Routines to configure the rasterizing process. More...

Data Structures
struct	internal_adaption

Macros
#define	CAPS_RSTR_DEFAULT_ROTATION (-90)

Functions
static void	print_area (const char *s, struct caps_area a)

static void	print_rect (const char *s, struct caps_rect r)

static int	check_less_or_equal (double v, double t)

static struct caps_rect	rect_scale (const struct caps_rect r, double scale_x, double scale_y)

static struct caps_rect	area_to_sz (struct caps_area a)

static struct caps_area	area_scale (const struct caps_area a, double scale_x, double scale_y)

static struct caps_area	margins_rotate (struct caps_area *mi, int rotation)

static struct caps_area	select_area_from_source (struct caps_rect source_sz, struct caps_rect media, struct caps_rect ptr, struct caps_area m)

static void	new_alignment (struct internal_adaption *i, enum caps_rstr_alignment alignment)

static void	new_rotated_print (struct internal_adaption *i, int rot, int imageable_area)

static int	orientation_differs (const struct caps_rect src, const struct caps_rect dst)

static int	page_auto_rotation_fit (struct internal_adaption i, const struct caps_rstr_page medium)

static int	page_auto_rotation_straight (struct internal_adaption i, const struct caps_rstr_page medium)

static int	page_rotation_guess (struct internal_adaption i, const struct caps_rstr_page medium, unsigned fit)

static int	page_rotation_on_orientation (struct internal_adaption i, const struct caps_rstr_page medium, enum caps_rstr_orientation orient)

static void	check_preconditions (const struct document_desc *job)

static void	scale_with_aspect_ratio (struct internal_adaption *i, int rotation)

void	page_setup (struct document_desc job, struct raster_adapt_preparation setup, const struct caps_rstr_page *page)

Detailed Description

Copyright: GNU General Public License 2 or later

Author: Jürgen Borleis

Version: 1.0.0

Warning: Use as experimental

These routines herein configure the rasterizing process according to printer driver settings, user settings and printig parameter settings. This includes content rotation, content scaling or cropping to ensure the best printing experience.

Macro Definition Documentation

◆ CAPS_RSTR_DEFAULT_ROTATION

#define CAPS_RSTR_DEFAULT_ROTATION (-90)

The default rotation direction if FAV_ROTATION_NONE and no user overwrite is defined Used whenever some kind of auto-rotation is required. This rotation defines a counter-clockwise rotation by -90 ° as the default (like all images show).
It corresponds to FAV_ROTATION_COUNTERCLOCKWISE

Function Documentation

◆ print_area()

static void print_area	(	const char *	s,
		struct caps_area	a
	)

static

◆ print_rect()

static void print_rect	(	const char *	s,
		struct caps_rect	r
	)

static

◆ check_less_or_equal()

static int check_less_or_equal	(	double	v,
		double	t
	)

static

Check if v is less or equal t

Parameters

[in]	v	The value which should be less or equal to `t`
[in]	t	The value to check `v` against

Return values

1	`v` <= `t`
0	`v` > `t`

Due to rounding imprecisions a less/equal check is not that trivial

Note: I added this function since "islessequal(v, t + 0.000001)" seems not working as expected (?????????).

◆ rect_scale()

static struct caps_rect rect_scale	(	const struct caps_rect	r,
		double	scale_x,
		double	scale_y
	)

static

Scale the rectangle information

Parameters

[in]	r	The rectangle information to scale
[in]	scale_x	Scale factor in horizontal direction
[in]	scale_y	Scale factor in vertical direction

Returns: The scaled rectangle information

◆ area_to_sz()

static struct caps_rect area_to_sz ( struct caps_area a )

static

Convert the rectangle formed by an area into a simple rectangle

Parameters

[in] a The area to convert

Returns: The rectangle information

◆ area_scale()

static struct caps_area area_scale	(	const struct caps_area	a,
		double	scale_x,
		double	scale_y
	)

static

Scale an area information

Parameters

[in]	a	The area information to scale
[in]	scale_x	Scale factor in horizontal direction
[in]	scale_y	Scale factor in vertical direction

Returns: The scaled area information

◆ margins_rotate()

static struct caps_area margins_rotate	(	struct caps_area *	mi,
		int	rotation
	)

static

Rotate the raw margin information

Parameters

[in]	mi	Margins (not coordinates!)
[in]	rotation	How to rotate, 0 °, 90 °, 180 °, 270 °, -90 °, -180 ° (from source to destination)

Returns: Rotated margins (from destination to source orientation)

Note: "raw" means, the four values aren't coordinates, they are margins instead.

If the source should be rotated by +90 °, then the destination margins must be rotated by -90 ° to be used on the source.

From "source to destination" means the user's expectation. Since this function is intended to rotate the margins from destination to source, we need to rotate the four margins into the opposite direction.

◆ select_area_from_source()

static struct caps_area select_area_from_source	(	struct caps_rect	source_sz,
		struct caps_rect	media,
		struct caps_rect	ptr,
		struct caps_area	m
	)

static

Locate and/or crop a given rectangle in the source area as the part which should be print

Parameters

[in]	source_sz	Real size and orientation of the source
[in]	media	Rotated size of media (destination)
[in]	ptr	Rotated size of printable area (destination)
[in]	m	Rotated raw margins (destination)

Returns: The crop area of the source, in the same orientation as media and ptr, which means in source orientation

Precondition: Both media, ptr and margins have the same orientation (the one of the source)

◆ new_alignment()

static void new_alignment	(	struct internal_adaption *	i,
		enum caps_rstr_alignment	alignment
	)

static

Put the raster into the printable area of the medium

Parameters

[in,out]	i	The whole extraction and print information
[in]	alignment	Alignment of the raster inside the printable area of the medium

