//********************************** Banshee Engine (www.banshee3d.com) **************************************************//
//**************** Copyright (c) 2016 Marko Pintera (marko.pintera@gmail.com). All rights reserved. **********************//
#pragma once

#include "BsCorePrerequisites.h"
#include "BsTexture.h"
#include "BsRenderTexture.h"
#include "BsModule.h"

namespace bs 
{
	/** @addtogroup Resources-Internal
	 *  @{
	 */

    /**
     * Defines interface for creation of textures. Render systems provide their own implementations.
	 *
	 * @note	Sim thread only.
     */
    class BS_CORE_EXPORT TextureManager : public Module<TextureManager>
    {
    public:
		virtual ~TextureManager() { }

		/** @copydoc Texture::create(const TEXTURE_DESC&) */
        SPtr<Texture> createTexture(const TEXTURE_DESC& desc);
			
		/**
		 * Creates a new 2D or 3D texture initialized using the provided pixel data. Texture will not have any mipmaps.
		 *
		 * @param[in]	desc  		Description of the texture to create. Must match the pixel data.
		 * @param[in]	pixelData	Data to initialize the texture width.
		 */
		SPtr<Texture> createTexture(const TEXTURE_DESC& desc, const SPtr<PixelData>& pixelData);

		/**
		 * Creates a completely empty and uninitialized Texture.
		 *
		 * @note	
		 * Internal method. Should only be used for very specific purposes, like deserialization, as it requires additional
		 * manual initialization that is not required normally.
		 */
		SPtr<Texture> _createEmpty();

		/**
		 * Creates a new RenderTexture and automatically generates a single color surface and (optionally) a depth/stencil 
		 * surface.
		 *
		 * @param[in]	colorDesc			Description of the color surface to create.
		 * @param[in]	createDepth			Determines will a depth/stencil buffer of the same size as the color buffer be
		 *									created for the render texture.
		 * @param[in]	depthStencilFormat	Format of the depth/stencil buffer if enabled.
		 */
		virtual SPtr<RenderTexture> createRenderTexture(const TEXTURE_DESC& colorDesc,
			bool createDepth = true, PixelFormat depthStencilFormat = PF_D32);

		/** 
		 * Creates a RenderTexture using the description struct. 
		 * 
		 * @param[in]	desc	Description of the render texture to create.
		 */
		virtual SPtr<RenderTexture> createRenderTexture(const RENDER_TEXTURE_DESC& desc);

		/**
		 * Gets the format which will be natively used for a requested format given the constraints of the current device.
		 *
		 * @note	Thread safe.
		 */
		virtual PixelFormat getNativeFormat(TextureType ttype, PixelFormat format, int usage, bool hwGamma) = 0;

	protected:
		/**
		 * Creates an empty and uninitialized render texture of a specific type. This is to be implemented by render 
		 * systems with their own implementations.
		 */
		virtual SPtr<RenderTexture> createRenderTextureImpl(const RENDER_TEXTURE_DESC& desc) = 0;

		mutable HTexture mDummyTexture;
    };

	namespace ct
	{
	/**
     * Defines interface for creation of textures. Render systems provide their own implementations.
	 *
	 * @note	Core thread only.
     */
    class BS_CORE_EXPORT TextureManager : public Module<TextureManager>
    {
    public:
		virtual ~TextureManager() { }

		/** @copydoc Module::onStartUp */
		void onStartUp() override;

		/** @copydoc Module::onShutDown */
		void onShutDown() override;

		/**
		 * @copydoc	bs::TextureManager::createTexture(const TEXTURE_DESC&)
		 * @param[in]	deviceMask		Mask that determines on which GPU devices should the object be created on.
		 */
		SPtr<Texture> createTexture(const TEXTURE_DESC& desc, GpuDeviceFlags deviceMask = GDF_DEFAULT);

		/**
		 * @copydoc bs::TextureManager::createRenderTexture(const RENDER_TEXTURE_DESC&) 
		 * @param[in]	deviceIdx		Index of the GPU device to create the object on.
		 */
		SPtr<RenderTexture> createRenderTexture(const RENDER_TEXTURE_DESC& desc, UINT32 deviceIdx = 0);

	protected:
		friend class bs::Texture;
		friend class Texture;
		friend class bs::RenderTexture;

		/**
		 * Creates an empty and uninitialized texture of a specific type. This is to be implemented	by render systems with
		 * their own implementations.
		 */
		virtual SPtr<Texture> createTextureInternal(const TEXTURE_DESC& desc, 
			const SPtr<PixelData>& initialData = nullptr, GpuDeviceFlags deviceMask = GDF_DEFAULT) = 0;

		/** @copydoc createRenderTexture */
		virtual SPtr<RenderTexture> createRenderTextureInternal(const RENDER_TEXTURE_DESC& desc, 
			UINT32 deviceIdx = 0) = 0;
    };
		}

	/** @} */
}