1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 #include <GLcommon/RangeManip.h>
17 
18 
rangeIntersection(const Range & r,Range & rOut) const19 bool Range::rangeIntersection(const Range& r,Range& rOut) const {
20     if(m_start > r.getEnd() || r.getStart() > m_end) return false;
21     int max_start = (m_start > r.getStart())? m_start:r.getStart();
22     int min_end = (m_end < r.getEnd())?m_end:r.getEnd();
23     int size = min_end - max_start;
24     if(size) {
25         rOut.setRange(max_start,min_end-max_start);
26         return true;
27     }
28     return false;
29 }
30 
rangeUnion(const Range & r,Range & rOut) const31 bool Range::rangeUnion(const Range& r,Range& rOut) const {
32     if(m_start > r.getEnd() || r.getStart() > m_end) return false;
33     int min_start = (m_start < r.getStart())?m_start:r.getStart();
34     int max_end = (m_end > r.getEnd())?m_end:r.getEnd();
35     int size =  max_end - min_start;
36     if(size) {
37         rOut.setRange(min_start,max_end-min_start);
38         return true;
39     }
40     return false;
41 }
42 
addRange(const Range & r)43 void RangeList::addRange(const Range& r) {
44     if(r.getSize())
45         list.push_back(r);
46 }
47 
addRanges(const RangeList & rl)48 void RangeList::addRanges(const RangeList& rl) {
49     for(int i =0; i< rl.size();i++) {
50        addRange(rl.list[i]);
51     }
52 }
53 
delRanges(const RangeList & rl,RangeList & deleted)54 void RangeList::delRanges(const RangeList& rl,RangeList& deleted) {
55     for(int i =0; i< rl.size();i++) {
56        delRange(rl.list[i],deleted);
57     }
58 }
59 
empty() const60 bool RangeList::empty() const{
61     return list.empty();
62 }
63 
size() const64 int  RangeList::size() const{
65     return list.size();
66 }
clear()67 void RangeList::clear() {
68     return list.clear();
69 }
70 
erase(unsigned int i)71 void RangeList::erase(unsigned int i) {
72     if(i > list.size()) return;
73     list.erase(list.begin() +i);
74 }
75 
delRange(const Range & r,RangeList & deleted)76 void RangeList::delRange(const Range& r,RangeList& deleted) {
77     if(r.getSize() == 0) return;
78 
79     Range intersection;
80     Range temp;
81     // compare new rect to each and any of the rects on the list
82     for (int i=0;i<(int)list.size();i++) { // i must be signed for i-- below
83      // if there is intersection
84      if (r.rangeIntersection(list[i],intersection)) {
85              Range old=list[i];
86          // remove old as it is about to be split
87          erase(i);
88          i--;
89          if (intersection!=old) { // otherwise split:
90              //intersection on right side
91              if(old.getStart() != intersection.getStart()) {
92                  list.insert(list.begin(),Range(old.getStart(),intersection.getStart() - old.getStart()));
93              }
94 
95              //intersection on left side
96              if(old.getEnd() != intersection.getEnd()) {
97                  list.insert(list.begin(),Range(intersection.getEnd(),old.getEnd() - intersection.getEnd()));
98              }
99          }
100          deleted.addRange(intersection);
101      }
102  }
103 }
104 
merge()105 void RangeList::merge() {
106     if(list.empty()) return;
107 
108     Range temp;
109     bool changed;
110 
111     do { // re-run if changed in last run
112         changed=0;
113         // run for each combinations of two rects in the list
114         for (int i=0;i<(((int)list.size())-1) && !changed ;i++)
115         {
116             for (int j=i+1;j<(int)list.size() && !changed ;j++)
117             {
118                if (list[i].rangeUnion(list[j],temp)) {
119                     // are them exactly one on left of the other
120                     list[i] = temp;
121                     erase(j);
122                     changed=1;
123                }
124             }
125         }
126     } while (changed);
127 }
128