[Complex Text Layouts] Add third-party TextServer dependencies (ICU, HarfBuzz, Graphite).

thirdparty/graphite/src/Intervals.cpp

@@ -0,0 +1,298 @@
+/*  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
+{
+    size_t l = 0, h = _exclusions.size();
+
+    while (l < h)
+    {
+        size_t 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