> ## Documentation Index
> Fetch the complete documentation index at: https://devdocs.xbox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Effets LampArray

> Effets LampArray

Appelez les fonctions de couleur d'[ILampArray](/fr/reference/lighting/lamparray/interfaces/ilamparray/ilamparray) dans la boucle de jeu pour produire des effets et des animations. Cette page présente quelques exemples.

Par souci de simplicité, ces exemples utilisent [ILampArray::SetColor](/fr/reference/lighting/lamparray/interfaces/ilamparray/methods/ilamparray_setcolor) lorsque c'est possible pour appliquer des couleurs à chaque Lamp d'un appareil. Les effets peuvent être produits sur des Lamps individuelles ou des ensembles de Lamps à l'aide d'[ILampArray::SetColorsForIndices](/fr/reference/lighting/lamparray/interfaces/ilamparray/methods/ilamparray_setcolorsforindices).

## Fondu et clignotement

Faites apparaître ou disparaître progressivement les Lamps en multipliant les valeurs RGB d'une couleur par un pourcentage croissant ou décroissant sur un intervalle de temps. Créez des effets de clignotement, de respiration ou de flash en effectuant des fondus entrants et sortants répétés.

L'exemple suivant fait clignoter toutes les Lamps d'un LampArray :

```cpp theme={null}
uint32_t currentFrame = 0;

// The total number of frames in one blink
const float blinkFrameCount = 90;

const float blinkFadeFrameCount = blinkFrameCount / 2;

// The color to fade in and out. In this example we'll use red.
const LampArrayColor mainColor = {0xFF /* r */, 0x0 /* g */, 0x0 /* b */, 0xFF /* a */};

Microsoft::WRL::ComPtr<ILampArray> lampArray;

void BlinkUpdateFrame(ILampArray* lampArrayToUpdate)
{
    LampArrayColor currentFrameColor = mainColor;

    float colorScale = 1.0;

    if (currentFrame < blinkFadeFrameCount)
    {
        // Fade out to black
        colorScale = (blinkFadeFrameCount - currentFrame) / blinkFadeFrameCount;
    }
    else
    {
        // Fade in to full color value
        colorScale = (currentFrame - blinkFadeFrameCount) / blinkFadeFrameCount;
    }

    currentFrameColor.r = static_cast<uint8_t>(mainColor.r * colorScale);
    currentFrameColor.g = static_cast<uint8_t>(mainColor.g * colorScale);
    currentFrameColor.b = static_cast<uint8_t>(mainColor.b * colorScale);

    // Apply the color
    lampArrayToUpdate->SetColor(currentFrameColor);

    // Increment our current frame, accounting for overflow
    if (++currentFrame > blinkFrameCount)
    {
        currentFrame = 0;
    }
}

void MainLoop(
    _In_ volatile bool& terminateLoop)
{
    color.a = 0xFF;

    while (!terminateLoop)
    {
        Sleep(50);

        BlinkUpdateFrame(lampArray.Get());
    }
} 
```

## Cycles de couleurs

Créez des cycles de couleurs en augmentant et en diminuant progressivement les valeurs de rouge, de vert et de bleu d'une couleur. Cela produit une transition entre un large éventail de couleurs du spectre RGB.

