Module image_render 

Pure image → ASCII-art kernel. Decodes nothing and touches no terminal; callers pass an already-decoded RgbaImage. Mirrors render’s discipline: plain inputs, plain cell outputs, exhaustively unit-tested.

Structs

Animation

Decoded animation: per-frame RGBA + the delay until the next frame, plus the loop count (None = infinite).

Enums

AnimationDecode

Outcome of decode_animation.

AsciiStyle

Rendering aesthetic.

Constants

BLOCK_SHADES

Block-shade ramp for --blocks under --no-color (no SGR available).

CELL_ASPECT

Terminal cells are about twice as tall as wide.

RAMP

Luminance ramp, darkest → brightest. Index by lum * (len-1) / 255.

Functions

decode_animation

Decode an animated image. Returns Static for a single-frame / non-animated source (caller falls back to decode_image), Animated for a playable multi-frame animation, or Unsupported when the source is animated but its frames can’t be decoded (so the caller can show the first frame and hint). GIF loop count comes from the NETSCAPE extension; other formats default to infinite. GIF, 8-bit APNG, and animated WebP decode to Animated; a 16-bit APNG (which the image crate rejects) decodes to Unsupported — both covered by tests/animation_decode.rs.

decode_image

Decode the full image bytes to RGBA8. For animated GIFs this yields the first frame. Returns the decoder error string on failure.

output_rows

How many cell rows render_image produces for an image of the given pixel dimensions at cols columns. Pure; used for scroll math.

parse_gif_loop_count

Extract the loop count from a GIF’s NETSCAPE2.0 application extension. Returns Some(0) for infinite, Some(n) for a finite count, or None when the extension is absent (callers treat that as infinite). The image crate’s high-level decoder does not expose this, so we read it directly.

render_image

Render the image to a grid of styled cells cols wide. color controls whether per-cell foreground color is set (false ≈ --no-color).

sniff_image_format

Identify an image by its leading bytes. Returns a short format name (for the status line) or None if the bytes are not a supported image. Content-based only — never guesses from a file extension — so text never misfires.