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/****************************************************************************\
Part of the XeTeX typesetting system
Copyright (c) 1994-2008 by SIL International
Copyright (c) 2009 by Jonathan Kew
Copyright (c) 2012-2015 by Khaled Hosny
SIL Author(s): Jonathan Kew
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE
FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Except as contained in this notice, the name of the copyright holders
shall not be used in advertising or otherwise to promote the sale,
use or other dealings in this Software without prior written
authorization from the copyright holders.
\****************************************************************************/
#include <w2c/config.h>
#include <assert.h>
#include <algorithm>
#include "XeTeXOTMath.h"
#include "XeTeX_web.h"
#include "XeTeXLayoutInterface.h"
#include "XeTeXFontInst.h"
int
get_ot_math_constant(int f, int n)
{
hb_ot_math_constant_t constant = (hb_ot_math_constant_t) n;
hb_position_t rval = 0;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
hb_font_t* hbFont = font->getHbFont();
rval = hb_ot_math_get_constant(hbFont, constant);
/* scale according to font size, except the ones that are percentages */
switch (constant) {
case HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN:
case HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN:
case HB_OT_MATH_CONSTANT_RADICAL_DEGREE_BOTTOM_RAISE_PERCENT:
break;
default:
rval = D2Fix(font->unitsToPoints(rval));
break;
}
}
return rval;
}
#define unknown ((hb_ot_math_constant_t)-1)
/* fontdimen IDs for math symbols font (family 2) */
#define math_x_height 5
#define math_quad 6
#define num1 8 /* numerator shift-up in display styles */
#define num2 9 /* numerator shift-up in non-display, non-\.{\\atop} */
#define num3 10 /* numerator shift-up in non-display \.{\\atop} */
#define denom1 11 /* denominator shift-down in display styles */
#define denom2 12 /* denominator shift-down in non-display styles */
#define sup1 13 /* superscript shift-up in uncramped display style */
#define sup2 14 /* superscript shift-up in uncramped non-display */
#define sup3 15 /* superscript shift-up in cramped styles */
#define sub1 16 /* subscript shift-down if superscript is absent */
#define sub2 17 /* subscript shift-down if superscript is present */
#define sup_drop 18 /* superscript baseline below top of large box */
#define sub_drop 19 /* subscript baseline below bottom of large box */
#define delim1 20 /* size of \.{\\atopwithdelims} delimiters */
#define delim2 21 /* size of \.{\\atopwithdelims} delimiters in non-displays */
#define axis_height 22 /* height of fraction lines above the baseline */
const hb_ot_math_constant_t TeX_sym_to_OT_map[] = {
unknown,
unknown,
unknown,
unknown,
unknown,
HB_OT_MATH_CONSTANT_ACCENT_BASE_HEIGHT, // x-height
unknown, // quad
unknown,
HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_DISPLAY_STYLE_SHIFT_UP,
HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_SHIFT_UP,
HB_OT_MATH_CONSTANT_STACK_TOP_SHIFT_UP,
HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_DISPLAY_STYLE_SHIFT_DOWN,
HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_SHIFT_DOWN,
HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP, // ??
HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP, // ??
HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP_CRAMPED,
HB_OT_MATH_CONSTANT_SUBSCRIPT_SHIFT_DOWN, // ??
HB_OT_MATH_CONSTANT_SUBSCRIPT_SHIFT_DOWN, // ??
HB_OT_MATH_CONSTANT_SUPERSCRIPT_BASELINE_DROP_MAX, // ??
HB_OT_MATH_CONSTANT_SUBSCRIPT_BASELINE_DROP_MIN, // ??
