Merge pull request #402 from treeform/dev

Seperate the idea layout and pixel bounds.

pixie.nimble

@@ -1,4 +1,4 @@
-version     = "4.0.5"
+version     = "4.1.0"
 author      = "Andre von Houck and Ryan Oldenburg"
 description = "Full-featured 2d graphics library for Nim."
 license     = "MIT"

src/pixie/contexts.nim

@@ -482,7 +482,7 @@ proc measureText*(ctx: Context, text: string): TextMetrics {.raises: [PixieError
   ## text (such as its width, for example).
   let
     font = newFont(ctx)
-    bounds = typeset(font, text).computeBounds()
+    bounds = typeset(font, text).layoutBounds()
   result.width = bounds.x
 
 proc getLineDash*(ctx: Context): seq[float32] {.inline, raises: [].} =

src/pixie/fonts.nim

@@ -467,7 +467,7 @@ proc typeset*(
   ## wrap: enable/disable text wrapping
   typeset(@[newSpan(text, font)], bounds, hAlign, vAlign, wrap)
 
-proc computeBounds*(arrangement: Arrangement): Vec2 {.raises: [].} =
+proc layoutBounds*(arrangement: Arrangement): Vec2 {.raises: [].} =
   ## Computes the width and height of the arrangement in pixels.
   if arrangement.runes.len > 0:
     for i in 0 ..< arrangement.runes.len:
@@ -481,13 +481,13 @@ proc computeBounds*(arrangement: Arrangement): Vec2 {.raises: [].} =
       # If the text ends with a new line, we need add another line height.
       result.y += finalRect.h
 
-proc computeBounds*(font: Font, text: string): Vec2 {.inline, raises: [].} =
+proc layoutBounds*(font: Font, text: string): Vec2 {.inline, raises: [].} =
   ## Computes the width and height of the text in pixels.
-  font.typeset(text).computeBounds()
+  font.typeset(text).layoutBounds()
 
-proc computeBounds*(spans: seq[Span]): Vec2 {.inline, raises: [].} =
+proc layoutBounds*(spans: seq[Span]): Vec2 {.inline, raises: [].} =
   ## Computes the width and height of the spans in pixels.
-  typeset(spans).computeBounds()
+  typeset(spans).layoutBounds()
 
 proc parseOtf*(buf: string): Typeface {.raises: [PixieError].} =
   result = Typeface()
@@ -500,34 +500,27 @@ proc parseSvgFont*(buf: string): Typeface {.raises: [PixieError].} =
   result = Typeface()
   result.svgFont = svgfont.parseSvgFont(buf)
 
-proc textUber(
-  target: Image | Mask,
-  arrangement: Arrangement,
-  transform = mat3(),
-  strokeWidth: float32 = 1.0,
-  lineCap = ButtCap,
-  lineJoin = MiterJoin,
-  miterLimit = defaultMiterLimit,
-  dashes: seq[float32] = @[],
-  stroke: static[bool] = false
-) =
+proc computePaths(arrangement: Arrangement): seq[Path] =
+  ## Takes an Arrangement and computes Paths for drawing.
+  ## Returns a seq of paths that match the seq of Spans in the arrangement.
+  ## If you only have one Span you will only get one Path.
   var line: int
   for spanIndex, (start, stop) in arrangement.spans:
     let
+      spanPath = newPath()
       font = arrangement.fonts[spanIndex]
       underlineThickness = font.typeface.underlineThickness * font.scale
       underlinePosition = font.typeface.underlinePosition * font.scale
       strikeoutThickness = font.typeface.strikeoutThickness * font.scale
       strikeoutPosition = font.typeface.strikeoutPosition * font.scale
     for runeIndex in start .. stop:
-      let position = arrangement.positions[runeIndex]
-
-      let path = font.typeface.getGlyphPath(arrangement.runes[runeIndex])
+      let
+        position = arrangement.positions[runeIndex]
+        path = font.typeface.getGlyphPath(arrangement.runes[runeIndex])
       path.transform(
         translate(position) *
         scale(vec2(font.scale))
       )
-
       var applyDecoration = true
       if runeIndex == arrangement.lines[line][1]:
         inc line
@@ -553,22 +546,30 @@ proc textUber(
             font.typeface.isCCW()
           )
 
