Refactor attribute specification: move to a separate file + standalone function for use in vertices

This commit is contained in:
Nikita Lisitsa 2020-10-23 12:10:11 +03:00
parent 08c62d6e3f
commit 440fa3777e
3 changed files with 453 additions and 389 deletions

View file

@ -0,0 +1,380 @@
#pragma once
#include <psemek/gfx/gl.hpp>
#include <psemek/geom/vector.hpp>
#include <psemek/geom/point.hpp>
#include <psemek/geom/matrix.hpp>
#include <vector>
#include <optional>
#include <array>
namespace psemek::gfx
{
struct attrib_description
{
GLuint index;
GLint size;
GLenum type;
GLboolean normalized;
GLsizei stride;
void const * pointer;
GLuint divisor;
};
using attribs_description = std::vector<attrib_description>;
template <typename T>
struct normalized
{
using type = T;
};
// skips a single attribute index
struct skip
{};
// skips bytes in the vertex
template <std::size_t N>
struct padding
{
static constexpr std::size_t size = N;
};
// instance attribute, for instanced meshes only
template <typename T>
struct instanced
{
using type = T;
};
template <typename ... Attribs>
attribs_description make_attribs_description();
namespace detail
{
template <typename Attrib>
struct attrib_traits;
template <>
struct attrib_traits<std::uint8_t>
{
using attrib_type = std::uint8_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::UNSIGNED_BYTE;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<std::int8_t>
{
using attrib_type = std::int8_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::BYTE;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<std::uint16_t>
{
using attrib_type = std::uint16_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::UNSIGNED_SHORT;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<std::int16_t>
{
using attrib_type = std::int16_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::SHORT;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<std::uint32_t>
{
using attrib_type = std::uint32_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::UNSIGNED_INT;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<std::int32_t>
{
using attrib_type = std::int32_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::INT;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<float>
{
using attrib_type = float;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::FLOAT;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<double>
{
using attrib_type = double;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::DOUBLE;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <typename T, std::size_t N>
struct attrib_traits<std::array<T, N>>
{
using attrib_type = std::array<T, N>;
static constexpr GLint size = N;
static constexpr GLenum type = attrib_traits<T>::type;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <typename T, std::size_t N>
struct attrib_traits<geom::vector<T, N>>
{
using attrib_type = geom::vector<T, N>;
static constexpr GLint size = N;
static constexpr GLenum type = attrib_traits<T>::type;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <typename T, std::size_t N>
struct attrib_traits<geom::point<T, N>>
{
using attrib_type = geom::point<T, N>;
static constexpr GLint size = N;
static constexpr GLenum type = attrib_traits<T>::type;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <typename T, std::size_t R, std::size_t C>
struct attrib_traits<geom::matrix<T, R, C>>
{
using attrib_type = geom::matrix<T, R, C>;
};
template <typename T>
struct attrib_traits<normalized<T>>
{
using attrib_type = T;
static constexpr GLint size = attrib_traits<T>::size;
static constexpr GLenum type = attrib_traits<T>::type;
static constexpr GLboolean normalized = gl::TRUE_;
};
template <typename T>
struct attrib_traits<instanced<T>>
{
using attrib_type = typename attrib_traits<T>::attrib_type;
static constexpr GLint size = attrib_traits<T>::size;
static constexpr GLenum type = attrib_traits<T>::type;
static constexpr GLboolean normalized = attrib_traits<T>::normalized;
