Qunxin Liu
1 year ago
parent
97c85ab2d0
commit
f072de9359
7 changed files with 592 additions and 516 deletions
@ -0,0 +1,532 @@ |
||||
/*
|
||||
* Copyright © 2024 Google, Inc. |
||||
* |
||||
* 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. |
||||
*/ |
||||
|
||||
#include "hb-subset-instancer-iup.hh" |
||||
|
||||
/* This file is a straight port of the following:
|
||||
* |
||||
* https://github.com/fonttools/fonttools/blob/main/Lib/fontTools/varLib/iup.py
|
||||
* |
||||
* Where that file returns optimzied deltas vector, we return optimized |
||||
* referenced point indices. |
||||
*/ |
||||
|
||||
constexpr static unsigned MAX_LOOKBACK = 8; |
||||
|
||||
static void _iup_contour_bound_forced_set (const hb_array_t<const contour_point_t> contour_points, |
||||
const hb_array_t<const int> x_deltas, |
||||
const hb_array_t<const int> y_deltas, |
||||
hb_set_t& forced_set, /* OUT */ |
||||
float tolerance = 0.f) |
||||
{ |
||||
unsigned len = contour_points.length; |
||||
unsigned next_i = 0; |
||||
for (int i = len - 1; i >= 0; i--) |
||||
{ |
||||
unsigned last_i = (len + i -1) % len; |
||||
for (unsigned j = 0; j < 2; j++) |
||||
{ |
||||
float cj, lcj, ncj; |
||||
int dj, ldj, ndj; |
||||
if (j == 0) |
||||
{ |
||||
cj = contour_points.arrayZ[i].x; |
||||
dj = x_deltas.arrayZ[i]; |
||||
lcj = contour_points.arrayZ[last_i].x; |
||||
ldj = x_deltas.arrayZ[last_i]; |
||||
ncj = contour_points.arrayZ[next_i].x; |
||||
ndj = x_deltas.arrayZ[next_i]; |
||||
} |
||||
else |
||||
{ |
||||
cj = contour_points.arrayZ[i].y; |
||||
dj = y_deltas.arrayZ[i]; |
||||
lcj = contour_points.arrayZ[last_i].y; |
||||
ldj = y_deltas.arrayZ[last_i]; |
||||
ncj = contour_points.arrayZ[next_i].y; |
||||
ndj = y_deltas.arrayZ[next_i]; |
||||
} |
||||
|
||||
float c1, c2; |
||||
int d1, d2; |
||||
if (lcj <= ncj) |
||||
{ |
||||
c1 = lcj; |
||||
c2 = ncj; |
||||
d1 = ldj; |
||||
d2 = ndj; |
||||
} |
||||
else |
||||
{ |
||||
c1 = ncj; |
||||
c2 = lcj; |
||||
d1 = ndj; |
||||
d2 = ldj; |
||||
} |
||||
|
||||
bool force = false; |
||||
if (c1 == c2) |
||||
{ |
||||
if (abs (d1 - d2) > tolerance && abs (dj) > tolerance) |
||||
force = true; |
||||
} |
||||
else if (c1 <= cj && cj <= c2) |
||||
{ |
||||
if (!(hb_min (d1, d2) - tolerance <= dj && |
||||
dj <= hb_max (d1, d2) + tolerance)) |
||||
force = true; |
||||
} |
||||
else |
||||
{ |
||||
if (d1 != d2) |
||||
{ |
||||
if (cj < c1) |
||||
{ |
||||
if (abs (dj) > tolerance && |
||||
abs (dj - d1) > tolerance && |
||||
((dj - tolerance < d1) != (d1 < d2))) |
||||
force = true; |
||||
} |
||||
else |
||||
{ |
||||
if (abs (dj) > tolerance && |
||||
abs (dj - d2) > tolerance && |
||||
((d2 < dj + tolerance) != (d1 < d2))) |
||||
force = true; |
||||
} |
||||
} |
||||
} |
||||
|
||||
if (force) |
||||
{ |
||||
forced_set.add (i); |
||||
break; |
||||
} |
||||
} |
||||
next_i = i; |
||||
} |
||||
} |
||||
|
||||
template <typename T, |
||||
hb_enable_if (hb_is_trivially_copyable (T))> |
||||
static bool rotate_array (const hb_array_t<const T>& org_array, |
||||
int k, |
||||
hb_vector_t<T>& out) |
||||
{ |
||||
unsigned n = org_array.length; |
||||
if (!n) return true; |
||||
