[skrifa] tthint: managing the graphics state

skrifa/src/outline/glyf/hint/code_state/mod.rs

@@ -4,5 +4,20 @@ mod args;
 
 pub use args::Args;
 
+/// Describes the source for a piece of bytecode.
+#[derive(Copy, Clone, PartialEq, Eq, Default, Debug)]
+#[repr(u8)]
+pub enum ProgramKind {
+    /// Program that initializes the function and instruction tables. Stored
+    /// in the `fpgm` table.
+    #[default]
+    Font = 0,
+    /// Program that initializes CVT and storage based on font size and other
+    /// parameters. Stored in the `prep` table.
+    ControlValue = 1,
+    /// Glyph specified program. Stored per-glyph in the `glyf` table.
+    Glyph = 2,
+}
+
 #[cfg(test)]
 pub(crate) use args::MockArgs;

skrifa/src/outline/glyf/hint/engine/arith.rs

@@ -1,9 +1,9 @@
 //! Arithmetic and math instructions.
 //!
+//! Implements 10 instructions.
+//!
 //! See <https://learn.microsoft.com/en-us/typography/opentype/spec/tt_instructions#arithmetic-and-math-instructions>
 
-// 10 instructions
-
 use super::{super::math, Engine, HintErrorKind, OpResult};
 
 impl<'a> Engine<'a> {