Add very basic SVG support

We need to refactor, so that SVGs are pre-rendered on each change
of scaling by librsvg directly, because some elements may be rasterized.

It would be best to also support building against resvg.
This commit is contained in:
Přemysl Eric Janouch 2021-11-09 19:42:43 +01:00
parent 1e380f695a
commit 1c5cc50939
Signed by: p
GPG Key ID: A0420B94F92B9493
7 changed files with 150 additions and 22 deletions

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@ -2,7 +2,7 @@ fastiv
======
'fastiv' is a fast image viewer, supporting BMP, PNG, GIF, JPEG, and optionally
RAW pictures. Currently, it's not particularly usable.
RAW and SVG pictures. Currently, it's not particularly usable.
Non-goals
---------
@ -19,7 +19,7 @@ Building and Running
--------------------
Build dependencies: Meson, pkg-config +
Runtime dependencies: gtk+-3.0, pixman-1, shared-mime-info, libpng>=1.5.4,
libturbojpeg, LibRaw (optional)
libturbojpeg, LibRaw (optional), librsvg-2.0 (optional)
$ git clone --recursive https://git.janouch.name/p/fastiv.git
$ meson builddir

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@ -23,6 +23,9 @@
#ifdef HAVE_LIBRAW
#include <libraw.h>
#endif // HAVE_LIBRAW
#ifdef HAVE_LIBRSVG
#include <librsvg/rsvg.h>
#endif // HAVE_LIBRSVG
#define WUFFS_IMPLEMENTATION
#define WUFFS_CONFIG__MODULES
@ -38,6 +41,7 @@
#include "wuffs-mirror-release-c/release/c/wuffs-v0.3.c"
#include "xdg.h"
#include "fastiv-io.h"
// A subset of shared-mime-info that produces an appropriate list of
// file extensions. Chiefly motivated by the suckiness of RAW images:
@ -50,6 +54,9 @@ const char *fastiv_io_supported_media_types[] = {
#ifdef HAVE_LIBRAW
"image/x-dcraw",
#endif // HAVE_LIBRAW
#ifdef HAVE_LIBRSVG
"image/svg+xml",
#endif // HAVE_LIBRSVG
NULL
};
@ -384,6 +391,81 @@ open_libraw(const gchar *data, gsize len, GError **error)
}
#endif // HAVE_LIBRAW ---------------------------------------------------------
#ifdef HAVE_LIBRSVG // --------------------------------------------------------
#ifdef FASTIV_RSVG_DEBUG
#include <cairo/cairo-script.h>
#include <cairo/cairo-svg.h>
#endif
// FIXME: librsvg rasterizes filters, so this method isn't fully appropriate.
static cairo_surface_t *
open_librsvg(const gchar *data, gsize len, GError **error)
{
RsvgHandle *handle =
rsvg_handle_new_from_data((const guint8 *) data, len, error);
if (!handle)
return NULL;
// TODO(p): Acquire this from somewhere else.
rsvg_handle_set_dpi(handle, 96);
double w = 0, h = 0;
if (!rsvg_handle_get_intrinsic_size_in_pixels(handle, &w, &h)) {
set_error(error, "cannot compute pixel dimensions");
g_object_unref(handle);
return NULL;
}
cairo_rectangle_t extents = {
.x = 0, .y = 0, .width = ceil(w), .height = ceil(h)};
cairo_surface_t *surface =
cairo_recording_surface_create(CAIRO_CONTENT_COLOR_ALPHA, &extents);
#ifdef FASTIV_RSVG_DEBUG
cairo_device_t *script = cairo_script_create("cairo.script");
cairo_surface_t *tee =
cairo_script_surface_create_for_target(script, surface);
cairo_t *cr = cairo_create(tee);
cairo_device_destroy(script);
cairo_surface_destroy(tee);
#else
cairo_t *cr = cairo_create(surface);
#endif
RsvgRectangle viewport = {.x = 0, .y = 0, .width = w, .height = h};
if (!rsvg_handle_render_document(handle, cr, &viewport, error)) {
cairo_surface_destroy(surface);
cairo_destroy(cr);
g_object_unref(handle);
return NULL;
}
cairo_destroy(cr);
g_object_unref(handle);
#ifdef FASTIV_RSVG_DEBUG
cairo_surface_t *svg = cairo_svg_surface_create("cairo.svg", w, h);
cr = cairo_create(svg);
cairo_set_source_surface(cr, surface, 0, 0);
cairo_paint(cr);
cairo_destroy(cr);
cairo_surface_destroy(svg);
cairo_surface_t *png =
cairo_image_surface_create(CAIRO_FORMAT_ARGB32, w * 10, h * 10);
cr = cairo_create(png);
cairo_scale(cr, 10, 10);
cairo_set_source_surface(cr, surface, 0, 0);
cairo_paint(cr);
cairo_destroy(cr);
cairo_surface_write_to_png(png, "cairo.png");
cairo_surface_destroy(png);
#endif
return surface;
}
#endif // HAVE_LIBRSVG --------------------------------------------------------
cairo_surface_t *
fastiv_io_open(const gchar *path, GError **error)
@ -399,6 +481,14 @@ fastiv_io_open(const gchar *path, GError **error)
if (!g_file_get_contents(path, &data, &len, error))
return NULL;
cairo_surface_t *surface = fastiv_io_open_from_data(data, len, error);
free(data);
return surface;
}
cairo_surface_t *
fastiv_io_open_from_data(const char *data, size_t len, GError **error)
{
wuffs_base__slice_u8 prefix =
wuffs_base__make_slice_u8((uint8_t *) data, len);
@ -433,11 +523,17 @@ fastiv_io_open(const gchar *path, GError **error)
// notably only continue with LIBRAW_FILE_UNSUPPORTED.
g_clear_error(error);
#endif // HAVE_LIBRAW ---------------------------------------------------------
#ifdef HAVE_LIBRSVG // --------------------------------------------------------
if ((surface = open_librsvg(data, len, error)))
break;
// XXX: It doesn't look like librsvg can return sensible errors.
g_clear_error(error);
#endif // HAVE_LIBRSVG --------------------------------------------------------
// TODO(p): Integrate gdk-pixbuf as a fallback (optional dependency).
set_error(error, "unsupported file type");
}
free(data);
return surface;
}

