Method Draw

GTE/Graphics/PlanarReflectionEffect.cpp:116–234

}

void PlanarReflectionEffect::Draw(std::shared_ptr<GraphicsEngine> const& engine,
    PVWUpdater& pvwMatrices)
{
    // Save the global state, to be restored later.
    std::shared_ptr<BlendState> saveBState = engine->GetBlendState();
    std::shared_ptr<DepthStencilState> saveDSState = engine->GetDepthStencilState();
    std::shared_ptr<RasterizerState> saveRState = engine->GetRasterizerState();

    // The depth range will be modified during drawing, so save the current
    // depth range for restoration later.
    float minDepth{}, maxDepth{};
    engine->GetDepthRange(minDepth, maxDepth);

    // Get the camera to store post-world transformations.
    std::shared_ptr<Camera> camera = pvwMatrices.GetCamera();

    // Get the current cull mode and reverse it. Allow for models that are
    // not necessarily set up with front or back face culling.
    if (saveRState->cull == RasterizerState::Cull::BACK)
    {
        mCullReverse->cull = RasterizerState::Cull::FRONT;
    }
    else if (saveRState->cull == RasterizerState::Cull::FRONT)
    {
        mCullReverse->cull = RasterizerState::Cull::BACK;
    }
    else
    {
        mCullReverse->cull = RasterizerState::Cull::NONE;
    }
    engine->Bind(mCullReverse);

    uint32_t const numPlanes = static_cast<uint32_t>(mPlaneVisuals.size());
    for (uint32_t i = 0, reference = 1; i < numPlanes; ++i, ++reference)
    {
        auto const& plane = mPlaneVisuals[i];

        // Render the plane to the stencil buffer only; that is, there are no
        // color writes or depth writes. The depth buffer is read so that
        // plane pixels occluded by other already drawn geometry are not
        // drawn. The stencil buffer value for pixels from plane i is (i+1).
        // The stencil buffer is updated at a pixel only when the depth test
        // passes at that pixel (the plane pixel is visible):
        //   face.fail is always false, so value KEEP is irrelevant
        //   face.depthFail = true, KEEP current stencil value
        //   face.pass = false, REPLACE current stencil value with (i+1)
        // for each face in { frontFace, backFace .
        mDSPass0->reference = reference;
        engine->SetDepthStencilState(mDSPass0);
        engine->SetBlendState(mNoColorWrites);
        engine->Draw(plane);

        // Render the plane again. The stencil buffer comparison is EQUAL, so
        // the color and depth are updated only at pixels generated by the
        // plane; the stencil values for such pixels is necessarily (i+1). The
        // depth buffer comparison is ALWAYS and the depth range settings
        // cause the depth to be updated to maximum depth at all pixels where
        // where the stencil values are (i+1). This allows us to draw the