Struct lodepng::ffi::Info

#[repr(C)]
pub struct Info {
    pub compression_method: c_uint,
    pub filter_method: c_uint,
    pub interlace_method: c_uint,
    pub color: ColorMode,
    pub background_defined: c_uint,
    pub background_r: c_uint,
    pub background_g: c_uint,
    pub background_b: c_uint,
    pub time_defined: c_uint,
    pub time: Time,
    pub phys_defined: c_uint,
    pub phys_x: c_uint,
    pub phys_y: c_uint,
    pub phys_unit: c_uint,
    pub unknown_chunks_data: [*mut c_uchar; 3],
    pub unknown_chunks_size: [usize; 3],
    // some fields omitted
}

Information about the PNG image, except pixels, width and height

Fields

compression_method: c_uint

compression method of the original file. Always 0.

filter_method: c_uint

filter method of the original file

interlace_method: c_uint

interlace method of the original file

color: ColorMode

color type and bits, palette and transparency of the PNG file

background_defined: c_uint

suggested background color chunk (bKGD) This color uses the same color mode as the PNG (except alpha channel), which can be 1-bit to 16-bit.

For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding the encoder writes the red one. For palette PNGs: When decoding, the RGB value will be stored, not a palette index. But when encoding, specify the index of the palette in background_r, the other two are then ignored.

The decoder does not use this background color to edit the color of pixels.

background_r: c_uint

red component of suggested background color

background_g: c_uint

green component of suggested background color

background_b: c_uint

blue component of suggested background color

time_defined: c_uint

set to 1 to make the encoder generate a tIME chunk

time: Time

time chunk (tIME)

phys_defined: c_uint

if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one

phys_x: c_uint

pixels per unit in x direction

phys_y: c_uint

pixels per unit in y direction

phys_unit: c_uint

may be 0 (unknown unit) or 1 (metre)

unknown_chunks_data: [*mut c_uchar; 3]

unknown chunks There are 3 buffers, one for each position in the PNG where unknown chunks can appear each buffer contains all unknown chunks for that position consecutively The 3 buffers are the unknown chunks between certain critical chunks: 0: IHDR-PLTE, 1: PLTE-IDAT, 2: IDAT-IEND Do not allocate or traverse this data yourself. Use the chunk traversing functions declared later, such as lodepng_chunk_next and lodepng_chunk_append, to read/write this struct.

unknown_chunks_size: [usize; 3]

Methods

impl Info

pub fn new() -> Self

pub fn text_keys_cstr(&self) -> TextKeysCStrIter

pub fn itext_keys(&self) -> ITextKeysIter

pub fn clear_text(&mut self)

use this to clear the texts again after you filled them in

pub fn add_text(&mut self, key: &str, str: &str) -> Result<(), Error>

push back both texts at once

pub fn clear_itext(&mut self)

use this to clear the itexts again after you filled them in

pub fn add_itext(
    &mut self,
    key: &str,
    langtag: &str,
    transkey: &str,
    text: &str
) -> Result<(), Error>

push back the 4 texts of 1 chunk at once

pub fn append_chunk(
    &mut self,
    position: ChunkPosition,
    chunk: ChunkRef
) -> Result<(), Error>

pub fn create_chunk<C: AsRef<[u8]>>(
    &mut self,
    position: ChunkPosition,
    chtype: C,
    data: &[u8]
) -> Result<(), Error>

pub fn get<Name: AsRef<[u8]>>(&self, index: Name) -> Option<ChunkRef>

pub fn unknown_chunks(&self, position: ChunkPosition) -> ChunksIter

Trait Implementations

impl Drop for Info

fn drop(&mut self)

Executes the destructor for this type.

impl Clone for Info

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Info

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.