+/* in trivial cases there is only one trivial run; called by ubidi_getRuns() */
+static void
+getSingleRun(UBiDi *pBiDi, UBiDiLevel level) {
+ /* simple, single-run case */
+ pBiDi->runs=pBiDi->simpleRuns;
+ pBiDi->runCount=1;
+
+ /* fill and reorder the single run */
+ pBiDi->runs[0].logicalStart=MAKE_INDEX_ODD_PAIR(0, level);
+ pBiDi->runs[0].visualLimit=pBiDi->length;
+}
+
+/* reorder the runs array (L2) ---------------------------------------------- */
+
+/*
+ * Reorder the same-level runs in the runs array.
+ * Here, runCount>1 and maxLevel>=minLevel>=paraLevel.
+ * All the visualStart fields=logical start before reordering.
+ * The "odd" bits are not set yet.
+ *
+ * Reordering with this data structure lends itself to some handy shortcuts:
+ *
+ * Since each run is moved but not modified, and since at the initial maxLevel
+ * each sequence of same-level runs consists of only one run each, we
+ * don't need to do anything there and can predecrement maxLevel.
+ * In many simple cases, the reordering is thus done entirely in the
+ * index mapping.
+ * Also, reordering occurs only down to the lowest odd level that occurs,
+ * which is minLevel|1. However, if the lowest level itself is odd, then
+ * in the last reordering the sequence of the runs at this level or higher
+ * will be all runs, and we don't need the elaborate loop to search for them.
+ * This is covered by ++minLevel instead of minLevel|=1 followed
+ * by an extra reorder-all after the reorder-some loop.
+ * About a trailing WS run:
+ * Such a run would need special treatment because its level is not
+ * reflected in levels[] if this is not a paragraph object.
+ * Instead, all characters from trailingWSStart on are implicitly at
+ * paraLevel.
+ * However, for all maxLevel>paraLevel, this run will never be reordered
+ * and does not need to be taken into account. maxLevel==paraLevel is only reordered
+ * if minLevel==paraLevel is odd, which is done in the extra segment.
+ * This means that for the main reordering loop we don't need to consider
+ * this run and can --runCount. If it is later part of the all-runs
+ * reordering, then runCount is adjusted accordingly.
+ */
+static void
+reorderLine(UBiDi *pBiDi, UBiDiLevel minLevel, UBiDiLevel maxLevel) {
+ Run *runs;
+ UBiDiLevel *levels;
+ int32_t firstRun, endRun, limitRun, runCount,
+ temp;
+
+ /* nothing to do? */
+ if(maxLevel<=(minLevel|1)) {
+ return;
+ }
+
+ /*
+ * Reorder only down to the lowest odd level
+ * and reorder at an odd minLevel in a separate, simpler loop.
+ * See comments above for why minLevel is always incremented.
+ */
+ ++minLevel;
+
+ runs=pBiDi->runs;
+ levels=pBiDi->levels;
+ runCount=pBiDi->runCount;
+
+ /* do not include the WS run at paraLevel<=old minLevel except in the simple loop */
+ if(pBiDi->trailingWSStart<pBiDi->length) {
+ --runCount;
+ }
+
+ while(--maxLevel>=minLevel) {
+ firstRun=0;
+
+ /* loop for all sequences of runs */
+ for(;;) {
+ /* look for a sequence of runs that are all at >=maxLevel */
+ /* look for the first run of such a sequence */
+ while(firstRun<runCount && levels[runs[firstRun].logicalStart]<maxLevel) {
+ ++firstRun;
+ }
+ if(firstRun>=runCount) {
+ break; /* no more such runs */
+ }
+
+ /* look for the limit run of such a sequence (the run behind it) */
+ for(limitRun=firstRun; ++limitRun<runCount && levels[runs[limitRun].logicalStart]>=maxLevel;) {}
+
+ /* Swap the entire sequence of runs from firstRun to limitRun-1. */
+ endRun=limitRun-1;
+ while(firstRun<endRun) {
+ temp=runs[firstRun].logicalStart;
+ runs[firstRun].logicalStart=runs[endRun].logicalStart;
+ runs[endRun].logicalStart=temp;
+
+ temp=runs[firstRun].visualLimit;
+ runs[firstRun].visualLimit=runs[endRun].visualLimit;
+ runs[endRun].visualLimit=temp;
+
+ ++firstRun;
+ --endRun;
+ }
+
+ if(limitRun==runCount) {
+ break; /* no more such runs */
+ } else {
+ firstRun=limitRun+1;
+ }
+ }
+ }
+
+ /* now do maxLevel==old minLevel (==odd!), see above */
+ if(!(minLevel&1)) {
+ firstRun=0;
+
+ /* include the trailing WS run in this complete reordering */
+ if(pBiDi->trailingWSStart==pBiDi->length) {
+ --runCount;
+ }
+
+ /* Swap the entire sequence of all runs. (endRun==runCount) */
+ while(firstRun<runCount) {
+ temp=runs[firstRun].logicalStart;
+ runs[firstRun].logicalStart=runs[runCount].logicalStart;
+ runs[runCount].logicalStart=temp;
+
+ temp=runs[firstRun].visualLimit;
+ runs[firstRun].visualLimit=runs[runCount].visualLimit;
+ runs[runCount].visualLimit=temp;
+
+ ++firstRun;
+ --runCount;
+ }
+ }
+}
+
projects / apple / icu.git / blobdiff