// Copyright 2021 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <array>
#include <memory>
#include <span>
#include <glad/glad.h>
#include "common/alignment.h"
#include "common/assert.h"
#include "video_core/renderer_opengl/gl_stream_buffer.h"
namespace OpenGL {
StreamBuffer::StreamBuffer() {
static constexpr GLenum flags = GL_MAP_WRITE_BIT | GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT;
buffer.Create();
glObjectLabel(GL_BUFFER, buffer.handle, -1, "Stream Buffer");
glNamedBufferStorage(buffer.handle, STREAM_BUFFER_SIZE, nullptr, flags);
mapped_pointer =
static_cast<u8*>(glMapNamedBufferRange(buffer.handle, 0, STREAM_BUFFER_SIZE, flags));
for (OGLSync& sync : fences) {
sync.Create();
}
}
std::pair<std::span<u8>, size_t> StreamBuffer::Request(size_t size) noexcept {
ASSERT(size < REGION_SIZE);
for (size_t region = Region(used_iterator), region_end = Region(iterator); region < region_end;
++region) {
fences[region].Create();
}
used_iterator = iterator;
for (size_t region = Region(free_iterator) + 1,
region_end = std::min(Region(iterator + size) + 1, NUM_SYNCS);
region < region_end; ++region) {
glClientWaitSync(fences[region].handle, 0, GL_TIMEOUT_IGNORED);
fences[region].Release();
}
if (iterator + size >= free_iterator) {
free_iterator = iterator + size;
}
if (iterator + size > STREAM_BUFFER_SIZE) {
for (size_t region = Region(used_iterator); region < NUM_SYNCS; ++region) {
fences[region].Create();
}
used_iterator = 0;
iterator = 0;
free_iterator = size;
for (size_t region = 0, region_end = Region(size); region <= region_end; ++region) {
glClientWaitSync(fences[region].handle, 0, GL_TIMEOUT_IGNORED);
fences[region].Release();
}
}
const size_t offset = iterator;
iterator = Common::AlignUp(iterator + size, MAX_ALIGNMENT);
return {std::span(mapped_pointer + offset, size), offset};
}
} // namespace OpenGL
