/* Copyright (C) 2006 The cairomm Development Team
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
#ifndef __CAIROMM_SCALEDFONT_H
#define __CAIROMM_SCALEDFONT_H
#include <cairomm/refptr.h>
#include <cairomm/fontoptions.h>
#include <cairomm/fontface.h>
#include <cairomm/matrix.h>
#include <cairomm/types.h>
#include <vector>
#ifdef CAIRO_HAS_FT_FONT
#include <cairo-ft.h>
#endif // CAIRO_HAS_FT_FONT
namespace Cairo
{
/** A ScaledFont is a font scaled to a particular size and device resolution. It
* is most useful for low-level font usage where a library or application wants
* to cache a reference to a scaled font to speed up the computation of metrics.
*/
class ScaledFont
{
public:
/** The underlying C cairo object type */
typedef cairo_scaled_font_t cobject;
/** Provides acces to the underlying C cairo object */
inline cobject* cobj() { return m_cobject; }
/** Provides acces to the underlying C cairo object */
inline const cobject* cobj() const { return m_cobject; }
#ifndef DOXYGEN_IGNORE_THIS
// For use only by the cairomm implementation.
inline ErrorStatus get_status() const
{ return cairo_scaled_font_status(const_cast<cairo_scaled_font_t*>(cobj())); }
// for RefPtr
void reference() const { cairo_scaled_font_reference(m_cobject); }
void unreference() const { cairo_scaled_font_destroy(m_cobject); }
#endif //DOXYGEN_IGNORE_THIS
/** Create a C++ wrapper object from the C instance. This C++ object should
* then be given to a RefPtr.
*/
explicit ScaledFont(cobject* cobj, bool has_reference = false);
ScaledFont(const ScaledFont&) = delete;
ScaledFont& operator=(const ScaledFont&) = delete;
virtual ~ScaledFont();
/** Creates a ScaledFont object from a font face and matrices that describe
* the size of the font and the environment in which it will be used.
*
* @param font_face A font face.
* @param font_matrix font space to user space transformation matrix for the
* font. In the simplest case of a N point font, this matrix is just a scale
* by N, but it can also be used to shear the font or stretch it unequally
* along the two axes. See Context::set_font_matrix().
* @param ctm user to device transformation matrix with which the font will be
* used.
* @param options options to use when getting metrics for the font and
* rendering with it.
*/
static RefPtr<ScaledFont> create(const RefPtr<FontFace>& font_face, const Matrix& font_matrix,
const Matrix& ctm, const FontOptions& options = FontOptions());
/* To keep 1.6.x ABI */
static RefPtr<ScaledFont> create(const RefPtr<FontFace>& font_face, const cairo_matrix_t& font_matrix,
const cairo_matrix_t& ctm, const FontOptions& options = FontOptions());
// NOTE: the constructor doesn't take a RefPtr<const FontFace> because the
// FontFace object can be changed in this constructor (in the case of user
// fonts, the FontFace becomes immutable, i.e. you can't call any set_*_func()
// functions any longer)
//We use an output paramter instead of the return value,
//for consistency with other get_*extents() methods in other classes,
//though they should probably all use the return value instead.
//but it is too late to change that now. murrayc:
/** Gets the metrics for a ScaledFont
* @since 1.8
* */
void get_extents(FontExtents& extents) const;
/** @deprecated Use get_extents() instead
* @since 1.2
* */
void extents(FontExtents& extents) const;
/** Gets the extents for a string of text. The extents describe a user-space
* rectangle that encloses the "inked" portion of the text drawn at the origin
* (0,0) (as it would be drawn by Context::show_text() if the cairo graphics
* state were set to the same font_face, font_matrix, ctm, and font_options as
* the ScaledFont object). Additionally, the x_advance and y_advance values
* indicate the amount by which the current point would be advanced by
* Context::show_text().
*
* Note that whitespace characters do not directly contribute to the size of
* the rectangle (extents.width and extents.height). They do contribute
* indirectly by changing the position of non-whitespace characters. In
* particular, trailing whitespace characters are likely to not affect the
* size of the rectangle, though they will affect the x_advance and y_advance
* values.
*
* @param utf8 a string of text, encoded in UTF-8.
* @param extents Returns the extents of the given string.
*
* @since 1.8
*/
void get_text_extents(const std::string& utf8, TextExtents& extents) const;
/** @deprecated Use get_text_extents() instead
* @since 1.2
* */
void text_extents(const std::string& utf8, TextExtents& extents) const;
/** Gets the extents for an array of glyphs. The extents describe a user-space
* rectangle that encloses the "inked" portion of the glyphs, (as they would
* be drawn by Context::show_glyphs() if the cairo graphics state were set to the
* same font_face, font_matrix, ctm, and font_options as the ScaledFont
* object). Additionally, the x_advance and y_advance values indicate the
* amount by which the current point would be advanced by Context::show_glyphs().
