From ca687005701304bf3b55670e0057a313411ef38b Mon Sep 17 00:00:00 2001 From: Simon Tatham Date: Sun, 20 Mar 2016 17:39:43 +0000 Subject: [PATCH] Fix downloading of variable-pitch X font glyphs. I had completely forgotten, when rendering each glyph to a server-side pixmap and downloading its contents, to only look at the part of the pixmap that XDrawImageString would have overwritten, as specified by the metrics in the XCharStruct. Now 'pterm -fn server:variable' doesn't randomly make up bitmap nonsense outside each character's bounding rectangle. --- unix/gtkfont.c | 45 ++++++++++++++++++++++++++++----------------- 1 file changed, 28 insertions(+), 17 deletions(-) diff --git a/unix/gtkfont.c b/unix/gtkfont.c index 2f7e4a61..725b1d4b 100644 --- a/unix/gtkfont.c +++ b/unix/gtkfont.c @@ -284,22 +284,12 @@ static int x11_font_width(XFontStruct *xfs, int sixteen_bit) } } -static int x11_font_has_glyph(XFontStruct *xfs, int byte1, int byte2) +static const XCharStruct *x11_char_struct(XFontStruct *xfs, + int byte1, int byte2) { int index; /* - * Not to be confused with x11font_has_glyph, which is a method of - * the x11font 'class' and hence takes a unifont as argument. This - * is the low-level function which grubs about in an actual - * XFontStruct to see if a given glyph exists. - * - * We must do this ourselves rather than letting Xlib's - * XTextExtents16 do the job, because XTextExtents will helpfully - * substitute the font's default_char for any missing glyph and - * not tell us it did so, which precisely won't help us find out - * which glyphs _are_ missing. - * * The man page for XQueryFont is rather confusing about how the * per_char array in the XFontStruct is laid out, because it gives * formulae for determining the two-byte X character code _from_ @@ -340,10 +330,27 @@ static int x11_font_has_glyph(XFontStruct *xfs, int byte1, int byte2) } if (!xfs->per_char) /* per_char NULL => everything in range exists */ - return TRUE; + return &xfs->max_bounds; + + return &xfs->per_char[index]; +} - return (xfs->per_char[index].ascent + xfs->per_char[index].descent > 0 || - xfs->per_char[index].width > 0); +static int x11_font_has_glyph(XFontStruct *xfs, int byte1, int byte2) +{ + /* + * Not to be confused with x11font_has_glyph, which is a method of + * the x11font 'class' and hence takes a unifont as argument. This + * is the low-level function which grubs about in an actual + * XFontStruct to see if a given glyph exists. + * + * We must do this ourselves rather than letting Xlib's + * XTextExtents16 do the job, because XTextExtents will helpfully + * substitute the font's default_char for any missing glyph and + * not tell us it did so, which precisely won't help us find out + * which glyphs _are_ missing. + */ + const XCharStruct *xcs = x11_char_struct(xfs, byte1, byte2); + return (xcs->ascent + xcs->descent > 0 || xcs->width > 0); } static unifont *x11font_create(GtkWidget *widget, const char *name, @@ -623,14 +630,18 @@ static void x11font_cairo_cache_glyph(x11font_individual *xfi, int glyphindex) int x, y; unsigned char *bitmap; Display *disp = GDK_DISPLAY_XDISPLAY(gdk_display_get_default()); + const XCharStruct *xcs = x11_char_struct(xfi->xfs, glyphindex >> 8, + glyphindex & 0xFF); bitmap = snewn(xfi->allsize, unsigned char); memset(bitmap, 0, xfi->allsize); image = XGetImage(disp, xfi->pixmap, 0, 0, xfi->pixwidth, xfi->pixheight, AllPlanes, XYPixmap); - for (y = 0; y < xfi->pixheight; y++) { - for (x = 0; x < xfi->pixwidth; x++) { + for (y = xfi->pixoriginy - xcs->ascent; + y < xfi->pixoriginy + xcs->descent; y++) { + for (x = xfi->pixoriginx + xcs->lbearing; + x < xfi->pixoriginx + xcs->rbearing; x++) { unsigned long pixel = XGetPixel(image, x, y); if (pixel) { int byteindex = y * xfi->rowsize + x/8; -- 2.45.2