OpenGLRenderingContext.h

/*
 * AUI Framework - Declarative UI toolkit for modern C++20
 * Copyright (C) 2020-2024 Alex2772 and Contributors
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
 
//
// Created by Alex2772 on 12/7/2021.
//
 
#pragma once
 
 
#include <AUI/Platform/CommonRenderingContext.h>
#include "ARenderingContextOptions.h"
#include "AUI/GL/OpenGLRenderer.h"
 
class OpenGLRenderingContext: public CommonRenderingContext {
public:
    OpenGLRenderingContext(const ARenderingContextOptions::OpenGL& config) : mConfig(config) {}
 
    void init(const Init& init) override;
    ~OpenGLRenderingContext() override;
 
    AImage makeScreenshot() override;
 
    void destroyNativeWindow(AWindowBase& window) override;
    void beginPaint(AWindowBase& window) override;
    void endPaint(AWindowBase& window) override;
    void beginResize(AWindowBase& window) override;
    void endResize(AWindowBase& window) override;
 
    [[nodiscard]]
    uint32_t getDefaultFb() const noexcept;
 
    void bindViewport();
 
    [[nodiscard]]
    glm::uvec2 viewportSize() const noexcept {
        return mViewportSize;
    }
 
    [[nodiscard]]
    uint32_t getSupersamplingRatio() const noexcept;
 
    [[nodiscard]]
    AOptional<gl::Framebuffer*> framebuffer() noexcept {
        if (auto fb = std::get_if<gl::Framebuffer>(&mFramebuffer)) {
            return fb;
        }
        return std::nullopt;
    }
 
    IRenderer& renderer() override {
        return *mRenderer;
    }
 
    static gl::Framebuffer newOffscreenRenderingFramebuffer(glm::uvec2 initialSize);
 
private:
    ARenderingContextOptions::OpenGL mConfig;
    struct NotTried{}; struct Failed{}; std::variant<NotTried, Failed, gl::Framebuffer> mFramebuffer;
    _<OpenGLRenderer> mRenderer;
    glm::uvec2 mViewportSize;
 
    static _<OpenGLRenderer> ourRenderer() {
        static _weak<OpenGLRenderer> g;
        if (auto v = g.lock()) {
            return v;
        }
        auto temp = _new<OpenGLRenderer>();
        g = temp;
        return temp;
    }
 
    void tryEnableFramebuffer(glm::uvec2 windowSize);
    void beginFramebuffer(glm::uvec2 windowSize);
    void endFramebuffer();
 
#if AUI_PLATFORM_WIN
    static HGLRC ourHrc;
    static void makeCurrent(HDC hdc) noexcept;
#elif AUI_PLATFORM_LINUX
    static GLXContext ourContext;
#elif AUI_PLATFORM_MACOS
    static void* ourContext;
#endif
 
};