L'exemple suivant effectue un cycle de couleurs RGB sur un LampArray.

```cpp theme={null}
uint32_t currentFrame = 0;

// The total number of frames in one cycle
const float cycleFrameCount = 180;

// The size of each "ramp" of the cycle (blending from one color to the next)
const float rampIntervalFrameCount = cycleFrameCount / 6;

// The color to set in each frame
LampArrayColor color = {};

Microsoft::WRL::ComPtr<ILampArray> lampArray;

void CycleUpdateFrame(ILampArray* lampArrayToUpdate)
{
    // Calculate the color for the current frame.
    if (currentFrame < rampIntervalFrameCount)
    {
        // Red -> yellow: increase g
        color.r = 0xFF;
        color.g = static_cast<BYTE>(0xFF * (currentFrame / rampIntervalFrameCount));
    }
    else if (currentFrame < (2 * rampIntervalFrameCount))
    {
        // Yellow -> green: decrease r
        color.r = static_cast<BYTE>(0xFF * (((2 * rampIntervalFrameCount) - currentFrame) / rampIntervalFrameCount));
        color.g = 0xFF;
    }
    else if (currentFrame < (3 * rampIntervalFrameCount))
    {
        // Green -> cyan: increase b
        color.g = 0xFF;
        color.b = static_cast<BYTE>(0xFF * ((currentFrame - (2 * rampIntervalFrameCount)) / rampIntervalFrameCount));
    }
    else if (currentFrame < (4 * rampIntervalFrameCount))
    {
        // Cyan -> blue: decrease g
        color.g = static_cast<BYTE>(0xFF * (((4 * rampIntervalFrameCount) - currentFrame) / rampIntervalFrameCount));
        color.b = 0xFF;
    }
    else if (currentFrame < (5 * rampIntervalFrameCount))
    {
        // Blue -> magenta: increase r
        color.r = static_cast<BYTE>(0xFF * ((currentFrame - (4 * rampIntervalFrameCount)) / rampIntervalFrameCount));
        color.b = 0xFF;
    }
    else
    {
        // Magenta -> red: decrease b
        color.r = 0xFF;
        color.b = static_cast<BYTE>(0xFF * ((cycleFrameCount - currentFrame) / rampIntervalFrameCount));
    }

    // Apply the color
    lampArrayToUpdate->SetColor(color);

    // Increment our current frame, accounting for overflow
    if (++currentFrame > cycleFrameCount)
    {
        currentFrame = 0;
    }
}

void MainLoop(
    _In_ volatile bool& terminateLoop)
{
    color.a = 0xFF;

    while (!terminateLoop)
    {
        Sleep(50);

        CycleUpdateFrame(lampArray.Get());
    }
}
```

## Effets basés sur la position

Utilisez [ILampInfo::GetPosition](/fr/reference/lighting/lamparray/interfaces/ilampinfo/methods/ilampinfo_getposition) et [ILampArray::GetBoundingBox](/fr/reference/lighting/lamparray/interfaces/ilamparray/methods/ilamparray_getboundingbox) pour créer des effets qui semblent se déplacer sur l'appareil, comme des ondulations ou des vagues.

