Reference

Types and constants

#define AY2D_ABI_VERSION 1u

typedef struct ay2d_model ay2d_model;          /* opaque */

typedef struct ay2d_canvas_info {
    float width, height;          /* pixels */
    float pixels_per_unit;
    float origin_x, origin_y;     /* the pixel at model unit (0, 0) */
} ay2d_canvas_info;

typedef struct ay2d_drawable {
    uint32_t mesh;                /* index, < ay2d_mesh_count */
    uint32_t texture;             /* index, < ay2d_texture_count */
    uint32_t flags;               /* AY2D_FLAG_* */
    float    opacity;             /* 0 to 1, times the texture's alpha */
    uint32_t vertex_count;
    uint32_t index_count;         /* a multiple of 3 */
    uint32_t mask_count;
    const float    *positions;    /* vertex_count xy pairs, model units */
    const float    *uvs;          /* vertex_count uv pairs, 0 to 1 */
    const uint16_t *indices;      /* triangle list */
    const uint32_t *masks;        /* meshes whose alpha clips this one */
} ay2d_drawable;

typedef struct ay2d_motion_facts {
    float   duration, fps;        /* seconds; the authored frame rate */
    int32_t looped;               /* 1 when authored to loop */
    int32_t composition;          /* 1 for a composition, 0 for a scene */
    float   fade_in, fade_out;    /* seconds, -1 when not authored */
    uint32_t event_count;
} ay2d_motion_facts;

typedef struct ay2d_event {
    uint32_t    motion;           /* the motion that fired it */
    float       time;             /* on that motion's clock */
    const char *name;             /* lives as long as the model */
} ay2d_event;

Neither blend flag set means normal blending.