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

# 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 lighting parameters
if ($_REQUEST["img"] == "0") {
    $c->addTitle(
        "Default Lighting<*br*><*size=10*>Ambient = 0.5, Diffuse = 0.5, Specular = ".
        "1, Shininess = 8");
} else if ($_REQUEST["img"] == "1") {
    $c->addTitle(
        "Matte (Non-Glossy) Lighting<*br*><*size=10*>Ambient = 0.5, Diffuse = 0.5, ".
        "Specular = 0, Shininess = 0");
    $c->setLighting(0.5, 0.5, 0, 0);
} else if ($_REQUEST["img"] == "2") {
    $c->addTitle(
        "Flat Lighting<*br*><*size=10*>Ambient = 1, Diffuse = 0, Specular = 0, ".
        "Shininess = 0");
    $c->setLighting(1, 0, 0, 0);
} else {
    $c->addTitle(
        "Strong Glossy Lighting<*br*><*size=10*>Ambient = 0.5, Diffuse = 0.5, ".
        "Specular = 4, Shininess = 32");
    $c->setLighting(0.5, 0.5, 4, 32);
}

# 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);

# Spline interpolate data to a 50 x 50 grid for a smooth surface
$c->setInterpolation(50, 50);

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

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