L'exemple suivant crée une vague de Lamps en fondu sortant qui se déplace de gauche à droite sur l'appareil. Notez que nous reprenons les concepts de mise à l'échelle de la section « Fondu et clignotement », mais Lamp par Lamp.

```cpp theme={null}
Microsoft::WRL::ComPtr<ILampArray> lampArray;

uint32_t currentFrame = 0;

// The total number of frames in one wave
const uint32_t waveFrameCount = 30;

// The number of frames it takes for each Lamp to fade out
const uint32_t fadeDurationInFrames = 10;

// Helper class for per-Lamp effect state information
struct LampContext
{
    uint32_t lampIndex;

    // How far to the right this Lamp is located compared to the total length of the device.
    float xPercentage;

    // The number of frames left in this Lamp's fade-out
    uint32_t fadeFramesRemaining;
};

std::vector<LampContext> lampContexts;

// The Lamp indices for the device, in sorted order by position from left to right
std::vector<uint32_t> indices;

// The colors to set in each frame
std::vector<LampArrayColor> colors;

// The index in the sorted array representing the peak of the wave
uint32_t lastUpdatedIndex = 0;

// The base color to use in the wave effect
const LampArrayColor mainColor = {0xFF /* r */, 0x0 /* g */, 0x0 /* b */, 0xFF /* a */};

void WaveUpdateFrame(ILampArray* lampArrayToUpdate)
{
    float framePercentage = (float)currentFrame / (float)myFrameCount;

    const uint32_t lampCount = lampArrayToUpdate->GetLampCount();
    for (uint32_t i = 0; i < lampCount; i++)
    {
        auto& lampContext = lampContexts[i];

        // Mark any Lamps for which we should start a new fade-out.
        // Use lastUpdatedIndex to track which Lamps we've started in this wave.
        if (i >= lastUpdatedIndex && lampContext.xPercentage <= framePercentage)
        {
            lastUpdatedIndex = i;

            // This Lamp should start at full brightness on this frame.
            lampContext.fadeFramesRemaining = fadeDurationInFrames + 1;
        }

        // Process fade-outs for any Lamps that have fade-out frames remaining
        if (lampContext.fadeFramesRemaining > 0)
        {
            lampContext.fadeFramesRemaining--;

            // Optimization: use the full strength color for the first fade-out frame (without scaling)
            if (lampContext.fadeFramesRemaining == fadeDurationInFrames)
            {
                colors[i] = mainColor;
            }
            else
            {
                // Scale the main color down based on how many fade-out frames are remaining for this Lamp.
                float scaleFactor = (float)lampContext.fadeFramesRemaining / (float)fadeDurationInFrames;

                auto& lampColor = colors[i];
                lampColor.r = static_cast<BYTE>(scaleFactor * mainColor.r);
                lampColor.g = static_cast<BYTE>(scaleFactor * mainColor.g);
                lampColor.b = static_cast<BYTE>(scaleFactor * mainColor.b);
            }
        }
    }

    // Apply the color
    lampArrayToUpdate->SetColorsForIndices(lampCount, indices.data(), colors.data());

    // Increment our current frame, accounting for overflow
    if (++currentFrame > waveFrameCount)
    {
        currentFrame = 0;

        // The peak of the wave also needs to wrap around
        lastUpdatedIndex = 0;
    }
}

HRESULT MainLoop(
    _In_ volatile bool& terminateLoop)
{
    color.a = 0xFF;

    // Set up contexts
    const uint32_t lampCount = lampArray->GetLampCount();
    for (uint32_t i = 0; i < lampCount; i++)
    {
        LampContext context = {};
        context.lampIndex = i;

        Microsoft::WRL::ComPtr<ILampInfo> lampInfo;
        RETURN_IF_FAILED(lampArray->GetLampInfo(i, &lampInfo));

        LampArrayPosition lampPosition = {};
        lampInfo->GetPosition(&lampPosition);

        // Our position values will be relative to the total length of the device.
        context.xPercentage = (float)lampPosition.xInMeters / (float)boundingBox.xInMeters;

        lampContexts.push_back(context);
    }

    // Sort the contexts by position from left to right
    std::sort(lampContexts.begin(),
        lampContexts.end(),
        [](LampContext const& a, LampContext const& b)
        {
            return a.xPercentage < b.xPercentage;
        });

    // Set up our indices buffer in sorted order
    for (uint32_t i = 0; i < lampCount; i++)
    {
        indices[i] = lampContexts[i].lampIndex;
    }

    colors.resize(lampCount);

    // Animation loop for the sample
    while (!terminateLoop)
    {
        Sleep(33);
        WaveUpdateFrame(lampArray.Get());
    }

    return S_OK;
}
```

## Voir aussi

[Vue d'ensemble de l'API d'éclairage](/fr/build/core-features/common/lighting/gc-lighting-toc)
[Référence ILampArray](/fr/reference/lighting/lamparray/interfaces/ilamparray/ilamparray)


## Related topics

- [LampArray](/ko/reference/lighting/lamparray/lamparray_members.md)
- [LampArray Basics](/build/core-features/common/lighting/lighting-basics.md)
- [LampArray 效果](/zh-CN/build/core-features/common/lighting/lighting-effects.md)
- [LampArray 효과](/ko/build/core-features/common/lighting/lighting-effects.md)
- [LampArray Effects](/build/core-features/common/lighting/lighting-effects.md)