////  Created by Bradley Austin Davis on 2016/05/15//  Copyright 2013-2016 High Fidelity, Inc.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html//#include "GL45Backend.h"#include <gpu/gl/GLBuffer.h> namespace gpu { namespace gl45 {    using namespace gpu::gl;     class GL45Buffer : public GLBuffer {        using Parent = GLBuffer;        static GLuint allocate() {            GLuint result;            glCreateBuffers(1, &result);            return result;        }     public:        GL45Buffer(const std::weak_ptr<GLBackend>& backend, const Buffer& buffer, GLBuffer* original) : Parent(backend, buffer, allocate()) {            glNamedBufferStorage(_buffer, _size == 0 ? 256 : _size, nullptr, GL_DYNAMIC_STORAGE_BIT);            if (original && original->_size) {                glCopyNamedBufferSubData(original->_buffer, _buffer, 0, 0, std::min(original->_size, _size));            }            Backend::setGPUObject(buffer, this);        }         void transfer() override {            Size offset;            Size size;            Size currentPage { 0 };            auto data = _gpuObject._renderSysmem.readData();            while (_gpuObject._renderPages.getNextTransferBlock(offset, size, currentPage)) {                glNamedBufferSubData(_buffer, (GLintptr)offset, (GLsizeiptr)size, data + offset);            }            (void)CHECK_GL_ERROR();            _gpuObject._renderPages._flags &= ~PageManager::DIRTY;        }    };} } using namespace gpu;using namespace gpu::gl;using namespace gpu::gl45;  GLuint GL45Backend::getBufferID(const Buffer& buffer) {    return GL45Buffer::getId<GL45Buffer>(*this, buffer);} GLuint GL45Backend::getBufferIDUnsynced(const Buffer& buffer) {    return GL45Buffer::getIdUnsynced<GL45Buffer>(*this, buffer);} GLBuffer* GL45Backend::syncGPUObject(const Buffer& buffer) {    return GL45Buffer::sync<GL45Buffer>(*this, buffer);}  bool GL45Backend::bindResourceBuffer(uint32_t slot, const BufferPointer& buffer) {    auto bo = getBufferIDUnsynced((*buffer));    if (bo) {        glBindBufferBase(GL_SHADER_STORAGE_BUFFER, slot, bo);         (void)CHECK_GL_ERROR();         assign(_resource._buffers[slot], buffer);         return true;    }     return false;} void GL45Backend::releaseResourceBuffer(uint32_t slot) {    auto& bufferReference = _resource._buffers[slot];    auto buffer = acquire(bufferReference);    if (buffer) {        glBindBufferBase(GL_SHADER_STORAGE_BUFFER, slot, 0);        reset(bufferReference);    }}