if (unlikely (!out.resize (n, false))) |
||||
return false; |
||||
|
||||
unsigned item_size = hb_static_size (T); |
||||
if (k < 0) |
||||
k = n - (-k) % n; |
||||
else |
||||
k %= n; |
||||
|
||||
hb_memcpy ((void *) out.arrayZ, (const void *) (org_array.arrayZ + n - k), k * item_size); |
||||
hb_memcpy ((void *) (out.arrayZ + k), (const void *) org_array.arrayZ, (n - k) * item_size); |
||||
return true; |
||||
} |
||||
|
||||
static bool rotate_set (const hb_set_t& org_set, |
||||
int k, |
||||
unsigned n, |
||||
hb_set_t& out) |
||||
{ |
||||
if (!n) return false; |
||||
k %= n; |
||||
if (k < 0) |
||||
k = n + k; |
||||
|
||||
if (k == 0) |
||||
{ |
||||
out.set (org_set); |
||||
} |
||||
else |
||||
{ |
||||
for (auto v : org_set) |
||||
out.add ((v + k) % n); |
||||
} |
||||
return !out.in_error (); |
||||
} |
||||
|
||||
/* Given two reference coordinates (start and end of contour_points array),
|
||||
* output interpolated deltas for points in between */ |
||||
static bool _iup_segment (const hb_array_t<const contour_point_t> contour_points, |
||||
const hb_array_t<const int> x_deltas, |
||||
const hb_array_t<const int> y_deltas, |
||||
const contour_point_t& p1, const contour_point_t& p2, |
||||
int p1_dx, int p2_dx, |
||||
int p1_dy, int p2_dy, |
||||
hb_vector_t<float>& interp_x_deltas, /* OUT */ |
||||
hb_vector_t<float>& interp_y_deltas /* OUT */) |
||||
{ |
||||
unsigned n = contour_points.length; |
||||
if (unlikely (!interp_x_deltas.resize (n, false) || |
||||
!interp_y_deltas.resize (n, false))) |
||||
return false; |
||||
|
||||
for (unsigned j = 0; j < 2; j++) |
||||
{ |
||||
float x1, x2, d1, d2; |
||||
float *out; |
||||
if (j == 0) |
||||
{ |
||||
x1 = p1.x; |
||||
x2 = p2.x; |
||||
d1 = p1_dx; |
||||
d2 = p2_dx; |
||||
out = interp_x_deltas.arrayZ; |
||||
} |
||||
else |
||||
{ |
||||
x1 = p1.y; |
||||
x2 = p2.y; |
||||
d1 = p1_dy; |
||||
d2 = p2_dy; |
||||
out = interp_y_deltas.arrayZ; |
||||
} |
||||
|
||||
if (x1 == x2) |
||||
{ |
||||
if (d1 == d2) |
||||
{ |
||||
for (unsigned i = 0; i < n; i++) |
||||
out[i] = d1; |
||||
} |
||||
else |
||||
{ |
||||
for (unsigned i = 0; i < n; i++) |
||||
out[i] = 0.f; |
||||
} |
||||
continue; |
||||
} |
||||
|
||||
if (x1 > x2) |
||||
{ |
||||
hb_swap (x1, x2); |
||||
hb_swap (d1, d2); |
||||
} |
||||
|
||||
float scale = (d2 - d1) / (x2 - x1); |
||||
for (unsigned i = 0; i < n; i++) |
||||
{ |
||||
float x = j == 0 ? contour_points.arrayZ[i].x : contour_points.arrayZ[i].y; |
||||
float d; |
||||
if (x <= x1) |
||||
d = d1; |
||||
else if (x >= x2) |
||||
d = d2; |
||||
else |
||||
d = d1 + (x - x1) * scale; |
||||
|
||||
out[i] = d; |
||||
} |
||||
} |
||||
return true; |
||||
} |
||||
|
||||
static bool _can_iup_in_between (const hb_array_t<const contour_point_t> contour_points, |
||||
const hb_array_t<const int> x_deltas, |
||||
const hb_array_t<const int> y_deltas, |
||||
const contour_point_t& p1, const contour_point_t& p2, |
||||
int p1_dx, int p2_dx, |
||||
int p1_dy, int p2_dy, |
||||
float tolerance) |
||||
{ |
||||
hb_vector_t<float> interp_x_deltas, interp_y_deltas; |
||||
if (!_iup_segment (contour_points, x_deltas, y_deltas, |
||||
p1, p2, p1_dx, p2_dx, p1_dy, p2_dy, |
