BackendRenderTarget.hpp

//
// TGUI - Texus' Graphical User Interface
// Copyright (C) 2012-2025 Bruno Van de Velde (vdv_b@tgui.eu)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
//    you must not claim that you wrote the original software.
//    If you use this software in a product, an acknowledgment
//    in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
//    and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
 
#ifndef TGUI_BACKEND_RENDER_TARGET_HPP
#define TGUI_BACKEND_RENDER_TARGET_HPP
 
#include <TGUI/Rect.hpp>
#include <TGUI/Color.hpp>
#include <TGUI/Sprite.hpp>
#include <TGUI/Text.hpp>
#include <TGUI/Outline.hpp>
#include <TGUI/RenderStates.hpp>

 
TGUI_MODULE_EXPORT namespace tgui
{
    class Widget;
    class RootContainer;

    class TGUI_API BackendRenderTarget
    {
    public:
 
        // Don't allow copying or moving, because we don't expect derived classes to handle it correctly
        BackendRenderTarget(const BackendRenderTarget&) = delete;
        BackendRenderTarget(BackendRenderTarget&&) = delete;
        BackendRenderTarget& operator=(const BackendRenderTarget&) = delete;
        BackendRenderTarget& operator=(BackendRenderTarget&&) = delete;

        BackendRenderTarget() = default;

        virtual ~BackendRenderTarget() = default;

        virtual void setClearColor(const Color& color) = 0;

        virtual void clearScreen() = 0;

        virtual void setView(FloatRect view, FloatRect viewport, Vector2f targetSize);

        virtual void drawGui(const std::shared_ptr<RootContainer>& root) = 0;

        virtual void drawWidget(const RenderStates& states, const std::shared_ptr<Widget>& widget);

        virtual void addClippingLayer(const RenderStates& states, FloatRect rect);

        virtual void removeClippingLayer();

        virtual void drawBorders(const RenderStates& states, const Borders& borders, Vector2f size, Color color);

        virtual void drawFilledRect(const RenderStates& states, Vector2f size, Color color);

        virtual void drawSprite(const RenderStates& states, const Sprite& sprite);

        virtual void drawText(const RenderStates& states, const Text& text);

        virtual void drawTextOutline(const RenderStates& states, const Text& text);

        virtual void drawTextWithoutOutline(const RenderStates& states, const Text& text);

        virtual void drawTriangle(const RenderStates& states, const Vertex& point1, const Vertex& point2, const Vertex& point3);

        virtual void drawCircle(const RenderStates& states, float size, const Color& backgroundColor, float borderThickness = 0, const Color& borderColor = {});

        virtual void drawRoundedRectangle(const RenderStates& states, const Vector2f& size, const Color& backgroundColor, float radius,
                                          const Borders& borders = {0}, const Color& borderColor = Color::Black);

        virtual void drawVertexArray(const RenderStates& states, const Vertex* vertices, std::size_t vertexCount,
                                     const unsigned int* indices, std::size_t indexCount, const std::shared_ptr<BackendTexture>& texture) = 0;

        TGUI_NODISCARD Vector2f getPixelsPerPoint() const;

    protected:

        virtual void updateClipping(FloatRect clipRect, FloatRect clipViewport) = 0;

    protected:
 
        FloatRect m_viewRect;
        FloatRect m_viewport;
        Vector2f  m_targetSize;
 
        std::vector<std::pair<FloatRect, FloatRect>> m_clipLayers;
        Vector2f m_pixelsPerPoint = {1, 1};
    };

}

 
#endif // TGUI_BACKEND_RENDER_TARGET_HPP