IRenderViewToTexture.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/.
 */
 
#pragma once
 
#include <glm/glm.hpp>
#include <AUI/Common/AStaticVector.h>
#include <AUI/Geometry2D/ARect.h>
#include <AUI/Render/ARenderContext.h>
 
class IRenderer;
class AView;
 
class IRenderViewToTexture {
public:
 
    struct InvalidArea {
        struct Empty {};
 
        struct Full {};
 
        using Rectangles = AStaticVector<ARect<int>, ARenderContext::Rectangles::capacity() - 1>;
 
        using Underlying = std::variant<Empty, Rectangles, Full>;
 
        template<aui::convertible_to<Underlying> F>
        InvalidArea(F&& u) noexcept: mUnderlying(std::forward<F>(u)) {}
        InvalidArea() noexcept: mUnderlying(Empty{}) {}
 
 
        [[nodiscard]]
        bool empty() const noexcept {
            return std::holds_alternative<Empty>(mUnderlying);
        }
 
        [[nodiscard]]
        bool full() const noexcept {
            return std::holds_alternative<Full>(mUnderlying);
        }
 
        void addRectangle(ARect<int> rhs);
 
        Rectangles* rectangles() noexcept {
            return std::get_if<Rectangles>(&mUnderlying);
        }
 
        const Rectangles* rectangles() const noexcept {
            return std::get_if<Rectangles>(&mUnderlying);
        }
 
    private:
        Underlying mUnderlying;
    };
 
 
 
 
    virtual bool begin(IRenderer& renderer, glm::ivec2 surfaceSize, IRenderViewToTexture::InvalidArea& invalidArea) = 0;
 
    virtual void end(IRenderer& renderer) = 0;
 
    virtual void draw(IRenderer& renderer) = 0;
 
    virtual ~IRenderViewToTexture() = default;
 
    static void enableForView(IRenderer& renderer, AView& view);
    static void disableForView(AView& view);
 
    [[nodiscard]]
    static bool isEnabledForView(AView& view);
};