set_cel_opacity

Append N frames with optional duration

Add a new (optionally nested) group layer

Add a new layer, optionally inside a named group

Shift hue/saturation/lightness of a cel — palette swaps, night scenes, shadows

Two-color gradient using Bayer 4×4 ordered dithering

Uniform dithered mix of two colors at a given density

Smooth linear gradient fill in a rectangle

Copy a rectangle to another position, layer, or frame

Create a new sprite with the given dimensions

Delete a frame

Delete a layer by name

Outlined or filled ellipses with separate x/y radii

Polyline through a point list with thickness

Plot individual pixels with per-pixel colors

Plot pixels on a specific layer/frame

Outlined or filled polygons from a point list

Draw text with anchors, faux bold, outline, drop shadow and letter spacing

Duplicate a frame range N times

Duplicate a layer with all cels, opacity, and blend mode, optionally into a group

Magic-eraser: make all pixels of a color transparent (with tolerance)

Make a rectangle transparent

Flatten all layers into one

List the bitmap and TrueType fonts available to drawtext

Width, height, advance and baseline extents — size a panel or centre a label without redrawing to find out

Merge a layer into the one below it

Cut a rectangle of pixels and paste it elsewhere

Shift cels by a delta across frames

Add a 1px outline around all opaque pixels

Copy selected layers' cels across a frame range

Rename a layer

Move a layer to a position in the stack

Replace one color with another (with tolerance), preserving alpha

Place a cel at x,y

Set the active frame

Set one frame's duration in ms

Set every frame's duration

Set the active layer (optionally creating it)

Set blend mode (multiply, screen, overlay, ... 19 modes)