||||
interp_x_deltas, interp_y_deltas)) |
||||
return false; |
||||
|
||||
unsigned num = contour_points.length; |
||||
|
||||
for (unsigned i = 0; i < num; i++) |
||||
{ |
||||
float dx = x_deltas.arrayZ[i] - interp_x_deltas.arrayZ[i]; |
||||
float dy = y_deltas.arrayZ[i] - interp_y_deltas.arrayZ[i]; |
||||
|
||||
if (sqrtf ((float)dx * dx + (float)dy * dy) > tolerance) |
||||
return false; |
||||
} |
||||
return true; |
||||
} |
||||
|
||||
static bool _iup_contour_optimize_dp (const contour_point_vector_t& contour_points, |
||||
const hb_vector_t<int>& x_deltas, |
||||
const hb_vector_t<int>& y_deltas, |
||||
const hb_set_t& forced_set, |
||||
float tolerance, |
||||
unsigned lookback, |
||||
hb_vector_t<unsigned>& costs, /* OUT */ |
||||
hb_vector_t<int>& chain /* OUT */) |
||||
{ |
||||
unsigned n = contour_points.length; |
||||
if (unlikely (!costs.resize (n, false) || |
||||
!chain.resize (n, false))) |
||||
return false; |
||||
|
||||
lookback = hb_min (lookback, MAX_LOOKBACK); |
||||
|
||||
for (unsigned i = 0; i < n; i++) |
||||
{ |
||||
unsigned best_cost = (i == 0 ? 1 : costs.arrayZ[i-1] + 1); |
||||
|
||||
costs.arrayZ[i] = best_cost; |
||||
chain.arrayZ[i] = (i == 0 ? -1 : i - 1); |
||||
|
||||
if (i > 0 && forced_set.has (i - 1)) |
||||
continue; |
||||
|
||||
int lookback_index = hb_max ((int) i - (int) lookback + 1, -1); |
||||
for (int j = i - 2; j >= lookback_index; j--) |
||||
{ |
||||
unsigned cost = j == -1 ? 1 : costs.arrayZ[j] + 1; |
||||
/* num points between i and j */ |
||||
unsigned num_points = i - j - 1; |
||||
unsigned p1 = (j == -1 ? n - 1 : j); |
||||
if (cost < best_cost && |
||||
_can_iup_in_between (contour_points.as_array ().sub_array (j + 1, num_points), |
||||
x_deltas.as_array ().sub_array (j + 1, num_points), |
||||
y_deltas.as_array ().sub_array (j + 1, num_points), |
||||
contour_points.arrayZ[p1], contour_points.arrayZ[i], |
||||
x_deltas.arrayZ[p1], x_deltas.arrayZ[i], |
||||
y_deltas.arrayZ[p1], y_deltas.arrayZ[i], |
||||
tolerance)) |
||||
{ |
||||
best_cost = cost; |
||||
costs.arrayZ[i] = best_cost; |
||||
chain.arrayZ[i] = j; |
||||
} |
||||
|
||||
if (j > 0 && forced_set.has (j)) |
||||
break; |
||||
} |
||||
} |
||||
return true; |
||||
} |
||||
|
||||
static bool _iup_contour_optimize (const hb_array_t<const contour_point_t> contour_points, |
||||
const hb_array_t<const int> x_deltas, |
||||
const hb_array_t<const int> y_deltas, |
||||
hb_array_t<bool> opt_indices, /* OUT */ |
||||
float tolerance = 0.f) |
||||
{ |
||||
unsigned n = contour_points.length; |
||||
if (opt_indices.length != n || |
||||
x_deltas.length != n || |
||||
y_deltas.length != n) |
||||
return false; |
||||
|
||||
bool all_within_tolerance = true; |
||||
for (unsigned i = 0; i < n; i++) |
||||
{ |
||||
int dx = x_deltas.arrayZ[i]; |
||||
int dy = y_deltas.arrayZ[i]; |
||||
if (sqrtf ((float)dx * dx + (float)dy * dy) > tolerance) |
||||
{ |
||||
all_within_tolerance = false; |
||||
break; |
||||
} |
||||
} |
||||
|
||||
/* If all are within tolerance distance, do nothing, opt_indices is
|
||||
* initilized to false */ |
||||
if (all_within_tolerance) |
||||
return true; |
||||
|
||||
