canvas.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
 *                                                                           *
 * Copyright(C) 2021-2025                                                    *
 * Visual Computing Lab                                                      *
 * ISTI - Italian National Research Council                                  *
 *                                                                           *
 * All rights reserved.                                                      *
 *                                                                           *
 * This program is free software; you can redistribute it and/or modify      *
 * it under the terms of the Mozilla Public License Version 2.0 as published *
 * by the Mozilla Foundation; either version 2 of the License, or            *
 * (at your option) any later version.                                       *
 *                                                                           *
 * This program is distributed in the hope that it will be useful,           *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the              *
 * Mozilla Public License Version 2.0                                        *
 * (https://www.mozilla.org/en-US/MPL/2.0/) for more details.                *
 ****************************************************************************/
 
#ifndef VCL_RENDER_CONCEPTS_CANVAS_H
#define VCL_RENDER_CONCEPTS_CANVAS_H
 
#include <vclib/concepts.h>
#include <vclib/space/core/color.h>
#include <vclib/space/core/point.h>
 
namespace vcl {
 
template<typename T>
concept CanvasConcept = requires (
    T&&                                       obj,
    void*                                     vPtr,
    uint                                      u,
    vcl::Point2i                              p,
    vcl::Color                                c,
    typename RemoveRef<T>::CallbackReadBuffer cbrb,
    std::string                               str) {
    typename RemoveRef<T>::CallbackReadBuffer;
 
    RemoveRef<T>(vPtr, u, u);
    RemoveRef<T>(vPtr, u, u, vPtr);
 
    { obj.size() } -> Point2Concept;
    { obj.viewId() } -> std::convertible_to<uint>;
 
    // non const requirements
    requires IsConst<T> || requires {
        { obj.setDefaultClearColor(c) } -> std::same_as<void>;
 
        { obj.onInit() } -> std::same_as<void>; // qt+opengl requires init
        { obj.onResize(u, u) } -> std::same_as<void>;
        { obj.onPaint() } -> std::same_as<void>;
 
        { obj.onReadDepth(p, cbrb) } -> std::same_as<bool>;
        { obj.onScreenshot(str) } -> std::same_as<bool>;
        { obj.onScreenshot(str, u, u) } -> std::same_as<bool>;
    };
};
 
} // namespace vcl
 
#endif // VCL_RENDER_CONCEPTS_CANVAS_H