Add support for opening Xcursor files

Sadly, they don't have a canonical extension, and they don't show up
in the browser.  We might want to employ some level of sniffing.
The first 16 bytes are enough to identify a lot.
This commit is contained in:
Přemysl Eric Janouch 2021-11-17 13:45:42 +01:00
parent e8754f43a6
commit db7a28b187
Signed by: p
GPG Key ID: A0420B94F92B9493
6 changed files with 151 additions and 3 deletions

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@ -20,7 +20,7 @@ Building and Running
Build dependencies: Meson, pkg-config + Build dependencies: Meson, pkg-config +
Runtime dependencies: gtk+-3.0, glib>=2.64, pixman-1, shared-mime-info, Runtime dependencies: gtk+-3.0, glib>=2.64, pixman-1, shared-mime-info,
spng>=0.7.0, libturbojpeg, LibRaw (optional), librsvg-2.0 (optional), spng>=0.7.0, libturbojpeg, LibRaw (optional), librsvg-2.0 (optional),
gdk-pixbuf-2.0 (optional) xcursor (optional), gdk-pixbuf-2.0 (optional)
$ git clone --recursive https://git.janouch.name/p/fastiv.git $ git clone --recursive https://git.janouch.name/p/fastiv.git
$ meson builddir $ meson builddir

