Add backend for accurate SVG scaling

This commit is contained in:
Přemysl Eric Janouch 2022-01-22 23:17:17 +01:00
parent b71d5dff57
commit 562e140a1e
Signed by: p
GPG Key ID: A0420B94F92B9493
2 changed files with 137 additions and 30 deletions

157
fiv-io.c
View File

@ -1596,6 +1596,65 @@ open_libraw(const gchar *data, gsize len, GError **error)
#endif // HAVE_LIBRAW ---------------------------------------------------------
#ifdef HAVE_RESVG // ----------------------------------------------------------
typedef struct {
FivIoRenderClosure parent;
resvg_render_tree *tree; ///< Loaded resvg tree
double width; ///< Normal width
double height; ///< Normal height
} FivIoRenderClosureResvg;
static void
load_resvg_destroy(void *closure)
{
FivIoRenderClosureResvg *self = closure;
resvg_tree_destroy(self->tree);
g_free(self);
}
static cairo_surface_t *
load_resvg_render_internal(
FivIoRenderClosureResvg *self, double scale, GError **error)
{
double w = ceil(self->width * scale), h = ceil(self->height * scale);
if (w > SHRT_MAX || h > SHRT_MAX) {
set_error(error, "image dimensions overflow");
return NULL;
}
cairo_surface_t *surface =
cairo_image_surface_create(CAIRO_FORMAT_ARGB32, w, h);
cairo_status_t surface_status = cairo_surface_status(surface);
if (surface_status != CAIRO_STATUS_SUCCESS) {
set_error(error, cairo_status_to_string(surface_status));
cairo_surface_destroy(surface);
return NULL;
}
uint32_t *pixels = (uint32_t *) cairo_image_surface_get_data(surface);
resvg_fit_to fit_to = {
scale == 1 ? RESVG_FIT_TO_TYPE_ORIGINAL : RESVG_FIT_TO_TYPE_ZOOM,
scale};
resvg_render(self->tree, fit_to, resvg_transform_identity(),
cairo_image_surface_get_width(surface),
cairo_image_surface_get_height(surface), (char *) pixels);
// TODO(p): Also apply colour management, we'll need to un-premultiply.
for (int i = 0; i < w * h; i++) {
uint32_t rgba = g_ntohl(pixels[i]);
pixels[i] = rgba << 24 | rgba >> 8;
}
cairo_surface_mark_dirty(surface);
return surface;
}
static cairo_surface_t *
load_resvg_render(FivIoRenderClosure *closure, double scale)
{
FivIoRenderClosureResvg *self = (FivIoRenderClosureResvg *) closure;
return load_resvg_render_internal(self, scale, NULL);
}
static const char *
load_resvg_error(int err)
{
@ -1627,6 +1686,7 @@ open_resvg(const gchar *data, gsize len, const gchar *uri, GError **error)
resvg_options *opt = resvg_options_create();
resvg_options_load_system_fonts(opt);
resvg_options_set_resources_dir(opt, g_file_peek_path(base_file));
// TODO(p): Acquire and set the right DPI for use.
resvg_render_tree *tree = NULL;
int err = resvg_parse_tree_from_data(data, len, opt, &tree);
resvg_options_destroy(opt);
@ -1636,40 +1696,23 @@ open_resvg(const gchar *data, gsize len, const gchar *uri, GError **error)
return NULL;
}
// TODO(p): Support retrieving a scaled-up/down version.
// TODO(p): See if there is a situation for resvg_get_image_viewbox().
resvg_size size = resvg_get_image_size(tree);
double w = ceil(size.width), h = ceil(size.height);
if (w > SHRT_MAX || h > SHRT_MAX) {
set_error(error, "image dimensions overflow");
resvg_tree_destroy(tree);
FivIoRenderClosureResvg *closure = g_malloc0(sizeof *closure);
closure->parent.render = load_resvg_render;
closure->tree = tree;
closure->width = size.width;
closure->height = size.height;
cairo_surface_t *surface = load_resvg_render_internal(closure, 1., error);
if (!surface) {
load_resvg_destroy(closure);
return NULL;
}
cairo_surface_t *surface =
cairo_image_surface_create(CAIRO_FORMAT_ARGB32, w, h);
cairo_status_t surface_status = cairo_surface_status(surface);
if (surface_status != CAIRO_STATUS_SUCCESS) {
set_error(error, cairo_status_to_string(surface_status));
cairo_surface_destroy(surface);
resvg_tree_destroy(tree);
return NULL;
}
uint32_t *pixels = (uint32_t *) cairo_image_surface_get_data(surface);
resvg_fit_to fit_to = { RESVG_FIT_TO_TYPE_ORIGINAL, 1. };
