JUCE/modules/juce_graphics/colour/juce_Colour.cpp

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited

   JUCE is an open source library subject to commercial or open-source
   licensing.

   By using JUCE, you agree to the terms of both the JUCE 7 End-User License
   Agreement and JUCE Privacy Policy.

   End User License Agreement: www.juce.com/juce-7-licence
   Privacy Policy: www.juce.com/juce-privacy-policy

   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

namespace ColourHelpers
{
    static uint8 floatToUInt8 (float n) noexcept
    {
        return n <= 0.0f ? 0 : (n >= 1.0f ? 255 : (uint8) roundToInt (n * 255.0f));
    }

    static float getHue (Colour col)
    {
        auto r = (int) col.getRed();
        auto g = (int) col.getGreen();
        auto b = (int) col.getBlue();

        auto hi = jmax (r, g, b);
        auto lo = jmin (r, g, b);

        float hue = 0.0f;

        if (hi > 0 && ! exactlyEqual (hi, lo))
        {
            auto invDiff = 1.0f / (float) (hi - lo);

            auto red   = (float) (hi - r) * invDiff;
            auto green = (float) (hi - g) * invDiff;
            auto blue  = (float) (hi - b) * invDiff;

            if      (r == hi)  hue = blue - green;
            else if (g == hi)  hue = 2.0f + red - blue;
            else               hue = 4.0f + green - red;

            hue *= 1.0f / 6.0f;

            if (hue < 0.0f)
                hue += 1.0f;
        }

        return hue;
    }

    //==============================================================================
    struct HSL
    {
        HSL (Colour col) noexcept
        {
            auto r = (int) col.getRed();
            auto g = (int) col.getGreen();
            auto b = (int) col.getBlue();

            auto hi = jmax (r, g, b);
            auto lo = jmin (r, g, b);

            if (hi < 0)
                return;

            lightness = ((float) (hi + lo) / 2.0f) / 255.0f;

            if (lightness <= 0.0f)
                return;

            hue = getHue (col);

            if (1.0f <= lightness)
                return;

            auto denominator = 1.0f - std::abs ((2.0f * lightness) - 1.0f);
            saturation = ((float) (hi - lo) / 255.0f) / denominator;
        }

        Colour toColour (Colour original) const noexcept
        {
            return Colour::fromHSL (hue, saturation, lightness, original.getAlpha());
        }

        static PixelARGB toRGB (float h, float s, float l, uint8 alpha) noexcept
        {
            auto v = l < 0.5f ? l * (1.0f + s) : l + s - (l * s);

            if (approximatelyEqual (v, 0.0f))
                return PixelARGB (alpha, 0, 0, 0);

            auto min = (2.0f * l) - v;
            auto sv = (v - min) / v;

            h = ((h - std::floor (h)) * 360.0f) / 60.0f;
            auto f = h - std::floor (h);
            auto vsf = v * sv * f;
            auto mid1 = min + vsf;
            auto mid2 = v - vsf;

            if      (h < 1.0f)  return PixelARGB (alpha, floatToUInt8 (v),    floatToUInt8 (mid1), floatToUInt8 (min));
            else if (h < 2.0f)  return PixelARGB (alpha, floatToUInt8 (mid2), floatToUInt8 (v),    floatToUInt8 (min));
            else if (h < 3.0f)  return PixelARGB (alpha, floatToUInt8 (min),  floatToUInt8 (v),    floatToUInt8 (mid1));
            else if (h < 4.0f)  return PixelARGB (alpha, floatToUInt8 (min),  floatToUInt8 (mid2), floatToUInt8 (v));
            else if (h < 5.0f)  return PixelARGB (alpha, floatToUInt8 (mid1), floatToUInt8 (min),  floatToUInt8 (v));
            else if (h < 6.0f)  return PixelARGB (alpha, floatToUInt8 (v),    floatToUInt8 (min),  floatToUInt8 (mid2));

            return PixelARGB (alpha, 0, 0, 0);
        }

        float hue = 0.0f, saturation = 0.0f, lightness = 0.0f;
    };

