/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright (C) 2014 David Herrmann systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . ***/ #pragma once #include #include #include #include "util.h" typedef struct term_char term_char_t; typedef struct term_charbuf term_charbuf_t; typedef struct term_color term_color; typedef struct term_attr term_attr; typedef struct term_cell term_cell; typedef struct term_line term_line; /* * Miscellaneous * Sundry things and external helpers. */ int mk_wcwidth(wchar_t ucs4); int mk_wcwidth_cjk(wchar_t ucs4); int mk_wcswidth(const wchar_t *str, size_t len); int mk_wcswidth_cjk(const wchar_t *str, size_t len); /* * Ageing * Redrawing terminals is quite expensive. Therefore, we avoid redrawing on * each single modification and mark modified cells instead. This way, we know * which cells to redraw on the next frame. However, a single DIRTY flag is not * enough for double/triple buffered screens, hence, we use an AGE field for * each cell. If the cell is modified, we simply increase the age by one. Each * framebuffer can then remember its last rendered age and request an update of * all newer cells. * TERM_AGE_NULL is special. If used as cell age, the cell must always be * redrawn (forced update). If used as framebuffer age, all cells are drawn. * This way, we can allow integer wrap-arounds. */ typedef uint64_t term_age_t; #define TERM_AGE_NULL 0 /* * Characters * Each cell in a terminal page contains only a single character. This is * usually a single UCS-4 value. However, Unicode allows combining-characters, * therefore, the number of UCS-4 characters per cell must be unlimited. The * term_char_t object wraps the internal combining char API so it can be * treated as a single object. */ struct term_char { /* never access this value directly */ uint64_t _value; }; struct term_charbuf { /* 3 bytes + zero-terminator */ uint32_t buf[4]; }; #define TERM_CHAR_INIT(_val) ((term_char_t){ ._value = (_val) }) #define TERM_CHAR_NULL TERM_CHAR_INIT(0) term_char_t term_char_set(term_char_t previous, uint32_t append_ucs4); term_char_t term_char_merge(term_char_t base, uint32_t append_ucs4); term_char_t term_char_dup(term_char_t ch); term_char_t term_char_dup_append(term_char_t base, uint32_t append_ucs4); const uint32_t *term_char_resolve(term_char_t ch, size_t *s, term_charbuf_t *b); unsigned int term_char_lookup_width(term_char_t ch); /* true if @ch is TERM_CHAR_NULL, otherwise false */ static inline bool term_char_is_null(term_char_t ch) { return ch._value == 0; } /* true if @ch is dynamically allocated and needs to be freed */ static inline bool term_char_is_allocated(term_char_t ch) { return !term_char_is_null(ch) && !(ch._value & 0x1); } /* true if (a == b), otherwise false; this is (a == b), NOT (*a == *b) */ static inline bool term_char_same(term_char_t a, term_char_t b) { return a._value == b._value; } /* true if (*a == *b), otherwise false; this is implied by (a == b) */ static inline bool term_char_equal(term_char_t a, term_char_t b) { const uint32_t *sa, *sb; term_charbuf_t ca, cb; size_t na, nb; sa = term_char_resolve(a, &na, &ca); sb = term_char_resolve(b, &nb, &cb); return na == nb && !memcmp(sa, sb, sizeof(*sa) * na); } /* free @ch in case it is dynamically allocated */ static inline term_char_t term_char_free(term_char_t ch) { if (term_char_is_allocated(ch)) term_char_set(ch, 0); return TERM_CHAR_NULL; } /* gcc _cleanup_ helpers */ #define _term_char_free_ _cleanup_(term_char_freep) static inline void term_char_freep(term_char_t *p) { term_char_free(*p); } /* * Attributes * Each cell in a terminal page can have its own set of attributes. These alter * the behavior of the renderer for this single cell. We use term_attr to * specify attributes. * The only non-obvious field is "ccode" for foreground and background colors. * This field contains the terminal color-code in case no full RGB information * was given by the host. It is also required for dynamic color palettes. If it * is set to TERM_CCODE_RGB, the "red", "green" and "blue" fields contain the * full RGB color. */ enum { /* dark color-codes */ TERM_CCODE_BLACK, TERM_CCODE_RED, TERM_CCODE_GREEN, TERM_CCODE_YELLOW, TERM_CCODE_BLUE, TERM_CCODE_MAGENTA, TERM_CCODE_CYAN, TERM_CCODE_WHITE, /* technically: light grey */ /* light color-codes */ TERM_CCODE_LIGHT_BLACK = TERM_CCODE_BLACK + 8, /* technically: dark grey */ TERM_CCODE_LIGHT_RED = TERM_CCODE_RED + 8, TERM_CCODE_LIGHT_GREEN = TERM_CCODE_GREEN + 8, TERM_CCODE_LIGHT_YELLOW = TERM_CCODE_YELLOW + 8, TERM_CCODE_LIGHT_BLUE = TERM_CCODE_BLUE + 8, TERM_CCODE_LIGHT_MAGENTA = TERM_CCODE_MAGENTA + 8, TERM_CCODE_LIGHT_CYAN = TERM_CCODE_CYAN + 8, TERM_CCODE_LIGHT_WHITE = TERM_CCODE_WHITE + 8, /* pseudo colors */ TERM_CCODE_FG, /* selected foreground color */ TERM_CCODE_BG, /* selected background color */ TERM_CCODE_RGB, /* color is specified as RGB */ TERM_CCODE_CNT, }; struct term_color { uint8_t ccode; uint8_t red; uint8_t green; uint8_t blue; }; struct term_attr { term_color fg; /* foreground color */ term_color bg; /* background color */ unsigned int bold : 1; /* bold font */ unsigned int italic : 1; /* italic font */ unsigned int underline : 1; /* underline text */ unsigned int inverse : 1; /* inverse fg/bg */ unsigned int protect : 1; /* protect from erase */ unsigned int blink : 1; /* blink text */ }; /* * Cells * The term_cell structure respresents a single cell in a terminal page. It * contains the stored character, the age of the cell and all its attributes. */ struct term_cell { term_char_t ch; /* stored char or TERM_CHAR_NULL */ term_age_t age; /* cell age or TERM_AGE_NULL */ term_attr attr; /* cell attributes */ unsigned int cwidth; /* cached term_char_lookup_width(cell->ch) */ }; /* * Lines * Instead of storing cells in a 2D array, we store them in an array of * dynamically allocated lines. This way, scrolling can be implemented very * fast without moving any cells at all. Similarly, the scrollback-buffer is * much simpler to implement. * We use term_line to store a single line. It contains an array of cells, a * fill-state which remembers the amount of blanks on the right side, a * separate age just for the line which can overwrite the age for all cells, * and some management data. */ struct term_line { term_line *lines_next; /* linked-list for histories */ term_line *lines_prev; /* linked-list for histories */ unsigned int width; /* visible width of line */ unsigned int n_cells; /* # of allocated cells */ term_cell *cells; /* cell-array */ term_age_t age; /* line age */ unsigned int fill; /* # of valid cells; starting left */ }; int term_line_new(term_line **out); term_line *term_line_free(term_line *line); #define _term_line_free_ _cleanup_(term_line_freep) DEFINE_TRIVIAL_CLEANUP_FUNC(term_line*, term_line_free); int term_line_reserve(term_line *line, unsigned int width, const term_attr *attr, term_age_t age, unsigned int protect_width); void term_line_set_width(term_line *line, unsigned int width); void term_line_write(term_line *line, unsigned int pos_x, term_char_t ch, unsigned int cwidth, const term_attr *attr, term_age_t age, bool insert_mode); void term_line_insert(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age); void term_line_delete(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age); void term_line_append_combchar(term_line *line, unsigned int pos_x, uint32_t ucs4, term_age_t age); void term_line_erase(term_line *line, unsigned int from, unsigned int num, const term_attr *attr, term_age_t age, bool keep_protected); void term_line_reset(term_line *line, const term_attr *attr, term_age_t age); void term_line_link(term_line *line, term_line **first, term_line **last); void term_line_link_tail(term_line *line, term_line **first, term_line **last); void term_line_unlink(term_line *line, term_line **first, term_line **last); #define TERM_LINE_LINK(_line, _head) term_line_link((_line), &(_head)->lines_first, &(_head)->lines_last) #define TERM_LINE_LINK_TAIL(_line, _head) term_line_link_tail((_line), &(_head)->lines_first, &(_head)->lines_last) #define TERM_LINE_UNLINK(_line, _head) term_line_unlink((_line), &(_head)->lines_first, &(_head)->lines_last)