mutter/cogl/cogl-pango/cogl-pango.h

/*
 * Cogl
 *
 * A Low Level GPU Graphics and Utilities API
 *
 * Copyright (C) 2008 OpenedHand
 * Copyright (C) 2012 Intel Corporation.
 *
 * 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.
 *
 * Authors:
 *   Neil Roberts <neil@linux.intel.com>
 *   Robert Bragg <robert@linux.intel.com>
 *   Matthew Allum  <mallum@openedhand.com>
 */

#ifndef __COGL_PANGO_H__
#define __COGL_PANGO_H__

#include <glib-object.h>
#include <pango/pango.h>
#include <pango/pangocairo.h>

/* XXX: Currently this header may be included both as an internal
 * header (within the cogl-pango implementation) and as a public
 * header.
 *
 * Since <cogl/cogl.h> should not be included for internal use we
 * determine the current context and switch between including cogl.h
 * or specific internal cogl headers here...
 */
#ifndef COGL_COMPILATION
#include <cogl/cogl.h>
#else
#include "cogl/cogl-context.h"
#include "cogl/cogl-macros.h"
#endif

G_BEGIN_DECLS

/* It's too difficult to actually subclass the pango cairo font
 * map. Instead we just make a fake set of macros that actually just
 * directly use the original type
 */
#define COGL_PANGO_TYPE_FONT_MAP        PANGO_TYPE_CAIRO_FONT_MAP
#define COGL_PANGO_FONT_MAP(obj)        (G_TYPE_CHECK_INSTANCE_CAST ((obj), COGL_PANGO_TYPE_FONT_MAP, CoglPangoFontMap))
#define COGL_PANGO_IS_FONT_MAP(obj)     (G_TYPE_CHECK_INSTANCE_TYPE ((obj), COGL_PANGO_TYPE_FONT_MAP))

typedef PangoCairoFontMap CoglPangoFontMap;

/**
 * cogl_pango_font_map_new:
 *
 * Creates a new font map.
 *
 * Return value: (transfer full): the newly created #PangoFontMap
 */
COGL_EXPORT PangoFontMap *
cogl_pango_font_map_new (void);

/**
 * cogl_pango_font_map_create_context:
 * @font_map: a #CoglPangoFontMap
 *
 * Create a [class@Pango.Context] for the given @font_map.
 *
 * Returns: (transfer full): the newly created context: free with [method@GObject.Object.unref].
 */
COGL_EXPORT PangoContext *
cogl_pango_font_map_create_context (CoglPangoFontMap *font_map);

/**
 * cogl_pango_font_map_set_resolution:
 * @font_map: a #CoglPangoFontMap
 * @dpi: The resolution in "dots per inch". (Physical inches aren't
 *       actually involved; the terminology is conventional.)
 *
 * Sets the resolution for the @font_map. 
 * 
 * This is a scale factor between points specified in a 
 * [struct@Pango.FontDescription] and Cogl units.
 * The default value is %96, meaning that a 10 point font will be 13
 * units high. (10 * 96. / 72. = 13.3).
 */
COGL_EXPORT void
cogl_pango_font_map_set_resolution (CoglPangoFontMap *font_map,
                                    double dpi);

/**
 * cogl_pango_font_map_clear_glyph_cache:
 * @font_map: a #CoglPangoFontMap
 *
 * Clears the glyph cache for @font_map.
 */
COGL_EXPORT void
cogl_pango_font_map_clear_glyph_cache (CoglPangoFontMap *font_map);

/**
 * cogl_pango_ensure_glyph_cache_for_layout:
 * @layout: A #PangoLayout
 *
 * This updates any internal glyph cache textures as necessary to be
 * able to render the given @layout.
 *
 * This api should be used to avoid mid-scene modifications of
 * glyph-cache textures which can lead to undefined rendering results.
 */
COGL_EXPORT void
cogl_pango_ensure_glyph_cache_for_layout (PangoLayout *layout);

