included targetrdf

targetrdf/common.hh

@@ -0,0 +1,138 @@
+//
+// Source code for the paper
+// 
+// D. Heck and T. Schloemer and O. Deussen, "Blue Noise Sampling with
+// Controlled Aliasing", ACM Trans. Graph., 2013, in press
+//
+// Copyright (C) 2012,2013 Daniel Heck and Thomas Schloemer
+//
+#ifndef COMMON_HH_INCLUDED
+#define COMMON_HH_INCLUDED
+
+#include <string>
+#include <vector>
+#include <cmath>
+#include <stdint.h>
+
+// -------------------- Math --------------------
+
+template <class T, class U>
+inline T Clamp(T x, U min, U max) {
+    if (x < min)
+	return min;
+    else if (x > max)
+	return max;
+    else
+	return x;
+}
+
+
+// -------------------- Utility --------------------
+
+bool HasSuffix(const std::string &s, const std::string &suffix);
+
+enum Endianness {
+    BigEndian, LittleEndian
+};
+
+Endianness SystemEndianness();
+void SwapEndian4(uint8_t *buf, int n);
+bool WriteFloats(FILE *fp, const float *p, int n, Endianness endian);
+bool ReadFloats(FILE *fp, float *p, int n, Endianness endian);
+
+void ReadPFM(int &width, int &height, float *&data, const char *fname);
+void WritePFM(int width, int height, const float *data, const char *fname);
+
+// Output floating point matrix as PGM image
+void SavePGM(float *p, int rows, int cols, const char *fname);
+
+
+// -------------------- Point --------------------
+
+struct Point {
+    float x, y;
+    Point(float x = 0, float y = 0) : x(x), y(y) {}
+};
+
+void LoadPoints(const std::string &fname, std::vector<Point> &points);
+void WritePoints(const std::string &fname, std::vector<Point> &points);
+
+// -------------------- Curve --------------------
+
+class Curve {
+    std::vector<float> y;
+public:
+    float x0, x1, dx;
+    Curve() { x0 = x1 = dx = 0.0f; }
+    Curve(const Curve &c);
+    Curve(int size, float x0, float x1);
+
+    float &operator[](size_t i) { return y[i]; }
+    const float &operator[](size_t i) const { return y[i]; }
+
+    int size() const { return (int)y.size(); }
+
+    int ToIndex(float x) const {
+        return static_cast<int>((x-x0)/dx);
+    }
+
+    float ToXCenter(int index) const {
+        return x0 + (index+0.5f)*dx;
+    }
+    float ToX(int index) const {
+        return x0 + index*dx;
+    }
+
+    // Evaluate curve at point 'x'. Use linear interpolation if 'x' falls
+    // between two bins.
+    float At(float x) const;
+
+    void Write(const std::string &fname);
+    static Curve Read(const std::string &fname);
+
+    void FilterGauss(const Curve &source, float sigma);
+};
+
+
+inline Curve FilterGauss(int nbins, const Curve &source, float sigma) {
+    Curve c(nbins, source.x0, source.x1);
+    c.FilterGauss(source, sigma);
+    return c;
+}
+
+float Integrate(const Curve &c, float x0, float x1, float *E = NULL);
+
+inline float Integrate(const Curve &c) {
+    return Integrate(c, c.x0, c.x1);
+}
+
+
+// -------------------- Toroidal distance --------------------
+
+inline static float Sqr(float x) {
+    return x*x;
+}
+  
+// Compute toroidal distance between points a and b. Both a and b must
+// lie inside the unit square.
+inline static float DistSqrToroidal(float const *a, float const *b) {
+    float dx = a[0]-b[0], dy = a[1]-b[1];
+    return Sqr(dx + (dx < -.5f) - (dx > .5f)) + 
+        Sqr(dy + (dy < -.5f) - (dy > .5f));
+}
+
+inline static float DistToroidal(float const *a, float const *b) {
+    return sqrtf(DistSqrToroidal(a, b));
+}
+
+// -------------------- RDF calculations --------------------
+
+void CalcRDF(Curve &c, size_t npts, const float *pts, 
+        float (*distfunc)(const float *, const float *) = DistToroidal);
+Curve CalcRDF(int numbins, size_t npts, const float *pts, 
+        float sigma = 0, float (*distfunc)(const float *, const float *) = DistToroidal);
+
+Curve RDF2Power(int npts, const Curve &rdf, int nbins, float x0, float x1);
+Curve Power2RDF(int npts, const Curve &power, int nbins, float x0, float x1, float smoothing);
+
+#endif