nhyatt/putty-source
1
0
Fork 0
mirror of https://git.tartarus.org/simon/putty.git synced 2025-05-09 21:52:10 -05:00
Code Issues Projects Releases Wiki Activity

GTK: use Cairo to read X font bitmaps from server

Browse Source 
When using an X server-side font with Cairo rendering, PuTTY takes the
rather horrible approach of rendering each glyph it uses into a depth-1
Pixmap and then copying the result into a Cairo surface that it uses
every time it wants to display that glyph.

Heretofore, the conversion of the Pixmap into a Cairo surface was done
by downloading it using XGetImage() and then manually re-arringing the
bits into a suitable form for Cairo.  But Cairo has a way of turning an
X Drawable (including a Pixmap) into a surface, and then it's just a
case of copying one surface to another using cairo_paint().  So that's
what PuTTY does now and the process is a little less unpleasant than it
was.
This commit is contained in:
Ben Harris 2025-04-21 21:16:40 +01:00
parent 5cf14b4f27
commit 11f4e2d8b5
1 changed files with 17 additions and 56 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
unix/unifont.c
View File

@ -27,6 +27,9 @@
#include "tree234.h"
#ifndef NOT_X_WINDOWS
#ifdef DRAW_TEXT_CAIRO
#include <cairo-xlib.h>
#endif
#include <gdk/gdkx.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
@ -131,7 +134,6 @@ static char *x11font_size_increment(unifont *font, int increment);
#ifdef DRAW_TEXT_CAIRO
struct cairo_cached_glyph {
cairo_surface_t *surface;
unsigned char *bitmap;
};
#endif
@ -165,13 +167,9 @@ typedef struct x11font_individual {
* X server paraphernalia for actually downloading the glyphs.
*/
Pixmap pixmap;
cairo_surface_t *pixmap_surface; /* Cairo version of pixmap. */
GC gc;
int pixwidth, pixheight, pixoriginx, pixoriginy;
/*
* Paraphernalia for loading the resulting bitmaps into Cairo.
*/
int rowsize, allsize, indexflip;
#endif
} x11font_individual;
@ -535,6 +533,7 @@ static unifont *x11font_create(GtkWidget *widget, const char *name,
xfont->fonts[i].glyphcache = NULL;
xfont->fonts[i].nglyphs = 0;
xfont->fonts[i].pixmap = None;
xfont->fonts[i].pixmap_surface = NULL;
xfont->fonts[i].gc = None;
#endif
}
@ -556,13 +555,14 @@ static void x11font_destroy(unifont *font)
#ifdef DRAW_TEXT_CAIRO
if (xfont->fonts[i].gc != None)
XFreeGC(disp, xfont->fonts[i].gc);
if (xfont->fonts[i].pixmap_surface != NULL)
cairo_surface_destroy(xfont->fonts[i].pixmap_surface);
if (xfont->fonts[i].pixmap != None)
XFreePixmap(disp, xfont->fonts[i].pixmap);
if (xfont->fonts[i].glyphcache) {
int j;
for (j = 0; j < xfont->fonts[i].nglyphs; j++) {
cairo_surface_destroy(xfont->fonts[i].glyphcache[j].surface);
sfree(xfont->fonts[i].glyphcache[j].bitmap);
}
sfree(xfont->fonts[i].glyphcache);
}
@ -671,29 +671,12 @@ static void x11font_cairo_setup(
xfi->pixoriginx = -xfi->xfs->min_bounds.lbearing;
xfi->pixoriginy = xfi->xfs->max_bounds.ascent;
xfi->rowsize = cairo_format_stride_for_width(CAIRO_FORMAT_A1,
xfi->pixwidth);
xfi->allsize = xfi->rowsize * xfi->pixheight;
{
/*
* Test host endianness and use it to set xfi->indexflip,
* which is XORed into our left-shift counts in order to
* implement the CAIRO_FORMAT_A1 specification, in which
* each bitmap byte is oriented LSB-first on little-endian
* platforms and MSB-first on big-endian ones.
*
* This is the same technique Cairo itself uses to test
* endianness, so hopefully it'll work in any situation
* where Cairo is usable at all.
*/
static const int endianness_test = 1;
xfi->indexflip = (*((char *) &endianness_test) == 1) ? 0 : 7;
}
xfi->pixmap = XCreatePixmap(
disp, GDK_DRAWABLE_XID(gtk_widget_get_window(ctx->u.cairo.widget)),
xfi->pixwidth, xfi->pixheight, 1);
xfi->pixmap_surface = cairo_xlib_surface_create_for_bitmap(
disp, xfi->pixmap, ScreenOfDisplay(disp, widgetscr),
xfi->pixwidth, xfi->pixheight);
gcvals.foreground = WhitePixel(disp, widgetscr);
gcvals.background = BlackPixel(disp, widgetscr);
gcvals.font = xfi->xfs->fid;
@ -705,31 +688,6 @@ static void x11font_cairo_setup(
static void x11font_cairo_cache_glyph(
Display *disp, x11font_individual *xfi, int glyphindex)
{
XImage *image;
int x, y;
unsigned char *bitmap;
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 = 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;
int bitindex = (x & 7) ^ xfi->indexflip;
bitmap[byteindex] |= 1U << bitindex;
}
}
}
XDestroyImage(image);
if (xfi->nglyphs <= glyphindex) {
/* Round up to the next multiple of 256 on the general
* principle that Unicode characters come in contiguous blocks
@ -741,13 +699,16 @@ static void x11font_cairo_cache_glyph(
while (old_nglyphs < xfi->nglyphs) {
xfi->glyphcache[old_nglyphs].surface = NULL;
xfi->glyphcache[old_nglyphs].bitmap = NULL;
old_nglyphs++;
}
}
xfi->glyphcache[glyphindex].bitmap = bitmap;
xfi->glyphcache[glyphindex].surface = cairo_image_surface_create_for_data(
bitmap, CAIRO_FORMAT_A1, xfi->pixwidth, xfi->pixheight, xfi->rowsize);
cairo_surface_mark_dirty(xfi->pixmap_surface);
xfi->glyphcache[glyphindex].surface = cairo_image_surface_create(
CAIRO_FORMAT_A1, xfi->pixwidth, xfi->pixheight);
cairo_t *cr = cairo_create(xfi->glyphcache[glyphindex].surface);
cairo_set_source_surface(cr, xfi->pixmap_surface, 0, 0);
cairo_paint(cr);
cairo_destroy(cr);
}
static void x11font_cairo_draw_glyph(unifont_drawctx *ctx,