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-rw-r--r--fastiv-io.c207
1 files changed, 99 insertions, 108 deletions
diff --git a/fastiv-io.c b/fastiv-io.c
index d8eadcd..ab25edd 100644
--- a/fastiv-io.c
+++ b/fastiv-io.c
@@ -603,53 +603,48 @@ fastiv_io_open_from_data(const char *data, size_t len, const gchar *path,
// NOTE: "It is important to note that when an image with an alpha channel is
// scaled, linear encoded, pre-multiplied component values must be used!"
#include <glib/gstdio.h>
-#include <png.h>
+#include <spng.h>
-static void
-redirect_png_error(png_structp pngp, const char *error)
-{
- set_error(png_get_error_ptr(pngp), error);
- png_longjmp(pngp, 1);
-}
-
-static void
-discard_png_warning(png_structp pngp, const char *warning)
-{
- (void) pngp;
- (void) warning;
-}
-
-static int
-check_png_thumbnail(
- png_structp pngp, png_infop infop, const gchar *target, time_t mtime)
+static int // tri-state
+check_spng_thumbnail_texts(struct spng_text *texts, uint32_t texts_len,
+ const gchar *target, time_t mtime)
{
// May contain Thumb::Image::Width Thumb::Image::Height,
// but those aren't interesting currently (would be for fast previews).
- int texts_len = 0;
- png_textp texts = NULL;
- png_get_text(pngp, infop, &texts, &texts_len);
-
- gboolean need_uri = TRUE, need_mtime = TRUE;
- for (int i = 0; i < texts_len; i++) {
- png_textp text = texts + i;
- if (!strcmp(text->key, "Thumb::URI")) {
- need_uri = FALSE;
+ bool need_uri = true, need_mtime = true;
+ for (uint32_t i = 0; i < texts_len; i++) {
+ struct spng_text *text = texts + i;
+ if (!strcmp(text->keyword, "Thumb::URI")) {
+ need_uri = false;
if (strcmp(target, text->text))
- return FALSE;
+ return false;
}
- if (!strcmp(text->key, "Thumb::MTime")) {
- need_mtime = FALSE;
+ if (!strcmp(text->keyword, "Thumb::MTime")) {
+ need_mtime = false;
if (atol(text->text) != mtime)
- return FALSE;
+ return false;
}
}
- return need_uri || need_mtime ? -1 : TRUE;
+ return need_uri || need_mtime ? -1 : true;
+}
+
+static int // tri-state
+check_spng_thumbnail(spng_ctx *ctx, const gchar *target, time_t mtime, int *err)
+{
+ uint32_t texts_len = 0;
+ if ((*err = spng_get_text(ctx, NULL, &texts_len)))
+ return false;
+
+ int result = false;
+ struct spng_text *texts = g_malloc0_n(texts_len, sizeof *texts);
+ if (!(*err = spng_get_text(ctx, texts, &texts_len)))
+ result = check_spng_thumbnail_texts(texts, texts_len, target, mtime);
+ g_free(texts);
+ return result;
}
-// TODO(p): Support spng as well (it can't premultiply alpha by itself,
-// but at least it won't gamma-adjust it for us).
static cairo_surface_t *
-read_png_thumbnail(
+read_spng_thumbnail(
const gchar *path, const gchar *uri, time_t mtime, GError **error)
{
FILE *fp;
@@ -658,96 +653,92 @@ read_png_thumbnail(
return NULL;
}
- cairo_surface_t *volatile surface = NULL;
- png_structp pngp = png_create_read_struct(
- PNG_LIBPNG_VER_STRING, error, redirect_png_error, discard_png_warning);
- png_infop infop = png_create_info_struct(pngp);
- if (!infop) {
+ cairo_surface_t *result = NULL;
+ errno = 0;
+ spng_ctx *ctx = spng_ctx_new(0);
+ if (!ctx) {
set_error(error, g_strerror(errno));
- goto fail_preread;
+ goto fail_init;
}
- volatile png_bytepp row_pointers = NULL;
- if (setjmp(png_jmpbuf(pngp))) {
- if (surface) {
- cairo_surface_destroy(surface);
- surface = NULL;
- }
+ int err;
+ size_t size = 0;
+ if ((err = spng_set_png_file(ctx, fp)) ||
+ (err = spng_set_image_limits(ctx, INT16_MAX, INT16_MAX)) ||
+ (err = spng_decoded_image_size(ctx, SPNG_FMT_RGBA8, &size))) {
+ set_error(error, spng_strerror(err));
+ goto fail;
+ }
+ if (check_spng_thumbnail(ctx, uri, mtime, &err) == false) {
+ set_error(error, err ? spng_strerror(err) : "mismatch");
goto fail;
}
- png_init_io(pngp, fp);
-
- // XXX: libpng will premultiply with the alpha, but it also gamma-adjust it.
- png_set_alpha_mode(pngp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
- png_read_info(pngp, infop);
- if (check_png_thumbnail(pngp, infop, uri, mtime) == FALSE)
- png_error(pngp, "mismatch");
-
- // Asking for at least 8-bit channels. This call is a superset of:
- // - png_set_palette_to_rgb(),
- // - png_set_tRNS_to_alpha(),
- // - png_set_expand_gray_1_2_4_to_8().
- png_set_expand(pngp);
-
- // Reduce the possibilities further to RGB or RGBA...
- png_set_gray_to_rgb(pngp);
-
- // ...and /exactly/ 8-bit channels.