    //==============================================================================
    struct HSB
    {
        HSB (Colour col) noexcept
        {
            auto r = (int) col.getRed();
            auto g = (int) col.getGreen();
            auto b = (int) col.getBlue();

            auto hi = jmax (r, g, b);
            auto lo = jmin (r, g, b);

            if (hi > 0)
            {
                saturation = (float) (hi - lo) / (float) hi;

                if (saturation > 0.0f)
                    hue = getHue (col);

                brightness = (float) hi / 255.0f;
            }
        }

        Colour toColour (Colour original) const noexcept
        {
            return Colour (hue, saturation, brightness, original.getAlpha());
        }

        static PixelARGB toRGB (float h, float s, float v, uint8 alpha) noexcept
        {
            v = jlimit (0.0f, 255.0f, v * 255.0f);
            auto intV = (uint8) roundToInt (v);

            if (s <= 0)
                return PixelARGB (alpha, intV, intV, intV);

            s = jmin (1.0f, s);
            h = ((h - std::floor (h)) * 360.0f) / 60.0f;
            auto f = h - std::floor (h);
            auto x = (uint8) roundToInt (v * (1.0f - s));

            if (h < 1.0f)   return PixelARGB (alpha, intV,    (uint8) roundToInt (v * (1.0f - (s * (1.0f - f)))), x);
            if (h < 2.0f)   return PixelARGB (alpha,          (uint8) roundToInt (v * (1.0f - s * f)), intV, x);
            if (h < 3.0f)   return PixelARGB (alpha, x, intV, (uint8) roundToInt (v * (1.0f - (s * (1.0f - f)))));
            if (h < 4.0f)   return PixelARGB (alpha, x,       (uint8) roundToInt (v * (1.0f - s * f)), intV);
            if (h < 5.0f)   return PixelARGB (alpha,          (uint8) roundToInt (v * (1.0f - (s * (1.0f - f)))), x, intV);
            return                 PixelARGB (alpha, intV, x, (uint8) roundToInt (v * (1.0f - s * f)));
        }

        float hue = 0.0f, saturation = 0.0f, brightness = 0.0f;
    };

    //==============================================================================
    struct YIQ
    {
        YIQ (Colour c) noexcept
        {
            auto r = c.getFloatRed();
            auto g = c.getFloatGreen();
            auto b = c.getFloatBlue();

            y = 0.2999f * r + 0.5870f * g + 0.1140f * b;
            i = 0.5957f * r - 0.2744f * g - 0.3212f * b;
            q = 0.2114f * r - 0.5225f * g - 0.3113f * b;
            alpha = c.getFloatAlpha();
        }

        Colour toColour() const noexcept
        {
            return Colour::fromFloatRGBA (y + 0.9563f * i + 0.6210f * q,
                                          y - 0.2721f * i - 0.6474f * q,
                                          y - 1.1070f * i + 1.7046f * q,
                                          alpha);
        }

        float y = 0.0f, i = 0.0f, q = 0.0f, alpha = 0.0f;
    };
}

//==============================================================================
bool Colour::operator== (const Colour& other) const noexcept    { return argb.getNativeARGB() == other.argb.getNativeARGB(); }
bool Colour::operator!= (const Colour& other) const noexcept    { return argb.getNativeARGB() != other.argb.getNativeARGB(); }

//==============================================================================
Colour::Colour (uint32 col) noexcept
    : argb (static_cast<uint8> ((col >> 24) & 0xff),
            static_cast<uint8> ((col >> 16) & 0xff),
            static_cast<uint8> ((col >> 8) & 0xff),
            static_cast<uint8> (col & 0xff))
{
}

Colour::Colour (uint8 red, uint8 green, uint8 blue) noexcept
{
    argb.setARGB (0xff, red, green, blue);
}

Colour Colour::fromRGB (uint8 red, uint8 green, uint8 blue) noexcept
{
    return Colour (red, green, blue);
}

