Greedy word-wrap over pre-measured, styled items. More...

#include "nilorea/n_wrap.h"

Include dependency graph for n_wrap.c:

Data Structures
struct	wrap_hit
	state for n_wrap_index_at's per-line callback More...
struct	wrap_span
	state for n_wrap_span_rects' per-line callback More...

Macros
#define	WRAP_NO_SPACE ((size_t)-1)
	no break point seen on the current line

Functions
size_t	n_wrap_index_at (const n_wrap_item *items, size_t count, double max_width, double line_height, double x, double y)
	The item boundary nearest a point: the inverse of n_wrap_layout(), for turning a click or a drag into a caret or a selection end.
size_t	n_wrap_layout (const n_wrap_item items, size_t count, double max_width, n_wrap_emit emit, void user)
	Break `items` into lines no wider than `max_width`.
size_t	n_wrap_span_rects (const n_wrap_item items, size_t count, double max_width, size_t lo, size_t hi, n_wrap_rect_emit emit, void user)
	The rectangles that cover the items [`lo`, `hi`): one per line the range touches, in order, for painting a selection highlight.
static void	wrap_hit_line (size_t first, size_t last, size_t line, double width, void *user)
static void	wrap_span_line (size_t first, size_t last, size_t line, double width, void *user)

Detailed Description

Greedy word-wrap over pre-measured, styled items.

Author: Castagnier Mickael

Version: 1.0

Definition in file n_wrap.c.

Data Structure Documentation

◆ wrap_hit

struct wrap_hit

state for n_wrap_index_at's per-line callback

Definition at line 125 of file n_wrap.c.

Collaboration diagram for wrap_hit:

Data Fields
int	found
const n_wrap_item *	items
size_t	result
size_t	want
double	x

◆ wrap_span

struct wrap_span

state for n_wrap_span_rects' per-line callback

Definition at line 202 of file n_wrap.c.

Collaboration diagram for wrap_span:

Data Fields
n_wrap_rect_emit	emit
size_t	hi
const n_wrap_item *	items
size_t	lo
size_t	n
void *	user

Macro Definition Documentation

◆ WRAP_NO_SPACE

#define WRAP_NO_SPACE ((size_t)-1)

no break point seen on the current line

Definition at line 30 of file n_wrap.c.

Referenced by n_wrap_layout().

Function Documentation

◆ n_wrap_index_at()

size_t n_wrap_index_at	(	const n_wrap_item *	items,
		size_t	count,
		double	max_width,
		double	line_height,
		double	x,
		double	y )

The item boundary nearest a point: the inverse of n_wrap_layout(), for turning a click or a drag into a caret or a selection end.

The point is in the laid-out text's own coordinates (0,0 = the first line's top-left), with every line line_height tall. The layout is the one n_wrap_layout() produces for the same items and max_width, so a hit can never disagree with what was drawn.

Within a line, a point on the left half of an item resolves to the boundary before it and on the right half to the boundary after it, so an atomic item (an emoji cell, an inline image) is selected whole or not at all. A point past a line's end resolves to that line's end; above the first line to 0; below the last line to count.

Parameters

items	the items given to n_wrap_layout(); may be NULL if `count` is 0
count	number of items
max_width	the width they were wrapped to
line_height	height of one line; a value <= 0 resolves every point to the first line
x	point, from the left edge
y	point, from the top edge

Returns: a boundary index in [0, count]: "before item i", count = after the last

Examples: ex_wrap.c.

Definition at line 176 of file n_wrap.c.

References wrap_hit::found, wrap_hit::items, n_wrap_layout(), wrap_hit::result, wrap_hit::want, wrap_hit_line(), and wrap_hit::x.

Referenced by main().

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◆ n_wrap_layout()

size_t n_wrap_layout	(	const n_wrap_item *	items,
		size_t	count,
		double	max_width,
		n_wrap_emit	emit,
		void *	user )

Break items into lines no wider than max_width.

Greedy: each line takes as much as fits, breaking at the last N_WRAP_SPACE that fits or, when the line holds no space, immediately before the item that overflows. An item that cannot fit even alone is placed alone rather than looping.

Parameters

items	pre-measured items; may be NULL when `count` is 0
count	number of items
max_width	the width to wrap to; a value <= 0 puts every non-empty line on its own item, since nothing but the first item of a line can ever fit
emit	called once per line, or NULL to only count lines (the measure pass, same breaks, no output)
user	cookie handed back to `emit`

Returns: the number of lines, always >= 1

Examples: ex_wrap.c.

Definition at line 50 of file n_wrap.c.

References n_wrap_item::flags, N_WRAP_NEWLINE, N_WRAP_SPACE, n_wrap_item::width, and WRAP_NO_SPACE.

Referenced by _wrap_words(), main(), md_flow(), n_wrap_index_at(), n_wrap_span_rects(), and run().

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◆ n_wrap_span_rects()

size_t n_wrap_span_rects	(	const n_wrap_item *	items,
		size_t	count,
		double	max_width,
		size_t	lo,
		size_t	hi,
		n_wrap_rect_emit	emit,
		void *	user )

The rectangles that cover the items [lo, hi): one per line the range touches, in order, for painting a selection highlight.

Uses the same layout as n_wrap_layout(), so the rectangles sit exactly under the drawn items. A space dropped at a line break belongs to no line and so lies under no rectangle; a line whose covered part has zero width (only a hard break) emits nothing. lo and hi may come in either order.

Parameters

items	the items given to n_wrap_layout()
count	number of items
max_width	the width they were wrapped to
lo	first boundary of the span
hi	other boundary (clamped to `count`)
emit	called once per covered line; may be NULL to only count
user	cookie handed back to `emit`