};
template <typename T>
struct is_padding : std::false_type
{};
template <std::size_t N>
struct is_padding<padding<N>> : std::true_type
{};
template <typename T>
struct is_instanced : std::false_type
{};
template <typename T>
struct is_instanced<instanced<T>> : std::true_type
{};
template <typename T>
struct remove_instanced
{
using type = T;
};
template <typename T>
struct remove_instanced<instanced<T>>
{
using type = T;
};
template <typename T>
struct is_matrix : std::false_type
{};
template <typename T, std::size_t R, std::size_t C>
struct is_matrix<geom::matrix<T, R, C>> : std::true_type
{};
template <typename Attr>
std::size_t attr_size()
{
if constexpr (std::is_same_v<Attr, skip>)
{
return 0;
}
else if constexpr (is_padding<Attr>::value)
{
return Attr::size;
}
else
{
return sizeof(typename attrib_traits<Attr>::attrib_type);
}
}
template <bool Instance, typename ... Attribs>
struct stride_helper;
template <bool Instance>
struct stride_helper<Instance>
{
static std::size_t stride()
{
return 0;
}
};
template <bool Instance, typename Attr1, typename ... Attribs>
struct stride_helper<Instance, Attr1, Attribs...>
{
static std::size_t stride()
{
std::size_t s = 0;
if constexpr (is_instanced<Attr1>::value == Instance)
{
s = attr_size<Attr1>();
}
return s + stride_helper<Instance, Attribs...>::stride();
}
};
template <bool Instance, typename ... Attribs>
struct make_attribs_description_impl;
template <bool Instance>
struct make_attribs_description_impl<Instance>
{
static void make(attribs_description &)
{}
static void make_impl(attribs_description &, std::size_t, std::size_t, std::size_t)
{ }
};
template <bool Instance, typename Attr1, typename ... Attribs>
struct make_attribs_description_impl<Instance, Attr1, Attribs...>
{
static void make(attribs_description & result)
{
std::size_t const stride = stride_helper<Instance, Attr1, Attribs...>::stride();
make_impl(result, 0, 0, stride);
}
static void make_impl(attribs_description & result, std::size_t index, std::size_t offset, std::size_t stride)
{
if constexpr (std::is_same_v<Attr1, skip>)
{
make_attribs_description_impl<Instance, Attribs...>::make_impl(result, index + 1, offset, stride);
}
else if constexpr (is_padding<Attr1>::value)
{
make_attribs_description_impl<Instance, Attribs...>::make_impl(result, index, offset + Attr1::size, stride);
}
else if constexpr (is_instanced<Attr1>::value == Instance)
{
using attr = typename remove_instanced<Attr1>::type;
if constexpr (is_matrix<attr>::value)
{
using T = typename attr::scalar_type;
using traits = attrib_traits<geom::vector<T, attr::columns>>;
for (std::size_t row = 0; row < attr::rows; ++row)
{
attrib_description attr;
attr.index = index + row;
attr.size = traits::size;
attr.type = traits::type;
attr.normalized = traits::normalized;
attr.stride = stride;
attr.pointer = reinterpret_cast<char const *>(offset + row * attr::columns * sizeof(T));
attr.divisor = Instance ? 1 : 0;
result.push_back(attr);
}
make_attribs_description_impl<Instance, Attribs...>::make_impl(result, index + attr::rows, offset + attr_size<Attr1>(), stride);
}
else
{
using traits = attrib_traits<Attr1>;
attrib_description attr;
attr.index = index;
attr.size = traits::size;
attr.type = traits::type;
attr.normalized = traits::normalized;
attr.stride = stride;
attr.pointer = reinterpret_cast<char const *>(offset);
attr.divisor = Instance ? 1 : 0;
result.push_back(attr);
make_attribs_description_impl<Instance, Attribs...>::make_impl(result, index + 1, offset + attr_size<Attr1>(), stride);
}
}
else
{
using attr = typename remove_instanced<Attr1>::type;
if constexpr (is_matrix<attr>::value)
{
make_attribs_description_impl<Instance, Attribs...>::make_impl(result, index + attr::rows, offset, stride);
}
else
{
make_attribs_description_impl<Instance, Attribs...>::make_impl(result, index + 1, offset, stride);
}
}
}
};
}
template <typename ... Attribs>
attribs_description make_attribs_description()
