💿🐜 Antkeeper source code https://antkeeper.com
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/*
* Copyright (C) 2023 Christopher J. Howard
*
* This file is part of Antkeeper source code.
*
* Antkeeper source code is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Antkeeper source code is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
*/
#include <engine/render/model.hpp>
#include <engine/resources/resource-loader.hpp>
#include <engine/resources/resource-manager.hpp>
#include <engine/render/vertex-attribute.hpp>
#include <engine/gl/vertex-attribute.hpp>
#include <engine/gl/drawing-mode.hpp>
#include <engine/math/numbers.hpp>
#include <engine/utility/hash/fnv1a.hpp>
#include <cstdint>
namespace render {
model::model()
{
vertex_array = std::make_shared<gl::vertex_array>();
vertex_buffer = std::make_shared<gl::vertex_buffer>();
}
} // namespace render
inline constexpr std::uint16_t vertex_attribute_position = 0b0000000000000001;
inline constexpr std::uint16_t vertex_attribute_uv = 0b0000000000000010;
inline constexpr std::uint16_t vertex_attribute_normal = 0b0000000000000100;
inline constexpr std::uint16_t vertex_attribute_tangent = 0b0000000000001000;
inline constexpr std::uint16_t vertex_attribute_color = 0b0000000000010000;
inline constexpr std::uint16_t vertex_attribute_bone = 0b0000000000100000;
inline constexpr std::uint16_t vertex_attribute_barycentric = 0b0000000001000000;
inline constexpr std::uint16_t vertex_attribute_morph_target = 0b0000000010000000;
inline constexpr std::uint16_t vertex_attribute_index = 0b0000000100000000;
template <>
std::unique_ptr<render::model> resource_loader<render::model>::load(::resource_manager& resource_manager, deserialize_context& ctx)
{
// Read vertex format
std::uint16_t vertex_format_flags = 0;
ctx.read16<std::endian::little>(reinterpret_cast<std::byte*>(&vertex_format_flags), 1);
// Read bone per vertex (if any)
std::uint8_t bones_per_vertex = 0;
if (vertex_format_flags & vertex_attribute_bone)
{
ctx.read8(reinterpret_cast<std::byte*>(&bones_per_vertex), 1);
}
// Read vertex count
std::uint32_t vertex_count = 0;
ctx.read32<std::endian::little>(reinterpret_cast<std::byte*>(&vertex_count), 1);
// Determine vertex size
std::size_t vertex_size = 0;
if (vertex_format_flags & vertex_attribute_position)
{
vertex_size += sizeof(float) * 3;
}
if (vertex_format_flags & vertex_attribute_uv)
{
vertex_size += sizeof(float) * 2;
}
if (vertex_format_flags & vertex_attribute_normal)
{
vertex_size += sizeof(float) * 3;
}
if (vertex_format_flags & vertex_attribute_tangent)
{
vertex_size += sizeof(float) * 4;
}
if (vertex_format_flags & vertex_attribute_color)
{
vertex_size += sizeof(float) * 4;
}
if (vertex_format_flags & vertex_attribute_bone)
{
vertex_size += sizeof(std::uint32_t) * bones_per_vertex;
vertex_size += sizeof(float) * bones_per_vertex;
}
if (vertex_format_flags & vertex_attribute_barycentric)
{
vertex_size += sizeof(float) * 3;
}
if (vertex_format_flags & vertex_attribute_morph_target)
{
vertex_size += sizeof(float) * 3;
}
// Allocate vertex data
std::vector<std::byte> vertex_data(vertex_count * vertex_size);
// Read vertices
if constexpr (std::endian::native == std::endian::little)
{
ctx.read8(vertex_data.data(), vertex_count * vertex_size);
}
else
{
std::byte* vertex_data_offset = vertex_data.data();
for (std::uint32_t i = 0; i < vertex_count; ++i)
{
if (vertex_format_flags & vertex_attribute_position)
{
ctx.read32<std::endian::little>(vertex_data_offset, 3);
vertex_data_offset += sizeof(float) * 3;
