#ifndef SW_FT_STROKER_H #define SW_FT_STROKER_H /***************************************************************************/ /* */ /* ftstroke.h */ /* */ /* FreeType path stroker (specification). */ /* */ /* Copyright 2002-2006, 2008, 2009, 2011-2012 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. */ /* */ /***************************************************************************/ #include "sw_ft_raster.h" /************************************************************** * * @type: * SW_FT_Stroker * * @description: * Opaque handler to a path stroker object. */ typedef struct SW_FT_StrokerRec_* SW_FT_Stroker; /************************************************************** * * @enum: * SW_FT_Stroker_LineJoin * * @description: * These values determine how two joining lines are rendered * in a stroker. * * @values: * SW_FT_STROKER_LINEJOIN_ROUND :: * Used to render rounded line joins. Circular arcs are used * to join two lines smoothly. * * SW_FT_STROKER_LINEJOIN_BEVEL :: * Used to render beveled line joins. The outer corner of * the joined lines is filled by enclosing the triangular * region of the corner with a straight line between the * outer corners of each stroke. * * SW_FT_STROKER_LINEJOIN_MITER_FIXED :: * Used to render mitered line joins, with fixed bevels if the * miter limit is exceeded. The outer edges of the strokes * for the two segments are extended until they meet at an * angle. If the segments meet at too sharp an angle (such * that the miter would extend from the intersection of the * segments a distance greater than the product of the miter * limit value and the border radius), then a bevel join (see * above) is used instead. This prevents long spikes being * created. SW_FT_STROKER_LINEJOIN_MITER_FIXED generates a miter * line join as used in PostScript and PDF. * * SW_FT_STROKER_LINEJOIN_MITER_VARIABLE :: * SW_FT_STROKER_LINEJOIN_MITER :: * Used to render mitered line joins, with variable bevels if * the miter limit is exceeded. The intersection of the * strokes is clipped at a line perpendicular to the bisector * of the angle between the strokes, at the distance from the * intersection of the segments equal to the product of the * miter limit value and the border radius. This prevents * long spikes being created. * SW_FT_STROKER_LINEJOIN_MITER_VARIABLE generates a mitered line * join as used in XPS. SW_FT_STROKER_LINEJOIN_MITER is an alias * for SW_FT_STROKER_LINEJOIN_MITER_VARIABLE, retained for * backwards compatibility. */ typedef enum SW_FT_Stroker_LineJoin_ { SW_FT_STROKER_LINEJOIN_ROUND = 0, SW_FT_STROKER_LINEJOIN_BEVEL = 1, SW_FT_STROKER_LINEJOIN_MITER_VARIABLE = 2, SW_FT_STROKER_LINEJOIN_MITER = SW_FT_STROKER_LINEJOIN_MITER_VARIABLE, SW_FT_STROKER_LINEJOIN_MITER_FIXED = 3 } SW_FT_Stroker_LineJoin; /************************************************************** * * @enum: * SW_FT_Stroker_LineCap * * @description: * These values determine how the end of opened sub-paths are * rendered in a stroke. * * @values: * SW_FT_STROKER_LINECAP_BUTT :: * The end of lines is rendered as a full stop on the last * point itself. * * SW_FT_STROKER_LINECAP_ROUND :: * The end of lines is rendered as a half-circle around the * last point. * * SW_FT_STROKER_LINECAP_SQUARE :: * The end of lines is rendered as a square around the * last point. */ typedef enum SW_FT_Stroker_LineCap_ { SW_FT_STROKER_LINECAP_BUTT = 0, SW_FT_STROKER_LINECAP_ROUND, SW_FT_STROKER_LINECAP_SQUARE } SW_FT_Stroker_LineCap; /************************************************************** * * @enum: * SW_FT_StrokerBorder * * @description: * These values are used to select a given stroke border * in @SW_FT_Stroker_GetBorderCounts and @SW_FT_Stroker_ExportBorder. * * @values: * SW_FT_STROKER_BORDER_LEFT :: * Select the left border, relative to the drawing direction. * * SW_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 @SW_FT_Outline_GetInsideBorder and * @SW_FT_Outline_GetOutsideBorder to get these. */ typedef enum SW_FT_StrokerBorder_ { SW_FT_STROKER_BORDER_LEFT = 0, SW_FT_STROKER_BORDER_RIGHT } SW_FT_StrokerBorder; /************************************************************** * * @function: * SW_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. */ SW_FT_Error SW_FT_Stroker_New( SW_FT_Stroker *astroker ); /************************************************************** * * @function: * SW_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 SW_FT_STROKER_LINEJOIN_MITER_FIXED and * SW_FT_STROKER_LINEJOIN_MITER_VARIABLE line join styles, * expressed as 16.16 fixed-point value. * * @note: * The radius is expressed in the same units as the outline * coordinates. */ void SW_FT_Stroker_Set( SW_FT_Stroker stroker, SW_FT_Fixed radius, SW_FT_Stroker_LineCap line_cap, SW_FT_Stroker_LineJoin line_join, SW_FT_Fixed miter_limit ); /************************************************************** * * @function: * SW_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 @SW_FT_Stroker_GetCounts and @SW_FT_Stroker_Export. * * @input: * stroker :: * The target stroker handle. * * outline :: * The source outline. * * * @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. * * * This function calls @SW_FT_Stroker_Rewind automatically. */ SW_FT_Error SW_FT_Stroker_ParseOutline( SW_FT_Stroker stroker, const SW_FT_Outline* outline); /************************************************************** * * @function: * SW_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. */ SW_FT_Error SW_FT_Stroker_GetCounts( SW_FT_Stroker stroker, SW_FT_UInt *anum_points, SW_FT_UInt *anum_contours ); /************************************************************** * * @function: * SW_FT_Stroker_Export * * @description: * Call this function after @SW_FT_Stroker_GetBorderCounts to * export all borders to your own @SW_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. */ void SW_FT_Stroker_Export( SW_FT_Stroker stroker, SW_FT_Outline* outline ); /************************************************************** * * @function: * SW_FT_Stroker_Done * * @description: * Destroy a stroker object. * * @input: * stroker :: * A stroker handle. Can be NULL. */ void SW_FT_Stroker_Done( SW_FT_Stroker stroker ); #endif // SW_FT_STROKER_H