Expose Ghostty's cursor shape enum to shaders:

// Macros for a more semantic usage. Though this could just be differed to the documentation too.
#define CURSORSTYLE_BLOCK 0
#define CURSORSTYLE_BLOCK_HOLLOW 1
#define CURSORSTYLE_BAR 2
#define CURSORSTYLE_UNDERLINE 3

uniform int iCursorStyle;

Use case: Shaders can render contextually appropriate effects—for example, a full-cell glow for block cursors vs. a vertical beam glow for bar cursors, or a subtle underline ripple for underline cursors. I found that when I was making my shader, I just wanted to know what type of cursor I had so I could easily change the shape of it.