--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libfreetype/include/freetype/ftstroke.h Mon Apr 25 01:46:54 2011 +0200
@@ -0,0 +1,716 @@
+/***************************************************************************/
+/* */
+/* ftstroke.h */
+/* */
+/* FreeType path stroker (specification). */
+/* */
+/* Copyright 2002, 2003, 2004, 2005, 2006, 2008, 2009 by */
+/* David Turner, Robert Wilhelm, and Werner Lemberg. */
+/* */
+/* This file is part of the FreeType project, and may only be used, */
+/* modified, and distributed under the terms of the FreeType project */
+/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
+/* this file you indicate that you have read the license and */
+/* understand and accept it fully. */
+/* */
+/***************************************************************************/
+
+
+#ifndef __FT_STROKE_H__
+#define __FT_STROKE_H__
+
+#include <ft2build.h>
+#include FT_OUTLINE_H
+#include FT_GLYPH_H
+
+
+FT_BEGIN_HEADER
+
+
+ /************************************************************************
+ *
+ * @section:
+ * glyph_stroker
+ *
+ * @title:
+ * Glyph Stroker
+ *
+ * @abstract:
+ * Generating bordered and stroked glyphs.
+ *
+ * @description:
+ * This component generates stroked outlines of a given vectorial
+ * glyph. It also allows you to retrieve the `outside' and/or the
+ * `inside' borders of the stroke.
+ *
+ * This can be useful to generate `bordered' glyph, i.e., glyphs
+ * displayed with a coloured (and anti-aliased) border around their
+ * shape.
+ */
+
+
+ /**************************************************************
+ *
+ * @type:
+ * FT_Stroker
+ *
+ * @description:
+ * Opaque handler to a path stroker object.
+ */
+ typedef struct FT_StrokerRec_* FT_Stroker;
+
+
+ /**************************************************************
+ *
+ * @enum:
+ * FT_Stroker_LineJoin
+ *
+ * @description:
+ * These values determine how two joining lines are rendered
+ * in a stroker.
+ *
+ * @values:
+ * FT_STROKER_LINEJOIN_ROUND ::
+ * Used to render rounded line joins. Circular arcs are used
+ * to join two lines smoothly.
+ *
+ * FT_STROKER_LINEJOIN_BEVEL ::
+ * Used to render beveled line joins; i.e., the two joining lines
+ * are extended until they intersect.
+ *
+ * FT_STROKER_LINEJOIN_MITER ::
+ * Same as beveled rendering, except that an additional line
+ * break is added if the angle between the two joining lines
+ * is too closed (this is useful to avoid unpleasant spikes
+ * in beveled rendering).
+ */
+ typedef enum FT_Stroker_LineJoin_
+ {
+ FT_STROKER_LINEJOIN_ROUND = 0,
+ FT_STROKER_LINEJOIN_BEVEL,
+ FT_STROKER_LINEJOIN_MITER
+
+ } FT_Stroker_LineJoin;
+
+
+ /**************************************************************
+ *
+ * @enum:
+ * FT_Stroker_LineCap
+ *
+ * @description:
+ * These values determine how the end of opened sub-paths are
+ * rendered in a stroke.
+ *
+ * @values:
+ * FT_STROKER_LINECAP_BUTT ::
+ * The end of lines is rendered as a full stop on the last
+ * point itself.
+ *
+ * FT_STROKER_LINECAP_ROUND ::
+ * The end of lines is rendered as a half-circle around the
+ * last point.
+ *
+ * FT_STROKER_LINECAP_SQUARE ::
+ * The end of lines is rendered as a square around the
+ * last point.
+ */
+ typedef enum FT_Stroker_LineCap_
+ {
+ FT_STROKER_LINECAP_BUTT = 0,
+ FT_STROKER_LINECAP_ROUND,
+ FT_STROKER_LINECAP_SQUARE
+
+ } FT_Stroker_LineCap;
+
+
+ /**************************************************************
+ *
+ * @enum:
+ * FT_StrokerBorder
+ *
+ * @description:
+ * These values are used to select a given stroke border
+ * in @FT_Stroker_GetBorderCounts and @FT_Stroker_ExportBorder.
