source: trunk/xgraph/jpgraph/Examples/colormaps.php

<?php // content="text/plain; charset=utf-8"
require_once ('../jpgraph.php');
require_once ('../jpgraph_canvas.php');
require_once ('../jpgraph_colormap.inc.php');

class ColorMapDriver {
        const WIDTH = 600; // Image width
        const LMARG = 90;  // Left margin
        const RMARG = 25;  // Right margin
        const MAPMARG = 35;  // Map margin between each map
        const MODHEIGHT = 30; // Module height (=Map height)
        const YSTART = 60; // Start coordinate for map list

    public function Draw($aTitle, $aStart, $aEnd, $n=64, $aReverse=false, $addColorNames = false ) {

            // Setup to draw colormap with names platoe colors
            $lmarg = ColorMapDriver::LMARG; // left margin
            $rmarg = ColorMapDriver::RMARG; // right margin
            $width = ColorMapDriver::WIDTH; // Overall image width

            // Module height
            $mh = ColorMapDriver::MODHEIGHT;

            // Step between each map
            $ymarg = $mh + ColorMapDriver::MAPMARG;

            if( $addColorNames ) {
                $ymarg += 50;
            }

        // Start position
        $xs=$lmarg; $ys=ColorMapDriver::YSTART;

        // Setup a basic canvas graph
        $height = ($aEnd-$aStart+1)*$ymarg+50;
        $graph = new CanvasGraph($width,$height);
        $graph->img->SetColor('darkgray');
        $graph->img->Rectangle(0,0,$width-1,$height-1);

            $t = new Text($aTitle, $width/2,5);
            $t->SetAlign('center','top');
            $t->SetFont(FF_ARIAL,FS_BOLD,14);
            $t->Stroke($graph->img);

            // Instantiate a colormap
                $cm = new ColorMap();
                $cm->InitRGB($graph->img->rgb);

        for( $mapidx=$aStart; $mapidx <= $aEnd; ++$mapidx, $ys += $ymarg ) {

                $cm->SetMap($mapidx,$aReverse);
                $n = $cm->SetNumColors($n);
                list( $mapidx, $maparray ) = $cm->GetCurrMap();
                $ncols = count($maparray);
                $colbuckets = $cm->GetBuckets();

                // The module width will depend on the actual number of colors
                $mw = round(($width-$lmarg-$rmarg)/$n);

                // Draw color map title (name)
                $t->Set('Basic colors: '.$ncols.',   Total colors: '.$n);
                $t->SetAlign('center','bottom');
                $t->SetAngle(0);
                $t->SetFont(FF_TIMES,FS_NORMAL,14);
                $t->Stroke($graph->img,$width/2,$ys-3);

                // Add the name/number of the map to the left
                $t->SetAlign('right','center');
                $t->Set('Map: '.$mapidx);
                $t->SetFont(FF_ARIAL,FS_NORMAL,14);
                $t->Stroke($graph->img,$xs-20,round($ys+$mh/2));

                // Setup text properties for the color names
                if( $addColorNames ) {
                        $t->SetAngle(30);
                        $t->SetFont(FF_ARIAL,FS_NORMAL,12);
                        $t->SetAlign('right','top');
                }

                // Loop through all colors in the map
                $x = $xs; $y = $ys; $k=0;
                for($i=0; $i < $n; ++$i){
                    $graph->img->SetColor($colbuckets[$i]);
                    $graph->img->FilledRectangle($x,$y,$x+$mw,$y+$mh);

                    // Mark all basic colors in the map with a bar and name
                    if( $i % (($n-$ncols)/($ncols-1)+1) == 0 ) {
                        $graph->img->SetColor('black');
                        $graph->img->FilledRectangle($x,$y+$mh+4,$x+$mw-1,$y+$mh+6);
                        if( $addColorNames ) {
                                $t->Set($maparray[$k++]);
                                $t->Stroke($graph->img,$x+$mw/2,$y+$mh+10);
                        }
                    }
                    $x += $mw;
                }

                // Draw a border around the map
                $graph->img->SetColor('black');
                $graph->img->Rectangle($xs,$ys,$xs+$mw*$n,$ys+$mh);

            }

        // Send back to client
        $graph->Stroke();
    }

}

$driver = new ColorMapDriver();

$title = "Standard maps";
$reverse = false;
$n = 64; $s=0; $e=9;
$showNames = false;


/*
$title = "Center maps";
$reverse = false;
$n = 64; $s=10; $e=14;
$showNames = false;
*/

/*
$title = "Continues maps";
$reverse = false;
$n = 64; $s=15; $e=21;
$showNames = false;
*/
$driver->Draw($title,$s,$e,$n,$reverse,$showNames);

?>