Where to locate the raster:

if the raster is smaller than the printable destination area and CAPS_RSTR_ALIGN_CENTER is set?
- in the center of the printable destination area?
- in the center of the destination medium?
if the raster is equal to the printable destination area and CAPS_RSTR_ALIGN_CENTER is set
- the margins are already considered

Note: : Currently the raster gets centered into the printable destination area if it is smaller

Precondition: The raster size must fit into the destination area, e.g. the printable area of the medium

◆ new_rotated_print()

static void new_rotated_print	(	struct internal_adaption *	i,
		int	rot,
		int	imageable_area
	)

static

Calculate the area from the source and locate it on the destination

Parameters

[in,out]	i	The whole extraction and print information
[in]	rot	Rotation from the source point of view
[in]	imageable_area	1 if the print should scale to the imageable area

In case of success, the internal_adaption::src_crop_area, internal_adaption::offset_y and internal_adaption::offset_y are filled and valid.

◆ orientation_differs()

static int orientation_differs	(	const struct caps_rect *	src,
		const struct caps_rect *	dst
	)

static

Check if both size rectangles have a different orientation (portrait versus landscape)

Parameters

[in]	src	The source rectangle
[in]	dst	The destination rectangle

Return values

0	Both rectangles have the same orientation
1	Both rectangles have a different orientation

◆ page_auto_rotation_fit()

static int page_auto_rotation_fit	(	struct internal_adaption *	i,
		const struct caps_rstr_page *	medium
	)

static

Find best rotation if the page should be printed in a scaled manner

Parameters

[in,out]	i	The whole extraction and print information
[in]	medium	The crude print configuration from the printer driver

Returns: Rotation value (0, 90, -90)

The algorithm selects the rotation with the largest possible scale.

Todo:: Create some images to explain

Precondition: internal_adaption::src_full_sz differs from internal_adaption::dst_full_sz in its ortientation

◆ page_auto_rotation_straight()

static int page_auto_rotation_straight	(	struct internal_adaption *	i,
		const struct caps_rstr_page *	medium
	)

static

Find best rotation if the page should be printed as-is

Parameters

[in,out]	i	The whole extraction and print information
[in]	medium	The crude print configuration from the printer driver

Returns: Rotation value (0, 90, -90)

The algorithm finds the least lost when cropping.

Todo:: Create some images to explain

Precondition: internal_adaption::src_full_sz differs from internal_adaption::dst_full_sz in its ortientation

◆ page_rotation_guess()

static int page_rotation_guess	(	struct internal_adaption *	i,
		const struct caps_rstr_page *	medium,
		unsigned	fit
	)

static

Try the best to image most of the source page to the destination medium (if not otherwise defined)

Parameters

[in,out]	i	The whole extraction and print information
[in]	medium	The crude print configuration from the printer driver
[in]	fit	Not 0 if the print should fit the destination.

Returns: Rotation value (0, 90, -90)

Todo:: Do we need to honor fit_to_page or fit_to_imageable_area here?

◆ page_rotation_on_orientation()

static int page_rotation_on_orientation	(	struct internal_adaption *	i,
		const struct caps_rstr_page *	medium,
		enum caps_rstr_orientation	orient
	)

static

Rotate on demand to force the given orient

Parameters

[in,out]	i	The whole extraction and print information
[in]	medium	The crude print configuration from the printer driver
[in]	orient	The user's orientation selection

Returns: Rotation value (0, 90, -90, 180)

Todo:: Do we need to honor fit_to_page or fit_to_imageable_area here?

Note: Adds a rotation on demand.

◆ check_preconditions()

static void check_preconditions ( const struct document_desc * job )

static

◆ scale_with_aspect_ratio()

static void scale_with_aspect_ratio	(	struct internal_adaption *	i,
		int	rotation
	)

static

Scale up or down the source to the destination while keeping the aspect ratio

Parameters

[in,out]	i	The whole extraction and print information
[in]	rotation	Rotation of the source to consider (0, 90, 180, 270, -90, -180)

Both axis are scaled with the same value to keep the aspect ratio.

Todo:: Think about predicable rounding the scale values.

◆ page_setup()

void page_setup	(	struct document_desc *	job,
		struct raster_adapt_preparation *	setup,
		const struct caps_rstr_page *	page
	)

Setup all required parameters for the current page in order to rasterize it in the next step

Parameters

[in,out]	job	Collected job info
[out]	setup	Setup how to raster the page
[in]	page	The crude print configuration from the printer driver

The calculations here are made when the printer driver calls caps_rstr_page_rasterize().

What we have:

the size and orientation of the source page (from the current document's page)
the settings from the user's printing parameters
the size and orientation of the target medium (from the printer driver)

What we calculate here:

how to convert the source page into the destination page
- depending on various flags this includes:
  - rotation
  - scaling
  - cropping
- the flags are
  - some defaults if no related user's printing parameters are given
  - the user's printing parameters itself
  - restrictions the printer has

Note: Called by caps_rstr_page_rasterize()

Todo:: Deal with fidelity

Data Structures

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ CAPS_RSTR_DEFAULT_ROTATION

Function Documentation

◆ print_area()

◆ print_rect()

◆ check_less_or_equal()

◆ rect_scale()

◆ area_to_sz()

◆ area_scale()

◆ margins_rotate()

◆ select_area_from_source()

◆ new_alignment()

◆ new_rotated_print()

◆ orientation_differs()

◆ page_auto_rotation_fit()

◆ page_auto_rotation_straight()

◆ page_rotation_guess()

◆ page_rotation_on_orientation()

◆ check_preconditions()

◆ scale_with_aspect_ratio()

◆ page_setup()