HB_OT_MATH_CONSTANT_DELIMITED_SUB_FORMULA_MIN_HEIGHT,
unknown, // using quad instead for now
HB_OT_MATH_CONSTANT_AXIS_HEIGHT
};
int
get_native_mathsy_param(int f, int n)
{
int rval = 0;
if (n == math_quad) {
rval = fontsize[f];
}
else if (n == delim2) { // XXX not sure what OT parameter we should use here;
// for now we use 1.5em, clamped to delim1 height
rval = std::min<int>(1.5 * fontsize[f], get_native_mathsy_param(f, delim1));
}
else {
if (n < sizeof(TeX_sym_to_OT_map) / sizeof(hb_ot_math_constant_t)) {
hb_ot_math_constant_t ot_index = TeX_sym_to_OT_map[n];
if (ot_index != unknown)
rval = get_ot_math_constant(f, (int)ot_index);
}
}
// fprintf(stderr, " math_sy(%d, %d) returns %.3f\n", f, n, Fix2D(rval));
return rval;
}
/* fontdimen IDs for math extension font (family 3) */
#define default_rule_thickness 8 /* thickness of \.{\\over} bars */
#define big_op_spacing1 9 /* minimum clearance above a displayed op */
#define big_op_spacing2 10 /* minimum clearance below a displayed op */
#define big_op_spacing3 11 /* minimum baselineskip above displayed op */
#define big_op_spacing4 12 /* minimum baselineskip below displayed op */
#define big_op_spacing5 13 /* padding above and below displayed limits */
const hb_ot_math_constant_t TeX_ext_to_OT_map[] = {
unknown,
unknown,
unknown,
unknown,
unknown,
HB_OT_MATH_CONSTANT_ACCENT_BASE_HEIGHT, // x-height
unknown, // quad
unknown,
HB_OT_MATH_CONSTANT_FRACTION_RULE_THICKNESS, // default_rule_thickness
HB_OT_MATH_CONSTANT_UPPER_LIMIT_GAP_MIN, // big_op_spacing1
HB_OT_MATH_CONSTANT_LOWER_LIMIT_GAP_MIN, // big_op_spacing2
HB_OT_MATH_CONSTANT_UPPER_LIMIT_BASELINE_RISE_MIN, // big_op_spacing3
HB_OT_MATH_CONSTANT_LOWER_LIMIT_BASELINE_DROP_MIN, // big_op_spacing4
HB_OT_MATH_CONSTANT_STACK_GAP_MIN // big_op_spacing5
};
int
get_native_mathex_param(int f, int n)
{
int rval = 0;
if (n == math_quad)
rval = fontsize[f];
else {
if (n < sizeof(TeX_ext_to_OT_map) / sizeof(hb_ot_math_constant_t)) {
hb_ot_math_constant_t ot_index = TeX_ext_to_OT_map[n];
if (ot_index != unknown)
rval = get_ot_math_constant(f, (int)ot_index);
}
}
// fprintf(stderr, " math_ex(%d, %d) returns %.3f\n", f, n, Fix2D(rval));
return rval;
}
int
get_ot_math_variant(int f, int g, int v, integer* adv, int horiz)
{
hb_codepoint_t rval = g;
*adv = -1;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
hb_font_t* hbFont = font->getHbFont();
hb_ot_math_glyph_variant_t variant[1];
unsigned int count = 1;
hb_ot_math_get_glyph_variants(hbFont, g, horiz ? HB_DIRECTION_RTL : HB_DIRECTION_TTB, v, &count, variant);
if (count > 0) {
rval = variant->glyph;
*adv = D2Fix(font->unitsToPoints(variant->advance));
}
}
return rval;
}
void*
get_ot_assembly_ptr(int f, int g, int horiz)
{
void* rval = NULL;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
hb_font_t* hbFont = font->getHbFont();
unsigned int count = hb_ot_math_get_glyph_assembly(hbFont, g, horiz ? HB_DIRECTION_RTL : HB_DIRECTION_TTB, 0, NULL, NULL, NULL);
if (count > 0) {
GlyphAssembly* a = (GlyphAssembly*) xmalloc(sizeof(GlyphAssembly));
a->count = count;
a->parts = (hb_ot_math_glyph_part_t*) xmalloc(count * sizeof(hb_ot_math_glyph_part_t));
hb_ot_math_get_glyph_assembly(hbFont, g, horiz ? HB_DIRECTION_RTL : HB_DIRECTION_TTB, 0, &a->count, a->parts, NULL);
rval = (void*) a;
}
}
return rval;
}
void
free_ot_assembly(GlyphAssembly* a)
{
if (!a)
return;
free (a->parts);
free (a);
}
int
get_ot_math_ital_corr(int f, int g)
{
hb_position_t rval = 0;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
hb_font_t* hbFont = font->getHbFont();
rval = hb_ot_math_get_glyph_italics_correction(hbFont, g);
rval = D2Fix(font->unitsToPoints(rval));
}
return rval;
}
int
get_ot_math_accent_pos(int f, int g)
{
hb_position_t rval = 0x7fffffffUL;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