Colour::Colour (uint8 red, uint8 green, uint8 blue, uint8 alpha) noexcept
{
    argb.setARGB (alpha, red, green, blue);
}

Colour Colour::fromRGBA (uint8 red, uint8 green, uint8 blue, uint8 alpha) noexcept
{
    return Colour (red, green, blue, alpha);
}

Colour::Colour (uint8 red, uint8 green, uint8 blue, float alpha) noexcept
{
    argb.setARGB (ColourHelpers::floatToUInt8 (alpha), red, green, blue);
}

Colour Colour::fromFloatRGBA (float red, float green, float blue, float alpha) noexcept
{
    return Colour (ColourHelpers::floatToUInt8 (red),
                   ColourHelpers::floatToUInt8 (green),
                   ColourHelpers::floatToUInt8 (blue), alpha);
}

Colour::Colour (float hue, float saturation, float brightness, float alpha) noexcept
    : argb (ColourHelpers::HSB::toRGB (hue, saturation, brightness, ColourHelpers::floatToUInt8 (alpha)))
{
}

Colour Colour::fromHSV (float hue, float saturation, float brightness, float alpha) noexcept
{
    return Colour (hue, saturation, brightness, alpha);
}

Colour Colour::fromHSL (float hue, float saturation, float lightness, float alpha) noexcept
{
    Colour hslColour;
    hslColour.argb = ColourHelpers::HSL::toRGB (hue, saturation, lightness, ColourHelpers::floatToUInt8 (alpha));

    return hslColour;
}

Colour::Colour (float hue, float saturation, float brightness, uint8 alpha) noexcept
    : argb (ColourHelpers::HSB::toRGB (hue, saturation, brightness, alpha))
{
}

Colour::Colour (PixelARGB argb_) noexcept
    : argb (argb_)
{
}

Colour::Colour (PixelRGB rgb) noexcept
    : argb (Colour (rgb.getInARGBMaskOrder()).argb)
{
}

Colour::Colour (PixelAlpha alpha) noexcept
    : argb (Colour (alpha.getInARGBMaskOrder()).argb)
{
}

//==============================================================================
PixelARGB Colour::getPixelARGB() const noexcept
{
    PixelARGB p (argb);
    p.premultiply();
    return p;
}

PixelARGB Colour::getNonPremultipliedPixelARGB() const noexcept
{
    return argb;
}

uint32 Colour::getARGB() const noexcept
{
    return argb.getInARGBMaskOrder();
}

//==============================================================================
bool Colour::isTransparent() const noexcept
{
    return getAlpha() == 0;
}

bool Colour::isOpaque() const noexcept
{
    return getAlpha() == 0xff;
}

Colour Colour::withAlpha (uint8 newAlpha) const noexcept
{
    PixelARGB newCol (argb);
    newCol.setAlpha (newAlpha);
    return Colour (newCol);
}

Colour Colour::withAlpha (float newAlpha) const noexcept
{
    jassert (newAlpha >= 0 && newAlpha <= 1.0f);

    PixelARGB newCol (argb);
    newCol.setAlpha (ColourHelpers::floatToUInt8 (newAlpha));
    return Colour (newCol);
}

Colour Colour::withMultipliedAlpha (float alphaMultiplier) const noexcept
{
    jassert (alphaMultiplier >= 0);

    PixelARGB newCol (argb);
    newCol.setAlpha ((uint8) jmin (0xff, roundToInt (alphaMultiplier * newCol.getAlpha())));
    return Colour (newCol);
}

//==============================================================================
Colour Colour::overlaidWith (Colour src) const noexcept
{
    auto destAlpha = getAlpha();

    if (destAlpha <= 0)
        return src;

    auto invA = 0xff - (int) src.getAlpha();
    auto resA = 0xff - (((0xff - destAlpha) * invA) >> 8);

    if (resA <= 0)
        return *this;

    auto da = (invA * destAlpha) / resA;

    return Colour ((uint8) (src.getRed()   + ((((int) getRed()   - src.getRed())   * da) >> 8)),
                   (uint8) (src.getGreen() + ((((int) getGreen() - src.getGreen()) * da) >> 8)),
                   (uint8) (src.getBlue()  + ((((int) getBlue()  - src.getBlue())  * da) >> 8)),
                   (uint8) resA);
}