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@ -23,4 +23,6 @@
extern const char *fastiv_io_supported_media_types[];
cairo_surface_t *fastiv_io_open(const gchar *path, GError **error);
cairo_surface_t *fastiv_io_open_from_data(
const char *data, size_t len, GError **error);
cairo_surface_t *fastiv_io_lookup_thumbnail(const gchar *target);

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@ -29,22 +29,28 @@ struct _FastivView {
G_DEFINE_TYPE(FastivView, fastiv_view, GTK_TYPE_WIDGET)
static int
get_display_width(FastivView *self)
static void
get_display_dimensions(FastivView *self, int *width, int *height)
{
*width = *height = 0;
if (!self->surface)
return 0;
return;
return ceil(cairo_image_surface_get_width(self->surface) * self->scale);
cairo_rectangle_t extents = {};
switch (cairo_surface_get_type(self->surface)) {
case CAIRO_SURFACE_TYPE_IMAGE:
extents.width = cairo_image_surface_get_width(self->surface);
extents.height = cairo_image_surface_get_height(self->surface);
break;
case CAIRO_SURFACE_TYPE_RECORDING:
(void) cairo_recording_surface_get_extents(self->surface, &extents);
break;
default:
g_assert_not_reached();
}
static int
get_display_height(FastivView *self)
{
if (!self->surface)
return 0;
return ceil(cairo_image_surface_get_height(self->surface) * self->scale);
*width = ceil(extents.width * self->scale);
*height = ceil(extents.height * self->scale);
}
static void
@ -60,15 +66,17 @@ static void
fastiv_view_get_preferred_height(
GtkWidget *widget, gint *minimum, gint *natural)
{
FastivView *self = FASTIV_VIEW(widget);
*minimum = *natural = get_display_height(self);
int width, height;
get_display_dimensions(FASTIV_VIEW(widget), &width, &height);
*minimum = *natural = height;
}
static void
fastiv_view_get_preferred_width(GtkWidget *widget, gint *minimum, gint *natural)
{
FastivView *self = FASTIV_VIEW(widget);
*minimum = *natural = get_display_width(self);
int width, height;
get_display_dimensions(FASTIV_VIEW(widget), &width, &height);
*minimum = *natural = width;
}
static void
@ -115,8 +123,8 @@ fastiv_view_draw(GtkWidget *widget, cairo_t *cr)
gtk_render_background(gtk_widget_get_style_context(widget), cr, 0, 0,
allocation.width, allocation.height);
int w = get_display_width(self);
int h = get_display_height(self);
int w, h;
get_display_dimensions(self, &w, &h);
double x = 0;
double y = 0;
@ -125,6 +133,23 @@ fastiv_view_draw(GtkWidget *widget, cairo_t *cr)
if (h < allocation.height)
y = round((allocation.height - h) / 2.);
// FIXME: Recording surfaces do not work well with CAIRO_SURFACE_TYPE_XLIB,
// we always get a shitty pixmap, where transparency contains junk.
if (cairo_surface_get_type(self->surface) == CAIRO_SURFACE_TYPE_RECORDING) {
cairo_surface_t *image =
cairo_image_surface_create(CAIRO_FORMAT_ARGB32, w, h);
cairo_t *tcr = cairo_create(image);
cairo_scale(tcr, self->scale, self->scale);
cairo_set_source_surface(tcr, self->surface, 0, 0);
cairo_paint(tcr);
cairo_destroy(tcr);
cairo_set_source_surface(cr, image, x, y);
cairo_paint(cr);
cairo_surface_destroy(image);
return TRUE;
}
// XXX: The rounding together with padding may result in up to
// a pixel's worth of made-up picture data.
cairo_rectangle(cr, x, y, w, h);

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

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@ -2,12 +2,14 @@ project('fastiv', 'c', default_options : ['c_std=gnu99'], version : '0.1.0')
# TODO(p): Use libraw_r later, when we start parallelizing/preloading.
libraw = dependency('libraw', required : get_option('libraw'))
librsvg = dependency('librsvg-2.0', required : get_option('librsvg'))
dependencies = [
dependency('gtk+-3.0'),
dependency('libturbojpeg'),
dependency('libpng', version : '>=1.5.4'),
dependency('pixman-1'),
libraw,
librsvg,
meson.get_compiler('c').find_library('m', required : false),
]
@ -15,6 +17,7 @@ conf = configuration_data()
conf.set_quoted('PROJECT_NAME', meson.project_name())
conf.set_quoted('PROJECT_VERSION', meson.project_version())
conf.set('HAVE_LIBRAW', libraw.found())
conf.set('HAVE_LIBRSVG', librsvg.found())
configure_file(
output : 'config.h',
configuration : conf,

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@ -1,2 +1,4 @@
option('libraw', type : 'feature', value : 'auto',
description : 'Build with RAW support, requires LibRaw')
option('librsvg', type : 'feature', value : 'auto',
description : 'Build with SVG support, requires librsvg')