resvg_render(tree, fit_to, resvg_transform_identity(),
cairo_image_surface_get_width(surface),
cairo_image_surface_get_height(surface), (char *) pixels);
resvg_tree_destroy(tree);
// TODO(p): Also apply colour management, we'll need to un-premultiply.
for (int i = 0; i < w * h; i++) {
uint32_t rgba = g_ntohl(pixels[i]);
pixels[i] = rgba << 24 | rgba >> 8;
}
cairo_surface_mark_dirty(surface);
cairo_surface_set_user_data(
surface, &fiv_io_key_render, closure, load_resvg_destroy);
return surface;
}
@ -1681,6 +1724,50 @@ open_resvg(const gchar *data, gsize len, const gchar *uri, GError **error)
#include <cairo/cairo-svg.h>
#endif
typedef struct {
FivIoRenderClosure parent;
RsvgHandle *handle; ///< Loaded rsvg handle
double width; ///< Normal width
double height; ///< Normal height
} FivIoRenderClosureLibrsvg;
static void
load_librsvg_destroy(void *closure)
{
FivIoRenderClosureLibrsvg *self = closure;
g_object_unref(self->handle);
g_free(self);
}
static cairo_surface_t *
load_librsvg_render(FivIoRenderClosure *closure, double scale)
{
FivIoRenderClosureLibrsvg *self = (FivIoRenderClosureLibrsvg *) closure;
RsvgRectangle viewport = {.x = 0, .y = 0,
.width = self->width * scale, .height = self->height * scale};
cairo_surface_t *surface = cairo_image_surface_create(
CAIRO_FORMAT_ARGB32, ceil(viewport.width), ceil(viewport.height));
GError *error = NULL;
cairo_t *cr = cairo_create(surface);
(void) rsvg_handle_render_document(self->handle, cr, &viewport, &error);
cairo_destroy(cr);
if (error) {
g_debug("%s", error->message);
g_error_free(error);
cairo_surface_destroy(surface);
return NULL;
}
cairo_status_t surface_status = cairo_surface_status(surface);
if (surface_status != CAIRO_STATUS_SUCCESS) {
g_debug("%s", cairo_status_to_string(surface_status));
cairo_surface_destroy(surface);
return NULL;
}
return surface;
}
// FIXME: librsvg rasterizes filters, so this method isn't fully appropriate.
static cairo_surface_t *
open_librsvg(const gchar *data, gsize len, const gchar *uri, GError **error)
@ -1744,7 +1831,14 @@ open_librsvg(const gchar *data, gsize len, const gchar *uri, GError **error)
}
cairo_destroy(cr);
g_object_unref(handle);
FivIoRenderClosureLibrsvg *closure = g_malloc0(sizeof *closure);
closure->parent.render = load_librsvg_render;
closure->handle = handle;
closure->width = w;
closure->height = h;
cairo_surface_set_user_data(
surface, &fiv_io_key_render, closure, load_librsvg_destroy);
#ifdef FIV_RSVG_DEBUG
cairo_surface_t *svg = cairo_svg_surface_create("cairo.svg", w, h);
@ -2438,6 +2532,7 @@ open_gdkpixbuf(
#endif // HAVE_GDKPIXBUF ------------------------------------------------------
// TODO(p): Check that all cairo_surface_set_user_data() calls succeed.
cairo_user_data_key_t fiv_io_key_exif;
cairo_user_data_key_t fiv_io_key_orientation;
cairo_user_data_key_t fiv_io_key_icc;
@ -2452,6 +2547,8 @@ cairo_user_data_key_t fiv_io_key_loops;
cairo_user_data_key_t fiv_io_key_page_next;
cairo_user_data_key_t fiv_io_key_page_previous;
cairo_user_data_key_t fiv_io_key_render;
cairo_surface_t *
fiv_io_open(
const gchar *uri, FivIoProfile profile, gboolean enhance, GError **error)

View File

@ -73,6 +73,16 @@ extern cairo_user_data_key_t fiv_io_key_page_next;
/// There is no wrap-around. This is a weak pointer.
extern cairo_user_data_key_t fiv_io_key_page_previous;
typedef struct _FivIoRenderClosure {
/// The rendering is allowed to fail.
cairo_surface_t *(*render)(struct _FivIoRenderClosure *, double scale);
} FivIoRenderClosure;
/// A FivIoRenderClosure for parametrized re-rendering of vector formats.
/// This is attached at the page level.
/// The rendered image will not have this key.
extern cairo_user_data_key_t fiv_io_key_render;
cairo_surface_t *fiv_io_open(
const gchar *uri, FivIoProfile profile, gboolean enhance, GError **error);
cairo_surface_t *fiv_io_open_from_data(const char *data, size_t len,