diff options
Diffstat (limited to 'freetype/src/autofit/afhints.h')
| -rw-r--r-- | freetype/src/autofit/afhints.h | 87 |
1 files changed, 50 insertions, 37 deletions
diff --git a/freetype/src/autofit/afhints.h b/freetype/src/autofit/afhints.h index 776b3c844..5f1507f80 100644 --- a/freetype/src/autofit/afhints.h +++ b/freetype/src/autofit/afhints.h @@ -27,7 +27,7 @@ FT_BEGIN_HEADER /* * The definition of outline glyph hints. These are shared by all - * script analysis routines (until now). + * writing system analysis routines (until now). */ typedef enum AF_Dimension_ @@ -62,15 +62,19 @@ FT_BEGIN_HEADER * * by David Turner and Werner Lemberg * - * http://www.tug.org/TUGboat/Articles/tb24-3/lemberg.pdf + * http://www.tug.org/TUGboat/Articles/tb24-3/lemberg.pdf + * + * with appropriate updates. * * * Segments * * `af_{cjk,latin,...}_hints_compute_segments' are the functions to - * find segments in an outline. A segment is a series of consecutive - * points that are approximately aligned along a coordinate axis. The - * analysis to do so is specific to a script. + * find segments in an outline. + * + * A segment is a series of consecutive points that are approximately + * aligned along a coordinate axis. The analysis to do so is specific + * to a writing system. * * A segment must have at least two points, except in the case of * `fake' segments that are generated to hint metrics appropriately, @@ -79,16 +83,17 @@ FT_BEGIN_HEADER * * Edges * + * `af_{cjk,latin,...}_hints_compute_edges' are the functions to find + * edges. + * * As soon as segments are defined, the auto-hinter groups them into * edges. An edge corresponds to a single position on the main * dimension that collects one or more segments (allowing for a small * threshold). * - * The auto-hinter first tries to grid fit edges, then to align - * segments on the edges unless it detects that they form a serif. - * - * `af_{cjk,latin,...}_hints_compute_edges' are the functions to find - * edges; they are specific to a script. + * As an example, the `latin' writing system first tries to grid-fit + * edges, then to align segments on the edges unless it detects that + * they form a serif. * * * A H @@ -107,6 +112,8 @@ FT_BEGIN_HEADER * * Stems * + * Stems are detected by `af_{cjk,latin,...}_hint_edges'. + * * Segments need to be `linked' to other ones in order to detect stems. * A stem is made of two segments that face each other in opposite * directions and that are sufficiently close to each other. Using @@ -127,17 +134,21 @@ FT_BEGIN_HEADER * The best candidate is stored in field `link' in structure * `AF_Segment'. * - * Stems are detected by `af_{cjk,latin,...}_hint_edges'. - * * In the above ASCII drawing, the best candidate for both AB and CD is * GH, while the best candidate for GH is AB. Similarly, the best * candidate for EF and GH is AB, while the best candidate for AB is * GH. * + * The detection and handling of stems is dependent on the writing + * system. + * * * Serifs * - * On the opposite, a serif has + * Serifs are detected by `af_{cjk,latin,...}_hint_edges'. + * + * In comparison to a stem, a serif (as handled by the auto-hinter + * module which takes care of the `latin' writing system) has * * best segment_1 = segment_2 && best segment_2 != segment_1 * @@ -147,8 +158,6 @@ FT_BEGIN_HEADER * The best candidate is stored in field `serif' in structure * `AF_Segment' (and `link' is set to NULL). * - * Serifs are detected by `af_{cjk,latin,...}_hint_edges'. - * * * Touched points * @@ -178,7 +187,8 @@ FT_BEGIN_HEADER * differ greatly) * * - inflection points (i.e., where the `in' and `out' angles are the - * same, but the curvature changes sign) + * same, but the curvature changes sign) [currently, such points + * aren't handled in the auto-hinter] * * `af_glyph_hints_align_strong_points' is the function which takes * care of such situations; it is equivalent to the TrueType `IP' @@ -226,7 +236,10 @@ FT_BEGIN_HEADER AF_FLAG_WEAK_INTERPOLATION = 1 << 8, /* all inflection points in the outline have this flag set */ - AF_FLAG_INFLECTION = 1 << 9 + AF_FLAG_INFLECTION = 1 << 9, + + /* the current point is very near to another one */ + AF_FLAG_NEAR = 1 << 10 } AF_Flags; @@ -330,31 +343,31 @@ FT_BEGIN_HEADER typedef struct AF_GlyphHintsRec_ { - FT_Memory memory; + FT_Memory memory; - FT_Fixed x_scale; - FT_Pos x_delta; + FT_Fixed x_scale; + FT_Pos x_delta; - FT_Fixed y_scale; - FT_Pos y_delta; + FT_Fixed y_scale; + FT_Pos y_delta; - FT_Int max_points; /* number of allocated points */ - FT_Int num_points; /* number of used points */ - AF_Point points; /* points array */ + FT_Int max_points; /* number of allocated points */ + FT_Int num_points; /* number of used points */ + AF_Point points; /* points array */ - FT_Int max_contours; /* number of allocated contours */ - FT_Int num_contours; /* number of used contours */ - AF_Point* contours; /* contours array */ + FT_Int max_contours; /* number of allocated contours */ + FT_Int num_contours; /* number of used contours */ + AF_Point* contours; /* contours array */ - AF_AxisHintsRec axis[AF_DIMENSION_MAX]; + AF_AxisHintsRec axis[AF_DIMENSION_MAX]; - FT_UInt32 scaler_flags; /* copy of scaler flags */ - FT_UInt32 other_flags; /* free for script-specific */ - /* implementations */ - AF_ScriptMetrics metrics; + FT_UInt32 scaler_flags; /* copy of scaler flags */ + FT_UInt32 other_flags; /* free for style-specific */ + /* implementations */ + AF_StyleMetrics metrics; - FT_Pos xmin_delta; /* used for warping */ - FT_Pos xmax_delta; + FT_Pos xmin_delta; /* used for warping */ + FT_Pos xmax_delta; } AF_GlyphHintsRec; @@ -416,8 +429,8 @@ FT_BEGIN_HEADER FT_Memory memory ); FT_LOCAL( void ) - af_glyph_hints_rescale( AF_GlyphHints hints, - AF_ScriptMetrics metrics ); + af_glyph_hints_rescale( AF_GlyphHints hints, + AF_StyleMetrics metrics ); FT_LOCAL( FT_Error ) af_glyph_hints_reload( AF_GlyphHints hints, |