/*
* Copyright © 2022 Behdad Esfahbod
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*/
#ifndef HB_GEOMETRY_HH
#define HB_GEOMETRY_HH
#include "hb.hh"
struct hb_extents_t
{
hb_extents_t () {}
hb_extents_t (
float xmin,
float ymin,
float xmax,
float ymax) :
xmin (xmin), ymin (ymin), xmax (xmax), ymax (ymax) {}
bool is_empty ()
const {
return xmin >= xmax || ymin >= ymax; }
bool is_void ()
const {
return xmin > xmax; }
void union_ (
const hb_extents_t &o)
{
xmin = hb_min (xmin, o.xmin);
ymin = hb_min (ymin, o.ymin);
xmax = hb_max (xmax, o.xmax);
ymax = hb_max (ymax, o.ymax);
}
void intersect (
const hb_extents_t &o)
{
xmin = hb_max (xmin, o.xmin);
ymin = hb_max (ymin, o.ymin);
xmax = hb_min (xmax, o.xmax);
ymax = hb_min (ymax, o.ymax);
}
void
add_point (
float x,
float y)
{
if (unlikely (is_void ()))
{
xmin = xmax = x;
ymin = ymax = y;
}
else
{
xmin = hb_min (xmin, x);
ymin = hb_min (ymin, y);
xmax = hb_max (xmax, x);
ymax = hb_max (ymax, y);
}
}
float xmin = 0.f;
float ymin = 0.f;
float xmax = -1.f;
float ymax = -1.f;
};
struct hb_transform_t
{
hb_transform_t () {}
hb_transform_t (
float xx,
float yx,
float xy,
float yy,
float x0,
float y0) :
xx (xx), yx (yx), xy (xy), yy (yy), x0 (x0), y0 (y0) {}
void multiply (
const hb_transform_t &o)
{
/* Copied from cairo, with "o" being "a" there and "this" being "b" there. */
hb_transform_t r;
r.xx = o.xx * xx + o.yx * xy;
r.yx = o.xx * yx + o.yx * yy;
r.xy = o.xy * xx + o.yy * xy;
r.yy = o.xy * yx + o.yy * yy;
r.x0 = o.x0 * xx + o.y0 * xy + x0;
r.y0 = o.x0 * yx + o.y0 * yy + y0;
*
this = r;
}
void transform_distance (
float &dx,
float &dy)
const
{
float new_x = xx * dx + xy * dy;
float new_y = yx * dx + yy * dy;
dx = new_x;
dy = new_y;
}
void transform_point (
float &x,
float &y)
const
{
transform_distance (x, y);
x += x0;
y += y0;
}
void transform_extents (hb_extents_t &extents)
const
{
float quad_x[4], quad_y[4];
quad_x[0] = extents.xmin;
quad_y[0] = extents.ymin;
quad_x[1] = extents.xmin;
quad_y[1] = extents.ymax;
quad_x[2] = extents.xmax;
quad_y[2] = extents.ymin;
quad_x[3] = extents.xmax;
quad_y[3] = extents.ymax;
extents = hb_extents_t {};
for (
unsigned i = 0; i < 4; i++)
{
transform_point (quad_x[i], quad_y[i]);
extents.add_point (quad_x[i], quad_y[i]);
}
}
void transform (
const hb_transform_t &o) { multiply (o); }
void translate (
float x,
float y)
{
if (x == 0.f && y == 0.f)
return;
x0 += xx * x + xy * y;
y0 += yx * x + yy * y;
}
void scale (
float scaleX,
float scaleY)
{
if (scaleX == 1.f && scaleY == 1.f)
return;
xx *= scaleX;
yx *= scaleX;
xy *= scaleY;
yy *= scaleY;
}
void rotate (
float rotation)
{
if (rotation == 0.f)
return;
// https://github.com/fonttools/fonttools/blob/f66ee05f71c8b57b5f519ee975e95edcd1466e14/Lib/fontTools/misc/transform.py#L240
rotation = rotation * HB_PI;
float c;
float s;
#ifdef HAVE_SINCOSF
sincosf (rotation, &s, &c);
#else
c = cosf (rotation);
s = sinf (rotation);
#endif
auto other = hb_transform_t{c, s, -s, c, 0.f, 0.f};
transform (other);
}
void skew (
float skewX,
float skewY)
{
if (skewX == 0.f && skewY == 0.f)
return;
// https://github.com/fonttools/fonttools/blob/f66ee05f71c8b57b5f519ee975e95edcd1466e14/Lib/fontTools/misc/transform.py#L255
skewX = skewX * HB_PI;
skewY = skewY * HB_PI;
auto other = hb_transform_t{1.f,
skewY ? tanf (skewY) : 0.f,
skewX ? tanf (skewX) : 0.f,
1.f,
0.f, 0.f};
transform (other);
}
float xx = 1.f;
float yx = 0.f;
float xy = 0.f;
float yy = 1.f;
float x0 = 0.f;
float y0 = 0.f;
};
struct hb_bounds_t
{
enum status_t {
UNBOUNDED,
BOUNDED,
EMPTY,
};
hb_bounds_t (status_t status) : status (status) {}
hb_bounds_t (
const hb_extents_t &extents) :
status (extents.is_empty () ? EMPTY : BOUNDED), extents (extents) {}
void union_ (
const hb_bounds_t &o)
{
if (o.status == UNBOUNDED)
status = UNBOUNDED;
else if (o.status == BOUNDED)
{
if (status == EMPTY)
*
this = o;
else if (status == BOUNDED)
extents.union_ (o.extents);
}
}
void intersect (
const hb_bounds_t &o)
{
if (o.status == EMPTY)
status = EMPTY;
else if (o.status == BOUNDED)
{
if (status == UNBOUNDED)
*
this = o;
else if (status == BOUNDED)
{
extents.intersect (o.extents);
if (extents.is_empty ())
status = EMPTY;
}
}
}
status_t status;
hb_extents_t extents;
};
struct hb_transform_decomposed_t
{
float translateX = 0;
float translateY = 0;
float rotation = 0;
// in degrees, counter-clockwise
float scaleX = 1;
float scaleY = 1;
float skewX = 0;
// in degrees, counter-clockwise
float skewY = 0;
// in degrees, counter-clockwise
float tCenterX = 0;
float tCenterY = 0;
operator bool ()
const
{
return translateX || translateY ||
rotation ||
scaleX != 1 || scaleY != 1 ||
skewX || skewY ||
tCenterX || tCenterY;
}
hb_transform_t to_transform ()
const
{
hb_transform_t t;
t.translate (translateX + tCenterX, translateY + tCenterY);
t.rotate (rotation);
t.scale (scaleX, scaleY);
t.skew (-skewX, skewY);
t.translate (-tCenterX, -tCenterY);
return t;
}
};
#endif /* HB_GEOMETRY_HH */