{
attribs_description result;
detail::make_attribs_description_impl<false, Attribs...>::make(result);
detail::make_attribs_description_impl<true, Attribs...>::make(result);
return result;
}
}

View file

@ -4,6 +4,7 @@
#include <psemek/gfx/drawable.hpp>
#include <psemek/gfx/array.hpp>
#include <psemek/gfx/buffer.hpp>
#include <psemek/gfx/attribs.hpp>
#include <psemek/geom/vector.hpp>
#include <psemek/geom/point.hpp>
@ -22,390 +23,32 @@
namespace psemek::gfx
{
template <typename T>
struct normalized
{
using type = T;
};
// skips a single attribute index
struct skip
{};
// skips bytes in the vertex
template <std::size_t N>
struct padding
{
static constexpr std::size_t size = N;
};
// instance attribute, for instanced meshes only
template <typename T>
struct instanced
{
using type = T;
};
template <typename Attrib>
struct attrib_traits;
template <>
struct attrib_traits<std::uint8_t>
{
using attrib_type = std::uint8_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::UNSIGNED_BYTE;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<std::int8_t>
{
using attrib_type = std::int8_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::BYTE;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<std::uint16_t>
{
using attrib_type = std::uint16_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::UNSIGNED_SHORT;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<std::int16_t>
{
using attrib_type = std::int16_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::SHORT;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<std::uint32_t>
{
using attrib_type = std::uint32_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::UNSIGNED_INT;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<std::int32_t>
{
using attrib_type = std::int32_t;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::INT;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<float>
{
using attrib_type = float;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::FLOAT;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <>
struct attrib_traits<double>
{
using attrib_type = double;
static constexpr GLint size = 1;
static constexpr GLenum type = gl::DOUBLE;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <typename T, std::size_t N>
struct attrib_traits<std::array<T, N>>
{
using attrib_type = std::array<T, N>;
static constexpr GLint size = N;
static constexpr GLenum type = attrib_traits<T>::type;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <typename T, std::size_t N>
struct attrib_traits<geom::vector<T, N>>
{
using attrib_type = geom::vector<T, N>;
static constexpr GLint size = N;
static constexpr GLenum type = attrib_traits<T>::type;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <typename T, std::size_t N>
struct attrib_traits<geom::point<T, N>>
{
using attrib_type = geom::point<T, N>;
static constexpr GLint size = N;
static constexpr GLenum type = attrib_traits<T>::type;
static constexpr GLboolean normalized = gl::FALSE_;
};
template <typename T, std::size_t R, std::size_t C>
struct attrib_traits<geom::matrix<T, R, C>>
{
using attrib_type = geom::matrix<T, R, C>;
};
template <typename T>
struct attrib_traits<normalized<T>>
{
using attrib_type = T;
static constexpr GLint size = attrib_traits<T>::size;
static constexpr GLenum type = attrib_traits<T>::type;
static constexpr GLboolean normalized = gl::TRUE_;
};
template <typename T>
struct attrib_traits<instanced<T>>
{
using attrib_type = typename attrib_traits<T>::attrib_type;
static constexpr GLint size = attrib_traits<T>::size;
static constexpr GLenum type = attrib_traits<T>::type;
static constexpr GLboolean normalized = attrib_traits<T>::normalized;
};
namespace detail
{
template <typename T>
struct is_padding : std::false_type
{};
template <std::size_t N>
struct is_padding<padding<N>> : std::true_type
{};
template <typename T>
struct is_instanced : std::false_type
{};
template <typename T>