+ *
+ * @values:
+ * FT_STROKER_BORDER_LEFT ::
+ * Select the left border, relative to the drawing direction.
+ *
+ * FT_STROKER_BORDER_RIGHT ::
+ * Select the right border, relative to the drawing direction.
+ *
+ * @note:
+ * Applications are generally interested in the `inside' and `outside'
+ * borders. However, there is no direct mapping between these and the
+ * `left' and `right' ones, since this really depends on the glyph's
+ * drawing orientation, which varies between font formats.
+ *
+ * You can however use @FT_Outline_GetInsideBorder and
+ * @FT_Outline_GetOutsideBorder to get these.
+ */
+ typedef enum FT_StrokerBorder_
+ {
+ FT_STROKER_BORDER_LEFT = 0,
+ FT_STROKER_BORDER_RIGHT
+
+ } FT_StrokerBorder;
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Outline_GetInsideBorder
+ *
+ * @description:
+ * Retrieve the @FT_StrokerBorder value corresponding to the
+ * `inside' borders of a given outline.
+ *
+ * @input:
+ * outline ::
+ * The source outline handle.
+ *
+ * @return:
+ * The border index. @FT_STROKER_BORDER_RIGHT for empty or invalid
+ * outlines.
+ */
+ FT_EXPORT( FT_StrokerBorder )
+ FT_Outline_GetInsideBorder( FT_Outline* outline );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Outline_GetOutsideBorder
+ *
+ * @description:
+ * Retrieve the @FT_StrokerBorder value corresponding to the
+ * `outside' borders of a given outline.
+ *
+ * @input:
+ * outline ::
+ * The source outline handle.
+ *
+ * @return:
+ * The border index. @FT_STROKER_BORDER_LEFT for empty or invalid
+ * outlines.
+ */
+ FT_EXPORT( FT_StrokerBorder )
+ FT_Outline_GetOutsideBorder( FT_Outline* outline );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_New
+ *
+ * @description:
+ * Create a new stroker object.
+ *
+ * @input:
+ * library ::
+ * FreeType library handle.
+ *
+ * @output:
+ * astroker ::
+ * A new stroker object handle. NULL in case of error.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Stroker_New( FT_Library library,
+ FT_Stroker *astroker );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_Set
+ *
+ * @description:
+ * Reset a stroker object's attributes.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * radius ::
+ * The border radius.
+ *
+ * line_cap ::
+ * The line cap style.
+ *
+ * line_join ::
+ * The line join style.
+ *
+ * miter_limit ::
+ * The miter limit for the FT_STROKER_LINEJOIN_MITER style,
+ * expressed as 16.16 fixed point value.
+ *
+ * @note:
+ * The radius is expressed in the same units as the outline
+ * coordinates.
+ */
+ FT_EXPORT( void )
+ FT_Stroker_Set( FT_Stroker stroker,
+ FT_Fixed radius,
+ FT_Stroker_LineCap line_cap,
+ FT_Stroker_LineJoin line_join,
+ FT_Fixed miter_limit );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_Rewind
+ *
+ * @description:
+ * Reset a stroker object without changing its attributes.
+ * You should call this function before beginning a new
+ * series of calls to @FT_Stroker_BeginSubPath or
+ * @FT_Stroker_EndSubPath.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ */
+ FT_EXPORT( void )
+ FT_Stroker_Rewind( FT_Stroker stroker );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_ParseOutline
+ *
+ * @description:
+ * A convenience function used to parse a whole outline with
+ * the stroker. The resulting outline(s) can be retrieved
+ * later by functions like @FT_Stroker_GetCounts and @FT_Stroker_Export.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * outline ::
+ * The source outline.
+ *
+ * opened ::
+ * A boolean. If~1, the outline is treated as an open path instead
+ * of a closed one.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ *
+ * @note:
+ * If `opened' is~0 (the default), the outline is treated as a closed
+ * path, and the stroker generates two distinct `border' outlines.
