| /* |
| ****************************************************************************** |
| * |
| * Copyright (C) 2000-2001, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| * |
| ****************************************************************************** |
| * file name: ushape.h |
| * encoding: US-ASCII |
| * tab size: 8 (not used) |
| * indentation:4 |
| * |
| * created on: 2000jun29 |
| * created by: Markus W. Scherer |
| */ |
| |
| #ifndef __USHAPE_H__ |
| #define __USHAPE_H__ |
| |
| #include "unicode/utypes.h" |
| |
| /** |
| * \file |
| * \brief C API: Arabic shaping |
| * |
| */ |
| |
| /** |
| * Shape Arabic text on a character basis. |
| * |
| * <p>This function performs basic operations for "shaping" Arabic text. It is most |
| * useful for use with legacy data formats and legacy display technology |
| * (simple terminals). All operations are performed on Unicode characters.</p> |
| * |
| * <p>Text-based shaping means that some character code points in the text are |
| * replaced by others depending on the context. It transforms one kind of text |
| * into another. In comparison, modern displays for Arabic text select |
| * appropriate, context-dependent font glyphs for each text element, which means |
| * that they transform text into a glyph vector.</p> |
| * |
| * <p>Text transformations are necessary when modern display technology is not |
| * available or when text needs to be transformed to or from legacy formats that |
| * use "shaped" characters. Since the Arabic script is cursive, connecting |
| * adjacent letters to each other, computers select images for each letter based |
| * on the surrounding letters. This usually results in four images per Arabic |
| * letter: initial, middle, final, and isolated forms. In Unicode, on the other |
| * hand, letters are normally stored abstract, and a display system is expected |
| * to select the necessary glyphs. (This makes searching and other text |
| * processing easier because the same letter has only one code.) It is possible |
| * to mimic this with text transformations because there are characters in |
| * Unicode that are rendered as letters with a specific shape |
| * (or cursive connectivity). They were included for interoperability with |
| * legacy systems and codepages, and for unsophisticated display systems.</p> |
| * |
| * <p>A second kind of text transformations is supported for Arabic digits: |
| * For compatibility with legacy codepages that only include European digits, |
| * it is possible to replace one set of digits by another, changing the |
| * character code points. These operations can be performed for either |
| * Arabic-Indic Digits (U+0660...U+0669) or Eastern (Extended) Arabic-Indic |
| * digits (U+06f0...U+06f9).</p> |
| * |
| * <p>Some replacements may result in more or fewer characters (code points). |
| * By default, this means that the destination buffer may receive text with a |
| * length different from the source length. Some legacy systems rely on the |
| * length of the text to be constant. They expect extra spaces to be added |
| * or consumed either next to the affected character or at the end of the |
| * text.</p> |
| * |
| * <p>For details about the available operations, see the description of the |
| * <code>U_SHAPE_...</code> options.</p> |
| * |
| * @param source The input text. |
| * |
| * @param sourceLength The number of UChars in <code>source</code>. |
| * |
| * @param dest The destination buffer that will receive the results of the |
| * requested operations. It may be <code>NULL</code> only if |
| * <code>destSize</code> is 0. The source and destination must not |
| * overlap. |
| * |
| * @param destSize The size (capacity) of the destination buffer in UChars. |
| * If <code>destSize</code> is 0, then no output is produced, |
| * but the necessary buffer size is returned ("preflighting"). |
| * |
| * @param options This is a 32-bit set of flags that specify the operations |
| * that are performed on the input text. If no error occurs, |
| * then the result will always be written to the destination |
| * buffer. |
| * |
| * @param pErrorCode must be a valid pointer to an error code value, |
| * which must not indicate a failure before the function call. |
| * |
| * @return The number of UChars written to the destination buffer. |
| * If an error occured, then no output was written, or it may be |
| * incomplete. If <code>U_BUFFER_OVERFLOW_ERROR</code> is set, then |
| * the return value indicates the necessary destination buffer size. |
| * @stable ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 |
| u_shapeArabic(const UChar *source, int32_t sourceLength, |
| UChar *dest, int32_t destSize, |
| uint32_t options, |
| UErrorCode *pErrorCode); |
| |
| /** |
| * Memory option: allow the result to have a different length than the source. |
