mipmaps_compute.hpp

#pragma once

#include "filter_compute.hpp"

namespace gli{
namespace detail
{
        template <typename texture_type, typename sampler_value_type, typename fetch_func, typename write_func, typename normalized_type, typename texel_type>
        inline void generate_mipmaps_1d
        (
                texture_type & Texture, fetch_func Fetch, write_func Write,
                typename texture_type::size_type BaseLayer, typename texture_type::size_type MaxLayer,
                typename texture_type::size_type BaseFace, typename texture_type::size_type MaxFace,
                typename texture_type::size_type BaseLevel, typename texture_type::size_type MaxLevel,
                filter Min
        )
        {
                typedef typename detail::interpolate<sampler_value_type>::type interpolate_type;
                typedef typename texture_type::extent_type extent_type;
                typedef typename texture_type::size_type size_type;
                typedef typename extent_type::value_type component_type;
                typedef typename detail::filterBase<detail::DIMENSION_1D, texture_type, interpolate_type, normalized_type, fetch_func, texel_type>::filterFunc filter_func;

                filter_func const Filter = detail::get_filter<filter_func, detail::DIMENSION_1D, texture_type, interpolate_type, normalized_type, fetch_func, texel_type, sampler_value_type>(FILTER_NEAREST, Min, false);
                GLI_ASSERT(Filter);

                for(size_type Layer = BaseLayer; Layer <= MaxLayer; ++Layer)
                for(size_type Face = BaseFace; Face <= MaxFace; ++Face)
                for(size_type Level = BaseLevel; Level < MaxLevel; ++Level)
                {
                        extent_type const& ExtentDst = Texture.extent(Level + 1);
                        normalized_type const& Scale = normalized_type(1) / normalized_type(max(ExtentDst - extent_type(1), extent_type(1)));

                        for(component_type i = 0; i < ExtentDst.x; ++i)
                        {
                                normalized_type const& SamplePosition(normalized_type(static_cast<typename normalized_type::value_type>(i)) * Scale);
                                texel_type const& Texel = Filter(Texture, Fetch, SamplePosition, Layer, Face, static_cast<sampler_value_type>(Level), texel_type(0));
                                Write(Texture, extent_type(i), Layer, Face, Level + 1, Texel);
                        }
                }
        }

        template <typename texture_type, typename sampler_value_type, typename fetch_func, typename write_func, typename normalized_type, typename texel_type>
        inline void generate_mipmaps_2d
        (
                texture_type & Texture, fetch_func Fetch, write_func Write,
                typename texture_type::size_type BaseLayer, typename texture_type::size_type MaxLayer,
                typename texture_type::size_type BaseFace, typename texture_type::size_type MaxFace,
                typename texture_type::size_type BaseLevel, typename texture_type::size_type MaxLevel,
                filter Min
        )
        {
                typedef typename detail::interpolate<sampler_value_type>::type interpolate_type;
                typedef typename texture_type::extent_type extent_type;
                typedef typename texture_type::size_type size_type;
                typedef typename extent_type::value_type component_type;
                typedef typename detail::filterBase<detail::DIMENSION_2D, texture_type, interpolate_type, normalized_type, fetch_func, texel_type>::filterFunc filter_func;

                filter_func const Filter = detail::get_filter<filter_func, detail::DIMENSION_2D, texture_type, interpolate_type, normalized_type, fetch_func, texel_type, sampler_value_type>(FILTER_NEAREST, Min, false);
                GLI_ASSERT(Filter);

                for(size_type Layer = BaseLayer; Layer <= MaxLayer; ++Layer)
                for(size_type Face = BaseFace; Face <= MaxFace; ++Face)
                for(size_type Level = BaseLevel; Level < MaxLevel; ++Level)
                {
                        extent_type const& ExtentDst = Texture.extent(Level + 1);
                        normalized_type const& Scale = normalized_type(1) / normalized_type(max(ExtentDst - extent_type(1), extent_type(1)));

                        for(component_type j = 0; j < ExtentDst.y; ++j)
                        for(component_type i = 0; i < ExtentDst.x; ++i)
                        {
                                normalized_type const& SamplePosition(normalized_type(i, j) * Scale);
                                texel_type const& Texel = Filter(Texture, Fetch, SamplePosition, Layer, Face, static_cast<sampler_value_type>(Level), texel_type(0));
                                Write(Texture, extent_type(i, j), Layer, Face, Level + 1, Texel);
                        }
                }
        }

        template <typename texture_type, typename sampler_value_type, typename fetch_func, typename write_func, typename normalized_type, typename texel_type>
        inline void generate_mipmaps_3d
        (
                texture_type & Texture, fetch_func Fetch, write_func Write,
                typename texture_type::size_type BaseLayer, typename texture_type::size_type MaxLayer,
                typename texture_type::size_type BaseFace, typename texture_type::size_type MaxFace,
                typename texture_type::size_type BaseLevel, typename texture_type::size_type MaxLevel,
                filter Min
        )
        {
                typedef typename detail::interpolate<sampler_value_type>::type interpolate_type;
                typedef typename texture_type::extent_type extent_type;
                typedef typename texture_type::size_type size_type;
                typedef typename extent_type::value_type component_type;
                typedef typename detail::filterBase<detail::DIMENSION_3D, texture_type, interpolate_type, normalized_type, fetch_func, texel_type>::filterFunc filter_func;

                filter_func const Filter = detail::get_filter<filter_func, detail::DIMENSION_3D, texture_type, interpolate_type, normalized_type, fetch_func, texel_type, sampler_value_type>(FILTER_NEAREST, Min, false);
                GLI_ASSERT(Filter);

                for(size_type Layer = BaseLayer; Layer <= MaxLayer; ++Layer)
                for(size_type Face = BaseFace; Face <= MaxFace; ++Face)
                for(size_type Level = BaseLevel; Level < MaxLevel; ++Level)
                {
                        extent_type const& ExtentDst = Texture.extent(Level + 1);
                        normalized_type const& Scale = normalized_type(1) / normalized_type(max(ExtentDst - extent_type(1), extent_type(1)));

                        for(component_type k = 0; k < ExtentDst.z; ++k)
                        for(component_type j = 0; j < ExtentDst.y; ++j)
                        for(component_type i = 0; i < ExtentDst.x; ++i)
                        {
                                normalized_type const& SamplePosition(normalized_type(i, j, k) * Scale);
                                texel_type const& Texel = Filter(Texture, Fetch, SamplePosition, Layer, Face, static_cast<sampler_value_type>(Level), texel_type(0));
                                Write(Texture, extent_type(i, j, k), Layer, Face, Level + 1, Texel);
                        }
                }
        }
}//namespace detail
}//namespace gli