.Dd July 25, 2019
.Dt PNG 3
.Os
.
.Sh NAME
.Nm png
.Nd basic PNG output
.
.Sh SYNOPSIS
.In png.h
.
.Ft void
.Fo pngHead
.Fa "FILE *file"
.Fa "uint32_t width"
.Fa "uint32_t height"
.Fa "uint8_t depth"
.Fa "uint8_t color"
.Fc
.
.Ft void
.Fn pngPalette "FILE *file" "const uint8_t *pal" "uint32_t len"
.
.Ft void
.Fn pngData "FILE *file" "const uint8_t *data" "uint32_t len"
.
.Ft void
.Fn pngTail "FILE *file"
.
.Sh DESCRIPTION
The
.Fn pngHead
function
writes the
.Sy IHDR
chunk to
.Fa file .
The
.Fa color
parameter can be one of
.Dv PNGGrayscale ,
.Dv PNGTruecolor
optionally
.Em or Ns 'ed
with
.Dv PNGAlpha ,
or
.Dv PNGIndexed .
.
.Pp
The
.Fn pngPalette
function
writes the
.Sy PLTE
chunk to
.Fa file .
.
.Pp
The
.Fn pngData
function
writes the
.Sy IDAT
chunk to
.Fa file
without compression.
The constants
.Dv PNGNone ,
.Dv PNGSub ,
.Dv PNGUp ,
.Dv PNGAverage ,
.Dv PNGPaeth
are defined
for use in PNG data.
.
.Pp
The
.Fn pngTail
function
writes the
.Sy IEND
chunk to
.Fa file .
.
.Sh ERRORS
Any errors from writing to
.Fa file
are handled by calling
.Xr err 3 .