*
* Note that whitespace glyphs do not contribute to the size of the rectangle
* (extents.width and extents.height).
*
* @param glyphs A vector of glyphs to calculate the extents of.
* @param extents Returns the extents for the array of glyphs.
*
* @since 1.8
**/
void get_glyph_extents(const std::vector<Glyph>& glyphs, TextExtents& extents);
/** @deprecated Use get_glyph_extents() instead
* @since 1.2
* */
void glyph_extents(const std::vector<Glyph>& glyphs, TextExtents& extents);
/** The FontFace with which this ScaledFont was created.
* @since 1.2
*/
RefPtr<FontFace> get_font_face() const;
/** Gets the FontOptions with which the ScaledFont was created.
* @since 1.2
*/
void get_font_options(FontOptions& options) const;
/** Gets the font matrix with which the ScaledFont was created.
* @since 1.2
*/
void get_font_matrix(Matrix& font_matrix) const;
/* To keep 1.6.x ABI */
void get_font_matrix(cairo_matrix_t& font_matrix) const;
/** Gets the CTM with which the ScaledFont was created.
* @since 1.2
*/
void get_ctm(Matrix& ctm) const;
/* To keep 1.6.x ABI */
void get_ctm(cairo_matrix_t& ctm) const;
/** Gets the type of scaled Font
* @since 1.2
*/
FontType get_type() const;
// FIXME: it'd be really nice not to assume a specific container (e.g.
// std::vector) here
/**
* @param x X position to place first glyph.
* @param y Y position to place first glyph.
* @param utf8 a string of text encoded in UTF-8.
* @param glyphs pointer to array of glyphs to fill.
* @param clusters pointer to array of cluster mapping information to fill.
* @cluster_flags cluster mapping flags
*
* Converts UTF-8 text to an array of glyphs, with cluster mapping, that can be
* used to render later.
*
* For details of how (@a clusters and @a cluster_flags map input
* UTF-8 text to the output glyphs see Context::show_text_glyphs().
*
* The output values can be readily passed to Context::show_text_glyphs()
* Context::show_glyphs(), or related functions, assuming that the exact
* same scaled font is used for the operation.
*
* @since 1.8
**/
void text_to_glyphs(double x,
double y,
const std::string& utf8,
std::vector<Glyph>& glyphs,
std::vector<TextCluster>& clusters,
TextClusterFlags& cluster_flags);
/** Stores the scale matrix of this scaled font into matrix. The scale matrix
* is product of the font matrix and the ctm associated with the scaled font,
* and hence is the matrix mapping from font space to device space.
*
* @param scale_matrix return value for the matrix.
*
* @since 1.8
*/
void get_scale_matrix(Matrix& scale_matrix) const;
protected:
/* Cairo::Matrix parameters changed to cairo_matrix_t */
ScaledFont(const RefPtr<FontFace>& font_face, const cairo_matrix_t& font_matrix,
const cairo_matrix_t& ctm, const FontOptions& options = FontOptions());
/** The underlying C cairo object that is wrapped by this ScaledFont */
cobject* m_cobject;
};
#ifdef CAIRO_HAS_FT_FONT
//TODO: Documentation.
/**
* @since 1.8
*/
class FtScaledFont : public ScaledFont
{
public:
/** Creates a ScaledFont From a FtFontFace.
*
* @since 1.8
*/
static RefPtr<FtScaledFont> create(const RefPtr<FtFontFace>& font_face, const Matrix& font_matrix,
const Matrix& ctm, const FontOptions& options = FontOptions());
/** Gets the FT_Face object from a FreeType backend font and scales it
* appropriately for the font. You must release the face with
* unlock_face() when you are done using it. Since the FT_Face object can be
* shared between multiple ScaledFont objects, you must not lock any other
* font objects until you unlock this one. A count is kept of the number of
* times lock_face() is called. unlock_face() must be called the same number
* of times.
*
* You must be careful when using this function in a library or in a threaded
* application, because freetype's design makes it unsafe to call freetype
* functions simultaneously from multiple threads, (even if using distinct
* FT_Face objects). Because of this, application code that acquires an
* FT_Face object with this call must add it's own locking to protect any use
* of that object, (and which also must protect any other calls into cairo as
* almost any cairo function might result in a call into the freetype
* library).
*
* @return The FT_Face object for font, scaled appropriately, or NULL if
* scaled_font is in an error state or there is insufficient memory.
*
* @since 1.8
*/
FT_Face lock_face();
/** Releases a face obtained with lock_face().
*
* @since 1.8
*/
void unlock_face();
protected:
FtScaledFont(const RefPtr<FtFontFace>& font_face, const Matrix& font_matrix,
const Matrix& ctm, const FontOptions& options = FontOptions());
};
#endif // CAIRO_HAS_FT_FONT
}
#endif // __CAIROMM_SCALEDFONT_H
// vim: ts=2 sw=2 et