Struct openexr::core::output_part::OutputPart

#[repr(transparent)]
pub struct OutputPart<'a> { /* fields omitted */ }

Implementations

impl<'a> OutputPart<'a>

pub fn new(
    multi_part_file: &MultiPartOutputFile,
    part_number: i32
) -> Result<OutputPart<'_>, Error>

Get an interface to the part part_number of the MultiPartOutputFile multi_part_file.

pub fn file_name(&self) -> &str

Get the filename this file is writing to.

pub fn header(&self) -> HeaderRef<'_>

Access to the file Header

pub fn set_frame_buffer(
    &mut self,
    frame_buffer: &FrameBuffer
) -> Result<(), Error>

Set the current frame buffer – copies the FrameBuffer object into the OutputPart object.

The current frame buffer is the source of the pixel data written to the file. The current frame buffer must be set at least once before OutputPart::write_pixels is called. The current frame buffer can be changed after each call to OutputPart::write_pixels.

Errors

• Error::InvalidArgument - If the pixel type of the Channels in the Header do not match the types in the frame buffer, or if the sampling rates do not match.

pub fn frame_buffer(&self) -> FrameBufferRef<'_>

Get a reference to the frame buffer.

pub unsafe fn write_pixels(&mut self, num_scan_lines: i32) -> Result<(), Error>

Write pixel data.

Retrieves the next num_scan_lines worth of data from the current frame buffer, starting with the scan line indicated by OutputPart::current_scan_line and stores the data in the output file, and progressing in the direction indicated by header().line_order().

To produce a complete and correct file, exactly m scan lines must be written, where m is equal to header().data_window().max.y - header().data_window().min.y + 1.

Errors

• Error::Io - If an I/O error occurs while writing the image data
• Error::InvalidArgument - If current_scan_line() + num_scan_lines is outside the data window.
• Error::Base - If any other error occurs.

Safety

This method is wildly unsafe as on the C++ side it’s reading from pointers offset from the base pointers supplied by the crate::core::frame_buffer::Slice in the FrameBuffer. In particular, by setting an crate::core::frame_buffer::SliceBuilder::origin you can cause write_pixels to read from arbitrary memory locations.

pub fn current_scan_line(&self) -> i32

Access to the current scan line:

Returns the y coordinate of the first scan line that will be read from the current frame buffer during the next call to OutputPart::write_pixels.

If line_order() == INCREASING_Y:

The current scan line before the first call to write_pixels() is header().data_window().min.y. After writing each scan line, the current scan line is incremented by 1.

If line_order() == DECREASING_Y:

The current scan line before the first call to write_pixels() is header().data_window().max.y. After writing each scan line, the current scan line is decremented by 1.

pub fn copy_pixels_from_file(&mut self, file: &InputFile) -> Result<(), Error>

Shortcut to copy all pixels from an InputFile into this file, without uncompressing and then recompressing the pixel data.

This file’s header must be compatible with the InputFile’s header: The two header’s “dataWindow”, “compression”, “lineOrder” and “channels” attributes must be the same.

Errors

• Error::InvalidArgument - If the headers do not match
• Error::LogicError - If scan lines have already been written to this file.

pub fn copy_pixels_from_part(
    &mut self,
    file: &mut InputPart<'_>
) -> Result<(), Error>

Shortcut to copy all pixels from an InputPart into this file, without uncompressing and then recompressing the pixel data.

This file’s header must be compatible with the InputPart’s header: The two header’s “dataWindow”, “compression”, “lineOrder” and “channels” attributes must be the same.

Errors

• Error::InvalidArgument - If the headers do not match
• Error::LogicError - If scan lines have already been written to this file.

pub fn update_preview_image(
    &mut self,
    new_pixels: &[PreviewRgba]
) -> Result<(), Error>

Updating the preview image:

Supplies a new set of pixels for the preview image attribute in the file’s header.

This is necessary because images are often stored in a file incrementally, a few scan lines at a time, while the image is being generated. Since the preview image is an attribute in the file’s header, it gets stored in the file as soon as the file is opened, but we may not know what the preview image should look like until we have written the last scan line of the main image.

Errors

• Error::LogicError - If the header does not contain a preview image
• Error::Base - If any other error occurs