pixie/README.md

Pixie - A full-featured 2D graphics library for Nim

Pixie is a 2D graphics library similar to Cairo and Skia written (almost) entirely in Nim.

This library is being actively developed and we'd be happy for you to use it.

nimble install pixie

Features:

• Typesetting and rasterizing text, including styled rich text via spans.
• Drawing paths, shapes and curves with even-odd and non-zero windings.
• Pixel-perfect AA quality.
• Supported file formats are PNG, BMP, JPG, SVG + more in development.
• Strokes with joins and caps.
• Shadows, glows and blurs.
• Complex masking: Subtract, Intersect, Exclude.
• Complex blends: Darken, Multiply, Color Dodge, Hue, Luminosity... etc.
• Many operations are SIMD accelerated.

Documentation

API reference: https://nimdocs.com/treeform/pixie/pixie.html

Image file formats

Format	Read	Write
PNG	✅	✅
JPEG	✅
BMP	✅	✅
GIF	✅
SVG	✅

Font file formats

Format	Read
TTF	✅
OTF	✅
SVG	✅

Joins and caps

Supported Caps:

• Butt
• Round
• Square

Supported Joins:

• Miter (with miter angle limit)
• Bevel
• Round

Blending & masking

Supported Blend Modes:

• Normal
• Darken
• Multiply
• ColorBurn
• Lighten
• Screen
• Color Dodge
• Overlay
• Soft Light
• Hard Light
• Difference
• Exclusion
• Hue
• Saturation
• Color
• Luminosity

Supported Mask Modes:

• Mask
• Overwrite
• Subtract Mask
• Intersect Mask
• Exclude Mask

SVG style paths:

Format	Supported	Description
M m	✅	move to
L l	✅	line to
h h	✅	horizontal line to
V v	✅	vertical line to
C c S s	✅	cublic to
Q q T t	✅	quadratic to
A a	✅	arc to
z	✅	close path

Realtime Examples

Here are some examples of using Pixie for realtime rendering with some popular windowing libraries:

• examples/realtime_glfw.nim
• examples/realtime_glut.nim
• examples/realtime_sdl.nim
• examples/realtime_win32.nim

Testing

nimble test

Examples

Text

examples/text.nim

var font = readFont("tests/fonts/Roboto-Regular_1.ttf")
font.size = 20

let text = "Typesetting is the arrangement and composition of text in graphic design and publishing in both digital and traditional medias."

image.fillText(font.typeset(text, bounds = vec2(180, 180)), vec2(10, 10))

Text spans

examples/text_spans.nim

let font = readFont("tests/fonts/Ubuntu-Regular_1.ttf")

proc style(font: Font, size: float32, color: ColorRGBA): Font =
  result = font
  result.size = size
  result.paint.color = color

let spans = @[
  newSpan("verb [with object] ", font.style(12, rgba(200, 200, 200, 255))),
  newSpan("strallow\n", font.style(36, rgba(0, 0, 0, 255))),
  newSpan("\nstral·low\n", font.style(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)))
]

image.fillText(typeset(spans, bounds = vec2(180, 180)), vec2(10, 10))

Square

examples/square.nim

let ctx = newContext(image)
ctx.fillStyle = rgba(255, 0, 0, 255)

let
  pos = vec2(50, 50)
  wh = vec2(100, 100)

ctx.fillRect(rect(pos, wh))

Line

examples/line.nim

let ctx = newContext(image)
ctx.strokeStyle = "#FF5C00"
ctx.lineWidth = 10

let
  start = vec2(25, 25)
  stop = vec2(175, 175)

ctx.strokeSegment(segment(start, stop))

Rounded rectangle

examples/rounded_rectangle.nim

let ctx = newContext(image)
ctx.fillStyle = rgba(0, 255, 0, 255)

let
  pos = vec2(50, 50)
  wh = vec2(100, 100)
  r = 25.0

ctx.fillRoundedRect(rect(pos, wh), r)

Heart

examples/heart.nim

image.fillPath(
  """
    M 20 60
    A 40 40 90 0 1 100 60
    A 40 40 90 0 1 180 60
    Q 180 120 100 180
    Q 20 120 20 60
    z
  """,
  parseHtmlColor("#FC427B").rgba
)

Masking

examples/masking.nim

let ctx = newContext(lines)
ctx.strokeStyle = "#F8D1DD"
ctx.lineWidth = 30

ctx.strokeSegment(segment(vec2(25, 25), vec2(175, 175)))
ctx.strokeSegment(segment(vec2(25, 175), vec2(175, 25)))

mask.fillPath(
  """
    M 20 60
    A 40 40 90 0 1 100 60
    A 40 40 90 0 1 180 60
    Q 180 120 100 180
    Q 20 120 20 60
    z
  """
)
lines.draw(mask)
image.draw(lines)

Gradient

examples/gradient.nim

let paint = Paint(
  kind: pkGradientRadial,
  gradientHandlePositions: @[
    vec2(100, 100),
    vec2(200, 100),
    vec2(100, 200)
  ],
  gradientStops: @[
    ColorStop(color: rgba(255, 0, 0, 255), position: 0),
    ColorStop(color: rgba(255, 0, 0, 40), position: 1.0),
  ]
)

image.fillPath(
  """
    M 20 60
    A 40 40 90 0 1 100 60
    A 40 40 90 0 1 180 60
    Q 180 120 100 180
    Q 20 120 20 60
    z
  """,
  paint
)

Image tiled

examples/image_tiled.nim

var path: Path
path.polygon(
  vec2(100, 100),
  70,
  sides = 8
)
image.fillPath(
  path,
  Paint(
    kind: pkImageTiled,
    image: readImage("tests/images/png/baboon.png"),
    imageMat: scale(vec2(0.08, 0.08))
  )
)

Shadow

examples/shadow.nim

let polygonImage = newImage(200, 200)

let ctx = newContext(polygonImage)
ctx.fillStyle = rgba(255, 255, 255, 255)

ctx.fillPolygon(
  vec2(100, 100),
  70,
  sides = 8
)

let shadow = polygonImage.shadow(
  offset = vec2(2, 2),
  spread = 2,
  blur = 10,
  color = rgba(0, 0, 0, 200)
)

image.draw(shadow)
image.draw(polygonImage)

Blur

examples/blur.nim

let mask = newMask(200, 200)
mask.fillPolygon(vec2(100, 100), 70, sides = 6)

blur.blur(20)
blur.draw(mask, blendMode = bmMask)

image.draw(trees)
image.draw(blur)

Tiger

examples/tiger.nim

let tiger = readImage("examples/data/tiger.svg")

image.draw(
  tiger,
  translate(vec2(100, 100)) *
  scale(vec2(0.2, 0.2)) *
  translate(vec2(-450, -450))
)