Skip to content

Wire Rendering

This page documents how Click renders wires in the ladder grid and how the encoder maps CSV wire tokens to binary flag bytes.

Wire flag bytes

Each cell has three flag bytes at fixed offsets:

Offset Name Purpose
+0x19 Segment Branch zone membership (see below)
+0x1D Right Horizontal connection to the right
+0x21 Down Vertical connection downward

Wire tokens are classified by (right, down) only — the segment flag is independent:

Right Down Token Meaning
1 0 - Horizontal wire
0 1 \| Vertical down
1 1 T Branch junction (right + down)
0 0 (blank) No wire

Instruction cells (contacts, coils) also set right=1 — they behave like horizontal wires with instruction data layered on top.

Left-edge rendering

Click renders the T's down-wire at the left edge of the cell, not the center. This means two cells can connect to a single T's down-wire — one from each side of that edge:

  1. Same-column (DOWN): A - directly below a T connects via the standard vertical edge.
  2. Diagonal (UP/RIGHT): A - one column to the LEFT and one row BELOW connects UP one row and ONE COLUMN TO THE RIGHT to the T. The -'s right-wire meets the T's down-wire at the shared cell boundary.
Connected:                          Not connected:
R, -, T, T, -, -, out(Y1)          R, -, T, T, -, -, out(Y1)
 , -, -, -, -, -, out(Y2)           , -,  , -, -, -, out(Y2)
      ^                                   ^
      B has "-" = bridge                  B is blank = gap

In the not-connected case: row 1 column A connects UP/RIGHT to T@B (rule 2), row 1 column C connects UP to T@C (rule 1), and the blank at B is the gap that keeps the two branches independent.

Segment flag

The segment flag (+0x19) determines branch zone membership. Getting it wrong causes contacts and wires to visually shift down to their own row in Click's editor.

Boundary rules

The encoder computes a per-row boundary column:

Row 0 is exempt — boundary=0, all non-blank cells get seg=1.

Row R (R > 0):

  1. Start with boundary = 0
  2. From row R-1 only: T at column C → boundary = max(boundary, C+2); | at column C → boundary = max(boundary, C+1)
  3. From rows 0..R-1: Contact/CompareContact at column C → boundary = max(boundary, C+2)
  4. Non-blank cells at col < boundary get seg=0; at col >= boundary get seg=1
  5. Blank cells and | cells are always seg=0

AF column segment rules

Single-rung buffers:

Cell type Row Segment
Coil 0 1
Coil 1+ 0
Timer any 0
NOP data cell any 1

In multi-rung buffers, all AF instruction cells get segment=0 regardless of type or row.

Note on native captures

Click's native segment flags track editor creation order — "insert row above" keeps the original row exempt rather than row 0. The encoder always treats row 0 as exempt, matching top-down construction. Native captures built via "insert row above" will show a different exempt row; don't use those for segment flag validation.

Instruction index

Click stores a per-cell instruction index at +0x0D, but the value reflects editor creation order, not a structural rule. Click accepts any ordering on paste. The encoder uses a deterministic scheme: condition-side instructions numbered in row-major column-major order, then AF-side instructions in row order.

Validation constraints

  • T and | tokens are rejected on the last row (vertical-down has nowhere to go)
  • T and | tokens are rejected on column A (leftmost condition column)
  • At most one NOP per rung