Method Bind

Source/Engine/Graphics/Materials/DecalMaterialShader.cpp:29–86

}

void DecalMaterialShader::Bind(BindParameters& params)
{
    // Prepare
    auto context = params.GPUContext;
    auto& view = params.RenderContext.View;
    auto& drawCall = *params.DrawCall;
    Span<byte> cb(_cbData.Get(), _cbData.Count());
    ASSERT_LOW_LAYER(cb.Length() >= sizeof(DecalMaterialShaderData));
    auto materialData = reinterpret_cast<DecalMaterialShaderData*>(cb.Get());
    cb = cb.Slice(sizeof(DecalMaterialShaderData));
    const bool isCameraInside = OrientedBoundingBox(Vector3::Half, drawCall.World).Contains(view.Position) == ContainmentType::Contains;

    // Setup parameters
    MaterialParameter::BindMeta bindMeta;
    bindMeta.Context = context;
    bindMeta.Constants = cb;
    bindMeta.Input = nullptr;
    bindMeta.Buffers = params.RenderContext.Buffers;
    bindMeta.CanSampleDepth = true;
    bindMeta.CanSampleGBuffer = false;
    MaterialParams::Bind(params.ParamsLink, bindMeta);

    // Decals use depth buffer to draw on top of the objects
    GPUTexture* depthBuffer = params.RenderContext.Buffers->DepthBuffer;
    GPUTextureView* depthBufferView = EnumHasAnyFlags(depthBuffer->Flags(), GPUTextureFlags::ReadOnlyDepthView) ? depthBuffer->ViewReadOnlyDepth() : depthBuffer->View();
    context->BindSR(0, depthBufferView);
    context->BindSR(1, depthBuffer->ViewStencil());

    // Setup material constants
    {
        Matrix::Transpose(drawCall.World, materialData->WorldMatrix);

        // Matrix for transformation from world space to decal object space
        Matrix invWorld;
        Matrix::Invert(drawCall.World, invWorld);
        Matrix::Transpose(invWorld, materialData->InvWorld);

        // Matrix for transformation from SV Position space to world space
        const Matrix offsetMatrix(
            2.0f * view.ScreenSize.Z, 0, 0, 0,
            0, -2.0f * view.ScreenSize.W, 0, 0,
            0, 0, 1, 0,
            -1.0f, 1.0f, 0, 1);
        const Matrix svPositionToWorld = offsetMatrix * view.IVP;
        Matrix::Transpose(svPositionToWorld, materialData->SvPositionToWorld);
        materialData->RenderLayersMask = (uint32)drawCall.SortKey; // Provided by GBufferPass::DrawDecals
    }

    // Bind constants
    if (_cb)
    {
        context->UpdateCB(_cb, _cbData.Get());
        context->BindCB(0, _cb);
    }

    // Bind pipeline
    context->SetState(isCameraInside ? _cache.Inside : _cache.Outside);
}