BansheeEngine/RenderBeast/Include/BsSamplerOverrides.h

#pragma once

#include "BsRenderBeastPrerequisites.h"

namespace BansheeEngine
{
	/**
	 * @brief	Contains data about an overridden sampler states for a single pass stage.
	 */
	struct StageSamplerOverrides
	{
		SPtr<SamplerStateCore>* stateOverrides;
		UINT32 numStates;
	};

	/**
	 * @brief	Contains data about an overridden sampler states for a single pass.
	 */
	struct PassSamplerOverrides
	{
		StageSamplerOverrides* stages;
		UINT32 numStages;
	};

	/**
	 * @brief	Contains data about an overridden sampler states in the entire material.
	 */
	struct MaterialSamplerOverrides
	{
		PassSamplerOverrides* passes;
		UINT32 numPasses;
		UINT32 refCount;
	};

	/**
	 * @brief	Helper class for generating sampler overrides.
	 */
	class BS_BSRND_EXPORT SamplerOverrideUtility
	{
	public:
		/**
		 * @brief	Generates a set of sampler overrides for the specified material. Overrides are
		 *			generates according to the provided render options. 
		 */
		static MaterialSamplerOverrides* generateSamplerOverrides(const SPtr<MaterialCore>& material, const SPtr<RenderBeastOptions>& options);

		/**
		 * @brief	Destroys sampler overrides previously generated with ::generateSamplerOverrides.
		 */
		static void destroySamplerOverrides(MaterialSamplerOverrides* overrides);

		/**
		 * @brief	Checks if the provided sampler state requires an override, in case the render options have
		 *			requirements not fulfilled by current sampler state (e.g. filtering type).
		 */
		static bool checkNeedsOverride(const SPtr<SamplerStateCore>& samplerState, const SPtr<RenderBeastOptions>& options);

		/**
		 * @brief	Generates a new sampler state override using the provided state as the basis. Overridden properties
		 *			are taken from the provided render options.
		 */
		static SPtr<SamplerStateCore> generateSamplerOverride(const SPtr<SamplerStateCore>& samplerState, const SPtr<RenderBeastOptions>& options);
	};
}