Positions and regions

Coordinates are never written directly. A position is always spelled in the language of grid lines — X2, X2+600, Y3-150. The only place raw millimetres are allowed is the site shape (polygon), because a site outline is survey data, not a design product.

This page covers grid references, offsets, ranges, regions and points. Compass words (N E S W) are in orientation and the a side; how a line is tokenised is in how a line is read.

koyu 1.0
name 位置の例
unit mm

grid X 0 6400 12800
grid Y 0 5600 11200

level L1 0 h:2700 slab:200

space /L1/ldk  ldk  X1..X2 Y1..Y2 + X2..X3 Y1..Y1+2800 name:LDK
space /L1/hall hall X2..X3 Y1+2800..Y2 name:廊下
space /L1/room room X1..X3 Y2..Y3 name:寝室
space /out     exterior name:外部

Grid lines

grid gives the coordinate system. Once per axis, two or more millimetre coordinates in ascending order. The names are assigned automatically — X1, X2, … and Y1, Y2, … — never by the author.

grid X 0 6400 12800 19200
grid Y 0 5600 7600 13200

• Out of order is an error (grid coordinates are written in ascending order)
• Fewer than two is an error
• Declaring an axis twice is an error — when layers are composed, only the entry declares it
• It must come before any line that uses it. A grid name referenced above its grid line gives Undefined grid line name

X is positive east, Y is positive north, z is positive up. Lengths are millimetres, a ratio along a segment is 0..1, and areas are reported in m² measured to wall centrelines.

Grid references and offsets

Spelling	Meaning
X2	the coordinate of grid line X2
X2+600	600 mm east of X2
Y3-150	150 mm south of Y3

The spelling is strict: axis letter, grid number, and an optional signed integer. Nothing else passes.

Written	Result
X2+600	6400 + 600
X2 + 600	three tokens; unreadable
X2+600.5	Undefined grid line name: X2+600.5 — offsets are whole millimetres
X2+600-100	the same — there is exactly one offset
X9	Undefined grid line name: X9 — no such grid line

An offset may run past the next grid line. X1..X2+6000 is fine even if it reaches beyond X3 — a grid line is a name for a coordinate, not the edge of a bay.

Ranges

A range is A..B, and both ends must be grid lines on the same axis.

Written	Result
X1..X2+3200	the X interval from 0 to 9600
X1..Y2	Both ends of a range are grid lines on the same axis
X2..X2	The region has zero width
X2..X1	the same rectangle as X1..X2. Stored normalised to ascending order

A reversed range folds into the ascending spelling because it is the same shape. Only the ascending spelling appears in the machine format and in diffs.

There is one exception: a band range must be written ascending. Inside a band the order of the members carries meaning, so a reversed range is not another spelling but a mistake (A band range is written in ascending order).

Regions

A region is exactly two tokens: one X range and one Y range. Their order is free, so Y1..Y2 X1..X2 is the same rectangle.

space /L1/room room X1..X3 Y2..Y3 name:寝室

Give three, or one, and you get A region is given as two ranges, X?..X? and Y?..Y?.

Unions of rectangles

+ is a token of its own — put whitespace around it. L shapes, U shapes, any number of rectangles.

space /L1/ldk ldk X1..X2 Y1..Y2 + X2..X3 Y1..Y1+2800 name:LDK

Each side of + is its own pair of X and Y ranges. Rectangles that overlap inside one space are an error (GEO01), and so is an overlap with another space on the same level (GEO02). No wall stands on the internal seam of a union — an L written as two rectangles behaves as one room.

A space may have no region at all. space /out exterior name:外部 is how exteriors and aggregation-only spaces are written. But a space that does have a region must have a determinable level and ceiling height (SUF02 / SUF01).

Points

Only the endpoints of a line are written as points — an X reference and a Y reference joined by a comma.

boundary /L1/a /L1/b
  line X3,Y1 X3+600,Y2-900

• X first, then Y. The other order gives A point is written X grid line first, then Y
• Both ends at the same point is an error
• Neither raw coordinates nor angles can be written. The endpoints of a line are always grid language

Deciding a position without writing a region

Two constructs give dimensions and let the position follow.

band supplies the extent, and its members carry only a width w:. The cut positions are derived by addition, and the widths must sum to the extent of the band or the file stops.

koyu 1.0
grid X 0 3600 5400
grid Y 0 4000
level L1 0 h:2400 slab:150
band X X1..X3 Y1..Y2
  space /L1/a room w:2000
  space /L1/b room w:rest

A derived cut is spelled as an offset from the largest grid line at or below that coordinate (the floor rule). The cut at 2000 above becomes X1+2000, never X3-3400. The two ends of the band, and both ends across it, keep the spelling that was written.

column writes no position at all. A column stands at each grid intersection that has floor on that level; x: and y: only narrow which intersections by grid name.

The one place raw coordinates are allowed

polygon /site -2600,-7000 38000,-7000 38000,19600 2000,21000 -2600,15000

polygon is the only line that writes a shape from free vertices off the grid. A site outline is given by survey, not produced by design, so it is admitted as an exception. Three or more x,y vertices in millimetres, in the same coordinate system as the grid.

Attributes that point at a position

The at: of an opening or a seg can be written either way.

Spelling	Meaning
at:0.3	a ratio along the segment. Clamped to fit (no diagnostic)
at:X2+450	an absolute position. Not clamped

An absolute position must be on the segment's axis — X references on horizontal segments, Y references on vertical ones. The wrong axis is OPN07 / SEG07; running off the end is OPN08 / SEG08.

At X1+200 the door (width 900) runs off the boundary segment (segment 0-6400mm, center allowed 450-5950mm)

The difference between the two spellings is whether it moves silently or stops. If the position was decided as a dimension on a drawing, write it as a grid reference.