let a = newMask(100, 100)
   a.fill(255)
 
-  var path: Path
+  let path = newPath()
   path.ellipse(a.width / 2, a.height / 2, 25, 25)
 
   let b = newMask(a.width, a.height)
@@ -66,7 +66,7 @@ block:
   let a = newMask(100, 100)
   a.fill(255)
 
-  var path: Path
+  let path = newPath()
   path.ellipse(a.width / 2, a.height / 2, 25, 25)
 
   let b = newImage(a.width, a.height)
@@ -82,7 +82,7 @@ block:
   writeFile("tests/images/masks/shifted.png", a.encodePng())
 
 block:
-  var path: Path
+  let path = newPath()
   path.rect(40, 40, 20, 20)
 
   let a = newMask(100, 100)
@@ -95,7 +95,7 @@ block:
 block:
   let mask = newMask(100, 100)
 
-  var path: Path
+  let path = newPath()
   path.ellipse(mask.width / 2, mask.height / 2, 25, 25)
 
   mask.fillPath(path)

tests/test_paths.nim

@@ -98,7 +98,7 @@ block:
   image.writeFile("tests/images/paths/pathYellowRectangle.png")
 
 block:
-  var path: Path
+  let path = newPath()
   path.moveTo(10, 10)
   path.lineTo(10, 90)
   path.lineTo(90, 90)
@@ -163,7 +163,7 @@ block:
 #     y = 10.0
 #     h = 80.0
 #     w = 80.0
-#   var path: Path
+#   let path = newPath()
 #   path.moveTo(x + r, y)
 #   path.arcTo(x + w, y, x + w, y + h, r)
 #   path.arcTo(x + w, y + h, x, y + h, r)
@@ -187,7 +187,7 @@ block:
 #     y = 10.0
 #     h = 80.0
 #     w = 80.0
-#   var path: Path
+#   let path = newPath()
 #   path.moveTo(x + r, y)
 #   path.arcTo(x + w, y, x + w, y + h, r)
 #   path.arcTo(x + w, y + h, x, y + h, r)
@@ -304,7 +304,7 @@ block:
     let
       image = newImage(60, 60)
     image.fill(rgba(255, 255, 255, 255))
-    var path: Path
+    let path = newPath()
     path.moveTo(-20, 0)
     path.lineTo(0, 0)
     let th = angle.float32.degToRad() + PI/2
@@ -532,7 +532,7 @@ block:
   surface.writeFile("tests/images/paths/arcTo3.png")
 
 block:
-  var path: Path
+  let path = newPath()
   path.rect(0, 0, 10, 10)
 
   doAssert path.fillOverlaps(vec2(5, 5))
@@ -542,7 +542,7 @@ block:
   doAssert not path.fillOverlaps(vec2(10, 10))
 
 block:
-  var path: Path
+  let path = newPath()
   path.ellipse(20, 20, 20, 10)
 
   doAssert not path.fillOverlaps(vec2(0, 0))
@@ -551,7 +551,7 @@ block:
   doAssert path.fillOverlaps(vec2(30, 20))
 
 block:
-  var path: Path
+  let path = newPath()
   path.rect(10, 10, 10, 10)
 
   doAssert path.strokeOverlaps(vec2(10, 10))
@@ -559,7 +559,7 @@ block:
   doAssert not path.strokeOverlaps(vec2(5, 5))
 
 block:
-  var path: Path
+  let path = newPath()
   path.ellipse(20, 20, 20, 10)
 
   doAssert not path.strokeOverlaps(vec2(0, 0))
@@ -570,7 +570,7 @@ block:
   doAssert not path.strokeOverlaps(vec2(19.4, 30.6))
 
 block:
-  var path: Path
+  let path = newPath()
   path.circle(50, 50, 30)
 
   var paint = Paint(kind: pkSolid, color: rgba(255, 0, 255, 255))
@@ -582,7 +582,7 @@ block:
   image.writeFile("tests/images/paths/opacityFill.png")
 
 block:
-  var path: Path
+  let path = newPath()
   path.circle(50, 50, 30)
 
   var paint = Paint(kind: pkSolid, color: rgba(255, 0, 255, 255))