RmlUi/Source/Core/FontEffectGlow.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_CORE_FONTEFFECTGLOW_H
#define RMLUI_CORE_FONTEFFECTGLOW_H

#include "../../Include/RmlUi/Core/ConvolutionFilter.h"
#include "../../Include/RmlUi/Core/FontEffect.h"
#include "../../Include/RmlUi/Core/FontEffectInstancer.h"

namespace Rml {

/**
    A font effect for rendering glow around text.

    Glow consists of an outline pass followed by a Gaussian blur pass.

 */

class FontEffectGlow : public FontEffect {
public:
	FontEffectGlow();
	virtual ~FontEffectGlow();

	bool Initialise(int width_outline, int width_blur, Vector2i offset);

	bool HasUniqueTexture() const override;

	bool GetGlyphMetrics(Vector2i& origin, Vector2i& dimensions, const FontGlyph& glyph) const override;

	void GenerateGlyphTexture(byte* destination_data, Vector2i destination_dimensions, int destination_stride, const FontGlyph& glyph) const override;

private:
	int width_outline, width_blur, combined_width;
	Vector2i offset;
	ConvolutionFilter filter_outline, filter_blur_x, filter_blur_y;
};

/**
    A concrete font effect instancer for the glow effect.
 */

class FontEffectGlowInstancer : public FontEffectInstancer {
public:
	FontEffectGlowInstancer();
	virtual ~FontEffectGlowInstancer();

	SharedPtr<FontEffect> InstanceFontEffect(const String& name, const PropertyDictionary& properties) override;

private:
	PropertyId id_width_outline, id_width_blur, id_offset_x, id_offset_y, id_color;
};

} // namespace Rml
#endif