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@ -30,6 +30,9 @@
#ifdef HAVE_LIBRSVG #ifdef HAVE_LIBRSVG
#include <librsvg/rsvg.h> #include <librsvg/rsvg.h>
#endif // HAVE_LIBRSVG #endif // HAVE_LIBRSVG
#ifdef HAVE_XCURSOR
#include <X11/Xcursor/Xcursor.h>
#endif // HAVE_XCURSOR
#ifdef HAVE_GDKPIXBUF #ifdef HAVE_GDKPIXBUF
#include <gdk/gdk.h> #include <gdk/gdk.h>
#include <gdk-pixbuf/gdk-pixbuf.h> #include <gdk-pixbuf/gdk-pixbuf.h>
@ -69,6 +72,9 @@ const char *fastiv_io_supported_media_types[] = {
#ifdef HAVE_LIBRSVG #ifdef HAVE_LIBRSVG
"image/svg+xml", "image/svg+xml",
#endif // HAVE_LIBRSVG #endif // HAVE_LIBRSVG
#ifdef HAVE_XCURSOR
"image/x-xcursor",
#endif // HAVE_XCURSOR
NULL NULL
}; };
@ -566,6 +572,132 @@ open_librsvg(const gchar *data, gsize len, const gchar *path, GError **error)
} }
#endif // HAVE_LIBRSVG -------------------------------------------------------- #endif // HAVE_LIBRSVG --------------------------------------------------------
#ifdef HAVE_XCURSOR //---------------------------------------------------------
// fmemopen is part of POSIX-1.2008, this exercise is technically unnecessary.
// libXcursor checks for EOF rather than -1, it may eat your hamster.
struct fastiv_io_xcursor {
XcursorFile parent;
unsigned char *data;
long position, len;
};
static int
fastiv_io_xcursor_read(XcursorFile *file, unsigned char *buf, int len)
{
struct fastiv_io_xcursor *fix = (struct fastiv_io_xcursor *) file;
if (fix->position < 0 || fix->position > fix->len) {
errno = EOVERFLOW;
return -1;
}
long n = MIN(fix->len - fix->position, len);
if (n > G_MAXINT) {
errno = EIO;
return -1;
}
memcpy(buf, fix->data + fix->position, n);
fix->position += n;
return n;
}
static int
fastiv_io_xcursor_write(G_GNUC_UNUSED XcursorFile *file,
G_GNUC_UNUSED unsigned char *buf, G_GNUC_UNUSED int len)
{
errno = EBADF;
return -1;
}
static int
fastiv_io_xcursor_seek(XcursorFile *file, long offset, int whence)
{
struct fastiv_io_xcursor *fix = (struct fastiv_io_xcursor *) file;
switch (whence) {
case SEEK_SET:
fix->position = offset;
break;
case SEEK_CUR:
fix->position += offset;
break;
case SEEK_END:
fix->position = fix->len + offset;
break;
default:
errno = EINVAL;
return -1;
}
// This is technically too late for fseek(), but libXcursor doesn't care.
if (fix->position < 0) {
errno = EINVAL;
return -1;
}
return fix->position;
}
static const XcursorFile fastiv_io_xcursor_adaptor = {
.closure = NULL,
.read = fastiv_io_xcursor_read,
.write = fastiv_io_xcursor_write,
.seek = fastiv_io_xcursor_seek,
};
static cairo_surface_t *
open_xcursor(const gchar *data, gsize len, GError **error)
{
if (len > G_MAXLONG) {
set_error(error, "size overflow");
return NULL;
}
struct fastiv_io_xcursor file = {
.parent = fastiv_io_xcursor_adaptor,
.data = (unsigned char *) data,
.position = 0,
.len = len,
};
XcursorImages *images = XcursorXcFileLoadAllImages(&file.parent);
if (!images) {
set_error(error, "general failure");
return NULL;
}
// Let's just arrange the pixel data in a recording surface.
static cairo_user_data_key_t key = {};
cairo_surface_t *recording =
cairo_recording_surface_create(CAIRO_CONTENT_COLOR_ALPHA, NULL);
cairo_surface_set_user_data(
recording, &key, images, (cairo_destroy_func_t) XcursorImagesDestroy);
cairo_t *cr = cairo_create(recording);
// Unpack horizontally by animation, vertically by size.
XcursorDim last_nominal = -1;
int x = 0, y = 0, row_height = 0;
for (int i = 0; i < images->nimage; i++) {
XcursorImage *image = images->images[i];
if (image->size != last_nominal) {
x = 0;
y += row_height;
row_height = 0;
last_nominal = image->size;
}
// TODO(p): Byte-swap if on big-endian. Wuffs doesn't even build there.
cairo_surface_t *source = cairo_image_surface_create_for_data(
(unsigned char *) image->pixels, CAIRO_FORMAT_ARGB32,
image->width, image->height, image->width * sizeof *image->pixels);
cairo_set_source_surface(cr, source, x, y);
cairo_surface_destroy(source);
cairo_paint(cr);
x += image->width;
row_height = MAX(row_height, (int) image->height);
}
cairo_destroy(cr);
return recording;
}
#endif // HAVE_XCURSOR --------------------------------------------------------
#ifdef HAVE_GDKPIXBUF // ------------------------------------------------------ #ifdef HAVE_GDKPIXBUF // ------------------------------------------------------
static cairo_surface_t * static cairo_surface_t *
@ -663,6 +795,14 @@ fastiv_io_open_from_data(const char *data, size_t len, const gchar *path,
g_clear_error(error); g_clear_error(error);
} }
#endif // HAVE_LIBRSVG -------------------------------------------------------- #endif // HAVE_LIBRSVG --------------------------------------------------------
#ifdef HAVE_XCURSOR //---------------------------------------------------------
if ((surface = open_xcursor(data, len, error)))
break;
if (error) {
g_debug("%s", (*error)->message);
g_clear_error(error);
}
#endif // HAVE_XCURSOR --------------------------------------------------------
#ifdef HAVE_GDKPIXBUF // ------------------------------------------------------ #ifdef HAVE_GDKPIXBUF // ------------------------------------------------------
// This is only used as a last resort, the rest above is special-cased. // This is only used as a last resort, the rest above is special-cased.
if ((surface = open_gdkpixbuf(data, len, error)) || if ((surface = open_gdkpixbuf(data, len, error)) ||