+ *
+ * If `opened' is~1, the outline is processed as an open path, and the
+ * stroker generates a single `stroke' outline.
+ *
+ * This function calls @FT_Stroker_Rewind automatically.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Stroker_ParseOutline( FT_Stroker stroker,
+ FT_Outline* outline,
+ FT_Bool opened );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_BeginSubPath
+ *
+ * @description:
+ * Start a new sub-path in the stroker.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * to ::
+ * A pointer to the start vector.
+ *
+ * open ::
+ * A boolean. If~1, the sub-path is treated as an open one.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ *
+ * @note:
+ * This function is useful when you need to stroke a path that is
+ * not stored as an @FT_Outline object.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Stroker_BeginSubPath( FT_Stroker stroker,
+ FT_Vector* to,
+ FT_Bool open );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_EndSubPath
+ *
+ * @description:
+ * Close the current sub-path in the stroker.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ *
+ * @note:
+ * You should call this function after @FT_Stroker_BeginSubPath.
+ * If the subpath was not `opened', this function `draws' a
+ * single line segment to the start position when needed.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Stroker_EndSubPath( FT_Stroker stroker );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_LineTo
+ *
+ * @description:
+ * `Draw' a single line segment in the stroker's current sub-path,
+ * from the last position.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * to ::
+ * A pointer to the destination point.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ *
+ * @note:
+ * You should call this function between @FT_Stroker_BeginSubPath and
+ * @FT_Stroker_EndSubPath.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Stroker_LineTo( FT_Stroker stroker,
+ FT_Vector* to );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_ConicTo
+ *
+ * @description:
+ * `Draw' a single quadratic Bézier in the stroker's current sub-path,
+ * from the last position.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * control ::
+ * A pointer to a Bézier control point.
+ *
+ * to ::
+ * A pointer to the destination point.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ *
+ * @note:
+ * You should call this function between @FT_Stroker_BeginSubPath and
+ * @FT_Stroker_EndSubPath.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Stroker_ConicTo( FT_Stroker stroker,
+ FT_Vector* control,
+ FT_Vector* to );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_CubicTo
+ *
+ * @description:
+ * `Draw' a single cubic Bézier in the stroker's current sub-path,
+ * from the last position.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * control1 ::
+ * A pointer to the first Bézier control point.
+ *
+ * control2 ::
+ * A pointer to second Bézier control point.
+ *
+ * to ::
+ * A pointer to the destination point.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ *
+ * @note:
+ * You should call this function between @FT_Stroker_BeginSubPath and
+ * @FT_Stroker_EndSubPath.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Stroker_CubicTo( FT_Stroker stroker,
+ FT_Vector* control1,
+ FT_Vector* control2,
+ FT_Vector* to );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_GetBorderCounts
+ *
+ * @description:
+ * Call this function once you have finished parsing your paths
+ * with the stroker. It returns the number of points and
+ * contours necessary to export one of the `border' or `stroke'
+ * outlines generated by the stroker.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * border ::
+ * The border index.
+ *
+ * @output:
+ * anum_points ::
+ * The number of points.
+ *
+ * anum_contours ::
+ * The number of contours.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ *
+ * @note:
+ * When an outline, or a sub-path, is `closed', the stroker generates
+ * two independent `border' outlines, named `left' and `right'.
+ *
+ * When the outline, or a sub-path, is `opened', the stroker merges
+ * the `border' outlines with caps. The `left' border receives all
+ * points, while the `right' border becomes empty.
+ *
+ * Use the function @FT_Stroker_GetCounts instead if you want to
+ * retrieve the counts associated to both borders.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Stroker_GetBorderCounts( FT_Stroker stroker,
+ FT_StrokerBorder border,
+ FT_UInt *anum_points,
+ FT_UInt *anum_contours );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_ExportBorder
+ *
+ * @description:
+ * Call this function after @FT_Stroker_GetBorderCounts to
+ * export the corresponding border to your own @FT_Outline
+ * structure.
+ *
+ * Note that this function appends the border points and
+ * contours to your outline, but does not try to resize its
+ * arrays.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * border ::
+ * The border index.
