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public/mathlib/quantize.h

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+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//
+//=============================================================================//
+#ifndef QUANTIZE_H
+#define QUANTIZE_H
+
+#ifndef STRING_H
+#include <string.h>
+#endif
+
+#define MAXDIMS 768
+#define MAXQUANT 16000
+
+
+#include <tier0/platform.h>
+
+struct Sample;
+
+struct QuantizedValue {
+	double MinError;											// minimum possible error. used
+	// for neighbor searches.
+	struct QuantizedValue *Children[2];						// splits
+	int32 value;											// only exists for leaf nodes
+	struct Sample *Samples;									// every sample quantized into this
+	// entry
+	int32 NSamples;											// how many were quantized to this.
+	int32 TotSamples;
+	double *ErrorMeasure;									// variance measure for each dimension
+	double TotalError;										// sum of errors
+	uint8 *Mean;											// average value of each dimension
+	uint8 *Mins;											// min box for children and this
+	uint8 *Maxs;											// max box for children and this
+	int NQuant;												// the number of samples which were
+															// quantzied to this node since the
+															// last time OptimizeQuantizer()
+															// was called.
+	int *Sums;												// sum used by OptimizeQuantizer
+	int sortdim;											// dimension currently sorted along.
+};
+
+struct Sample {
+	int32 ID;												// identifier of this sample. can
+															// be used for any purpose.
+	int32 Count;											// number of samples this sample
+															// represents
+	int32 QNum;										   // what value this sample ended up quantized
+															// to.
+	struct QuantizedValue *qptr;							// ptr to what this was quantized to.
+	uint8 Value[1];										   // array of values for multi-dimensional
+	// variables.
+};
+
+void FreeQuantization(struct QuantizedValue *t);
+
+struct QuantizedValue *Quantize(struct Sample *s, int nsamples, int ndims,
+								int nvalues, uint8 *weights, int value0=0);
+
+int CompressSamples(struct Sample *s, int nsamples, int ndims);
+
+struct QuantizedValue *FindMatch(uint8 const *sample,
+								 int ndims,uint8 *weights,
+								 struct QuantizedValue *QTable);
+void PrintSamples(struct Sample const *s, int nsamples, int ndims);
+
+struct QuantizedValue *FindQNode(struct QuantizedValue const *q, int32 code);
+
+inline struct Sample *NthSample(struct Sample *s, int i, int nd)
+{
+	uint8 *r=(uint8 *) s;
+	r+=i*(sizeof(*s)+(nd-1));
+	return (struct Sample *) r;
+}
+
+inline struct Sample *AllocSamples(int ns, int nd)
+{
+	size_t size5=(sizeof(struct Sample)+(nd-1))*ns;
+	void *ret=new uint8[size5];
+	memset(ret,0,size5);
+	for(int i=0;i<ns;i++)
+		NthSample((struct Sample *)ret,i,nd)->Count=1;
+	return (struct Sample *) ret;
+}
+
+
+// MinimumError: what is the min error which will occur if quantizing
+// a sample to the given qnode? This is just the error if the qnode
+// is a leaf.
+double MinimumError(struct QuantizedValue const *q, uint8 const *sample,
+					int ndims, uint8 const *weights);
+double MaximumError(struct QuantizedValue const *q, uint8 const *sample,
+					int ndims, uint8 const *weights);
+
+void PrintQTree(struct QuantizedValue const *p,int idlevel=0);
+void OptimizeQuantizer(struct QuantizedValue *q, int ndims);
+
+// RecalculateVelues: update the means in a sample tree, based upon
+// the samples. can be used to reoptimize when samples are deleted,
+// for instance.
+
+void RecalculateValues(struct QuantizedValue *q, int ndims);
+
+extern double SquaredError;	// may be reset and examined. updated by
+															// FindMatch()
+
+
+
+
+// the routines below can be used for uniform quantization via dart-throwing.
+typedef void (*GENERATOR)(void *);    // generate a random sample
+typedef double (*COMPARER)(void const *a, void const *b);
+
+void *DartThrow(int NResults, int NTries, size_t itemsize, GENERATOR gen,
+				COMPARER cmp);
+void *FindClosestDart(void *items,int NResults, size_t itemsize,
+					  COMPARER cmp, void *lookfor, int *idx);
+
+
+
+
+// color quantization of 24 bit images
+#define QUANTFLAGS_NODITHER 1	// don't do Floyd-steinberg dither
+
+extern void ColorQuantize(
+uint8 const	*pImage,			// 4 byte pixels ARGB
+int			nWidth,
+int			nHeight,
+int			nFlags, 			// QUANTFLAGS_xxx
+int			nColors,			// # of colors to fill in in palette
+uint8		*pOutPixels,		// where to store resulting 8 bit pixels
+uint8		*pOutPalette,		// where to store resulting 768-byte palette
+int			nFirstColor);		// first color to use in mapping
+
+
+
+
+
+#endif