source: nanovis/branches/1.2/Axis.h @ 5394

/* -*- mode: c++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
 * Copyright (c) 2004-2013  HUBzero Foundation, LLC
 *
 * Authors: George A. Howlett <gah@purdue.edu>
 */
#ifndef NV_AXIS_H
#define NV_AXIS_H

#include <stdlib.h>
#include <string.h>

#include <cmath>
#include <limits>

#include "Chain.h"

#ifndef NAN
#define NAN (std::numeric_limits<double>::quiet_NaN())
#endif

namespace nv {

class Axis;

class TickIter
{
public:
    void setStartingLink(ChainLink *linkPtr)
    {
        _linkPtr = linkPtr;
    }

    bool next()
    {
        if (_linkPtr == NULL) {
            return false;
        }
        _linkPtr = _linkPtr->next();
        return (_linkPtr != NULL);
    }

    float getValue()
    {
        union {
            float x;
            void *clientData;
        } value;
        value.clientData = _linkPtr->getValue();
        return value.x;
    }

private:
    ChainLink *_linkPtr;
};

/**
 * Class containing information where the ticks (major or
 * minor) will be displayed on the graph.
 */
class Ticks
{
public:
    Ticks(int numTicks) :
        reqNumTicks(numTicks),
        _autoscale(true),
        _numTicks(0),
        _ticks(NULL)
    {
    }

    ~Ticks()
    {
        if (_ticks != NULL) {
            delete [] _ticks;
        }
        _chain.reset();
    }

    void setTicks(float *ticks, int nTicks)
    {
        _ticks = ticks, _numTicks = nTicks;
    }

    int numTicks()
    {
        return _numTicks;
    }

    double tick(int i)
    {
        if ((i < 0) || (i >= _numTicks)) {
            return NAN;
        }
        return _ticks[i];
    }

    void reset()
    {
        _chain.reset();
    }

    float step()
    {
        return _step;
    }

    void append (float x)
    {
        _chain.append(getClientData(x));
    }

    void setValues(double initial, double step, unsigned int nSteps)
    {
        _initial = initial, _step = step, _nSteps = nSteps;
    }

    bool autoscale()
    {
        return _autoscale;
    }

    void sweepTicks()
    {
        if (_autoscale) {
            if (_ticks != NULL) {
                delete [] _ticks;
            }
            setTicks();
        }
    }

    bool firstTick(TickIter &iter)
    {
        ChainLink *linkPtr;

        linkPtr = _chain.firstLink();
        iter.setStartingLink(linkPtr);
        return (linkPtr != NULL);
    }

    int reqNumTicks;            /**< Default number of ticks to be displayed. */

private:
    void setTicks();    /**< Routine used internally to create the array
                                 * of ticks as defined by a given sweep. */
    void *getClientData(float x)
    {
        union {
            float x;
            void *clientData;
        } value;
        value.x = x;
        return value.clientData;
    }

    bool _autoscale;            /**< Indicates if the ticks are autoscaled. */
    /* 
     * Tick locations may be generated in two fashions
     */
    /* 1. an array of values provided by the user. */
    int _numTicks;              /* # of ticks on axis */
    float *_ticks;              /* Array of tick values (alloc-ed).  Right now
                                 * it's a float so we don't have to allocate
                                 * store for the list of ticks generated.  In
                                 * the future when we store both the tick
                                 * label and the value in the list, we may
                                 * extend this to a double.
                                 */
    /*
     * 2. a defined sweep of initial, step, and nsteps.  This in turn
     *    will generate the an array of values.
     */
    double _initial;            /**< Initial value */
    double _step;               /**< Size of interval */
    unsigned int _nSteps;       /**< Number of intervals. */

    /**
     *This finally generates a list of ticks values that exclude duplicate
     * minor ticks (that are always represented by major ticks).  In the
     * future, the string representing the tick label will be stored in 
     * the chain.
     */
    Chain _chain;
};

/**
 * Class contains options controlling how the axis will be
 * displayed.
 */
class Axis
{
public:
    /// Flags associated with the axis.
    enum AxisFlags {
        AUTOSCALE  = (1<<0),
        DESCENDING = (1<<1),
        LOGSCALE   = (1<<2),
        TIGHT_MIN  = (1<<3),
        TIGHT_MAX  = (1<<4)
    };