Colour Colour::interpolatedWith (Colour other, float proportionOfOther) const noexcept
{
    if (proportionOfOther <= 0)
        return *this;

    if (proportionOfOther >= 1.0f)
        return other;

    PixelARGB c1 (getPixelARGB());
    PixelARGB c2 (other.getPixelARGB());
    c1.tween (c2, (uint32) roundToInt (proportionOfOther * 255.0f));
    c1.unpremultiply();

    return Colour (c1);
}

//==============================================================================
float Colour::getFloatRed() const noexcept      { return getRed()   / 255.0f; }
float Colour::getFloatGreen() const noexcept    { return getGreen() / 255.0f; }
float Colour::getFloatBlue() const noexcept     { return getBlue()  / 255.0f; }
float Colour::getFloatAlpha() const noexcept    { return getAlpha() / 255.0f; }

//==============================================================================
void Colour::getHSB (float& h, float& s, float& v) const noexcept
{
    ColourHelpers::HSB hsb (*this);
    h = hsb.hue;
    s = hsb.saturation;
    v = hsb.brightness;
}

void Colour::getHSL (float& h, float& s, float& l) const noexcept
{
    ColourHelpers::HSL hsl (*this);
    h = hsl.hue;
    s = hsl.saturation;
    l = hsl.lightness;
}

float Colour::getHue() const noexcept           { return ColourHelpers::HSB (*this).hue; }
float Colour::getSaturation() const noexcept    { return ColourHelpers::HSB (*this).saturation; }
float Colour::getBrightness() const noexcept    { return ColourHelpers::HSB (*this).brightness; }

float Colour::getSaturationHSL() const noexcept { return ColourHelpers::HSL (*this).saturation; }
float Colour::getLightness() const noexcept     { return ColourHelpers::HSL (*this).lightness; }

Colour Colour::withHue (float h) const noexcept          { ColourHelpers::HSB hsb (*this); hsb.hue = h;        return hsb.toColour (*this); }
Colour Colour::withSaturation (float s) const noexcept   { ColourHelpers::HSB hsb (*this); hsb.saturation = s; return hsb.toColour (*this); }
Colour Colour::withBrightness (float v) const noexcept   { ColourHelpers::HSB hsb (*this); hsb.brightness = v; return hsb.toColour (*this); }

Colour Colour::withSaturationHSL (float s) const noexcept { ColourHelpers::HSL hsl (*this); hsl.saturation = s; return hsl.toColour (*this); }
Colour Colour::withLightness (float l) const noexcept     { ColourHelpers::HSL hsl (*this); hsl.lightness = l;  return hsl.toColour (*this); }

float Colour::getPerceivedBrightness() const noexcept
{
    return std::sqrt (0.241f * square (getFloatRed())
                    + 0.691f * square (getFloatGreen())
                    + 0.068f * square (getFloatBlue()));
}

//==============================================================================
Colour Colour::withRotatedHue (float amountToRotate) const noexcept
{
    ColourHelpers::HSB hsb (*this);
    hsb.hue += amountToRotate;
    return hsb.toColour (*this);
}

Colour Colour::withMultipliedSaturation (float amount) const noexcept
{
    ColourHelpers::HSB hsb (*this);
    hsb.saturation = jmin (1.0f, hsb.saturation * amount);
    return hsb.toColour (*this);
}

Colour Colour::withMultipliedSaturationHSL (float amount) const noexcept
{
    ColourHelpers::HSL hsl (*this);
    hsl.saturation = jmin (1.0f, hsl.saturation * amount);
    return hsl.toColour (*this);
}

Colour Colour::withMultipliedBrightness (float amount) const noexcept
{
    ColourHelpers::HSB hsb (*this);
    hsb.brightness = jmin (1.0f, hsb.brightness * amount);
    return hsb.toColour (*this);
}