struct is_instanced<instanced<T>> : std::true_type
{};
template <typename T>
struct remove_instanced
{
using type = T;
};
template <typename T>
struct remove_instanced<instanced<T>>
{
using type = T;
};
template <typename T>
struct is_matrix : std::false_type
{};
template <typename T, std::size_t R, std::size_t C>
struct is_matrix<geom::matrix<T, R, C>> : std::true_type
{};
template <typename Attr>
std::size_t attr_size()
{
if constexpr (std::is_same_v<Attr, skip>)
{
return 0;
}
else if constexpr (is_padding<Attr>::value)
{
return Attr::size;
}
else
{
return sizeof(typename attrib_traits<Attr>::attrib_type);
}
}
template <bool InstanceSetup, typename ... Attribs>
struct stride_helper;
template <bool InstanceSetup>
struct stride_helper<InstanceSetup>
{
static std::size_t stride()
{
return 0;
}
};
template <bool InstanceSetup, typename Attr1, typename ... Attribs>
struct stride_helper<InstanceSetup, Attr1, Attribs...>
{
static std::size_t stride()
{
std::size_t s = 0;
if constexpr (is_instanced<Attr1>::value == InstanceSetup)
{
s = attr_size<Attr1>();
}
return s + stride_helper<InstanceSetup, Attribs...>::stride();
}
};
struct mesh_setup_result
{
std::size_t stride;
std::size_t max_index;
};
template <bool InstanceSetup, typename ... Attribs>
struct mesh_setup_base;
template <bool InstanceSetup>
struct mesh_setup_base<InstanceSetup>
{
static mesh_setup_result setup()
{
return {0, 0};
}
static std::size_t setup_impl(std::size_t index, std::size_t, std::size_t)
{
return index;
}
};
template <bool InstanceSetup, typename Attr1, typename ... Attribs>
struct mesh_setup_base<InstanceSetup, Attr1, Attribs...>
{
static mesh_setup_result setup()
{
std::size_t const stride = stride_helper<InstanceSetup, Attr1, Attribs...>::stride();
auto const max_index = setup_impl(0, 0, stride);
return {stride, max_index};
}
static std::size_t setup_impl(std::size_t index, std::size_t offset, std::size_t stride)
{
if constexpr (std::is_same_v<Attr1, skip>)
{
return mesh_setup_base<InstanceSetup, Attribs...>::setup_impl(index + 1, offset, stride);
}
else if constexpr (is_padding<Attr1>::value)
{
return mesh_setup_base<InstanceSetup, Attribs...>::setup_impl(index, offset + Attr1::size, stride);
}
else if constexpr (is_instanced<Attr1>::value == InstanceSetup)
{
using attr = typename remove_instanced<Attr1>::type;
if constexpr (is_matrix<attr>::value)
{
using T = typename attr::scalar_type;
using traits = attrib_traits<geom::vector<T, attr::columns>>;
for (std::size_t row = 0; row < attr::rows; ++row)
{
gl::EnableVertexAttribArray(index + row);
gl::VertexAttribPointer(index + row, traits::size, traits::type, traits::normalized, stride, reinterpret_cast<char const *>(offset + row * attr::columns * sizeof(T)));
if (InstanceSetup)
gl::VertexAttribDivisor(index + row, 1);
}
return mesh_setup_base<InstanceSetup, Attribs...>::setup_impl(index + attr::rows, offset + attr_size<Attr1>(), stride);
}
else
{
if (InstanceSetup)
gl::VertexAttribDivisor(index, 1);
using traits = attrib_traits<Attr1>;
gl::EnableVertexAttribArray(index);
gl::VertexAttribPointer(index, traits::size, traits::type, traits::normalized, stride, reinterpret_cast<char const *>(offset));
return mesh_setup_base<InstanceSetup, Attribs...>::setup_impl(index + 1, offset + attr_size<Attr1>(), stride);
}
}
else
{
using attr = typename remove_instanced<Attr1>::type;
if constexpr (is_matrix<attr>::value)
{
return mesh_setup_base<InstanceSetup, Attribs...>::setup_impl(index + attr::rows, offset, stride);
}
else
{
return mesh_setup_base<InstanceSetup, Attribs...>::setup_impl(index + 1, offset, stride);
}
}
}
};
template <typename ... Attribs>
using mesh_vertex_setup = mesh_setup_base<false, Attribs...>;
template <typename ... Attribs>
using mesh_instance_setup = mesh_setup_base<true, Attribs...>;
template <typename ... Args>
struct has_instanced_attribs_impl
: std::false_type
{};
template <typename T, typename ... Args>
struct has_instanced_attribs_impl<T, Args...>