}
if (vertex_format_flags & vertex_attribute_uv)
{
ctx.read32<std::endian::little>(vertex_data_offset, 2);
vertex_data_offset += sizeof(float) * 2;
}
if (vertex_format_flags & vertex_attribute_normal)
{
ctx.read32<std::endian::little>(vertex_data_offset, 3);
vertex_data_offset += sizeof(float) * 3;
}
if (vertex_format_flags & vertex_attribute_tangent)
{
ctx.read32<std::endian::little>(vertex_data_offset, 4);
vertex_data_offset += sizeof(float) * 4;
}
if (vertex_format_flags & vertex_attribute_color)
{
ctx.read32<std::endian::little>(vertex_data_offset, 4);
vertex_data_offset += sizeof(float) * 4;
}
if (vertex_format_flags & vertex_attribute_bone)
{
ctx.read32<std::endian::little>(vertex_data_offset, bones_per_vertex);
ctx.read32<std::endian::little>(vertex_data_offset, bones_per_vertex);
vertex_data_offset += sizeof(std::uint32_t) * bones_per_vertex;
vertex_data_offset += sizeof(float) * bones_per_vertex;
}
if (vertex_format_flags & vertex_attribute_barycentric)
{
ctx.read32<std::endian::little>(vertex_data_offset, 3);
vertex_data_offset += sizeof(float) * 3;
}
if (vertex_format_flags & vertex_attribute_morph_target)
{
ctx.read32<std::endian::little>(vertex_data_offset, 3);
vertex_data_offset += sizeof(float) * 3;
}
}
}
// Allocate model
std::unique_ptr<render::model> model = std::make_unique<render::model>();
// Resize model VBO and upload vertex data
gl::vertex_buffer& vbo = *model->get_vertex_buffer();
vbo.resize(vertex_data.size(), vertex_data);
// Free vertex data
vertex_data.clear();
// Bind vertex attributes to VAO
gl::vertex_array& vao = *model->get_vertex_array();
gl::vertex_attribute attribute;
attribute.buffer = &vbo;
attribute.offset = 0;
attribute.stride = vertex_size;
if (vertex_format_flags & vertex_attribute_position)
{
attribute.type = gl::vertex_attribute_type::float_32;
attribute.components = 3;
vao.bind(render::vertex_attribute::position, attribute);
attribute.offset += sizeof(float) * attribute.components;
}
if (vertex_format_flags & vertex_attribute_uv)
{
attribute.type = gl::vertex_attribute_type::float_32;
attribute.components = 2;
vao.bind(render::vertex_attribute::uv, attribute);
attribute.offset += sizeof(float) * attribute.components;
}
if (vertex_format_flags & vertex_attribute_normal)
{
attribute.type = gl::vertex_attribute_type::float_32;
attribute.components = 3;
vao.bind(render::vertex_attribute::normal, attribute);
attribute.offset += sizeof(float) * attribute.components;
}
if (vertex_format_flags & vertex_attribute_tangent)
{
attribute.type = gl::vertex_attribute_type::float_32;
attribute.components = 4;
vao.bind(render::vertex_attribute::tangent, attribute);
attribute.offset += sizeof(float) * attribute.components;
}
if (vertex_format_flags & vertex_attribute_color)
{
attribute.type = gl::vertex_attribute_type::float_32;
attribute.components = 4;
vao.bind(render::vertex_attribute::color, attribute);
attribute.offset += sizeof(float) * attribute.components;
}
if (vertex_format_flags & vertex_attribute_bone)
{
attribute.type = gl::vertex_attribute_type::uint_16;
attribute.components = bones_per_vertex;
vao.bind(render::vertex_attribute::bone_index, attribute);
attribute.offset += sizeof(std::uint32_t) * attribute.components;
attribute.type = gl::vertex_attribute_type::float_32;
attribute.components = bones_per_vertex;
vao.bind(render::vertex_attribute::bone_weight, attribute);
attribute.offset += sizeof(float) * attribute.components;
}
if (vertex_format_flags & vertex_attribute_barycentric)
