howardjones/network-weathermap

<?php

namespace Weathermap\Core;

/**
 * Utility class used for colour calculations in Weathermap.
 *
 * Allows representation of any RGBA colour, plus some special
 * pseudocolours.
 */
class Colour
{
    protected $red;
    protected $green;
    protected $blue;
    protected $alpha;

    // take in an existing value and create a Colour object for it
    public function __construct()
    {
        $this->alpha = 255;

        // a set of 3 colours
        if (func_num_args() === 3) {
            $this->red = func_get_arg(0);
            $this->green = func_get_arg(1);
            $this->blue = func_get_arg(2);
        }

        if (func_num_args() === 1) {
            // an array of 3 colours
            if (gettype(func_get_arg(0)) === 'array') {
                $ary = func_get_arg(0);
                $this->red = $ary[0];
                $this->green = $ary[1];
                $this->blue = $ary[2];
            } else {
                // a single scalar argument - should be a 'special' colour
                $arg = func_get_arg(0);

                switch ($arg) {
                    case "none":
                        $this->red = -1;
                        $this->green = -1;
                        $this->blue = -1;
                        break;
                    case "copy":
                        $this->red = -2;
                        $this->green = -2;
                        $this->blue = -2;
                        break;
                    case "contrast":
                        $this->red = -3;
                        $this->green = -3;
                        $this->blue = -3;
                        break;
                    default:
                        throw new \Exception("Unknown special colour type");
                }
            }
        }
    }

    /**
     * @return int[]
     */
    public function getComponents()
    {
        return array($this->red, $this->green, $this->blue);
    }

    /**
     * return true if two colours are identical
     *
     * @param Colour $colour2
     * @return bool
     * @throws WeathermapInternalFail
     */
    public function equals($colour2)
    {
        if (null == $colour2) {
            throw new WeathermapInternalFail('Comparison With Null');
        }

        if ($this->red == $colour2->red && $this->green == $colour2->green
            && $this->blue == $colour2->blue && $this->alpha == $colour2->alpha
        ) {
            return true;
        }
        return false;
    }

    /**
     * take this colour, and that colour, and make a new one in the ratio given
     *
     * @param Colour $colour2
     * @param float $ratio
     * @return Colour
     */
    public function blendWith($colour2, $ratio)
    {
        $newRed = $this->red + ($colour2->red - $this->red) * $ratio;
        $newGreen = $this->green + ($colour2->green - $this->green) * $ratio;
        $newBlue = $this->blue + ($colour2->blue - $this->blue) * $ratio;

        return new Colour($newRed, $newGreen, $newBlue);
    }

    // Is this a transparent/none colour?
    public function isRealColour()
    {
        if ($this->red >= 0 && $this->green >= 0 && $this->blue >= 0) {
            return true;
        }

        return false;
    }

    // Is this a transparent/none colour?
    public function isNone()
    {
        if ($this->red == -1 && $this->green == -1 && $this->blue == -1) {
            return true;
        }

        return false;
    }

    // Is this a contrast colour?
    public function isContrast()
    {
        if ($this->red == -3 && $this->green == -3 && $this->blue == -3) {
            return true;
        }

        return false;
    }

    // Is this a copy colour?
    public function isCopy()
    {
        if ($this->red == -2 && $this->green == -2 && $this->blue == -2) {
            return true;
        }
        return false;
    }

    // allocate a colour in the appropriate image context
    // - things like scale colours are used in multiple images now (the scale, several nodes, the main map...)
    public function gdAllocate($gdImageRef)
    {
        if (false === $this->isRealColour()) {
            return null;
        }

        return ImageUtility::myImageColorAllocate($gdImageRef, $this->red, $this->green, $this->blue);
    }

    // based on an idea from: http://www.bennadel.com/index.cfm?dax=blog:902.view
    public function getContrastingColourAsArray()
    {
        if (!$this->isRealColour()) {
            MapUtility::warn("You can't make a contrast with 'none' - guessing black. [WMWARN43]\n");
            return array(0, 0, 0);
        }

        if ((($this->red + $this->green + $this->blue) > 500) || ($this->green > 140)) {
            return array(0, 0, 0);
        }

        return array(255, 255, 255);
    }

    public function getContrastingColour()
    {
        return new Colour($this->getContrastingColourAsArray());
    }

    // make a printable version, for debugging
    // - optionally take a format string, so we can use it for other things (like WriteConfig, or hex in stylesheets)
    public function asString($format = 'RGB(%d,%d,%d)')
    {
        if ($this->isNone()) {
            return 'none';
        }
        if ($this->isCopy()) {
            return 'copy';
        }
        if ($this->isContrast()) {
            return 'contrast';
        }
        return sprintf($format, $this->red, $this->green, $this->blue);
    }

    public function __toString()
    {
        return $this->asString();
    }

    /**
     * Produce a string ready to drop into a config file by WriteConfig
     */
    public function asConfig()
    {
        return $this->asString('%d %d %d');
    }

    public function asHTML()
    {
        if (true === $this->isRealColour()) {
            return $this->asString('#%02x%02x%02x');
        }

        return '';
    }

    public function asArray()
    {
        return array($this->red, $this->green, $this->blue, $this->alpha);
    }
}