std.png

rfc 2083 decode to RGBA8 and encode; all color types, depths, interlace, tRNS

PngError

pub PngError :: errors {
    not_png,
    corrupt,
    unsupported,
    too_big,
}

• not_png: no PNG signature
• corrupt: truncated chunk, bad CRC, or bad image data
• unsupported: color type, depth or method not in the spec
• too_big: past 2^28 pixels

Image

pub Image :: struct {
    width: u32,
    height: u32,
    pixels: []u8,
}

width * height RGBA pixels, 4 bytes each, rows top to bottom

Image.at

pub at :: fn(self: *Self, x: u32, y: u32) -> u32

0,0 is top left; returns r | g << 8 | b << 16 | a << 24

image

pub image :: fn(a: *Arena, width: u32, height: u32) -> Image

all pixels transparent black; in a

decode

pub decode :: fn(a: *Arena, data: []const u8) -> Image ! PngError

pixels in a

encode

pub encode :: fn(a: *Arena, img: Image, level: u32) -> []const u8

file bytes in a; zlib level 0..9; RGB8 if all opaque, else RGBA8