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@ -86,7 +86,10 @@ get_surface_dimensions(FastivView *self, double *width, double *height)
*height = cairo_image_surface_get_height(self->surface); *height = cairo_image_surface_get_height(self->surface);
return; return;
case CAIRO_SURFACE_TYPE_RECORDING: case CAIRO_SURFACE_TYPE_RECORDING:
(void) cairo_recording_surface_get_extents(self->surface, &extents); if (!cairo_recording_surface_get_extents(self->surface, &extents))
cairo_recording_surface_ink_extents(self->surface,
&extents.x, &extents.y, &extents.width, &extents.height);
*width = extents.width; *width = extents.width;
*height = extents.height; *height = extents.height;
return; return;

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@ -8,4 +8,4 @@ Terminal=false
StartupNotify=true StartupNotify=true
Categories=Graphics;2DGraphics;Viewer; Categories=Graphics;2DGraphics;Viewer;
# TODO(p): Generate this list from source files. # TODO(p): Generate this list from source files.
MimeType=image/png;image/bmp;image/gif;image/jpeg;image/x-dcraw;image/svg+xml; MimeType=image/png;image/bmp;image/gif;image/jpeg;image/x-dcraw;image/svg+xml;image/x-xcursor;

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@ -3,6 +3,7 @@ project('fastiv', 'c', default_options : ['c_std=gnu99'], version : '0.1.0')
# TODO(p): Use libraw_r later, when we start parallelizing/preloading. # TODO(p): Use libraw_r later, when we start parallelizing/preloading.
libraw = dependency('libraw', required : get_option('libraw')) libraw = dependency('libraw', required : get_option('libraw'))
librsvg = dependency('librsvg-2.0', required : get_option('librsvg')) librsvg = dependency('librsvg-2.0', required : get_option('librsvg'))
xcursor = dependency('xcursor', required : get_option('xcursor'))
gdkpixbuf = dependency('gdk-pixbuf-2.0', required : get_option('gdk-pixbuf')) gdkpixbuf = dependency('gdk-pixbuf-2.0', required : get_option('gdk-pixbuf'))
dependencies = [ dependencies = [
dependency('gtk+-3.0'), dependency('gtk+-3.0'),
@ -12,6 +13,7 @@ dependencies = [
dependency('pixman-1'), dependency('pixman-1'),
libraw, libraw,
librsvg, librsvg,
xcursor,
gdkpixbuf, gdkpixbuf,
meson.get_compiler('c').find_library('m', required : false), meson.get_compiler('c').find_library('m', required : false),
] ]
@ -21,6 +23,7 @@ conf.set_quoted('PROJECT_NAME', meson.project_name())
conf.set_quoted('PROJECT_VERSION', meson.project_version()) conf.set_quoted('PROJECT_VERSION', meson.project_version())
conf.set('HAVE_LIBRAW', libraw.found()) conf.set('HAVE_LIBRAW', libraw.found())
conf.set('HAVE_LIBRSVG', librsvg.found()) conf.set('HAVE_LIBRSVG', librsvg.found())
conf.set('HAVE_XCURSOR', xcursor.found())
conf.set('HAVE_GDKPIXBUF', gdkpixbuf.found()) conf.set('HAVE_GDKPIXBUF', gdkpixbuf.found())
configure_file( configure_file(
output : 'config.h', output : 'config.h',

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@ -2,5 +2,7 @@ option('libraw', type : 'feature', value : 'auto',
description : 'Build with RAW support, requires LibRaw') description : 'Build with RAW support, requires LibRaw')
option('librsvg', type : 'feature', value : 'auto', option('librsvg', type : 'feature', value : 'auto',
description : 'Build with SVG support, requires librsvg') description : 'Build with SVG support, requires librsvg')
option('xcursor', type : 'feature', value : 'auto',
description : 'Build with Xcursor support, requires libXcursor')
option('gdk-pixbuf', type : 'feature', value : 'auto', option('gdk-pixbuf', type : 'feature', value : 'auto',
description : 'Build with a fallback to the gdk-pixbuf library') description : 'Build with a fallback to the gdk-pixbuf library')