| * @stable ICU 2.0 |
| */ |
| #define U_SHAPE_LENGTH_GROW_SHRINK 0 |
| |
| /** |
| * Memory option: the result must have the same length as the source. |
| * If more room is necessary, then try to consume spaces next to modified characters. |
| * @stable ICU 2.0 |
| */ |
| #define U_SHAPE_LENGTH_FIXED_SPACES_NEAR 1 |
| |
| /** |
| * Memory option: the result must have the same length as the source. |
| * If more room is necessary, then try to consume spaces at the end of the text. |
| * @stable ICU 2.0 |
| */ |
| #define U_SHAPE_LENGTH_FIXED_SPACES_AT_END 2 |
| |
| /** |
| * Memory option: the result must have the same length as the source. |
| * If more room is necessary, then try to consume spaces at the beginning of the text. |
| * @stable ICU 2.0 |
| */ |
| #define U_SHAPE_LENGTH_FIXED_SPACES_AT_BEGINNING 3 |
| |
| /** Bit mask for memory options. @stable ICU 2.0 */ |
| #define U_SHAPE_LENGTH_MASK 3 |
| |
| |
| /** Direction indicator: the source is in logical (keyboard) order. @stable ICU 2.0 */ |
| #define U_SHAPE_TEXT_DIRECTION_LOGICAL 0 |
| |
| /** |
| * Direction indicator: |
| * the source is in visual LTR order, |
| * the leftmost displayed character stored first. |
| * @stable ICU 2.0 |
| */ |
| #define U_SHAPE_TEXT_DIRECTION_VISUAL_LTR 4 |
| |
| /** Bit mask for direction indicators. @stable ICU 2.0 */ |
| #define U_SHAPE_TEXT_DIRECTION_MASK 4 |
| |
| |
| /** Letter shaping option: do not perform letter shaping. @stable ICU 2.0 */ |
| #define U_SHAPE_LETTERS_NOOP 0 |
| |
| /** Letter shaping option: replace abstract letter characters by "shaped" ones. @stable ICU 2.0 */ |
| #define U_SHAPE_LETTERS_SHAPE 8 |
| |
| /** Letter shaping option: replace "shaped" letter characters by abstract ones. @stable ICU 2.0 */ |
| #define U_SHAPE_LETTERS_UNSHAPE 0x10 |
| |
| /** |
| * Letter shaping option: replace abstract letter characters by "shaped" ones. |
| * The only difference with U_SHAPE_LETTERS_SHAPE is that Tashkeel letters |
| * are always "shaped" into the isolated form instead of the medial form |
| * (selecting code points from the Arabic Presentation Forms-B block). |
| * @stable ICU 2.0 |
| */ |
| #define U_SHAPE_LETTERS_SHAPE_TASHKEEL_ISOLATED 0x18 |
| |
| /** Bit mask for letter shaping options. @stable ICU 2.0 */ |
| #define U_SHAPE_LETTERS_MASK 0x18 |
| |
| |
| /** Digit shaping option: do not perform digit shaping. @stable ICU 2.0 */ |
| #define U_SHAPE_DIGITS_NOOP 0 |
| |
| /** |
| * Digit shaping option: |
| * Replace European digits (U+0030...) by Arabic-Indic digits. |
| * @stable ICU 2.0 |
| */ |
| #define U_SHAPE_DIGITS_EN2AN 0x20 |
| |
| /** |
| * Digit shaping option: |
| * Replace Arabic-Indic digits by European digits (U+0030...). |
| * @stable ICU 2.0 |
| */ |
| #define U_SHAPE_DIGITS_AN2EN 0x40 |
| |
| /** |
| * Digit shaping option: |
| * Replace European digits (U+0030...) by Arabic-Indic digits if the most recent |
| * strongly directional character is an Arabic letter |
| * (<code>u_charDirection()</code> result <code>U_RIGHT_TO_LEFT_ARABIC</code> [AL]).<br> |
| * The direction of "preceding" depends on the direction indicator option. |
| * For the first characters, the preceding strongly directional character |
| * (initial state) is assumed to be not an Arabic letter |
| * (it is <code>U_LEFT_TO_RIGHT</code> [L] or <code>U_RIGHT_TO_LEFT</code> [R]). |
| * @stable ICU 2.0 |
| */ |
| #define U_SHAPE_DIGITS_ALEN2AN_INIT_LR 0x60 |
| |
| /** |
| * Digit shaping option: |
| * Replace European digits (U+0030...) by Arabic-Indic digits if the most recent |
| * strongly directional character is an Arabic letter |
| * (<code>u_charDirection()</code> result <code>U_RIGHT_TO_LEFT_ARABIC</code> [AL]).<br> |
| * The direction of "preceding" depends on the direction indicator option. |
| * For the first characters, the preceding strongly directional character |
| * (initial state) is assumed to be an Arabic letter. |
| * @stable ICU 2.0 |
| */ |
| #define U_SHAPE_DIGITS_ALEN2AN_INIT_AL 0x80 |
| |
| /** Not a valid option value. May be replaced by a new option. @stable ICU 2.0 */ |
| #define U_SHAPE_DIGITS_RESERVED 0xa0 |
| |
| /** Bit mask for digit shaping options. @stable ICU 2.0 */ |
| #define U_SHAPE_DIGITS_MASK 0xe0 |
| |
| |
| /** Digit type option: Use Arabic-Indic digits (U+0660...U+0669). @stable ICU 2.0 */ |
| #define U_SHAPE_DIGIT_TYPE_AN 0 |
| |
| /** Digit type option: Use Eastern (Extended) Arabic-Indic digits (U+06f0...U+06f9). @stable ICU 2.0 */ |
| #define U_SHAPE_DIGIT_TYPE_AN_EXTENDED 0x100 |
| |
| /** Not a valid option value. May be replaced by a new option. @stable ICU 2.0 */ |
| #define U_SHAPE_DIGIT_TYPE_RESERVED 0x200 |
| |
| /** Bit mask for digit type options. @stable ICU 2.0 */ |
| #define U_SHAPE_DIGIT_TYPE_MASK 0x3f00 |
| |
| #endif |
