92 lines
3.5 KiB
C++
92 lines
3.5 KiB
C++
///////////////////////////////////////////////////////////////////////////////////////////////////
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// OpenGL Image Copyright (c) 2008 - 2011 G-Truc Creation (www.g-truc.net)
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///////////////////////////////////////////////////////////////////////////////////////////////////
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// Created : 2008-12-19
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// Updated : 2010-09-27
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// Licence : This source is under MIT License
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// File : gli/gtx/fetch.inl
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///////////////////////////////////////////////////////////////////////////////////////////////////
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namespace gli{
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namespace gtx{
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namespace fetch
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{
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template <typename genType>
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inline genType texelFetch
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(
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texture2D const & Image,
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texture2D::dimensions_type const & TexCoord,
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texture2D::level_type const & Level
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)
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{
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assert(Image[Level].format() == R8U || Image[Level].format() == RG8U || Image[Level].format() == RGB8U || Image[Level].format() == RGBA8U);
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texture2D::dimensions_type Dimensions = Image[Level].dimensions();
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texture2D::value_type const * const Data = Image[Level].data();
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return reinterpret_cast<genType const * const>(Data)[TexCoord.x + TexCoord.y * Dimensions.x];
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}
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template <typename genType>
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inline genType textureLod
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(
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texture2D const & Image,
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texture2D::texcoord_type const & TexCoord,
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texture2D::level_type const & Level
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)
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{
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assert(Image[Level].format() == R8U || Image[Level].format() == RG8U || Image[Level].format() == RGB8U || Image[Level].format() == RGBA8U);
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texture2D::dimensions_type Dimensions = Image[Level].dimensions();
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texture2D::value_type const * const Data = Image[Level].data();
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std::size_t s_below = std::size_t(glm::floor(TexCoord.s * float(Dimensions.x - 1)));
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std::size_t s_above = std::size_t(glm::ceil( TexCoord.s * float(Dimensions.x - 1)));
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std::size_t t_below = std::size_t(glm::floor(TexCoord.t * float(Dimensions.y - 1)));
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std::size_t t_above = std::size_t(glm::ceil( TexCoord.t * float(Dimensions.y - 1)));
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float s_step = 1.0f / float(Dimensions.x);
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float t_step = 1.0f / float(Dimensions.y);
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float s_below_normalized = s_below / float(Dimensions.x);
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float s_above_normalized = s_above / float(Dimensions.x);
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float t_below_normalized = t_below / float(Dimensions.y);
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float t_above_normalized = t_above / float(Dimensions.y);
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genType Value1 = reinterpret_cast<genType const * const>(Data)[s_below + t_below * Dimensions.x];
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genType Value2 = reinterpret_cast<genType const * const>(Data)[s_above + t_below * Dimensions.x];
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genType Value3 = reinterpret_cast<genType const * const>(Data)[s_above + t_above * Dimensions.x];
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genType Value4 = reinterpret_cast<genType const * const>(Data)[s_below + t_above * Dimensions.x];
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float BlendA = float(TexCoord.s - s_below_normalized) * float(Dimensions.x - 1);
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float BlendB = float(TexCoord.s - s_below_normalized) * float(Dimensions.x - 1);
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float BlendC = float(TexCoord.t - t_below_normalized) * float(Dimensions.y - 1);
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genType ValueA(glm::mix(Value1, Value2, BlendA));
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genType ValueB(glm::mix(Value4, Value3, BlendB));
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return genType(glm::mix(ValueA, ValueB, BlendC));
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}
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template <typename genType>
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void texelWrite
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(
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texture2D & Image,
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texture2D::dimensions_type const & Texcoord,
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texture2D::level_type const & Level,
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genType const & Color
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)
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{
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genType * Data = (genType*)Image[Level].data();
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std::size_t Index = Texcoord.x + Texcoord.y * Image[Level].dimensions().x;
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std::size_t Capacity = Image[Level].capacity();
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assert(Index < Capacity);
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*(Data + Index) = Color;
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}
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}//namespace fetch
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}//namespace gtx
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}//namespace gli
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