Reference

Expressions

ay2d_expression_count, ay2d_expression_id, ay2d_expression_index

uint32_t    ay2d_expression_count(const ay2d_model *m);
const char *ay2d_expression_id(const ay2d_model *m, uint32_t i);
int32_t     ay2d_expression_index(const ay2d_model *m, const char *name);

The expressions: the file's, then any you added. Thread: frame.

ay2d_expression_set, ay2d_expression_clear, ay2d_expression_shown

ay2d_status ay2d_expression_set(ay2d_model *m, uint32_t i, float fade_in);
ay2d_status ay2d_expression_clear(ay2d_model *m, float fade_out);
int32_t     ay2d_expression_shown(const ay2d_model *m);

Shows one expression, fading from the one before; clears it; and tells you which is shown (−1 for none). Fades work as for motions. Thread: frame.