Initial commit

BlueNoise/RangeList.cpp

@@ -0,0 +1,139 @@
+// $Id: RangeList.cpp,v 1.4 2006/01/24 03:22:14 zr Exp $
+
+#define _USE_MATH_DEFINES
+#include <math.h>
+#include <stdio.h>
+#include <cstring>
+
+#include "RangeList.h"
+
+///
+
+static const float kSmallestRange = .000001f;
+
+RangeList::RangeList(float min, float max)
+{
+	numRanges = 0;
+	rangesSize = 8;
+	ranges = new RangeEntry[rangesSize];
+	reset(min, max);
+}
+
+RangeList::~RangeList()
+{
+	delete[] ranges;
+}
+
+void RangeList::reset(float min, float max)
+{
+	numRanges = 1;
+	ranges[0].min = min;
+	ranges[0].max = max;
+}
+
+void RangeList::deleteRange(int pos)
+{
+	if (pos<numRanges-1) {
+		memmove(&ranges[pos], &ranges[pos+1], sizeof(*ranges)*(numRanges-(pos+1)));
+	}
+	numRanges--;
+}
+
+void RangeList::insertRange(int pos, float min, float max)
+{
+	if (numRanges==rangesSize) {
+		RangeEntry *tmp = new RangeEntry[rangesSize];
+		memcpy(tmp, ranges, numRanges*sizeof(*tmp));
+		delete[] ranges;
+		ranges = tmp;
+	}
+
+	if (pos<numRanges) {
+		memmove(&ranges[pos+1], &ranges[pos], sizeof(*ranges)*(numRanges-pos));
+	}
+
+	ranges[pos].min = min;
+	ranges[pos].max = max;
+	numRanges++;
+}
+
+void RangeList::subtract(float a, float b)
+{
+	static const float twoPi = (float) (M_PI*2);
+
+	if (a>twoPi) {
+		subtract(a-twoPi, b-twoPi);
+	} else if (b<0) {
+		subtract(a+twoPi, b+twoPi);
+	} else if (a<0) {
+		subtract(0, b);
+		subtract(a+twoPi,twoPi);
+	} else if (b>twoPi) {
+		subtract(a, twoPi);
+		subtract(0, b-twoPi);
+	} else if (numRanges==0) {
+		;
+	} else {
+		int pos;
+
+		if (a<ranges[0].min) {
+			pos = -1;
+		} else {
+			int lo=0, mid=0, hi=numRanges;
+
+			while (lo<hi-1) {
+				mid = (lo+hi)>>1;
+				if (ranges[mid].min<a) {
+					lo = mid;
+				} else {
+					hi = mid;
+				}
+			}
+
+			pos = lo;
+		}
+
+		if (pos==-1) {
+			pos = 0;
+		} else if (a<ranges[pos].max) {
+			float c = ranges[pos].min;
+			float d = ranges[pos].max;
+			if (a-c<kSmallestRange) {
+				if (b<d) {
+					ranges[pos].min = b;
+				} else {
+					deleteRange(pos);
+				}
+			} else {
+				ranges[pos].max = a;
+				if (b<d) {
+					insertRange(pos+1, b, d);
+				}
+				pos++;
+			}
+		} else {
+			if (pos<numRanges-1 && b>ranges[pos+1].min) {
+				pos++;
+			} else {
+				return;
+			}
+		}
+
+		while (pos<numRanges && b>ranges[pos].min) {
+			if (ranges[pos].max-b<kSmallestRange) {
+				deleteRange(pos);
+			} else {
+				ranges[pos].min = b;
+			}
+		}
+	}
+}
+
+void RangeList::print()
+{
+	printf("[");
+	for (int i=0; i<numRanges; i++) {
+		printf("(%f,%f)%s", ranges[i].min, ranges[i].max, (i==numRanges-1)?"":", ");
+	}
+	printf("]\n");
+}