Method Draw

GTE/Graphics/PlanarShadowEffect.cpp:99–201

}

void PlanarShadowEffect::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();

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

    // Draw the the shadow caster.
    engine->Draw(mCasterVisuals);

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

        // Enable default depth state. Enable the stencil state so that the
        // shadow can be clipped by the plane. The stencil values are set
        // whenever the corresponding plane pixels are visible. No blending
        // is used in this pass.
        mDSPass0->reference = reference;
        engine->SetDepthStencilState(mDSPass0);
        engine->SetBlendState(saveBState);
        engine->Draw(plane);
    
        // Disable the depth buffer reading so that no depth-buffer fighting
        // occurs. The drawing of pixels is controlled solely by the stencil
        // value. Blend the shadow color with the pixels drawn on the
        // projection plane.
        mDSPass1->reference = reference;
        engine->SetDepthStencilState(mDSPass1);
        engine->SetBlendState(mShadowBlend);

        // Set the projection matrix relative to the projector (light).
        Matrix4x4<float> projectionMatrix{};
        if (!GetProjectionMatrix(i, projectionMatrix))
        {
            // The shadow should not be cast because the caster is on the far
            // side of the world plane.
            continue;
        }

        camera->SetPreViewMatrix(projectionMatrix);

        // Draw the caster again, but temporarily use a material effect so
        // that the shadow color is blended onto the plane. TODO: This
        // drawing pass should use a visible set relative to the projector so
        // that the objects thare are out of view of the camera (not in the
        // camera's visible set) can cast shadows.
        for (size_t j = 0; j < mCasterVisuals.size(); ++j)
        {
            // Save the currently attached visual effect.
            auto const& visual = mCasterVisuals[j];
            mSaveVisualEffects[j] = visual->GetEffect();

            // Draw the shadow using the current plane's shadow color.