Drawing Helpers

lc_plugin::drawing provides reader post-processing helpers for operations that need access to the drawing after parsing. LinkCAD passes Drawing to Reader::post_process().

Python exposes equivalent drawing helper methods on linkcad.v1.db.Drawing.

Key Public Items

Item	Purpose
Drawing	Host-owned drawing handle for reader post-processing.
BooleanOperation	Layer-level boolean operation.
MergeLayerPolarityResult	Result of deferred-polarity materialization.

Enums

pub enum BooleanOperation {
    Or,
    AMinusB,
}

pub enum MergeLayerPolarityResult {
    Success,
    Cancelled,
    Failure,
}

BooleanOperation::Or unions the operand layer into the result layer. BooleanOperation::AMinusB subtracts the operand layer from the result layer.

Host Construction

pub unsafe fn from_raw(ptr: *mut LcDrawing) -> Self;

This method is public for ABI glue. Format plugins should use the Drawing passed to Reader::post_process().

Post-Processing Methods

Method	Description
boolean_layers_by_name(op, result_layer, operand_layer, resolution) -> bool	Run a layer boolean operation. result_layer is operand A and receives the output.
merge_layer_polarity_group(group_name, resolution, progress, progress_from, progress_to) -> MergeLayerPolarityResult	Materialize one deferred-polarity group.
merge_all_polarity_groups(resolution, progress, progress_from, progress_to) -> MergeLayerPolarityResult	Materialize all deferred-polarity groups in one batch.
destroy_layer_by_name(layer: &str) -> bool	Destroy a layer if it exists.
rename_layer(from: &str, to: &str) -> bool	Rename a layer.

String inputs that contain an interior NUL byte return false or MergeLayerPolarityResult::Failure instead of panicking.

Reader Post-Process Example

impl Reader for ExampleReader {
    fn parse_file(
        &mut self,
        _path: &str,
        builder: &mut DrawingBuilder,
        _file_size: i64,
        _current_file: i32,
        _file_count: i32,
    ) -> bool {
        builder.open_cell_by_name("TOP", true, false);
        builder.select_layer_by_name("metal");
        builder.create_rectangle(Point::new(0, 0), Point::new(10_000, 10_000));
        builder.close_cell();
        true
    }

    fn post_process(
        &mut self,
        phase: Phase,
        drawing: &mut Drawing,
        progress: Option<&mut DrawingBuilder>,
        log: &mut EventLog,
        resolution: &Resolution,
    ) -> bool {
        if phase != Phase::ParsedAll {
            return true;
        }

        match drawing.merge_all_polarity_groups(resolution, progress, 0, 100) {
            MergeLayerPolarityResult::Success => true,
            MergeLayerPolarityResult::Cancelled => false,
            MergeLayerPolarityResult::Failure => {
                log.error("Could not merge layer polarity groups");
                false
            }
        }
    }
}

Progress Range

progress_from and progress_to map the operation’s internal progress to a percentage interval in the host progress bar. Pass the progress builder from Reader::post_process() when available so cancellation is detected and progress updates are visible.