RmlUi_Renderer_GL2.h

/*
 * This source file is part of RmlUi, the HTML/CSS Interface Middleware
 *
 * For the latest information, see http://github.com/mikke89/RmlUi
 *
 * Copyright (c) 2008-2010 CodePoint Ltd, Shift Technology Ltd
 * Copyright (c) 2019-2023 The RmlUi Team, and contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */

#ifndef RMLUI_BACKENDS_RENDERER_GL2_H
#define RMLUI_BACKENDS_RENDERER_GL2_H

#include <RmlUi/Core/RenderInterface.h>

class RenderInterface_GL2 : public Rml::RenderInterface {
public:
	RenderInterface_GL2();

	// The viewport should be updated whenever the window size changes.
	void SetViewport(int viewport_width, int viewport_height);

	// Sets up OpenGL states for taking rendering commands from RmlUi.
	void BeginFrame();
	void EndFrame();

	// Optional, can be used to clear the framebuffer.
	void Clear();

	// -- Inherited from Rml::RenderInterface --

	Rml::CompiledGeometryHandle CompileGeometry(Rml::Span<const Rml::Vertex> vertices, Rml::Span<const int> indices) override;
	void ReleaseGeometry(Rml::CompiledGeometryHandle geometry) override;
	void RenderGeometry(Rml::CompiledGeometryHandle handle, Rml::Vector2f translation, Rml::TextureHandle texture) override;

	Rml::TextureHandle LoadTexture(Rml::Vector2i& texture_dimensions, const Rml::String& source) override;
	Rml::TextureHandle GenerateTexture(Rml::Span<const Rml::byte> source, Rml::Vector2i source_dimensions) override;
	void ReleaseTexture(Rml::TextureHandle texture_handle) override;

	void EnableScissorRegion(bool enable) override;
	void SetScissorRegion(Rml::Rectanglei region) override;

	void EnableClipMask(bool enable) override;
	void RenderToClipMask(Rml::ClipMaskOperation operation, Rml::CompiledGeometryHandle geometry, Rml::Vector2f translation) override;

	void SetTransform(const Rml::Matrix4f* transform) override;

	// Can be passed to RenderGeometry() to enable texture rendering without changing the bound texture.
	static const Rml::TextureHandle TextureEnableWithoutBinding = Rml::TextureHandle(-1);

private:
	struct GeometryView {
		Rml::Span<const Rml::Vertex> vertices;
		Rml::Span<const int> indices;
	};

	int viewport_width = 0;
	int viewport_height = 0;
	bool transform_enabled = false;
};

#endif