SCHIXELS (Schematic Pixels)

Definition

A Schixel (SCX) is the fundamental unit of measurement and grid alignment within the SchemWeb environment.

1 SCX = 100 base coordinate units.
scx: Refers to the X-axis coordinate in Schixels.
scy: Refers to the Y-axis coordinate in Schixels.
sxy: Refers to a coordinate pair or a generic measurement in Schixel units.

Why Schixels?

Schematic drawings are technically unitless and scale-independent. However, humans and layout algorithms require a predictable “rhythm” to the placement of components. Standard pixels are too granular and vary by display density.

1. Predictability: A 100-unit grid ensures that every “wire” and “connector” lands on a clean, snapping coordinate.
2. Readability: It is easier for an engineer to understand “Device is 3 SCX wide” than “Device is 300.42 pixels wide.”
3. Deterministic Layout: By using a coarse 100-unit base, we prevent “pixel drift” where components are off-alignment by microscopic amounts, which traditionally causes “jagged” or “aliased” connection lines.

Usage in SchemWeb

– Grid Snapping: All nodes and groups MUST snap to the 1 SCX (100 unit) grid.
– Device Width: A standard device is typically 3 SCX wide.
– Spacing: Vertical spacing between devices in a rack or group is typically 1 SCX or 2 SCX depending on port density.
– Signal Flow: Transmitters are encouraged to be placed at lower `scx` values (Left), while Receivers are placed at higher `scx` values (Right).