/**
 * cogl_pango_font_map_set_use_mipmapping:
 * @font_map: a #CoglPangoFontMap
 * @value: %TRUE to enable the use of mipmapping
 *
 * Sets whether the renderer for the passed font map should use
 * mipmapping when rendering a [class@Pango.Layout].
 */
COGL_EXPORT void
cogl_pango_font_map_set_use_mipmapping (CoglPangoFontMap *font_map,
                                        gboolean value);

/**
 * cogl_pango_font_map_get_use_mipmapping:
 * @font_map: a #CoglPangoFontMap
 *
 * Retrieves whether the [class@CoglPango.Renderer] used by @font_map will use
 * mipmapping when rendering the glyphs.
 *
 * Return value: %TRUE if mipmapping is used, %FALSE otherwise.
 */
COGL_EXPORT gboolean
cogl_pango_font_map_get_use_mipmapping (CoglPangoFontMap *font_map);

/**
 * cogl_pango_font_map_get_renderer:
 * @font_map: a #CoglPangoFontMap
 *
 * Retrieves the [class@CoglPango.Renderer] for the passed @font_map.
 *
 * Return value: (transfer none): a #PangoRenderer
 */
COGL_EXPORT PangoRenderer *
cogl_pango_font_map_get_renderer (CoglPangoFontMap *font_map);

/**
 * cogl_pango_show_layout: (skip)
 * @framebuffer: A #CoglFramebuffer to draw too.
 * @layout: a #PangoLayout
 * @x: X coordinate to render the layout at
 * @y: Y coordinate to render the layout at
 * @color: color to use when rendering the layout
 *
 * Draws a solidly coloured @layout on the given @framebuffer at (@x,
 * @y) within the `framebuffer`'s current model-view coordinate space.
 */
COGL_EXPORT void
cogl_pango_show_layout (CoglFramebuffer *framebuffer,
                        PangoLayout *layout,
                        float x,
                        float y,
                        const CoglColor *color);

/**
 * cogl_pango_show_layout_line: (skip)
 * @framebuffer: A #CoglFramebuffer to draw too.
 * @line: a #PangoLayoutLine
 * @x: X coordinate to render the line at
 * @y: Y coordinate to render the line at
 * @color: color to use when rendering the line
 *
 * Draws a solidly coloured @line on the given @framebuffer at (@x,
 * @y) within the `framebuffer`'s current model-view coordinate space.
 */
COGL_EXPORT void
cogl_pango_show_layout_line (CoglFramebuffer *framebuffer,
                             PangoLayoutLine *line,
                             float x,
                             float y,
                             const CoglColor *color);


#define COGL_PANGO_TYPE_RENDERER                (cogl_pango_renderer_get_type ())
#define COGL_PANGO_RENDERER(obj)                (G_TYPE_CHECK_INSTANCE_CAST ((obj), COGL_PANGO_TYPE_RENDERER, CoglPangoRenderer))
#define COGL_PANGO_RENDERER_CLASS(klass)        (G_TYPE_CHECK_CLASS_CAST ((klass), COGL_PANGO_TYPE_RENDERER, CoglPangoRendererClass))
#define COGL_PANGO_IS_RENDERER(obj)             (G_TYPE_CHECK_INSTANCE_TYPE ((obj), COGL_PANGO_TYPE_RENDERER))
#define COGL_PANGO_IS_RENDERER_CLASS(klass)     (G_TYPE_CHECK_CLASS_TYPE ((klass),  COGL_PANGO_TYPE_RENDERER))
#define COGL_PANGO_RENDERER_GET_CLASS(obj)      (G_TYPE_INSTANCE_GET_CLASS ((obj), COGL_PANGO_TYPE_RENDERER, CoglPangoRendererClass))

/* opaque types */
typedef struct _CoglPangoRenderer      CoglPangoRenderer;
typedef struct _CoglPangoRendererClass CoglPangoRendererClass;

COGL_EXPORT GType cogl_pango_renderer_get_type (void) G_GNUC_CONST;

G_END_DECLS

#endif /* __COGL_PANGO_H__ */