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Diffstat (limited to 'gfx/graphite2/src/Intervals.cpp')
| -rw-r--r-- | gfx/graphite2/src/Intervals.cpp | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/gfx/graphite2/src/Intervals.cpp b/gfx/graphite2/src/Intervals.cpp new file mode 100644 index 000000000..9b1da5a1b --- /dev/null +++ b/gfx/graphite2/src/Intervals.cpp @@ -0,0 +1,299 @@ +/* GRAPHITE2 LICENSING + + Copyright 2010, SIL International + All rights reserved. + + This library is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation; either version 2.1 of License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should also have received a copy of the GNU Lesser General Public + License along with this library in the file named "LICENSE". + If not, write to the Free Software Foundation, 51 Franklin Street, + Suite 500, Boston, MA 02110-1335, USA or visit their web page on the + internet at http://www.fsf.org/licenses/lgpl.html. + +Alternatively, the contents of this file may be used under the terms of the +Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public +License, as published by the Free Software Foundation, either version 2 +of the License or (at your option) any later version. +*/ +#include <algorithm> +#include <cmath> +#include <limits> + +#include "inc/Intervals.h" +#include "inc/Segment.h" +#include "inc/Slot.h" +#include "inc/debug.h" +#include "inc/bits.h" + +using namespace graphite2; + +#include <cmath> + +inline +Zones::Exclusion Zones::Exclusion::split_at(float p) { + Exclusion r(*this); + r.xm = x = p; + return r; +} + +inline +void Zones::Exclusion::left_trim(float p) { + x = p; +} + +inline +Zones::Exclusion & Zones::Exclusion::operator += (Exclusion const & rhs) { + c += rhs.c; sm += rhs.sm; smx += rhs.smx; open = false; + return *this; +} + +inline +uint8 Zones::Exclusion::outcode(float val) const { + float p = val; + //float d = std::numeric_limits<float>::epsilon(); + float d = 0.; + return ((p - xm >= d) << 1) | (x - p > d); +} + +void Zones::exclude_with_margins(float xmin, float xmax, int axis) { + remove(xmin, xmax); + weightedAxis(axis, xmin-_margin_len, xmin, 0, 0, _margin_weight, xmin-_margin_len, 0, 0, false); + weightedAxis(axis, xmax, xmax+_margin_len, 0, 0, _margin_weight, xmax+_margin_len, 0, 0, false); +} + +namespace +{ + +inline +bool separated(float a, float b) { + return a != b; + //int exp; + //float res = frexpf(fabs(a - b), &exp); + //return (*(unsigned int *)(&res) > 4); + //return std::fabs(a-b) > std::numeric_limits<float>::epsilon(); // std::epsilon may not work. but 0.5 fails exising 64 bit tests + //return std::fabs(a-b) > 0.5f; +} + +} + +void Zones::insert(Exclusion e) +{ +#if !defined GRAPHITE2_NTRACING + addDebug(&e); +#endif + e.x = max(e.x, _pos); + e.xm = min(e.xm, _posm); + if (e.x >= e.xm) return; + + for (iterator i = _exclusions.begin(), ie = _exclusions.end(); i != ie && e.x < e.xm; ++i) + { + const uint8 oca = e.outcode(i->x), + ocb = e.outcode(i->xm); + if ((oca & ocb) != 0) continue; + + switch (oca ^ ocb) // What kind of overlap? + { + case 0: // e completely covers i + // split e at i.x into e1,e2 + // split e2 at i.mx into e2,e3 + // drop e1 ,i+e2, e=e3 + *i += e; + e.left_trim(i->xm); + break; + case 1: // e overlaps on the rhs of i + // split i at e->x into i1,i2 + // split e at i.mx into e1,e2 + // trim i1, insert i2+e1, e=e2 + if (!separated(i->xm, e.x)) break; + if (separated(i->x,e.x)) { i = _exclusions.insert(i,i->split_at(e.x)); ++i; } + *i += e; + e.left_trim(i->xm); + break; + case 2: // e overlaps on the lhs of i + // split e at i->x into e1,e2 + // split i at e.mx into i1,i2 + // drop e1, insert e2+i1, trim i2 + if (!separated(e.xm, i->x)) return; + if (separated(e.xm, i->xm)) i = _exclusions.insert(i,i->split_at(e.xm)); + *i += e; + return; + case 3: // i completely covers e + // split i at e.x into i1,i2 + // split i2 at e.mx into i2,i3 + // insert i1, insert e+i2 + if (separated(e.xm, i->xm)) i = _exclusions.insert(i,i->split_at(e.xm)); + i = _exclusions.insert(i, i->split_at(e.x)); + *++i += e; + return; + } + + ie = _exclusions.end(); + } +} + + +void Zones::remove(float x, float xm) +{ +#if !defined GRAPHITE2_NTRACING + removeDebug(x, xm); +#endif + x = max(x, _pos); + xm = min(xm, _posm); + if (x >= xm) return; + + for (iterator i = _exclusions.begin(), ie = _exclusions.end(); i != ie; ++i) + { + const uint8 oca = i->outcode(x), + ocb = i->outcode(xm); + if ((oca & ocb) != 0) continue; + + switch (oca ^ ocb) // What kind of overlap? + { + case 0: // i completely covers e + if (separated(i->x, x)) { i = _exclusions.insert(i,i->split_at(x)); ++i; } + GR_FALLTHROUGH; + // no break + case 1: // i overlaps on the rhs of e + i->left_trim(xm); + return; + case 2: // i overlaps on the lhs of e + i->xm = x; + if (separated(i->x, i->xm)) break; + GR_FALLTHROUGH; + // no break + case 3: // e completely covers i + i = _exclusions.erase(i); + --i; + break; + } + + ie = _exclusions.end(); + } +} + + +Zones::const_iterator Zones::find_exclusion_under(float x) const +{ + int l = 0, h = _exclusions.size(); + + while (l < h) + { + int const p = (l+h) >> 1; + switch (_exclusions[p].outcode(x)) + { + case 0 : return _exclusions.begin()+p; + case 1 : h = p; break; + case 2 : + case 3 : l = p+1; break; + } + } + + return _exclusions.begin()+l; +} + + +float Zones::closest(float origin, float & cost) const +{ + float best_c = std::numeric_limits<float>::max(), + best_x = 0; + + const const_iterator start = find_exclusion_under(origin); + + // Forward scan looking for lowest cost + for (const_iterator i = start, ie = _exclusions.end(); i != ie; ++i) + if (i->track_cost(best_c, best_x, origin)) break; + + // Backward scan looking for lowest cost + // We start from the exclusion to the immediate left of start since we've + // already tested start with the right most scan above. + for (const_iterator i = start-1, ie = _exclusions.begin()-1; i != ie; --i) + if (i->track_cost(best_c, best_x, origin)) break; + + cost = (best_c == std::numeric_limits<float>::max() ? -1 : best_c); + return best_x; +} + + +// Cost and test position functions + +bool Zones::Exclusion::track_cost(float & best_cost, float & best_pos, float origin) const { + const float p = test_position(origin), + localc = cost(p - origin); + if (open && localc > best_cost) return true; + + if (localc < best_cost) + { + best_cost = localc; + best_pos = p; + } + return false; +} + +inline +float Zones::Exclusion::cost(float p) const { + return (sm * p - 2 * smx) * p + c; +} + + +float Zones::Exclusion::test_position(float origin) const { + if (sm < 0) + { + // sigh, test both ends and perhaps the middle too! + float res = x; + float cl = cost(x); + if (x < origin && xm > origin) + { + float co = cost(origin); + if (co < cl) + { + cl = co; + res = origin; + } + } + float cr = cost(xm); + return cl > cr ? xm : res; + } + else + { + float zerox = smx / sm + origin; + if (zerox < x) return x; + else if (zerox > xm) return xm; + else return zerox; + } +} + + +#if !defined GRAPHITE2_NTRACING + +void Zones::jsonDbgOut(Segment *seg) const { + + if (_dbg) + { + for (Zones::idebugs s = dbgs_begin(), e = dbgs_end(); s != e; ++s) + { + *_dbg << json::flat << json::array + << objectid(dslot(seg, (Slot *)(s->_env[0]))) + << reinterpret_cast<ptrdiff_t>(s->_env[1]); + if (s->_isdel) + *_dbg << "remove" << Position(s->_excl.x, s->_excl.xm); + else + *_dbg << "exclude" << json::flat << json::array + << s->_excl.x << s->_excl.xm + << s->_excl.sm << s->_excl.smx << s->_excl.c + << json::close; + *_dbg << json::close; + } + } +} + +#endif + |