{
attribute.type = gl::vertex_attribute_type::float_32;
attribute.components = 3;
vao.bind(render::vertex_attribute::barycentric, attribute);
attribute.offset += sizeof(float) * attribute.components;
}
if (vertex_format_flags & vertex_attribute_morph_target)
{
attribute.type = gl::vertex_attribute_type::float_32;
attribute.components = 3;
vao.bind(render::vertex_attribute::target, attribute);
attribute.offset += sizeof(float) * attribute.components;
}
// Read model bounds
ctx.read32<std::endian::little>(reinterpret_cast<std::byte*>(model->get_bounds().min_point.data()), 3);
ctx.read32<std::endian::little>(reinterpret_cast<std::byte*>(model->get_bounds().max_point.data()), 3);
// Read material count
std::uint16_t material_count = 0;
ctx.read16<std::endian::little>(reinterpret_cast<std::byte*>(&material_count), 1);
// Allocate material groups
model->get_groups().resize(material_count);
// Read materials
for (auto& group: model->get_groups())
{
// Read material name length
std::uint8_t material_name_length = 0;
ctx.read8(reinterpret_cast<std::byte*>(&material_name_length), 1);
// Read material name
std::string material_name(static_cast<std::size_t>(material_name_length), '\0');
ctx.read8(reinterpret_cast<std::byte*>(material_name.data()), material_name_length);
// Generate group ID by hashing material name
group.id = hash::fnv1a32<char>(material_name);
// Set group drawing mode
group.drawing_mode = gl::drawing_mode::triangles;
// Read offset to index of first vertex
ctx.read32<std::endian::little>(reinterpret_cast<std::byte*>(&group.start_index), 1);
// Read vertex count
ctx.read32<std::endian::little>(reinterpret_cast<std::byte*>(&group.index_count), 1);
// Slugify material filename
std::string material_filename = material_name + ".mtl";
std::replace(material_filename.begin(), material_filename.end(), '_', '-');
// Load group material
group.material = resource_manager.load<render::material>(material_filename);
}
// Read skeleton
if (vertex_format_flags & vertex_attribute_bone)
{
::skeleton& skeleton = model->get_skeleton();
pose& bind_pose = skeleton.bind_pose;
// Read bone count
std::uint16_t bone_count = 0;
ctx.read16<std::endian::little>(reinterpret_cast<std::byte*>(&bone_count), 1);
// Read bones
for (std::uint16_t i = 0; i < bone_count; ++i)
{
// Read bone key
hash::fnv1a32_t bone_key = {};
ctx.read32<std::endian::little>(reinterpret_cast<std::byte*>(&bone_key), 1);
// Read parent bone index
std::uint16_t parent_bone_index = i;
ctx.read16<std::endian::little>(reinterpret_cast<std::byte*>(&parent_bone_index), 1);
// Construct bone identifier
::bone bone = make_bone(i, parent_bone_index);
// Add bone to bone map
skeleton.bone_map[bone_key] = bone;
// Get reference to the bone's bind pose transform
auto& bone_transform = bind_pose[bone];
// Read bone translation
ctx.read32<std::endian::little>(reinterpret_cast<std::byte*>(bone_transform.translation.data()), 3);
// Read bone rotation
ctx.read32<std::endian::little>(reinterpret_cast<std::byte*>(&bone_transform.rotation.r), 1);
ctx.read32<std::endian::little>(reinterpret_cast<std::byte*>(bone_transform.rotation.i.data()), 3);
// Set bone scale
bone_transform.scale = {1, 1, 1};
// Read bone length
float bone_length = 0.0f;
ctx.read32<std::endian::little>(reinterpret_cast<std::byte*>(&bone_length), 1);
}
// Calculate inverse skeleton-space bind pose
::concatenate(skeleton.bind_pose, skeleton.inverse_bind_pose);
::inverse(skeleton.inverse_bind_pose, skeleton.inverse_bind_pose);
}
return model;
}