RmlUi/Source/Core/BitmapFont/FontFaceHandle.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 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
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 * THE SOFTWARE.
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 */

#ifndef RMLUICOREBITMAPFONTFONTFACEHANDLE_H
#define RMLUICOREBITMAPFONTFONTFACEHANDLE_H

#include "../UnicodeRange.h"
#include "../../../Include/RmlUi/Core/Font.h"
#include "../../../Include/RmlUi/Core/FontEffect.h"
#include "../../../Include/RmlUi/Core/FontGlyph.h"
#include "../../../Include/RmlUi/Core/Geometry.h"
#include "../../../Include/RmlUi/Core/String.h"
#include "../../../Include/RmlUi/Core/Texture.h"
#include "../FontFaceHandle.h"
#include "BitmapFontDefinitions.h"

namespace Rml {
namespace Core {
namespace BitmapFont {

/**
	@author Peter Curry
 */

class FontFaceHandle : public Rml::Core::FontFaceHandle
{
public:
	FontFaceHandle();
	virtual ~FontFaceHandle();

	/// Initialises the handle so it is able to render text.
	/// @param[in] ft_face The FreeType face that this handle is rendering.
	/// @param[in] charset The comma-separated list of unicode ranges this handle must support.
	/// @param[in] size The size, in points, of the face this handle should render at.
	/// @return True if the handle initialised successfully and is ready for rendering, false if an error occured.
	bool Initialise(BitmapFontDefinitions *bm_face, const String& charset, int size);

	/// Returns the width a string will take up if rendered with this handle.
	/// @param[in] string The string to measure.
	/// @param[in] prior_character The optionally-specified character that immediately precedes the string. This may have an impact on the string width due to kerning.
	/// @return The width, in pixels, this string will occupy if rendered with this handle.
	int GetStringWidth(const WString& string, word prior_character = 0) const;

	/// Generates, if required, the layer configuration for a given array of font effects.
	/// @param[in] font_effects The list of font effects to generate the configuration for.
	/// @return The index to use when generating geometry using this configuration.
	int GenerateLayerConfiguration(Rml::Core::FontEffectMap& font_effects);

	/// Generates the texture data for a layer (for the texture database).
	/// @param[out] texture_data The pointer to be set to the generated texture data.
	/// @param[out] texture_dimensions The dimensions of the texture.
	/// @param[in] layer_id The id of the layer to request the texture data from.
	/// @param[in] texture_id The index of the texture within the layer to generate.
	bool GenerateLayerTexture(const byte*& texture_data, Vector2i& texture_dimensions, FontEffect* layer_id, int texture_id);

	/// Generates the geometry required to render a single line of text.
	/// @param[out] geometry An array of geometries to generate the geometry into.
	/// @param[in] string The string to render.
	/// @param[in] position The position of the baseline of the first character to render.
	/// @param[in] colour The colour to render the text.
	/// @return The width, in pixels, of the string geometry.
	int GenerateString(GeometryList& geometry, const WString& string, const Vector2f& position, const Colourb& colour, int layer_configuration = 0) const;

	/// Generates the geometry required to render a line above, below or through a line of text.
	/// @param[out] geometry The geometry to append the newly created geometry into.
	/// @param[in] position The position of the baseline of the lined text.
	/// @param[in] width The width of the string to line.
	/// @param[in] height The height to render the line at.
	/// @param[in] colour The colour to draw the line in.
	void GenerateLine(Geometry* geometry, const Vector2f& position, int width, Font::Line height, const Colourb& colour) const;

	const String & GetTextureSource() const
	{
		return texture_source;
	}

	unsigned int GetTextureWidth() const
	{
		return texture_width;
	}

	unsigned int GetTextureHeight() const
	{
		return texture_height;
	}

protected:
	/// Destroys the handle.
	virtual void OnReferenceDeactivate();

private:
	void GenerateMetrics(BitmapFontDefinitions *bm_face);

	void BuildGlyphMap(BitmapFontDefinitions *bm_face, const UnicodeRange& unicode_range);
	void BuildGlyph(FontGlyph& glyph, CharacterInfo *ft_glyph);
	int GetKerning(word lhs, word rhs) const;

	// Generates (or shares) a layer derived from a font effect.
	virtual FontFaceLayer* GenerateLayer(FontEffect* font_effect);

	BitmapFontDefinitions * bm_face;
	String texture_source;
	String texture_directory;
	unsigned int texture_width;
	unsigned int texture_height;
};

}
}
}

#endif