Refactor gltf_mesh

This commit is contained in:
Nikita Lisitsa 2023-01-14 03:35:12 +03:00
parent 514f4006ef
commit 437714288b
2 changed files with 118 additions and 63 deletions

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@ -1,40 +1,30 @@
#pragma once
#include <psemek/gfx/buffer.hpp>
#include <psemek/gfx/array.hpp>
#include <psemek/gfx/gltf_parser.hpp>
#include <psemek/gfx/drawable.hpp>
#include <psemek/gfx/texture.hpp>
#include <psemek/util/span.hpp>
#include <optional>
#include <unordered_map>
#include <functional>
namespace psemek::gfx
{
struct gltf_mesh
{
struct mesh
struct primitive
{
struct primitive
{
gfx::array vao;
std::optional<std::size_t> material;
std::size_t index_count;
std::size_t index_offset;
GLenum index_type;
void draw() const;
};
std::vector<primitive> primitives;
gfx::drawable * drawable;
std::optional<std::size_t> material;
};
std::vector<gfx::buffer> buffers;
virtual gltf_asset::material const & material(std::size_t index) const = 0;
virtual gfx::texture_2d const & texture(std::size_t index) const = 0;
virtual util::span<primitive const> mesh(std::string_view name) const = 0;
std::unordered_map<std::string, mesh> meshes;
gltf_mesh() = default;
gltf_mesh(gltf_asset const & asset, std::vector<util::span<char const>> const & buffers);
virtual ~gltf_mesh() {}
};
std::unique_ptr<gltf_mesh> make_gltf_mesh(gltf_asset const & asset, std::function<std::vector<char>(std::string const &)> uri_loader);
}

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@ -1,67 +1,132 @@
#include <psemek/gfx/gltf_mesh.hpp>
#include <psemek/gfx/array.hpp>
#include <psemek/gfx/buffer.hpp>
#include <psemek/util/hstring.hpp>
#include <psemek/io/memory_stream.hpp>
#include <stdexcept>
namespace psemek::gfx
{
void gltf_mesh::mesh::primitive::draw() const
namespace
{
vao.bind();
gl::DrawElements(gl::TRIANGLES, index_count, index_type, reinterpret_cast<void const *>(index_offset));
}
gltf_mesh::gltf_mesh(gltf_asset const & asset, std::vector<util::span<char const>> const & buffers)
{
if (buffers.size() != asset.buffers.size())
throw std::runtime_error("wrong number of glTF buffers");
for (auto buffer : buffers)
this->buffers.emplace_back().load(buffer.data(), buffer.size(), gl::STATIC_DRAW);
for (auto const & node : asset.nodes)
struct drawable_impl
: drawable
{
auto & target_mesh = meshes[node.name];
gfx::array vao;
std::size_t index_count;
std::size_t index_offset;
GLenum index_type;
auto const & mesh = asset.meshes[node.mesh];
for (auto const & primitive : mesh.primitives)
void draw() const override
{
auto & target_primitive = target_mesh.primitives.emplace_back();
target_primitive.material = primitive.material;
vao.bind();
gl::DrawElements(gl::TRIANGLES, index_count, index_type, reinterpret_cast<void const *>(index_offset));
}
};
target_primitive.vao.bind();
struct gltf_mesh_impl
: gltf_mesh
{
gltf_mesh_impl(gltf_asset const & asset, std::function<std::vector<char>(std::string const &)> uri_loader);
gltf_asset::material const & material(std::size_t index) const override
{
return materials_[index];
}
gfx::texture_2d const & texture(std::size_t index) const override
{
return textures_[index];
}
util::span<primitive const> mesh(std::string_view name) const override
{
return meshes_.at(name);
}
private:
std::vector<gltf_asset::material> materials_;
std::vector<gfx::texture_2d> textures_;
std::vector<gfx::buffer> buffers_;
std::vector<std::unique_ptr<drawable_impl>> drawables_;
std::unordered_map<util::hstring, std::vector<primitive>> meshes_;
};
gltf_mesh_impl::gltf_mesh_impl(gltf_asset const & asset, std::function<std::vector<char>(std::string const &)> uri_loader)
{
materials_ = asset.materials;
for (auto const & buffer : asset.buffers)
{
auto data = uri_loader(buffer.uri);
buffers_.emplace_back().load(data.data(), data.size(), gl::STATIC_DRAW);
}
for (auto const & texture : asset.textures)
{
auto data = uri_loader(texture.uri);
auto & target = textures_.emplace_back();
target.load(gfx::read_png(io::memory_istream(data.data(), data.data() + data.size())));
target.linear_mipmap_filter();
target.anisotropy();
target.generate_mipmap();
}
for (auto const & node : asset.nodes)
{
auto & target_mesh = meshes_[node.name];
auto const & mesh = asset.meshes[node.mesh];
for (auto const & primitive : mesh.primitives)
{
auto const & indices_accessor = asset.accessors[primitive.indices];
auto const & indices_view = asset.buffer_views[indices_accessor.buffer_view];
drawables_.push_back(std::make_unique<drawable_impl>());
auto & drawable = *drawables_.back();
gl::BindBuffer(gl::ELEMENT_ARRAY_BUFFER, this->buffers[indices_view.buffer].id());
target_primitive.index_offset = indices_view.offset;
target_primitive.index_type = indices_accessor.component_type;
target_primitive.index_count = indices_accessor.count;
}
drawable.vao.bind();
std::pair<GLuint, std::optional<std::size_t>> attributes[3] =
{
{0, primitive.position},
{1, primitive.normal},
{2, primitive.texcoord},
};
{
auto const & indices_accessor = asset.accessors[primitive.indices];
auto const & indices_view = asset.buffer_views[indices_accessor.buffer_view];
for (auto const & attribute : attributes)
{
if (!attribute.second) continue;
gl::BindBuffer(gl::ELEMENT_ARRAY_BUFFER, buffers_[indices_view.buffer].id());
drawable.index_offset = indices_view.offset;
drawable.index_type = indices_accessor.component_type;
drawable.index_count = indices_accessor.count;
}
auto const & accessor = asset.accessors[*attribute.second];
auto const & view = asset.buffer_views[accessor.buffer_view];
std::pair<GLuint, std::optional<std::size_t>> attributes[3] =
{
{0, primitive.position},
{1, primitive.normal},
{2, primitive.texcoord},
};
gl::BindBuffer(gl::ARRAY_BUFFER, this->buffers[view.buffer].id());
gl::EnableVertexAttribArray(attribute.first);
gl::VertexAttribPointer(attribute.first, accessor.type, accessor.component_type, accessor.normalized, 0, reinterpret_cast<void const *>(view.offset));
for (auto const & attribute : attributes)
{
if (!attribute.second) continue;
auto const & accessor = asset.accessors[*attribute.second];
auto const & view = asset.buffer_views[accessor.buffer_view];
gl::BindBuffer(gl::ARRAY_BUFFER, buffers_[view.buffer].id());
gl::EnableVertexAttribArray(attribute.first);
gl::VertexAttribPointer(attribute.first, accessor.type, accessor.component_type, accessor.normalized, 0, reinterpret_cast<void const *>(view.offset));
}
target_mesh.push_back({&drawable, primitive.material});
}
}
}
}
std::unique_ptr<gltf_mesh> make_gltf_mesh(gltf_asset const & asset, std::function<std::vector<char>(std::string const &)> uri_loader)
{
return std::make_unique<gltf_mesh_impl>(asset, std::move(uri_loader));
}
}