Colour Colour::withMultipliedLightness (float amount) const noexcept
{
    ColourHelpers::HSL hsl (*this);
    hsl.lightness = jmin (1.0f, hsl.lightness * amount);
    return hsl.toColour (*this);
}

//==============================================================================
Colour Colour::brighter (float amount) const noexcept
{
    jassert (amount >= 0.0f);
    amount = 1.0f / (1.0f + amount);

    return Colour ((uint8) (255 - (amount * (255 - getRed()))),
                   (uint8) (255 - (amount * (255 - getGreen()))),
                   (uint8) (255 - (amount * (255 - getBlue()))),
                   getAlpha());
}

Colour Colour::darker (float amount) const noexcept
{
    jassert (amount >= 0.0f);
    amount = 1.0f / (1.0f + amount);

    return Colour ((uint8) (amount * getRed()),
                   (uint8) (amount * getGreen()),
                   (uint8) (amount * getBlue()),
                   getAlpha());
}

//==============================================================================
Colour Colour::greyLevel (float brightness) noexcept
{
    auto level = ColourHelpers::floatToUInt8 (brightness);
    return Colour (level, level, level);
}

//==============================================================================
Colour Colour::contrasting (float amount) const noexcept
{
   return overlaidWith ((getPerceivedBrightness() >= 0.5f
                           ? Colours::black
                           : Colours::white).withAlpha (amount));
}

Colour Colour::contrasting (Colour target, float minContrast) const noexcept
{
    ColourHelpers::YIQ bg (*this);
    ColourHelpers::YIQ fg (target);

    if (std::abs (bg.y - fg.y) >= minContrast)
        return target;

    auto y1 = jmax (0.0f, bg.y - minContrast);
    auto y2 = jmin (1.0f, bg.y + minContrast);
    fg.y = (std::abs (y1 - bg.y) > std::abs (y2 - bg.y)) ? y1 : y2;

    return fg.toColour();
}

Colour Colour::contrasting (Colour colour1,
                            Colour colour2) noexcept
{
    auto b1 = colour1.getPerceivedBrightness();
    auto b2 = colour2.getPerceivedBrightness();
    float best = 0.0f, bestDist = 0.0f;

    for (float i = 0.0f; i < 1.0f; i += 0.02f)
    {
        auto d1 = std::abs (i - b1);
        auto d2 = std::abs (i - b2);
        auto dist = jmin (d1, d2, 1.0f - d1, 1.0f - d2);

        if (dist > bestDist)
        {
            best = i;
            bestDist = dist;
        }
    }

    return colour1.overlaidWith (colour2.withMultipliedAlpha (0.5f))
                  .withBrightness (best);
}

//==============================================================================
String Colour::toString() const
{
    return String::toHexString ((int) argb.getInARGBMaskOrder());
}

Colour Colour::fromString (StringRef encodedColourString)
{
    return Colour (CharacterFunctions::HexParser<uint32>::parse (encodedColourString.text));
}

String Colour::toDisplayString (const bool includeAlphaValue) const
{
    return String::toHexString ((int) (argb.getInARGBMaskOrder() & (includeAlphaValue ? 0xffffffff : 0xffffff)))
                  .paddedLeft ('0', includeAlphaValue ? 8 : 6)
                  .toUpperCase();
}


//==============================================================================
//==============================================================================
#if JUCE_UNIT_TESTS

class ColourTests final : public UnitTest
{
public:
    ColourTests()
        : UnitTest ("Colour", UnitTestCategories::graphics)
    {}

    void runTest() override
    {
        auto testColour = [this] (Colour colour,
                                  uint8 expectedRed, uint8 expectedGreen, uint8 expectedBlue,
                                  uint8 expectedAlpha = 255, float expectedFloatAlpha = 1.0f)
        {
            expectEquals (colour.getRed(),        expectedRed);
            expectEquals (colour.getGreen(),      expectedGreen);
            expectEquals (colour.getBlue(),       expectedBlue);
            expectEquals (colour.getAlpha(),      expectedAlpha);
            expectEquals (colour.getFloatAlpha(), expectedFloatAlpha);
        };

        beginTest ("Constructors");
        {
            Colour c1;
            testColour (c1, (uint8) 0, (uint8) 0, (uint8) 0, (uint8) 0, 0.0f);