- // Alternatively, use png_set_expand_16() above to obtain 16-bit channels.
- png_set_scale_16(pngp);
-
- // PNG uses RGBA order, we want either ARGB (BE) or BGRA (LE).
- if (G_BYTE_ORDER == G_LITTLE_ENDIAN) {
- png_set_bgr(pngp);
- png_set_add_alpha(pngp, 0xFFFF, PNG_FILLER_AFTER);
- png_set_swap(pngp);
- } else {
- // This doesn't change a row's `color_type` in png_do_read_filler(),
- // and the following transformation thus ignores it.
- png_set_add_alpha(pngp, 0xFFFF, PNG_FILLER_BEFORE);
- png_set_swap_alpha(pngp);
+ uint32_t *data = g_malloc0(size);
+ if ((err = spng_decode_image(ctx, data, size, SPNG_FMT_RGBA8,
+ SPNG_DECODE_TRNS | SPNG_DECODE_GAMMA))) {
+ set_error(error, spng_strerror(err));
+ goto fail_data;
}
- (void) png_set_interlace_handling(pngp);
- png_read_update_info(pngp, infop);
+ // The specification does not say where the required metadata should be,
+ // it could very well be broken up into two parts.
+ if (check_spng_thumbnail(ctx, uri, mtime, &err) != true) {
+ set_error(
+ error, err ? spng_strerror(err) : "mismatch or not a thumbnail");
+ goto fail_data;
+ }
- png_uint_32 w = png_get_image_width(pngp, infop);
- png_uint_32 h = png_get_image_height(pngp, infop);
- if (w > INT16_MAX || h > INT16_MAX)
- png_error(pngp, "the image is too large");
+ struct spng_ihdr ihdr = {};
+ spng_get_ihdr(ctx, &ihdr);
+ cairo_surface_t *surface = cairo_image_surface_create(
+ CAIRO_FORMAT_ARGB32, ihdr.width, ihdr.height);
- 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)
- png_error(pngp, cairo_status_to_string(surface_status));
-
- size_t row_bytes = png_get_rowbytes(pngp, infop);
- g_assert((size_t) cairo_image_surface_get_stride(surface) == row_bytes);
+ if (surface_status != CAIRO_STATUS_SUCCESS) {
+ set_error(error, cairo_status_to_string(surface_status));
+ cairo_surface_destroy(surface);
+ goto fail_data;
+ }
- unsigned char *buffer = cairo_image_surface_get_data(surface);
- png_uint_32 height = png_get_image_height(pngp, infop);
- if (!(row_pointers = calloc(height, sizeof *row_pointers)))
- png_error(pngp, g_strerror(errno));
- for (size_t y = 0; y < height; y++)
- row_pointers[y] = buffer + y * row_bytes;
+ g_assert((size_t) cairo_image_surface_get_stride(surface) *
+ cairo_image_surface_get_height(surface) == size);
+ // pixman can be mildly abused to do this operation, but it won't be faster.
+ uint32_t *output = (uint32_t *) cairo_image_surface_get_data(surface);
cairo_surface_flush(surface);
- png_read_image(pngp, row_pointers);
- cairo_surface_mark_dirty(surface);
- // The specification does not say where the required metadata should be,
- // it could very well be broken up into two parts.
- png_read_end(pngp, infop);
- if (check_png_thumbnail(pngp, infop, uri, mtime) != TRUE)
- png_error(pngp, "mismatch or not a thumbnail");
+ struct spng_trns trns = {};
+ if (ihdr.color_type == SPNG_COLOR_TYPE_GRAYSCALE_ALPHA ||
+ ihdr.color_type == SPNG_COLOR_TYPE_TRUECOLOR_ALPHA ||
+ !spng_get_trns(ctx, &trns)) {
+ for (size_t i = size / sizeof *output; i--; ) {
+ uint8_t *unit = (uint8_t *) &data[i],
+ a = unit[3],
+ b = unit[2] * a / 255,
+ g = unit[1] * a / 255,
+ r = unit[0] * a / 255;
+ output[i] = a << 24 | r << 16 | g << 8 | b;
+ }
+ } else {
+ for (size_t i = size / sizeof *output; i--; ) {
+ uint8_t *unit = (uint8_t *) &data[i],
+ a = unit[3],
+ b = unit[2],
+ g = unit[1],
+ r = unit[0];
+ output[i] = a << 24 | r << 16 | g << 8 | b;
+ }
+ }
+ cairo_surface_mark_dirty((result = surface));
+fail_data:
+ free(data);
fail:
- free(row_pointers);
-fail_preread:
- png_destroy_read_struct(&pngp, &infop, NULL);
+ spng_ctx_free(ctx);
+fail_init:
fclose(fp);
- return surface;
+ return result;
}
cairo_surface_t *
@@ -772,7 +763,7 @@ fastiv_io_lookup_thumbnail(const gchar *target)
for (gsize i = 0; !result && i < G_N_ELEMENTS(sizes); i++) {
gchar *path = g_strdup_printf(
"%s/thumbnails/%s/%s.png", cache_dir, sizes[i], sum);
- result = read_png_thumbnail(path, uri, st.st_mtim.tv_sec, &error);
+ result = read_spng_thumbnail(path, uri, st.st_mtim.tv_sec, &error);
if (error) {
g_debug("%s: %s", path, error->message);
g_clear_error(&error);
generated by cgit v1.2.3-70-g09d2 (git 2.50.0) at 2025-11-04 15:58:46 +0000