: has_instanced_attribs_impl<Args...>
{};
template <typename T, typename ... Args>
struct has_instanced_attribs_impl<instanced<T>, Args...>
: std::true_type
{};
template <typename ... Args>
constexpr bool has_instanced_attribs = has_instanced_attribs_impl<Args...>::value;
template <typename T>
struct gl_type;
struct index_type_to_gl_enum;
template <>
struct gl_type<std::uint8_t>
struct index_type_to_gl_enum<std::uint8_t>
{
static constexpr GLenum value = gl::UNSIGNED_BYTE;
};
template <>
struct gl_type<std::uint16_t>
struct index_type_to_gl_enum<std::uint16_t>
{
static constexpr GLenum value = gl::UNSIGNED_SHORT;
};
template <>
struct gl_type<std::uint32_t>
struct index_type_to_gl_enum<std::uint32_t>
{
static constexpr GLenum value = gl::UNSIGNED_INT;
};
template <typename T>
static constexpr GLenum gl_type_v = gl_type<T>::value;
static constexpr GLenum index_type_to_gl_enum_v = index_type_to_gl_enum<T>::value;
inline std::size_t index_size(GLenum type)
{
@ -452,6 +95,7 @@ namespace psemek::gfx
return std::nullopt;
}
}
}
/* A generic mesh class
@ -471,6 +115,8 @@ namespace psemek::gfx
mesh(mesh const &) = delete;
mesh & operator = (mesh const &) = delete;
void setup(attribs_description const & attribs);
template <typename ... Attribs>
void setup();
@ -560,31 +206,7 @@ namespace psemek::gfx
template <typename ... Attribs>
void mesh::setup()
{
array_.bind();
for (std::size_t i = 0; i < info_.max_attribute_index_; ++i)
gl::DisableVertexAttribArray(i);
if (!vertex_buffer_) vertex_buffer_ = buffer{};
vertex_buffer_.bind();
auto vertex_setup = detail::mesh_vertex_setup<Attribs...>::setup();
info_.stride_ = vertex_setup.stride;
info_.max_attribute_index_ = vertex_setup.max_index;
if constexpr (detail::has_instanced_attribs<Attribs...>)
{
if (!instance_buffer_) instance_buffer_ = buffer{};
instance_buffer_.bind();
auto instance_setup = detail::mesh_instance_setup<Attribs...>::setup();
info_.instance_stride_ = instance_setup.stride;
info_.instanced_ = true;
info_.max_attribute_index_ = std::max(info_.max_attribute_index_, instance_setup.max_index);
}
else
{
info_.instance_stride_ = 0;
info_.instanced_ = false;
}
setup(make_attribs_description<Attribs...>());
}
template <typename Vertex>
@ -645,7 +267,7 @@ namespace psemek::gfx
info_.index_count_ = index_count;
info_.indexed_ = true;
info_.primitive_type_ = primitive_type;
info_.index_type_ = detail::gl_type_v<Index>;
info_.index_type_ = detail::index_type_to_gl_enum_v<Index>;
}
template <typename Vertex, typename Index>

View file

@ -29,6 +29,68 @@ namespace psemek::gfx
return *this;
}
void mesh::setup(attribs_description const & attribs)
{
assert(!attribs.empty());
array_.bind();
for (std::size_t i = 0; i < info_.max_attribute_index_; ++i)
gl::DisableVertexAttribArray(i);
std::size_t max_index = 0;
bool instanced = false;
std::size_t stride = 0;
std::size_t instance_stride = 0;
for (auto const & a : attribs)
{
max_index = std::max<std::size_t>(max_index, a.index);
if (a.divisor == 0)
{
stride = a.stride;
}
else
{
assert(a.divisor == 1);
instance_stride = a.stride;
instanced = true;
}
}
info_.max_attribute_index_ = max_index;
info_.stride_ = stride;
info_.instance_stride_ = instance_stride;
info_.instanced_ = instanced;
if (!vertex_buffer_) vertex_buffer_ = buffer{};
vertex_buffer_.bind();
for (auto const & a : attribs)
{
if (a.divisor != 0) continue;
gl::EnableVertexAttribArray(a.index);
gl::VertexAttribPointer(a.index, a.size, a.type, a.normalized, a.stride, a.pointer);
}
if (instanced)
{
if (!instance_buffer_) instance_buffer_ = buffer{};
instance_buffer_.bind();
for (auto const & a : attribs)
{
if (a.divisor == 0) continue;
gl::EnableVertexAttribArray(a.index);
gl::VertexAttribPointer(a.index, a.size, a.type, a.normalized, a.stride, a.pointer);
gl::VertexAttribDivisor(a.index, a.divisor);
}
}
}
void mesh::draw() const
{
draw(0, is_indexed() ? index_count() : vertex_count(), instance_count());