            Colour c2 ((uint32) 0);
            testColour (c2, (uint8) 0, (uint8) 0, (uint8) 0, (uint8) 0, 0.0f);

            Colour c3 ((uint32) 0xffffffff);
            testColour (c3, (uint8) 255, (uint8) 255, (uint8) 255, (uint8) 255, 1.0f);

            Colour c4 (0, 0, 0);
            testColour (c4, (uint8) 0, (uint8) 0, (uint8) 0, (uint8) 255, 1.0f);

            Colour c5 (255, 255, 255);
            testColour (c5, (uint8) 255, (uint8) 255, (uint8) 255, (uint8) 255, 1.0f);

            Colour c6 ((uint8) 0, (uint8) 0, (uint8) 0, (uint8) 0);
            testColour (c6, (uint8) 0, (uint8) 0, (uint8) 0, (uint8) 0, 0.0f);

            Colour c7 ((uint8) 255, (uint8) 255, (uint8) 255, (uint8) 255);
            testColour (c7, (uint8) 255, (uint8) 255, (uint8) 255, (uint8) 255, 1.0f);

            Colour c8 ((uint8) 0, (uint8) 0, (uint8) 0, 0.0f);
            testColour (c8, (uint8) 0, (uint8) 0, (uint8) 0, (uint8) 0, 0.0f);

            Colour c9 ((uint8) 255, (uint8) 255, (uint8) 255, 1.0f);
            testColour (c9, (uint8) 255, (uint8) 255, (uint8) 255, (uint8) 255, 1.0f);
        }

        beginTest ("HSV");
        {
            // black
            testColour (Colour::fromHSV (0.0f, 0.0f, 0.0f, 1.0f), 0, 0, 0);
            // white
            testColour (Colour::fromHSV (0.0f, 0.0f, 1.0f, 1.0f), 255, 255, 255);
            // red
            testColour (Colour::fromHSV (0.0f, 1.0f, 1.0f, 1.0f), 255, 0, 0);
            testColour (Colour::fromHSV (1.0f, 1.0f, 1.0f, 1.0f), 255, 0, 0);
            // lime
            testColour (Colour::fromHSV (120 / 360.0f, 1.0f, 1.0f, 1.0f), 0, 255, 0);
            // blue
            testColour (Colour::fromHSV (240 / 360.0f, 1.0f, 1.0f, 1.0f), 0, 0, 255);
            // yellow
            testColour (Colour::fromHSV (60 / 360.0f, 1.0f, 1.0f, 1.0f), 255, 255, 0);
            // cyan
            testColour (Colour::fromHSV (180 / 360.0f, 1.0f, 1.0f, 1.0f), 0, 255, 255);
            // magenta
            testColour (Colour::fromHSV (300 / 360.0f, 1.0f, 1.0f, 1.0f), 255, 0, 255);
            // silver
            testColour (Colour::fromHSV (0.0f, 0.0f, 0.75f, 1.0f), 191, 191, 191);
            // grey
            testColour (Colour::fromHSV (0.0f, 0.0f, 0.5f, 1.0f), 128, 128, 128);
            // maroon
            testColour (Colour::fromHSV (0.0f, 1.0f, 0.5f, 1.0f), 128, 0, 0);
            // olive
            testColour (Colour::fromHSV (60 / 360.0f, 1.0f, 0.5f, 1.0f), 128, 128, 0);
            // green
            testColour (Colour::fromHSV (120 / 360.0f, 1.0f, 0.5f, 1.0f), 0, 128, 0);
            // purple
            testColour (Colour::fromHSV (300 / 360.0f, 1.0f, 0.5f, 1.0f), 128, 0, 128);
            // teal
            testColour (Colour::fromHSV (180 / 360.0f, 1.0f, 0.5f, 1.0f), 0, 128, 128);
            // navy
            testColour (Colour::fromHSV (240 / 360.0f, 1.0f, 0.5f, 1.0f), 0, 0, 128);
        }

