BackendRenderTargetGLES2.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_GLES2_HPP
#define TGUI_BACKEND_RENDER_TARGET_GLES2_HPP
 
#include <TGUI/Backend/Renderer/GLES2/BackendTextureGLES2.hpp>
 
#if !TGUI_BUILD_AS_CXX_MODULE
    #include <TGUI/Backend/Renderer/BackendRenderTarget.hpp>
#endif

 
TGUI_MODULE_EXPORT namespace tgui
{
    class TGUI_API BackendRenderTargetGLES2 : public BackendRenderTarget
    {
    public:

        BackendRenderTargetGLES2();

        ~BackendRenderTargetGLES2() override;

        void setClearColor(const Color& color) override;

        void clearScreen() override;

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

        void drawGui(const std::shared_ptr<RootContainer>& root) override;

        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) override;

    protected:

        void updateClipping(FloatRect clipRect, FloatRect clipViewport) override;

        // Calls glEnableVertexAttribArray and glVertexAttribPointer.
        // Called only once when using a VAO (GLES 3.x), but on every draw when using GLES 2.0
        void setVertexAttribs();

        // Creates the vertex and index buffers
        void createBuffers();

    protected:
 
        unsigned int m_shaderProgram = 0;
        unsigned int m_vertexArray = 0;
        unsigned int m_vertexBuffer = 0;
        unsigned int m_indexBuffer = 0;
        std::size_t m_vertexBufferSize = 0;
        std::size_t m_indexBufferSize = 0;
 
        std::unique_ptr<BackendTextureGLES2> m_emptyTexture;
        std::shared_ptr<BackendTextureGLES2> m_currentTexture;
 
        Transform m_projectionTransform;
        int m_projectionMatrixShaderUniformLocation = 0;
        unsigned int m_positionShaderLocation = 0;
        unsigned int m_colorShaderLocation = 1;
        unsigned int m_texCoordShaderLocation = 2;
    };

}

 
#endif // TGUI_BACKEND_RENDER_TARGET_GLES2_HPP