diff options
Diffstat (limited to 'src/nvim/globals.h')
| -rw-r--r-- | src/nvim/globals.h | 55 |
1 files changed, 28 insertions, 27 deletions
diff --git a/src/nvim/globals.h b/src/nvim/globals.h index 51bc3f1289..20e5353b51 100644 --- a/src/nvim/globals.h +++ b/src/nvim/globals.h @@ -131,38 +131,39 @@ typedef off_t off_T; /* * The characters and attributes cached for the screen. */ -typedef char_u schar_T; -typedef unsigned short sattr_T; - -/* - * The characters that are currently on the screen are kept in ScreenLines[]. - * It is a single block of characters, the size of the screen plus one line. - * The attributes for those characters are kept in ScreenAttrs[]. - * - * "LineOffset[n]" is the offset from ScreenLines[] for the start of line 'n'. - * The same value is used for ScreenLinesUC[] and ScreenAttrs[]. - * - * Note: before the screen is initialized and when out of memory these can be - * NULL. - */ +typedef char_u schar_T[(MAX_MCO+1) * 4 + 1]; +typedef int16_t sattr_T; + +/// ScreenLines[] contains a copy of the whole screen, as it currently is +/// displayed. It is a single block of screen cells, the size of the screen +/// plus one line. The extra line used as a buffer while redrawing a window +/// line, so it can be compared with the previous state of that line. This way +/// we can avoid sending bigger updates than neccessary to the Ul layer. +/// +/// Screen cells are stored as NUL-terminated UTF-8 strings, and a cell can +/// contain up to MAX_MCO composing characters after the base character. +/// The composing characters are to be drawn on top of the original character. +/// The content after the NUL is not defined (so comparison must be done a +/// single cell at a time). Double-width characters are stored in the left cell, +/// and the right cell should only contain the empty string. When a part of the +/// screen is cleared, the cells should be filled with a single whitespace char. +/// +/// ScreenAttrs[] contains the highlighting attribute for each cell. +/// LineOffset[n] is the offset from ScreenLines[] and ScreenAttrs[] for the +/// start of line 'n'. These offsets are in general not linear, as full screen +/// scrolling is implemented by rotating the offsets in the LineOffset array. +/// LineWraps[] is an array of boolean flags indicating if the screen line wraps +/// to the next line. It can only be true if a window occupies the entire screen +/// width. +/// +/// +/// Note: before the screen is initialized and when out of memory these can be +/// NULL. EXTERN schar_T *ScreenLines INIT(= NULL); EXTERN sattr_T *ScreenAttrs INIT(= NULL); EXTERN unsigned *LineOffset INIT(= NULL); EXTERN char_u *LineWraps INIT(= NULL); /* line wraps to next line */ -/* - * When using Unicode characters (in UTF-8 encoding) the character in - * ScreenLinesUC[] contains the Unicode for the character at this position, or - * NUL when the character in ScreenLines[] is to be used (ASCII char). - * The composing characters are to be drawn on top of the original character. - * ScreenLinesC[0][off] is only to be used when ScreenLinesUC[off] != 0. - * Note: These three are only allocated when enc_utf8 is set! - */ -EXTERN u8char_T *ScreenLinesUC INIT(= NULL); /* decoded UTF-8 characters */ -EXTERN u8char_T *ScreenLinesC[MAX_MCO]; /* composing characters */ -EXTERN int Screen_mco INIT(= 0); /* value of p_mco used when - allocating ScreenLinesC[] */ - EXTERN int screen_Rows INIT(= 0); /* actual size of ScreenLines[] */ EXTERN int screen_Columns INIT(= 0); /* actual size of ScreenLines[] */ |