memfb_element_reader Struct Reference

Data Fields
size_t	frame_offset
size_t	size_per_band
size_t	plane_offset
size_t	plane_linesize
HqBool	multiple_planes
unsigned int	height
unsigned int	bandheight

Detailed Description

Data needed for reading memfb element planes. These assume a contiguous layout in memory for all frames of a sheet. When using the framebuffer support, it checks that all sheets have the same rendered_sheet_size, all frames have the same rendered_size_per_band, the same rendered_frame_size, and all planes have the same linesize.

We can calculate the offset of this plane knowing the frame's omitted index, the plane's omitted index, and the rendered size of frames and planes. We can calculate the band number from the line and band height to calculate the offset of the start of the band from the frame, add the plane offset to get the start of the plane in the band, and use the plane's linesize to find the start of the line in the plane. If there is more than one plane per frame, then we also need to limit the number of lines read to the end of the band to avoid encroaching onto another channel.

Field Documentation

bandheight

unsigned int memfb_element_reader::bandheight

Band height, copied here for easy access and to avoid casting.

frame_offset

size_t memfb_element_reader::frame_offset

Offset of frame from start of sheet buffer.

height

unsigned int memfb_element_reader::height

Raster height, copied here for easy access and to avoid casting.

multiple_planes

HqBool memfb_element_reader::multiple_planes

Are there more than one plane per frame?

plane_linesize

size_t memfb_element_reader::plane_linesize

Size of each line in plane.

plane_offset

size_t memfb_element_reader::plane_offset

Offset of this plane in contiguous band memory.

size_per_band

size_t memfb_element_reader::size_per_band

Size of all planes in each band of a frame.

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The documentation for this struct was generated from the following file:

• lib/skinkit/src/hvdmemfb.c