        beginTest ("HSL");
        {
            // black
            testColour (Colour::fromHSL (0.0f, 0.0f, 0.0f, 1.0f), 0, 0, 0);
            // white
            testColour (Colour::fromHSL (0.0f, 0.0f, 1.0f, 1.0f), 255, 255, 255);
            // red
            testColour (Colour::fromHSL (0.0f, 1.0f, 0.5f, 1.0f), 255, 0, 0);
            testColour (Colour::fromHSL (1.0f, 1.0f, 0.5f, 1.0f), 255, 0, 0);
            // lime
            testColour (Colour::fromHSL (120 / 360.0f, 1.0f, 0.5f, 1.0f), 0, 255, 0);
            // blue
            testColour (Colour::fromHSL (240 / 360.0f, 1.0f, 0.5f, 1.0f), 0, 0, 255);
            // yellow
            testColour (Colour::fromHSL (60 / 360.0f, 1.0f, 0.5f, 1.0f), 255, 255, 0);
            // cyan
            testColour (Colour::fromHSL (180 / 360.0f, 1.0f, 0.5f, 1.0f), 0, 255, 255);
            // magenta
            testColour (Colour::fromHSL (300 / 360.0f, 1.0f, 0.5f, 1.0f), 255, 0, 255);
            // silver
            testColour (Colour::fromHSL (0.0f, 0.0f, 0.75f, 1.0f), 191, 191, 191);
            // grey
            testColour (Colour::fromHSL (0.0f, 0.0f, 0.5f, 1.0f), 128, 128, 128);
            // maroon
            testColour (Colour::fromHSL (0.0f, 1.0f, 0.25f, 1.0f), 128, 0, 0);
            // olive
            testColour (Colour::fromHSL (60 / 360.0f, 1.0f, 0.25f, 1.0f), 128, 128, 0);
            // green
            testColour (Colour::fromHSL (120 / 360.0f, 1.0f, 0.25f, 1.0f), 0, 128, 0);
            // purple
            testColour (Colour::fromHSL (300 / 360.0f, 1.0f, 0.25f, 1.0f), 128, 0, 128);
            // teal
            testColour (Colour::fromHSL (180 / 360.0f, 1.0f, 0.25f, 1.0f), 0, 128, 128);
            // navy
            testColour (Colour::fromHSL (240 / 360.0f, 1.0f, 0.25f, 1.0f), 0, 0, 128);
        }

        beginTest ("Modifiers");
        {
            Colour red (255, 0, 0);
            testColour (red, 255, 0, 0);

            testColour (red.withHue (120.0f / 360.0f), 0, 255, 0);
            testColour (red.withSaturation (0.5f), 255, 128, 128);
            testColour (red.withSaturationHSL (0.5f), 191, 64, 64);
            testColour (red.withBrightness (0.5f), 128, 0, 0);
            testColour (red.withLightness (1.0f), 255, 255, 255);
            testColour (red.withRotatedHue (120.0f / 360.0f), 0, 255, 0);
            testColour (red.withRotatedHue (480.0f / 360.0f), 0, 255, 0);
            testColour (red.withRotatedHue (-240.0f / 360.0f), 0, 255, 0);
            testColour (red.withRotatedHue (-600.0f / 360.0f), 0, 255, 0);
            testColour (red.withMultipliedSaturation (0.0f), 255, 255, 255);
            testColour (red.withMultipliedSaturationHSL (0.0f), 128, 128, 128);
            testColour (red.withMultipliedBrightness (0.5f), 128, 0, 0);
            testColour (red.withMultipliedLightness (2.0f), 255, 255, 255);
            testColour (red.withMultipliedLightness (1.0f), 255, 0, 0);
            testColour (red.withLightness (red.getLightness()), 255, 0, 0);
        }
    }
};

static ColourTests colourTests;

#endif

} // namespace juce