Enum tfm::ligkern::lang::Operation

pub enum Operation {
    Kern(Number),
    KernAtIndex(u16),
    Ligature {
        char_to_insert: Char,
        post_lig_operation: PostLigOperation,
        post_lig_tag_invalid: bool,
    },
    EntrypointRedirect(u16, bool),
}

A lig/kern operation to perform.

Variants

Kern(Number)

Insert a kern between the current character and the next character.

The variant payload is the size of the kern.

KernAtIndex(u16)

Insert a kern between the current character and the next character.

The variant payload is the index of the kern in the kerns array.

Ligature

Fields

char_to_insert: Char

Character to insert.

post_lig_operation: PostLigOperation

What to do after inserting the character.

post_lig_tag_invalid: bool

If the tag in the .tfm file was invalid, this will be true. In this case the post_lig_operation will be PostLigOperation::RetainNeitherMoveToInserted.

This field is used in the .tfm validation function to generate a warning for this case. We could also generate a warning in the deserialization code itself but then the ordering of the warning would be incorrect with respect to other validation warnings.

Perform a ligature step. This inserts char_to_insert between the left and right characters, and then performs the post-lig operation.

EntrypointRedirect(u16, bool)

If the entrypoint for a character is this operation, go to the instruction indexed by the payload.

This redirect mechanism exists because in .tfm files entrypoints are u8s but lig/kern programs can contain more than 256 instructions.

If this operation is encountered in another situation, it is an unconditional stop.

The boolean value in the payload is true if the boundary character should be serialized inside the instruction.

Trait Implementations

impl Clone for Operation

fn clone(&self) -> Operation

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Operation

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq<Operation> for Operation

fn eq(&self, other: &Operation) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Operation

impl Eq for Operation

impl StructuralEq for Operation

impl StructuralPartialEq for Operation