-      when stroke:
-        when type(target) is Image:
-          for paint in font.paints:
-            target.strokePath(
-              path,
-              paint,
-              transform,
-              strokeWidth,
-              lineCap,
-              lineJoin,
-              miterLimit,
-              dashes
-            )
-        else: # target is Mask
+      spanPath.addPath(path)
+    result.add(spanPath)
+
+proc textUber(
+  target: Image | Mask,
+  arrangement: Arrangement,
+  transform = mat3(),
+  strokeWidth: float32 = 1.0,
+  lineCap = ButtCap,
+  lineJoin = MiterJoin,
+  miterLimit = defaultMiterLimit,
+  dashes: seq[float32] = @[],
+  stroke: static[bool] = false
+) =
+  let spanPaths = arrangement.computePaths()
+  for spanIndex in 0 ..< arrangement.spans.len:
+    let path = spanPaths[spanIndex]
+    when stroke:
+      when type(target) is Image:
+        let font = arrangement.fonts[spanIndex]
+        for paint in font.paints:
           target.strokePath(
             path,
+            paint,
             transform,
             strokeWidth,
             lineCap,
@@ -576,12 +577,33 @@ proc textUber(
             miterLimit,
             dashes
           )
-      else:
-        when type(target) is Image:
-          for paint in font.paints:
-            target.fillPath(path, paint, transform)
-        else: # target is Mask
-          target.fillPath(path, transform)
+      else: # target is Mask
+        target.strokePath(
+          path,
+          transform,
+          strokeWidth,
+          lineCap,
+          lineJoin,
+          miterLimit,
+          dashes
+        )
+    else:
+      when type(target) is Image:
+        let font = arrangement.fonts[spanIndex]
+        for paint in font.paints:
+          target.fillPath(path, paint, transform)
+      else: # target is Mask
+        target.fillPath(path, transform)
+
+proc computeBounds*(
+  arrangement: Arrangement,
+  transform = mat3()
+): Rect =
+  let fullPath = newPath()
+  for path in arrangement.computePaths():
+    fullPath.addPath(path)
+  fullPath.transform(transform)
+  fullPath.computeBounds()
 
 proc fillText*(
   target: Image | Mask,

tests/test_fonts.nim

@@ -16,14 +16,14 @@ block:
   var font = readFont("tests/fonts/Roboto-Regular_1.ttf")
   font.size = 24
 
-  let bounds = font.computeBounds("Word")
+  let bounds = font.layoutBounds("Word")
   doAssert bounds == vec2(56, 28)
 
 block:
   var font = readFont("tests/fonts/Roboto-Regular_1.ttf")
   font.size = 24
 
-  let bounds = font.computeBounds("Word\n")
+  let bounds = font.layoutBounds("Word\n")
   doAssert bounds == vec2(56, 56)
 
 block:
@@ -996,6 +996,43 @@ block:
 
   doDiff(image, "spans6")
 
+block:
+
+  let typeface1 = readTypeface("tests/fonts/PinyonScript.ttf")
+
+  var font1 = newFont(typeface1)
+  font1.size = 82
+  font1.lineHeight = 60
+  font1.paint = "#000000"
+
+  let spans = @[
+    newSpan("Fancy text", font1),
+  ]
+
+  let image = newImage(400, 400)
+  image.fill(rgba(255, 255, 255, 255))
+  let ctx = newContext(image)
+  ctx.fillStyle = "#FFD6D6"
+  ctx.fillRect(rect(40, 170, 320, 60))
+
+  let
+    arrangement = typeset(spans, bounds = vec2(320, 60))
+    snappedBounds = arrangement.computeBounds().snapToPixels()
+    textImage = newImage(snappedBounds.w.int, snappedBounds.h.int)
+  textImage.fillText(arrangement, translate(-snappedBounds.xy))
+
+  image.draw(textImage, translate(snappedBounds.xy + vec2(40, 170)))
+
+  # Enable this to show bounds
+  # ctx.strokeStyle = "#FF0000"
+  # ctx.translate(vec2(40, 170))
+  # ctx.strokeRect(arrangement.computeBounds())
+
+  # Enable this to show how text is drawing directly
+  # image.fillText(arrangement, translate(vec2(40, 170)))
+
+  doDiff(image, "spans7")
+
 block:
   var font = readFont("tests/fonts/Roboto-Regular_1.ttf")
   font.size = 36