/// @brief Include to sample 2d textures.
/// @file gli/sampler2d.hpp

#pragma once

#include "sampler.hpp"
#include "texture2d.hpp"
#include "core/mipmaps_compute.hpp"
#include "core/convert_func.hpp"

namespace gli
{
	/// 2d texture sampler
	/// @tparam T Sampler can fetch, write and interpret any texture format but will expose and process the data through type T conversions.
	/// @tparam P Precision in term of ULPs
	template <typename T, qualifier P = defaultp>
	class sampler2d : public sampler
	{
	private:
		typedef typename detail::interpolate<T>::type interpolate_type;

	public:
		typedef texture2d texture_type;
		typedef typename texture_type::size_type size_type;
		typedef typename texture_type::extent_type extent_type;
		typedef interpolate_type level_type;
		typedef vec<2, interpolate_type, P> normalized_type;
		typedef vec<4, T, P> texel_type;

		sampler2d(texture_type const& Texture, wrap Wrap, filter Mip = FILTER_NEAREST, filter Min = FILTER_NEAREST, texel_type const& BorderColor = texel_type(0, 0, 0, 1));

		/// Access the sampler texture object
		texture_type const& operator()() const;

		/// Fetch a texel from the sampler texture
		texel_type texel_fetch(extent_type const& TexelCoord, size_type const& Level) const;

		/// Write a texel in the sampler texture
		void texel_write(extent_type const& TexelCoord, size_type const& Level, texel_type const& Texel);

		/// Clear the sampler texture with a uniform texel
		void clear(texel_type const& Texel);

		/// Sample the sampler texture at a specific level
		texel_type texture_lod(normalized_type const& SampleCoord, level_type Level) const;

		/// Generate all the mipmaps of the sampler texture from the texture base level
		void generate_mipmaps(filter Minification);

		/// Generate the mipmaps of the sampler texture from the texture base level to the texture max level included
		void generate_mipmaps(size_type BaseLevel, size_type MaxLevel, filter Minification);

	private:
		typedef typename detail::convert<texture_type, T, P>::func convert_type;
		typedef typename detail::convert<texture_type, T, P>::fetchFunc fetch_type;
		typedef typename detail::convert<texture_type, T, P>::writeFunc write_type;
		typedef typename detail::filterBase<detail::DIMENSION_2D, texture_type, interpolate_type, normalized_type, fetch_type, texel_type>::filterFunc filter_type;

		texture_type Texture;
		convert_type Convert;
		texel_type BorderColor;
		filter_type Filter;
	};

	typedef sampler2d<float> fsampler2D;
	typedef sampler2d<double> dsampler2D;
	typedef sampler2d<unsigned int> usampler2D;
	typedef sampler2d<int> isampler2D;

}//namespace gli

#include "./core/sampler2d.inl"
