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Optimized performance for low-bit-rate terminals. #199

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51015a5
Optimized performance for low-bit-rate terminals.
yesthatjwz Mar 1, 2025
650ea8b
Detect when -lncurses also requires -lncursesw for waddnwstr, e.g. li…
yesthatjwz Mar 1, 2025
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98 changes: 65 additions & 33 deletions cmatrix.c
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Original file line number Diff line number Diff line change
Expand Up @@ -86,6 +86,7 @@ int console = 0;
int xwindow = 0;
int lock = 0;
cmatrix **matrix = (cmatrix **) NULL;
cmatrix **omatrix = (cmatrix **) NULL;
int *length = NULL; /* Length of cols in each line */
int *spaces = NULL; /* Spaces left to fill */
int *updates = NULL; /* What does this do again? */
Expand Down Expand Up @@ -196,12 +197,17 @@ void var_init() {
if (matrix != NULL) {
free(matrix[0]);
free(matrix);
free(omatrix[0]);
free(omatrix);
}

matrix = nmalloc(sizeof(cmatrix *) * (LINES + 1));
omatrix = nmalloc(sizeof(cmatrix *) * (LINES + 1));
matrix[0] = nmalloc(sizeof(cmatrix) * (LINES + 1) * COLS);
omatrix[0] = nmalloc(sizeof(cmatrix) * (LINES + 1) * COLS);
for (i = 1; i <= LINES; i++) {
matrix[i] = matrix[i - 1] + COLS;
omatrix[i] = omatrix[i - 1] + COLS;
}

if (length != NULL) {
Expand All @@ -223,6 +229,7 @@ void var_init() {
for (i = 0; i <= LINES; i++) {
for (j = 0; j <= COLS - 1; j += 2) {
matrix[i][j].val = -1;
omatrix[i][j].val = -1;
}
}

Expand Down Expand Up @@ -333,6 +340,7 @@ int main(int argc, char *argv[]) {
int changes = 0;
char *msg = "";
char *tty = NULL;
NCURSES_ATTR_T oattr = 0;

srand((unsigned) time(NULL));
setlocale(LC_ALL, "");
Expand Down Expand Up @@ -754,24 +762,54 @@ if (console) {
}
}
}
/* A simple hack */
if (!oldstyle) {
y = 1;
z = LINES;
} else {
y = 0;
z = LINES - 1;
}
for (i = y; i <= z; i++) {
move(i - y, j);
}

/* A simple hack */
if (!oldstyle) {
y = 1;
z = LINES;
} else {
y = 0;
z = LINES - 1;
}

// Update horizontally so that we can omit a move() if the last
// insertion already advanced the cursor to there.

int ox = -1, oy = -1;
for (i = y; i <= z; i++) {
for (j = 0; j <= COLS - 1; j += 2) {

if (omatrix[i][j].val == matrix[i][j].val &&
omatrix[i][j].is_head == matrix[i][j].is_head) {
continue;
}

omatrix[i][j] = matrix[i][j];

// Move to the next column using a space instead of "\e[24;80H"
if (ox == j - 1 && oy == i - y) {
addch(' ');
} else {
move(i - y, j);
}

ox = j + 1;
oy = i - y;

NCURSES_ATTR_T attr = 0;

if (matrix[i][j].val == 0 || (matrix[i][j].is_head && !rainbow)) {
if (console || xwindow) {
attron(A_ALTCHARSET);
attr |= A_ALTCHARSET;
}
attron(COLOR_PAIR(COLOR_WHITE));
attr |= COLOR_PAIR(COLOR_WHITE);
if (bold) {
attron(A_BOLD);
attr |= A_BOLD;
}
if (attr != oattr) {
attrset(attr);
oattr = attr;
}
if (matrix[i][j].val == 0) {
if (console || xwindow) {
Expand All @@ -785,13 +823,6 @@ if (console) {
addch(matrix[i][j].val);
}

attroff(COLOR_PAIR(COLOR_WHITE));
if (bold) {
attroff(A_BOLD);
}
if (console || xwindow) {
attroff(A_ALTCHARSET);
}
} else {
if (rainbow) {
int randomColor = rand() % 6;
Expand All @@ -817,27 +848,36 @@ if (console) {
break;
}
}
attron(COLOR_PAIR(mcolor));
attr |= COLOR_PAIR(mcolor);
if (matrix[i][j].val == 1) {
if (bold) {
attron(A_BOLD);
attr |= A_BOLD;
}
addch('|');
if (bold) {
attroff(A_BOLD);
attr |= A_BOLD;
}
} else {
if (console || xwindow) {
attron(A_ALTCHARSET);
attr |= A_ALTCHARSET;
}
if (bold == 2 ||
(bold == 1 && matrix[i][j].val % 2 == 0)) {
attron(A_BOLD);
attr |= A_BOLD;
}
if (attr != oattr) {
attrset(attr);
oattr = attr;
}
if (matrix[i][j].val == -1) {
addch(' ');
} else if (lambda && matrix[i][j].val != ' ') {
addstr("λ");
} else if (matrix[i][j].val < 0xFF) {
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Should this be < 0x7f instead? That's where UTF-8 goes multibyte. I think this will mis-display characters in the Latin-1 block.

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These are 32 bit Unicode characters, not multi-byte UTF-8 sequences.

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"These" are indeed wchar_t but addch says vaguely it expects a "character" (but takes a single byte) and so it's not clear to me whether we can write ¶ the pilcrow or similar which are outside ASCII though fit in a single byte. If the terminal speaks UTF-8 (as a modern terminal probably does) then there needs to be 2 bytes emitted by the curses implementation to make that symbol.

I tried to see what happens here and discovered that I'm sufficiently rusty that I wasn't able to write a working test (the painkillers and/or broken left hand may not have helped but eh) but if it does work to emit addch a value like 0xB4 on an UTF-8 terminal that probably deserves a comment.

// If it's not a unichar, write it the easy way.
// Valgrind tells me that addwstr is doing an
// invalid read on Rasperry Pi + Debian 12.
addch(matrix[i][j].val);
} else {
/* addch doesn't seem to work with unicode
* characters and there was no direct equivalent.
Expand All @@ -849,15 +889,7 @@ if (console) {
char_array[1] = 0;
addwstr(char_array);
}
if (bold == 2 ||
(bold == 1 && matrix[i][j].val % 2 == 0)) {
attroff(A_BOLD);
}
if (console || xwindow) {
attroff(A_ALTCHARSET);
}
}
attroff(COLOR_PAIR(mcolor));
}
}
}
Expand Down
7 changes: 7 additions & 0 deletions configure.ac
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Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,13 @@ then
AC_CHECK_LIB(tinfo, tgetent, CURSES_LIB="-ltinfo" CURSES_LIB_NAME=tinfo)
fi

dnl If this is ncurses, waddnwstr might be in ncursesw instead.
if eval "test x$CURSES_LIB_NAME = xncurses"
then
AC_CHECK_LIB(ncurses, waddnwstr, [],
AC_CHECK_LIB(ncursesw, waddnwstr, CURSES_LIB="$CURSES_LIB -lncursesw"))
fi

if eval "test x$CURSES_LIB_NAME = x"
then
AC_MSG_WARN([
Expand Down