    Axis(const char *name);

    ~Axis()
    {
        if (_name != NULL) {
            free((void *)_name);
        }
        if (_units != NULL) {
            free((void *)_units);
        }
        if (_title != NULL) {
            free((void *)_title);
        }
    }

    bool firstMajor(TickIter& iter)
    {
        return _major.firstTick(iter);
    }

    bool firstMinor(TickIter& iter)
    {
        return _minor.firstTick(iter);
    }

    void resetRange();

    void fixRange(double min, double max);

    void setScale(double min, double max);

    double scale() const
    {
        return _scale;
    }

    double range() const
    {
        return _range;
    }

    double dataMin() const
    {
        return _valueMin;
    }

    double dataMax() const
    {
        return _valueMax;
    }

    double min() const
    {
        return _min;
    }

    double max() const
    {
        return _max;
    }

    void setLimits(double min, double max)
    {
        _reqMin = min, _reqMax = max;
    }

    void unsetLimits()
    {
        setLimits(NAN, NAN);
    }

    double map(double x);

    double invMap(double x);

    const char *name()
    {
        return _name;
    }

    void name(const char *name)
    {
        if (_name != NULL) {
            free((void *)_name);
        }
        _name = strdup(name);
    }

    const char *units()
    {
        return _units;
    }

    void units(const char *units)
    {
        if (_units != NULL) {
            free((void *)_units);
        }
        _units = strdup(units);
    }

    const char *title()
    {
        return _title;
    }

    void title(const char *title)
    {
        if (_title != NULL) {
            free((void *)_title);
        }
        _title = strdup(title);
    }

    void setDescendingOption(bool value)
    {
        if (value) {
            _flags |= DESCENDING;
        } else {
            _flags &= ~DESCENDING;
        }
    }

    void setTightMinOption(bool value)
    {
        if (value) {
            _flags |= TIGHT_MIN;
        } else {
            _flags &= ~TIGHT_MIN;
        }
    }

    void setTightMaxOption(bool value)
    {
        if (value) {
            _flags |= TIGHT_MAX;
        } else {
            _flags &= ~TIGHT_MAX;
        }
    }

    void setLogScaleOption(bool value)
    {
        if (value) {
            _flags |= LOGSCALE;
        } else {
            _flags &= ~LOGSCALE;
        }
    }

    void setMajorStepOption(double value)
    {
        _reqStep = value;       // Setting to 0.0 resets step to "auto"
    }

    void setNumMinorTicksOption(int n)
    {
        _minor.reqNumTicks = n;
    }

    void setNumMajorTicksOption(int n)
    {
        _major.reqNumTicks = n;
    }

private:
    void logScale();

    void linearScale();

    bool inRange(double x);

    void makeTicks();

    const char *_name;          /**< Name of the axis. Malloc-ed */

    unsigned int _flags;

    const char *_title;         /**< Title of the axis. */

    const char *_units;         /**< Units of the axis. */

    double _valueMin, _valueMax; /**< The limits of the data. */

    double _reqMin, _reqMax;    /**< Requested axis bounds. Consult the
                                 * axisPtr->flags field for
                                 * Axis::CONFIG_MIN and Axis::CONFIG_MAX
                                 * to see if the requested bound have
                                 * been set.  They override the
                                 * computed range of the axis
                                 * (determined by auto-scaling). */

    double _min, _max;          /**< Smallest and largest major tick values for
                                 * the axis.  If loose, the tick values lie
                                 * outside the range of data values.  If
                                 * tight, they lie interior to the limits of
                                 * the data. */

    double _range;              /**< Range of values on axis (_max - _min) */
    double _scale;              /**< Scale factor for axis (1.0/_range) */

    double _reqStep;            /**< If > 0.0, overrides the computed major tick
                                 * interval.  Otherwise a stepsize is
                                 * automatically calculated, based upon the
                                 * range of elements mapped to the axis. The
                                 * default value is 0.0. */

    Ticks _major, _minor;
};

}

#endif