- /*
- * 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/gl/vertex-buffer.hpp>
- #include <stdexcept>
- #include <glad/gl.h>
- #include <utility>
-
- namespace gl {
-
- namespace
- {
- static constexpr GLenum buffer_usage_lut[] =
- {
- GL_STREAM_DRAW,
- GL_STREAM_READ,
- GL_STREAM_COPY,
- GL_STATIC_DRAW,
- GL_STATIC_READ,
- GL_STATIC_COPY,
- GL_DYNAMIC_DRAW,
- GL_DYNAMIC_READ,
- GL_DYNAMIC_COPY
- };
- }
-
- vertex_buffer::vertex_buffer(buffer_usage usage, std::size_t size, std::span<const std::byte> data):
- m_usage{usage},
- m_size{size}
- {
- if (!data.empty())
- {
- // Bounds check
- if (data.size() < size)
- {
- throw std::out_of_range("Vertex buffer construct operation exceeded data bounds.");
- }
- }
-
- const GLenum gl_usage = buffer_usage_lut[std::to_underlying(m_usage)];
- glCreateBuffers(1, &m_gl_named_buffer);
- glNamedBufferData(m_gl_named_buffer, static_cast<GLsizeiptr>(m_size), data.empty() ? nullptr : data.data(), gl_usage);
- }
-
- vertex_buffer::vertex_buffer(const vertex_buffer& buffer):
- vertex_buffer(buffer.m_usage, buffer.m_size)
- {
- copy(buffer, m_size);
- }
-
- vertex_buffer::vertex_buffer(vertex_buffer&& buffer):
- m_gl_named_buffer{std::exchange(buffer.m_gl_named_buffer, 0)},
- m_usage{std::move(buffer.m_usage)},
- m_size{std::exchange(buffer.m_size, 0)}
- {}
-
- vertex_buffer::~vertex_buffer()
- {
- if (m_gl_named_buffer)
- {
- glDeleteBuffers(1, &m_gl_named_buffer);
- }
- }
-
- vertex_buffer& vertex_buffer::operator=(const vertex_buffer& buffer)
- {
- repurpose(buffer.m_usage, buffer.m_size);
- copy(buffer, m_size);
-
- return *this;
- }
-
- vertex_buffer& vertex_buffer::operator=(vertex_buffer&& buffer)
- {
- if (m_gl_named_buffer)
- {
- glDeleteBuffers(1, &m_gl_named_buffer);
- }
-
- m_gl_named_buffer = std::exchange(buffer.m_gl_named_buffer, 0);
- m_usage = std::move(buffer.m_usage);
- m_size = std::exchange(buffer.m_size, 0);
-
- return *this;
- }
-
- void vertex_buffer::repurpose(buffer_usage usage, std::size_t size, std::span<const std::byte> data)
- {
- if (!data.empty())
- {
- // Bounds check
- if (data.size() < size)
- {
- throw std::out_of_range("Vertex buffer resize operation exceeded data bounds.");
- }
- }
-
- m_usage = usage;
- m_size = size;
-
- const auto gl_usage = buffer_usage_lut[std::to_underlying(m_usage)];
- glNamedBufferData(m_gl_named_buffer, static_cast<GLsizeiptr>(m_size), data.empty() ? nullptr : data.data(), gl_usage);
- }
-
- void vertex_buffer::write(std::size_t offset, std::span<const std::byte> data)
- {
- // Ignore empty write operations
- if (data.empty())
- {
- return;
- }
-
- // Bounds check
- if (offset + data.size() > m_size)
- {
- throw std::out_of_range("Vertex buffer write operation exceeded buffer bounds.");
- }
-
- glNamedBufferSubData(m_gl_named_buffer, static_cast<GLintptr>(offset), static_cast<GLsizeiptr>(data.size()), data.data());
- }
-
- void vertex_buffer::read(std::size_t offset, std::span<std::byte> data) const
- {
- // Ignore empty read operations
- if (data.empty())
- {
- return;
- }
-
- // Bounds check
- if (offset + data.size() > m_size)
- {
- throw std::out_of_range("Vertex buffer read operation exceeded buffer bounds.");
- }
-
- glGetNamedBufferSubData(m_gl_named_buffer, static_cast<GLintptr>(offset), static_cast<GLsizeiptr>(data.size()), data.data());
- }
-
- void vertex_buffer::copy(const vertex_buffer& read_buffer, std::size_t copy_size, std::size_t read_offset, std::size_t write_offset)
- {
- // Bounds check
- if (read_offset + copy_size > read_buffer.m_size)
- {
- throw std::out_of_range("Vertex buffer copy operation exceeded read buffer bounds.");
- }
- if (write_offset + copy_size > m_size)
- {
- throw std::out_of_range("Vertex buffer copy operation exceeded write buffer bounds.");
- }
-
- glCopyNamedBufferSubData(read_buffer.m_gl_named_buffer, m_gl_named_buffer, static_cast<GLintptr>(read_offset), static_cast<GLintptr>(write_offset), static_cast<GLsizeiptr>(copy_size));
- }
-
- } // namespace gl
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