+ *
+ * outline ::
+ * The target outline handle.
+ *
+ * @note:
+ * Always call this function after @FT_Stroker_GetBorderCounts to
+ * get sure that there is enough room in your @FT_Outline object to
+ * receive all new data.
+ *
+ * When an outline, or a sub-path, is `closed', the stroker generates
+ * two independent `border' outlines, named `left' and `right'
+ *
+ * When the outline, or a sub-path, is `opened', the stroker merges
+ * the `border' outlines with caps. The `left' border receives all
+ * points, while the `right' border becomes empty.
+ *
+ * Use the function @FT_Stroker_Export instead if you want to
+ * retrieve all borders at once.
+ */
+ FT_EXPORT( void )
+ FT_Stroker_ExportBorder( FT_Stroker stroker,
+ FT_StrokerBorder border,
+ FT_Outline* outline );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_GetCounts
+ *
+ * @description:
+ * Call this function once you have finished parsing your paths
+ * with the stroker. It returns the number of points and
+ * contours necessary to export all points/borders from the stroked
+ * outline/path.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * @output:
+ * anum_points ::
+ * The number of points.
+ *
+ * anum_contours ::
+ * The number of contours.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Stroker_GetCounts( FT_Stroker stroker,
+ FT_UInt *anum_points,
+ FT_UInt *anum_contours );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_Export
+ *
+ * @description:
+ * Call this function after @FT_Stroker_GetBorderCounts to
+ * export all borders to your own @FT_Outline structure.
+ *
+ * Note that this function appends the border points and
+ * contours to your outline, but does not try to resize its
+ * arrays.
+ *
+ * @input:
+ * stroker ::
+ * The target stroker handle.
+ *
+ * outline ::
+ * The target outline handle.
+ */
+ FT_EXPORT( void )
+ FT_Stroker_Export( FT_Stroker stroker,
+ FT_Outline* outline );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Stroker_Done
+ *
+ * @description:
+ * Destroy a stroker object.
+ *
+ * @input:
+ * stroker ::
+ * A stroker handle. Can be NULL.
+ */
+ FT_EXPORT( void )
+ FT_Stroker_Done( FT_Stroker stroker );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Glyph_Stroke
+ *
+ * @description:
+ * Stroke a given outline glyph object with a given stroker.
+ *
+ * @inout:
+ * pglyph ::
+ * Source glyph handle on input, new glyph handle on output.
+ *
+ * @input:
+ * stroker ::
+ * A stroker handle.
+ *
+ * destroy ::
+ * A Boolean. If~1, the source glyph object is destroyed
+ * on success.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ *
+ * @note:
+ * The source glyph is untouched in case of error.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Glyph_Stroke( FT_Glyph *pglyph,
+ FT_Stroker stroker,
+ FT_Bool destroy );
+
+
+ /**************************************************************
+ *
+ * @function:
+ * FT_Glyph_StrokeBorder
+ *
+ * @description:
+ * Stroke a given outline glyph object with a given stroker, but
+ * only return either its inside or outside border.
+ *
+ * @inout:
+ * pglyph ::
+ * Source glyph handle on input, new glyph handle on output.
+ *
+ * @input:
+ * stroker ::
+ * A stroker handle.
+ *
+ * inside ::
+ * A Boolean. If~1, return the inside border, otherwise
+ * the outside border.
+ *
+ * destroy ::
+ * A Boolean. If~1, the source glyph object is destroyed
+ * on success.
+ *
+ * @return:
+ * FreeType error code. 0~means success.
+ *
+ * @note:
+ * The source glyph is untouched in case of error.
+ */
+ FT_EXPORT( FT_Error )
+ FT_Glyph_StrokeBorder( FT_Glyph *pglyph,
+ FT_Stroker stroker,
+ FT_Bool inside,
+ FT_Bool destroy );
+
+ /* */
+
+FT_END_HEADER
+
+#endif /* __FT_STROKE_H__ */
+
+
+/* END */
+
+
+/* Local Variables: */
+/* coding: utf-8 */
+/* End: */