commit 6be057f060543bb0f3ed9423904263617cdffffe
parent 41fdabbf7c517f8d524b70cbd78238cc319ccef3
Author: NRK <nrk@disroot.org>
Date:   Thu, 24 Mar 2022 02:00:00 +0600

introduce drw_fontset_getwidth_clamp()

getting the width of a string is an O(n) operation, and in many cases
users only care about getting the width upto a certain number.

instead of calling drw_fontset_getwidth() and *then* clamping the
result, this patch introduces drw_fontset_getwidth_clamp() function,
similar to strnlen(), which will stop once we reach n.

the `invert` parameter was overloaded internally to preserve the API,
however library users should be calling drw_fontset_getwidth_clamp() and
not depend upon internal behavior of drw_text().

Diffstat:
Mdrw.c | 19+++++++++++++++++--
Mdrw.h | 1+
2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drw.c b/drw.c @@ -268,7 +268,7 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp return 0; if (!render) { - w = ~w; + w = invert ? invert : ~invert; } else { XSetForeground(drw->dpy, drw->gc, drw->scheme[invert ? ColFg : ColBg].pixel); XFillRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w, h); @@ -300,7 +300,13 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp if (ew + tmpw > w) { overflow = 1; - utf8strlen = ellipsis_len; + /* called from drw_fontset_getwidth_clamp(): + * it wants the width AFTER the overflow + */ + if (!render) + x += tmpw; + else + utf8strlen = ellipsis_len; } else if (curfont == usedfont) { utf8strlen += utf8charlen; text += utf8charlen; @@ -397,6 +403,15 @@ drw_fontset_getwidth(Drw *drw, const char *text) return drw_text(drw, 0, 0, 0, 0, 0, text, 0); } +unsigned int +drw_fontset_getwidth_clamp(Drw *drw, const char *text, unsigned int n) +{ + unsigned int tmp = 0; + if (drw && drw->fonts && text && n) + tmp = drw_text(drw, 0, 0, 0, 0, 0, text, n); + return MIN(n, tmp); +} + void drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w, unsigned int *h) { diff --git a/drw.h b/drw.h @@ -35,6 +35,7 @@ void drw_free(Drw *drw); Fnt *drw_fontset_create(Drw* drw, const char *fonts[], size_t fontcount); void drw_fontset_free(Fnt* set); unsigned int drw_fontset_getwidth(Drw *drw, const char *text); +unsigned int drw_fontset_getwidth_clamp(Drw *drw, const char *text, unsigned int n); void drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w, unsigned int *h); /* Colorscheme abstraction */