/* If there's exactly one point, return it */ |
||||
if (n == 1) |
||||
{ |
||||
opt_indices.arrayZ[0] = true; |
||||
return true; |
||||
} |
||||
|
||||
/* If all deltas are exactly the same, return just one (the first one) */ |
||||
bool all_deltas_are_equal = true; |
||||
for (unsigned i = 1; i < n; i++) |
||||
if (x_deltas.arrayZ[i] != x_deltas.arrayZ[0] || |
||||
y_deltas.arrayZ[i] != y_deltas.arrayZ[0]) |
||||
{ |
||||
all_deltas_are_equal = false; |
||||
break; |
||||
} |
||||
|
||||
if (all_deltas_are_equal) |
||||
{ |
||||
opt_indices.arrayZ[0] = true; |
||||
return true; |
||||
} |
||||
|
||||
/* else, solve the general problem using Dynamic Programming */ |
||||
hb_set_t forced_set; |
||||
_iup_contour_bound_forced_set (contour_points, x_deltas, y_deltas, forced_set, tolerance); |
||||
|
||||
if (!forced_set.is_empty ()) |
||||
{ |
||||
int k = n - 1 - forced_set.get_max (); |
||||
if (k < 0) |
||||
return false; |
||||
|
||||
hb_vector_t<int> rot_x_deltas, rot_y_deltas; |
||||
contour_point_vector_t rot_points; |
||||
hb_set_t rot_forced_set; |
||||
if (!rotate_array (contour_points, k, rot_points) || |
||||
!rotate_array (x_deltas, k, rot_x_deltas) || |
||||
!rotate_array (y_deltas, k, rot_y_deltas) || |
||||
!rotate_set (forced_set, k, n, rot_forced_set)) |
||||
return false; |
||||
|
||||
hb_vector_t<unsigned> costs; |
||||
hb_vector_t<int> chain; |
||||
|
||||
if (!_iup_contour_optimize_dp (rot_points, rot_x_deltas, rot_y_deltas, |
||||
rot_forced_set, tolerance, n, |
||||
costs, chain)) |
||||
return false; |
||||
|
||||
hb_set_t solution; |
||||
int index = n - 1; |
||||
while (index != -1) |
||||
{ |
||||
solution.add (index); |
||||
index = chain.arrayZ[index]; |
||||
} |
||||
|
||||
if (solution.is_empty () || |
||||
forced_set.get_population () > solution.get_population ()) |
||||
return false; |
||||
|
||||
for (unsigned i : solution) |
||||
opt_indices.arrayZ[i] = true; |
||||
|
||||
hb_vector_t<bool> rot_indices; |
||||
const hb_array_t<const bool> opt_indices_array (opt_indices.arrayZ, opt_indices.length); |
||||
rotate_array (opt_indices_array, -k, rot_indices); |
||||
|
||||
for (unsigned i = 0; i < n; i++) |
||||
opt_indices.arrayZ[i] = rot_indices.arrayZ[i]; |
||||
} |
||||
else |
||||
{ |
||||
hb_vector_t<int> repeat_x_deltas, repeat_y_deltas; |
||||
contour_point_vector_t repeat_points; |
||||
|
||||
if (unlikely (!repeat_x_deltas.resize (n * 2, false) || |
||||
!repeat_y_deltas.resize (n * 2, false) || |
||||
!repeat_points.resize (n * 2, false))) |
||||
return false; |
||||
|
||||
unsigned contour_point_size = hb_static_size (contour_point_t); |
||||
for (unsigned i = 0; i < n; i++) |
||||
{ |
||||
hb_memcpy ((void *) repeat_x_deltas.arrayZ, (const void *) x_deltas.arrayZ, n * sizeof (float)); |
||||
hb_memcpy ((void *) (repeat_x_deltas.arrayZ + n), (const void *) x_deltas.arrayZ, n * sizeof (float)); |
||||
|
||||
hb_memcpy ((void *) repeat_y_deltas.arrayZ, (const void *) y_deltas.arrayZ, n * sizeof (float)); |
||||
hb_memcpy ((void *) (repeat_y_deltas.arrayZ + n), (const void *) y_deltas.arrayZ, n * sizeof (float)); |
||||
|
||||
hb_memcpy ((void *) repeat_points.arrayZ, (const void *) contour_points.arrayZ, n * contour_point_size); |
