## @file
# Implementation of Chart::Points
#
# written by
# @author david bonner (dbonner@cs.bu.edu)
#
# maintained by the
# @author Chart Group at Geodetic Fundamental Station Wettzell (Chart@fs.wettzell.de)
# @date 2014-10-14
# @version 2.4.8
#

## @class Chart::Points
# Points class derived from class Base.
#
# This class provides all functions which are specific to
# points
#
package Chart::Points;

use Chart::Base '2.4.8';
use GD;
use Carp;
use strict;

@Chart::Points::ISA     = qw(Chart::Base);
$Chart::Points::VERSION = '2.4.8';

#>>>>>>>>>>>>>>>>>>>>>>>>>>#
#  public methods go here  #
#<<<<<<<<<<<<<<<<<<<<<<<<<<#

#>>>>>>>>>>>>>>>>>>>>>>>>>>>#
#  private methods go here  #
#<<<<<<<<<<<<<<<<<<<<<<<<<<<#

## @fn private _draw_data
# finally get around to plotting the data
sub _draw_data
{
    my $self      = shift;
    my $data      = $self->{'dataref'};
    my $misccolor = $self->_color_role_to_index('misc');
    my ( $x1, $x2, $x3, $y1, $y2, $y3, $mod );
    my ( $width, $height, $delta, $map, $delta_num, $zero_offset );
    my ( $i, $j, $color, $brush );
    my $diff;

    # init the imagemap data field if they want it
    if ( $self->true( $self->{'imagemap'} ) )
    {
        $self->{'imagemap_data'} = [];
    }

    # find the delta value between data points, as well
    # as the mapping constant
    $width  = $self->{'curr_x_max'} - $self->{'curr_x_min'};
    $height = $self->{'curr_y_max'} - $self->{'curr_y_min'};
    $delta  = $width / ( $self->{'num_datapoints'} > 0 ? $self->{'num_datapoints'} : 1 );
    $diff   = ( $self->{'max_val'} - $self->{'min_val'} );
    $diff   = 1 if $diff == 0;
    $map    = $height / $diff;

    #for a xy-plot, use this delta and maybe an offset for the zero-axes
    if ( $self->true( $self->{'xy_plot'} ) )
    {
        $diff      = ( $self->{'x_max_val'} - $self->{'x_min_val'} );
        $diff      = 1 if $diff == 0;
        $delta_num = $width / $diff;

        if ( $self->{'x_min_val'} <= 0 && $self->{'x_max_val'} >= 0 )
        {
            $zero_offset = abs( $self->{'x_min_val'} ) * abs($delta_num);
        }
        elsif ( $self->{'x_min_val'} > 0 || $self->{'x_max_val'} < 0 )
        {
            $zero_offset = -$self->{'x_min_val'} * $delta_num;
        }
        else
        {
            $zero_offset = 0;
        }
    }

    # get the base x-y values
    if ( $self->false( $self->{'xy_plot'} ) )
    {
        $x1 = $self->{'curr_x_min'} + ( $delta / 2 );
    }
    else
    {
        $x1 = $self->{'curr_x_min'};
    }
    if ( $self->{'min_val'} >= 0 )
    {
        $y1  = $self->{'curr_y_max'};
        $mod = $self->{'min_val'};
    }
    elsif ( $self->{'max_val'} <= 0 )
    {
        $y1  = $self->{'curr_y_min'};
        $mod = $self->{'max_val'};
    }
    else
    {
        $y1 = $self->{'curr_y_min'} + ( $map * $self->{'max_val'} );
        $mod = 0;
        $self->{'gd_obj'}->line( $self->{'curr_x_min'}, $y1, $self->{'curr_x_max'}, $y1, $misccolor );
    }

    # draw the points
    for $i ( 1 .. $self->{'num_datasets'} )
    {

        # get the color for this dataset, and set the brush
        $color = $self->_color_role_to_index( 'dataset' . ( $i - 1 ) );
        my $offset = 0;
        ( $brush, $offset ) = $self->_prepare_brush( $color, 'point', 'dataset' . ( $i - 1 ) );
        $self->{'gd_obj'}->setBrush($brush);

        # draw every point for this dataset
        for $j ( 0 .. $self->{'num_datapoints'} )
        {

            # don't try to draw anything if there's no data
            if ( defined( $data->[$i][$j] ) )
            {
                if ( $self->true( $self->{'xy_plot'} ) )
                {
                    $x2 = $x1 + $delta_num * $data->[0][$j] + $zero_offset;
                    $x3 = $x2;
                }
                else
                {
                    $x2 = $x1 + ( $delta * $j );
                    $x3 = $x2;
                }
                $y2 = $y1 - ( ( $data->[$i][$j] - $mod ) * $map );
                $y3 = $y2;

                # draw the point only if it is within the chart borders
                if ( $data->[$i][$j] <= $self->{'max_val'} && $data->[$i][$j] >= $self->{'min_val'} )
                {
                    $self->{'gd_obj'}->line( $x2, $y2, $x3, $y3, gdBrushed );
                }

                # store the imagemap data if they asked for it
                if ( $self->true( $self->{'imagemap'} ) )
                {
                    $self->{'imagemap_data'}->[$i][$j] = [ $x2, $y2 ];
                }
            }
        }
    }

    # and finaly box it off
    $self->{'gd_obj'}
      ->rectangle( $self->{'curr_x_min'}, $self->{'curr_y_min'}, $self->{'curr_x_max'}, $self->{'curr_y_max'}, $misccolor );
    return;

}

## be a good module and return 1
1;
