// 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/OpenGLFunctions.h"

#include <cctype>

namespace dawn_native { namespace opengl {

    MaybeError OpenGLFunctions::Initialize(GetProcAddress getProc) {
        DAWN_TRY(mVersion.Initialize(getProc));
        if (mVersion.IsES()) {
            DAWN_TRY(LoadOpenGLESProcs(getProc, mVersion.GetMajor(), mVersion.GetMinor()));
        } else {
            DAWN_TRY(LoadDesktopGLProcs(getProc, mVersion.GetMajor(), mVersion.GetMinor()));
        }

        InitializeSupportedGLExtensions();

        return {};
    }

    void OpenGLFunctions::InitializeSupportedGLExtensions() {
        int32_t numExtensions;
        GetIntegerv(GL_NUM_EXTENSIONS, &numExtensions);

        for (int32_t i = 0; i < numExtensions; ++i) {
            const char* extensionName = reinterpret_cast<const char*>(GetStringi(GL_EXTENSIONS, i));
            mSupportedGLExtensionsSet.insert(extensionName);
        }
    }

    bool OpenGLFunctions::IsGLExtensionSupported(const char* extension) const {
        ASSERT(extension != nullptr);
        return mSupportedGLExtensionsSet.count(extension) != 0;
    }

    const OpenGLVersion& OpenGLFunctions::GetVersion() const {
        return mVersion;
    }

    bool OpenGLFunctions::IsAtLeastGL(uint32_t majorVersion, uint32_t minorVersion) const {
        return mVersion.IsDesktop() && mVersion.IsAtLeast(majorVersion, minorVersion);
    }

    bool OpenGLFunctions::IsAtLeastGLES(uint32_t majorVersion, uint32_t minorVersion) const {
        return mVersion.IsES() && mVersion.IsAtLeast(majorVersion, minorVersion);
    }

}}  // namespace dawn_native::opengl