hb_font_t* hbFont = font->getHbFont();
rval = hb_ot_math_get_glyph_top_accent_attachment(hbFont, g);
rval = D2Fix(font->unitsToPoints(rval));
}
return rval;
}
int
ot_min_connector_overlap(int f)
{
hb_position_t rval = 0;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
hb_font_t* hbFont = font->getHbFont();
rval = hb_ot_math_get_min_connector_overlap(hbFont, HB_DIRECTION_RTL);
rval = D2Fix(font->unitsToPoints(rval));
}
return rval;
}
static int
getMathKernAt(int f, int g, hb_ot_math_kern_t side, int height)
{
hb_position_t rval = 0;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
hb_font_t* hbFont = font->getHbFont();
rval = hb_ot_math_get_glyph_kerning(hbFont, g, side, height);
}
return rval;
}
static float
glyph_height(int f, int g)
{
float rval = 0.0;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXLayoutEngine engine = (XeTeXLayoutEngine)fontlayoutengine[f];
getGlyphHeightDepth(engine, g, &rval, NULL);
}
return rval;
}
static float
glyph_depth(int f, int g)
{
float rval = 0.0;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXLayoutEngine engine = (XeTeXLayoutEngine)fontlayoutengine[f];
getGlyphHeightDepth(engine, g, NULL, &rval);
}
return rval;
}
// keep in sync with xetex.web
#define sup_cmd 0
#define sub_cmd 1
int
get_ot_math_kern(int f, int g, int sf, int sg, int cmd, int shift)
{
int rval = 0;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
int kern = 0, skern = 0;
float corr_height_top = 0.0, corr_height_bot = 0.0;
if (cmd == sup_cmd) { // superscript
corr_height_top = font->pointsToUnits(glyph_height(f, g));
corr_height_bot = -font->pointsToUnits(glyph_depth(sf, sg) + Fix2D(shift));
kern = getMathKernAt(f, g, HB_OT_MATH_KERN_TOP_RIGHT, corr_height_top);
skern = getMathKernAt(sf, sg, HB_OT_MATH_KERN_BOTTOM_LEFT, corr_height_top);
rval = kern + skern;
kern = getMathKernAt(f, g, HB_OT_MATH_KERN_TOP_RIGHT, corr_height_bot);
skern = getMathKernAt(sf, sg, HB_OT_MATH_KERN_BOTTOM_LEFT, corr_height_bot);
if ((kern + skern) < rval)
rval = kern + skern;
} else if (cmd == sub_cmd) { // subscript
corr_height_top = font->pointsToUnits(glyph_height(sf, sg) - Fix2D(shift));
corr_height_bot = -font->pointsToUnits(glyph_depth(f, g));
kern = getMathKernAt(f, g, HB_OT_MATH_KERN_BOTTOM_RIGHT, corr_height_top);
skern = getMathKernAt(sf, sg, HB_OT_MATH_KERN_TOP_LEFT, corr_height_top);
rval = kern + skern;
kern = getMathKernAt(f, g, HB_OT_MATH_KERN_BOTTOM_RIGHT, corr_height_bot);
skern = getMathKernAt(sf, sg, HB_OT_MATH_KERN_TOP_LEFT, corr_height_bot);
if ((kern + skern) < rval)
rval = kern + skern;
} else {
assert(0); // we should not reach here
}
return D2Fix(font->unitsToPoints(rval));
}
return 0;
}
int
ot_part_count(const GlyphAssembly* a)
{
return a->count;
}
int
ot_part_glyph(const GlyphAssembly* a, int i)
{
return a->parts[i].glyph;
}
int
ot_part_is_extender(const GlyphAssembly* a, int i)
{
return (a->parts[i].flags & HB_MATH_GLYPH_PART_FLAG_EXTENDER) != 0;
}
int
ot_part_start_connector(int f, const GlyphAssembly* a, int i)
{
int rval = 0;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
rval = D2Fix(font->unitsToPoints(a->parts[i].start_connector_length));
}
return rval;
}
int
ot_part_end_connector(int f, const GlyphAssembly* a, int i)
{
int rval = 0;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
rval = D2Fix(font->unitsToPoints(a->parts[i].end_connector_length));
}
return rval;
}
int
ot_part_full_advance(int f, const GlyphAssembly* a, int i)
{
int rval = 0;
if (fontarea[f] == OTGR_FONT_FLAG) {
XeTeXFontInst* font = (XeTeXFontInst*)getFont((XeTeXLayoutEngine)fontlayoutengine[f]);
rval = D2Fix(font->unitsToPoints(a->parts[i].full_advance));
}
return rval;
}
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