Sundries

Sundries supplies the layout bridge between dimensions and drawings. A ruler fits repeated distances into one span, a grid combines two rulers, and a tile repeats one geometry value. They are regular Ruby objects, not another drawing DSL, so applications can inspect and test a layout before creating any SVG elements. Export is the separate output-oriented part of the component.

Choose a layout model

Choose by the value the rest of the program needs, not only by the visible repetition:

Need	Use	Result
Repeat one SVG template in the document	DSL `Tile`, `TileX`, or `TileY`	`<defs>` plus positioned `<use>` elements
Copy independently editable SVG subtrees	`Duplicate`, `DuplicateX`, or `DuplicateY`	separate element trees
Inspect repeated cells and their bounds in Ruby	`Sevgi::Sundries::Tile`	geometry values without SVG output
Fit major and minor intervals into one span	`Ruler` or `RulerEven`	inspectable distances and margins
Combine two fitted rulers	`SVG.Grid` or `Sevgi::Sundries::Grid`	lines, points, cells, and a fitted canvas

Rulers

Ruler fits whole major intervals inside a span. unit is the smallest step; multiple says how many units form one major interval. Requested margins are minimums. Any distance left after fitting whole major intervals is split between them while preserving an asymmetric start/end difference:

ruler = Sevgi::Sundries::Ruler.new(
  brut: 103,
  unit: 1,
  multiple: 10,
  margins: [5]
)

ruler.n       # => 9 major intervals
ruler.ds      # major distances
ruler.hs      # halfway distances
ruler.ms      # minor distances
ruler.margins # => [6.5, 6.5]
ruler.d       # => 90.0 fitted distance, excluding margins
ruler.waste   # => 13.0 margins plus unfitted remainder

Use RulerEven when the number of major intervals must be even. The compact readers u, n, and d mean interval length, count, and fitted distance. su, sn, and sd describe the source subinterval.

Grid

Grid combines one horizontal and one vertical ruler. In library mode, SVG.Grid builds both rulers from a canvas and preserves that canvas's size, unit, and name while replacing its margins with the fitted values:

canvas = SVG.Canvas width: 80, height: 50, margins: [5]
grid = SVG.Grid canvas, unit: 1, multiple: 10

drawing = SVG :inkscape, grid.canvas do
  Draw grid.x.major.lines, class: %w[guide horizontal], stroke: "silver"
  Draw grid.y.major.lines, class: %w[guide vertical], stroke: "silver"
end

drawing.Render

Axis names describe line direction: grid.x produces horizontal lines, and grid.y produces vertical lines. The positions of horizontal lines therefore come from the vertical ruler, and vice versa. Each major, minor, or halfway query has three representations:

Reader	Value	Typical use
`lines`	geometry `Line` objects	pass a complete set to `Draw`
`points`	pairs of geometry `Point` objects	place marks at both endpoints
`xys`	pairs of plain coordinate Arrays	feed data-only consumers

canvas = SVG.Canvas width: 80, height: 50, margins: [5]
grid = SVG.Grid canvas, unit: 1, multiple: 10

grid.x.major.lines  # geometry Line objects, suitable for Draw
grid.x.halve.points # endpoint Point pairs
grid.y.minor.xys    # plain coordinate pairs

Grid also inherits tile accessors. grid.rowbox(i) and grid.colbox(i) are useful when a hatch or another operation should be constrained to one row or column. This is the pattern used by guide-sheet consumers:

canvas = SVG.Canvas width: 80, height: 50, margins: [5]
grid = SVG.Grid canvas, unit: 1, multiple: 10

SVG :inkscape, grid.canvas do
  Hatch grid.rowbox(0), angle: -30, step: grid.x.su, stroke: "silver"
end.Render

Tiles

Tile arranges copies of one geometry value into rows and columns. The source element's bounding box sets the cell pitch, and indexing is row-first:

cell = Sevgi::Geometry::Rect[8, 4]
tile = Sevgi::Sundries::Tile.new(cell, position: [10, 20], nx: 3, ny: 2)

tile[1][2].position # row 1, column 2
tile.rowbox(1)      # bounds of the second row
tile.colbox(2)      # bounds of the third column
tile.box            # bounds of the complete layout

Use this Ruby object when later calculations need the cells or their bounds. Use the DSL words Tile, TileX, or TileY instead when the output should define one SVG template and repeat it with <use> elements.

Export

SVG output needs no native graphics libraries. PDF and PNG export are optional:

canvas = SVG.Canvas width: 40, height: 40, unit: :px
drawing = SVG :minimal, canvas do
  circle cx: 20, cy: 20, r: 16, fill: "tomato"
end

drawing.PNG "badge.png", dpi: 144
drawing.PDF "badge.pdf"

Applications that keep output policy outside the document can call the component directly. The file suffix selects the format when format: is omitted, and the return value is the expanded output path:

canvas = SVG.Canvas width: 40, height: 40, unit: :px
drawing = SVG(:minimal, canvas) { circle cx: 20, cy: 20, r: 16, fill: "tomato" }
Sevgi::Sundries::Export.call(drawing.Render, "badge.png", width: 320)

Export width and height control output dimensions; they do not replace the SVG canvas or repair its viewBox or visible geometry. Define those relationships in the drawing before export. Use css: only for deliberate export-only styling.

PDF and PNG output uses Cairo, librsvg, and HexaPDF. If one is missing, Sevgi raises a component error. Ordinary SVG rendering still works without them.

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