src/dawn/native/opengl/BackendGL.cpp

// Copyright 2019 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "dawn/native/opengl/BackendGL.h"

#include <utility>

#include "dawn/native/OpenGLBackend.h"
#include "dawn/native/opengl/AdapterGL.h"

namespace dawn::native::opengl {

// Implementation of the OpenGL backend's BackendConnection

Backend::Backend(InstanceBase* instance, wgpu::BackendType backendType)
    : BackendConnection(instance, backendType) {}

std::vector<Ref<AdapterBase>> Backend::DiscoverDefaultAdapters() {
    // The OpenGL backend needs at least "getProcAddress" to discover an adapter.
    return {};
}

ResultOrError<std::vector<Ref<AdapterBase>>> Backend::DiscoverAdapters(
    const AdapterDiscoveryOptionsBase* optionsBase) {
    // TODO(cwallez@chromium.org): For now only create a single OpenGL adapter because don't
    // know how to handle MakeCurrent.
    DAWN_INVALID_IF(mCreatedAdapter, "The OpenGL backend can only create a single adapter.");

    ASSERT(static_cast<wgpu::BackendType>(optionsBase->backendType) == GetType());
    const AdapterDiscoveryOptions* options =
        static_cast<const AdapterDiscoveryOptions*>(optionsBase);

    DAWN_INVALID_IF(options->getProc == nullptr, "AdapterDiscoveryOptions::getProc must be set");

    Ref<Adapter> adapter = AcquireRef(
        new Adapter(GetInstance(), static_cast<wgpu::BackendType>(optionsBase->backendType)));
    DAWN_TRY(adapter->InitializeGLFunctions(options->getProc));
    DAWN_TRY(adapter->Initialize());

    mCreatedAdapter = true;
    std::vector<Ref<AdapterBase>> adapters{std::move(adapter)};
    return std::move(adapters);
}

BackendConnection* Connect(InstanceBase* instance, wgpu::BackendType backendType) {
    return new Backend(instance, backendType);
}

}  // namespace dawn::native::opengl