Is there a high resolution video of https://www.youtube.com/watch?v=MYtm9YG4tMM by any chance?

I am looking at the composite operators for Cairo. Is there an existing interface of using them in Racket?

https://cairographics.org/operators/

The list of all operators: https://www.cairographics.org/manual/cairo-cairo-t.html#cairo-operator-t

I see CAIRO_OPERATOR_XOR, CAIRO_OPERATOR_ADD and CAIRO_OPERATOR_SATURATE in draw/unsafe/cairo.rkt but some are missing.

https://github.com/racket/draw/blob/a6558bdc18438e784c23d452ffd877dac867a7fd/draw-lib/racket/draw/unsafe/cairo.rkt#L415

Hmm. They are not missing after all, the C header file has the same number of operators.

typedef enum _cairo_operator { CAIRO_OPERATOR_CLEAR,

`CAIRO_OPERATOR_SOURCE,`
`CAIRO_OPERATOR_OVER,`
`CAIRO_OPERATOR_IN,`
`CAIRO_OPERATOR_OUT,`
`CAIRO_OPERATOR_ATOP,`

`CAIRO_OPERATOR_DEST,`
`CAIRO_OPERATOR_DEST_OVER,`
`CAIRO_OPERATOR_DEST_IN,`
`CAIRO_OPERATOR_DEST_OUT,`
`CAIRO_OPERATOR_DEST_ATOP,`

`CAIRO_OPERATOR_XOR,`
`CAIRO_OPERATOR_ADD,`
`CAIRO_OPERATOR_SATURATE`

} cairo_operator_t;

I see that draw-bitmap from dc% has a mask, but I have trouble mapping the description to low-level operators.

Sorry something came up today and I can’t make it :disappointed:

The missing ones seem to say “since 1.10”