1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
|
#ifndef VEGA_LAYOUT_H
#define VEGA_LAYOUT_H
#include "shape.h"
/* A paragraph set into lines (docs/design/004-text.md): its bidi levels
* (UAX #9), a font for each grapheme cluster, lines broken where UAX #14
* allows and they fit (spaces at a line's end hang past it), and each
* line's runs (one level, one script, one font) shaped and put in visual
* order. Positions are in the first font's units: x from the paragraph's
* left edge, y up from the line's baseline. */
typedef struct {
uint32_t glyph; /* its font's: its symbol is VEGA_GLYPH_SYMBOLS + glyph */
uint32_t cluster; /* the paragraph index of the first character it came from */
int32_t x, y, advance;
uint32_t font; /* which of the fonts */
} VegaPlaced;
typedef struct {
size_t first, count; /* its glyphs, left to right */
size_t start, end; /* the characters it holds, [start, end) */
int32_t left, width; /* where it starts and how far what shows goes */
} VegaLine;
typedef struct {
VegaLine *lines;
size_t line_count;
VegaPlaced *glyphs;
size_t glyph_count;
int level; /* the paragraph's: odd is right to left, and its lines align right */
int32_t width; /* the widest line's */
/* what setting the paragraph works in, kept for the next */
void *work;
size_t work_size, lines_allocated, glyphs_allocated;
} VegaLayout;
/* What text is set in: fonts in order of preference, each cluster in the
* first that has all its characters (default ignorables aside: shaping
* hides them), a cluster of Common and Inherited characters (spaces,
* digits, punctuation) in the font before it when that one has them; no
* font having them all, the first that has its first character, else the
* first font. has says whether a font has a character, NULL whether its
* character map does: a font whose glyphs are not all at hand can say it
* lacks the others. */
enum { VEGA_LAYOUT_FONTS = 16 };
typedef struct {
const VegaShaping *fonts[VEGA_LAYOUT_FONTS];
unsigned count;
bool (*has)(void *context, unsigned font, uint32_t code);
void *context;
} VegaFonts;
/* Set count characters in lines of at most width (0: no limit) in the
* fonts; direction is VEGA_BIDI_AUTO, _LTR or _RTL. The layout holds the
* result until it is set again; false without memory, or when a run's font
* has no plan for its script (nor for Common). */
bool vega_layout(VegaLayout *, VegaShaper *, const VegaFonts *, const uint32_t *codes, size_t count, int direction,
int32_t width);
void vega_layout_free(VegaLayout *);
#endif
|
