<?php
require_once("../lib/phpchartdir.php");

# This script can draw different charts depending on the chartIndex
$chartIndex = (int)($_REQUEST["img"]);

# The x and y coordinates of the grid
$dataX = array(-10, -8, -6, -4, -2, 0, 2, 4, 6, 8, 10);
$dataY = array(-10, -8, -6, -4, -2, 0, 2, 4, 6, 8, 10);

# The values at the grid points. In this example, we will compute the values using the formula z = x
# * sin(y) + y * sin(x).
$dataZ = array_pad(array(), count($dataX) * count($dataY), 0);
for($yIndex = 0; $yIndex < count($dataY); ++$yIndex) {
    $y = $dataY[$yIndex];
    for($xIndex = 0; $xIndex < count($dataX); ++$xIndex) {
        $x = $dataX[$xIndex];
        $dataZ[$yIndex * count($dataX) + $xIndex] = $x * sin($y) + $y * sin($x);
    }
}

# Create a SurfaceChart object of size 380 x 400 pixels, with white (ffffff) background and grey
# (888888) border.
$c = new SurfaceChart(380, 400, 0xffffff, 0x888888);

# Demonstrate various shading methods
if ($chartIndex == 0) {
    $c->addTitle("11 x 11 Data Points\nSmooth Shading");
} else if ($chartIndex == 1) {
    $c->addTitle("11 x 11 Points - Spline Fitted to 50 x 50\nSmooth Shading");
    $c->setInterpolation(50, 50);
} else if ($chartIndex == 2) {
    $c->addTitle("11 x 11 Data Points\nRectangular Shading");
    $c->setShadingMode(RectangularShading);
} else {
    $c->addTitle("11 x 11 Data Points\nTriangular Shading");
    $c->setShadingMode(TriangularShading);
}

# Set the center of the plot region at (175, 200), and set width x depth x height to 200 x 200 x 160
# pixels
$c->setPlotRegion(175, 200, 200, 200, 160);

# Set the plot region wall thichness to 5 pixels
$c->setWallThickness(5);

# Set the elevation and rotation angles to 45 and 60 degrees
$c->setViewAngle(45, 60);

# Set the perspective level to 35
$c->setPerspective(35);

# Set the data to use to plot the chart
$c->setData($dataX, $dataY, $dataZ);

# Set contour lines to semi-transparent black (c0000000)
$c->setContourColor(0xc0000000);

# Output the chart
header("Content-type: image/jpeg");
print($c->makeChart2(JPG));
?>