Struct DebugVisitor 

pub struct DebugVisitor;

A debug implementation of CharStringVisitor that just prints the operators and their operands.

Example

use allsorts::binary::read::ReadScope;
use allsorts::cff::charstring::{ArgumentsStack, CharStringVisitorContext, DebugVisitor};
use allsorts::cff::CFFError;
use allsorts::cff::{self, CFFFont, CFFVariant, CFF};
use allsorts::font::MatchingPresentation;
use allsorts::font_data::FontData;
use allsorts::tables::{OpenTypeData, OpenTypeFont};
use allsorts::{tag, Font};

fn main() -> Result<(), CFFError> {
    // Read the font
    let buffer = std::fs::read("tests/fonts/opentype/Klei.otf").unwrap();
    let otf = ReadScope::new(&buffer).read::<OpenTypeFont<'_>>()?;
    let offset_table = match otf.data {
        OpenTypeData::Single(ttf) => ttf,
        OpenTypeData::Collection(_) => unreachable!(),
    };

    let cff_table_data = offset_table
        .read_table(&otf.scope, tag::CFF)?
        .expect("missing CFF table");
    let cff = cff_table_data.read::<CFF<'_>>()?;

    // Glyph to visit
    let glyph_id = 741; // U+2116 NUMERO SIGN

    // Set up CharString visitor
    let font = &cff.fonts[0];
    let local_subrs = match &font.data {
        CFFVariant::CID(_) => None, // Will be resolved on request.
        CFFVariant::Type1(type1) => type1.local_subr_index.as_ref(),
    };

    let mut visitor = DebugVisitor;
    let variable = None;
    let mut ctx = CharStringVisitorContext::new(
        glyph_id,
        &font.char_strings_index,
        local_subrs,
        &cff.global_subr_index,
        variable,
    );
    let mut stack = ArgumentsStack {
        data: &mut [0.0; cff::MAX_OPERANDS],
        len: 0,
        max_len: cff::MAX_OPERANDS,
    };
    ctx.visit(CFFFont::CFF(font), &mut stack, &mut visitor)?;
    Ok(())
}

Trait Implementations

impl CharStringVisitor<f32, CFFError> for DebugVisitor

fn visit( &mut self, op: VisitOp, stack: &ArgumentsStack<'_, f32>, ) -> Result<(), CFFError>

Called for each operator in the CharString, except for callsubr and callgsubr — these are handled by enter/exit_subr.

fn enter_subr(&mut self, index: SubroutineIndex) -> Result<(), CFFError>

Called prior to entering a subroutine.

fn exit_subr(&mut self) -> Result<(), E>

Called when returning from a subroutine.

fn enter_seac(&mut self, _seac: SeacChar, _dx: T, _dy: T) -> Result<(), E>

Called before entering a component of an accented character.

fn exit_seac(&mut self, _seac: SeacChar) -> Result<(), E>

Called when returning from a component of an accented character.

fn hint_data(&mut self, _op: VisitOp, _hints: &[u8]) -> Result<(), E>

Called with the hint data that follows the hintmask and cntrmask operators.