class TermBuf::Grid

• TermBuf::Grid
• Reference
• Object

Overview

A rectangular array of cells.

Cells live in one flat slice, so a row is a contiguous Slice view and scrolling is a run of memmoves. Alongside them the grid keeps a hash per row, recomputed lazily, which is what lets the painter recognise a scrolled band without comparing cells.

The grid is the only place that knows a wide character occupies two cells, and it never lets those two get out of step: writing to either half blanks both first.

Defined in:

termbuf/core/grid.cr

Constant Summary

FNV_OFFSET = 14695981039346656037_u64

FNV_PRIME = 1099511628211_u64

Constructors

• .new(width : Int32, height : Int32, blank : Cell = Cell.blank)

Instance Method Summary

• #==(other : Grid) : Bool

  Whether both grids hold the same cells.

• #[](x : Int32, y : Int32) : Cell

  The cell at (x, y).

• #[]=(x : Int32, y : Int32, cell : Cell) : Nil

  Writes one cell without regard for wide character pairing.

• #[]?(x : Int32, y : Int32) : Cell | Nil

  The cell at (x, y), or nil if it is off the grid.

• #bounds : Rect

  The rectangle covering every cell.

• #clear(cell : Cell = Cell.blank) : Nil

  Sets every cell of the grid to cell.

• #clip_wide(rect : Rect, blank : Cell = Cell.blank) : Nil

  Blanks any wide character straddling the left or right edge of rect, so that filling or scrolling the rectangle cannot tear one in half.

• #contains?(x : Int32, y : Int32) : Bool

  Whether (x, y) is on the grid.

• #copy_from(other : Grid) : Nil

  Replaces this grid's contents with other's, which must be the same size.

• #damage : Damage

  Which rows have changed, and over what span.

• #detach(x : Int32, y : Int32, blank : Cell = Cell.blank) : Nil

  Blanks both halves of the wide character overlapping column x, if one does.

• #fill(rect : Rect, cell : Cell) : Nil

  Sets every cell of rect to cell.

• #height : Int32

  Rows down.

• #place(x : Int32, y : Int32, cell : Cell, blank : Cell = Cell.blank) : Int32

  Places cell at (x, y), blanking the other half of any wide character it displaces.

• #resize(width : Int32, height : Int32, blank : Cell = Cell.blank) : Nil

  Resizes the grid, keeping whatever content still fits anchored at the top left and filling the rest with blank.

• #row(y : Int32) : Slice(Cell)

  The cells of row y, as a view into the grid's own storage.

• #row_hash(y : Int32) : UInt64

  FNV-1a hash of row y, recomputed only when the row has been written to since it was last asked for.

• #row_span(rect : Rect, y : Int32) : Slice(Cell)

  The cells of row y within rect's columns.

• #scroll(rect : Rect, lines : Int32, blank : Cell = Cell.blank, & : Slice(Cell) -> ) : Nil

  Moves the contents of rect by lines rows, positive scrolling up so that content moves toward the top and blank rows appear at the bottom.

• #scroll(rect : Rect, lines : Int32, blank : Cell = Cell.blank) : Nil

  Scrolls without inspecting the rows that leave.

• #to_text(pool : ClusterPool = ClusterPool.new) : String

  Renders the grid as text, one line per row, for specs and debugging.

• #width : Int32

  Columns across.

Constructor Detail

Instance Method Detail