||||
hb_memcpy ((void *) (repeat_points.arrayZ + n), (const void *) contour_points.arrayZ, n * contour_point_size); |
||||
} |
||||
|
||||
hb_vector_t<unsigned> costs; |
||||
hb_vector_t<int> chain; |
||||
if (!_iup_contour_optimize_dp (repeat_points, repeat_x_deltas, repeat_y_deltas, |
||||
forced_set, tolerance, n, |
||||
costs, chain)) |
||||
return false; |
||||
|
||||
unsigned best_cost = n + 1; |
||||
int len = costs.length; |
||||
hb_set_t best_sol; |
||||
for (int start = n - 1; start < len; start++) |
||||
{ |
||||
hb_set_t solution; |
||||
int i = start; |
||||
int lookback = start - (int) n; |
||||
while (i > lookback) |
||||
{ |
||||
solution.add (i % n); |
||||
i = chain.arrayZ[i]; |
||||
} |
||||
if (i == lookback) |
||||
{ |
||||
unsigned cost_i = i < 0 ? 0 : costs.arrayZ[i]; |
||||
unsigned cost = costs.arrayZ[start] - cost_i; |
||||
if (cost <= best_cost) |
||||
{ |
||||
best_sol.set (solution); |
||||
best_cost = cost; |
||||
} |
||||
} |
||||
} |
||||
|
||||
for (unsigned i = 0; i < n; i++) |
||||
if (best_sol.has (i)) |
||||
opt_indices.arrayZ[i] = true; |
||||
} |
||||
return true; |
||||
} |
||||
|
||||
bool iup_delta_optimize (const contour_point_vector_t& contour_points, |
||||
const hb_vector_t<int>& x_deltas, |
||||
const hb_vector_t<int>& y_deltas, |
||||
hb_vector_t<bool>& opt_indices, /* OUT */ |
||||
float tolerance) |
||||
{ |
||||
if (!opt_indices.resize (contour_points.length)) |
||||
return false; |
||||
|
||||
hb_vector_t<unsigned> end_points; |
||||
unsigned count = contour_points.length; |
||||
if (unlikely (!end_points.alloc (count))) |
||||
return false; |
||||
|
||||
for (unsigned i = 0; i < count - 4; i++) |
||||
if (contour_points.arrayZ[i].is_end_point) |
||||
end_points.push (i); |
||||
|
||||
/* phantom points */ |
||||
for (unsigned i = count - 4; i < count; i++) |
||||
end_points.push (i); |
||||
|
||||
if (end_points.in_error ()) return false; |
||||
|
||||
unsigned start = 0; |
||||
for (unsigned end : end_points) |
||||
{ |
||||
unsigned len = end - start + 1; |
||||
if (!_iup_contour_optimize (contour_points.as_array ().sub_array (start, len), |
||||
x_deltas.as_array ().sub_array (start, len), |
||||
y_deltas.as_array ().sub_array (start, len), |
||||
opt_indices.as_array ().sub_array (start, len), |
||||
tolerance)) |
||||
return false; |
||||
start = end + 1; |
||||
} |
||||
return true; |
||||
} |
||||
@ -0,0 +1,37 @@ |
||||
/*
|
||||
* Copyright © 2024 Google, Inc. |
||||
* |
||||
* 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_SUBSET_INSTANCER_IUP_HH |
||||
#define HB_SUBSET_INSTANCER_IUP_HH |
||||
|
||||
#include "hb-subset-plan.hh" |
||||
/* given contour points and deltas, optimize a set of referenced points within error
|
||||
* tolerance. Returns optimized referenced point indices */ |
||||
HB_INTERNAL bool iup_delta_optimize (const contour_point_vector_t& contour_points, |
||||
const hb_vector_t<int>& x_deltas, |
||||
const hb_vector_t<int>& y_deltas, |
||||
hb_vector_t<bool>& opt_indices, /* OUT */ |
||||
float tolerance = 0.f); |
||||
|
||||
#endif /* HB_SUBSET_INSTANCER_IUP_HH */ |
||||
Loading…
Reference in new issue