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-rw-r--r--src/3rdparty/libpng/pngtrans.c247
1 files changed, 101 insertions, 146 deletions
diff --git a/src/3rdparty/libpng/pngtrans.c b/src/3rdparty/libpng/pngtrans.c
index 137f555..6a6908d 100644
--- a/src/3rdparty/libpng/pngtrans.c
+++ b/src/3rdparty/libpng/pngtrans.c
@@ -1,7 +1,7 @@
/* pngtrans.c - transforms the data in a row (used by both readers and writers)
*
- * Last changed in libpng 1.5.1 [February 3, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
* Copyright (c) 1998-2011 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -424,170 +424,119 @@ png_do_packswap(png_row_infop row_info, png_bytep row)
#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
-/* Remove filler or alpha byte(s) */
+/* Remove a channel - this used to be 'png_do_strip_filler' but it used a
+ * somewhat weird combination of flags to determine what to do. All the calls
+ * to png_do_strip_filler are changed in 1.5.2 to call this instead with the
+ * correct arguments.
+ *
+ * The routine isn't general - the channel must be the channel at the start or
+ * end (not in the middle) of each pixel.
+ */
void /* PRIVATE */
-png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags)
+png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
{
- png_debug(1, "in png_do_strip_filler");
-
+ png_bytep sp = row; /* source pointer */
+ png_bytep dp = row; /* destination pointer */
+ png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */
+
+ /* At the start sp will point to the first byte to copy and dp to where
+ * it is copied to. ep always points just beyond the end of the row, so
+ * the loop simply copies (channels-1) channels until sp reaches ep.
+ *
+ * at_start: 0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+ * nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
+ */
+
+ /* GA, GX, XG cases */
+ if (row_info->channels == 2)
{
- png_bytep sp = row;
- png_bytep dp = row;
- png_uint_32 row_width = row_info->width;
- png_uint_32 i;
-
- if ((row_info->color_type == PNG_COLOR_TYPE_RGB ||
- (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
- (flags & PNG_FLAG_STRIP_ALPHA))) &&
- row_info->channels == 4)
+ if (row_info->bit_depth == 8)
{
- if (row_info->bit_depth == 8)
- {
- /* This converts from RGBX or RGBA to RGB */
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- dp += 3; sp += 4;
- for (i = 1; i < row_width; i++)
- {
- *dp++ = *sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- sp++;
- }
- }
+ if (at_start) /* Skip initial filler */
+ ++sp;
+ else /* Skip initial channel and, for sp, the filler */
+ sp += 2, ++dp;
- /* This converts from XRGB or ARGB to RGB */
- else
- {
- for (i = 0; i < row_width; i++)
- {
- sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- }
- }
- row_info->pixel_depth = 24;
- row_info->rowbytes = row_width * 3;
- }
+ /* For a 1 pixel wide image there is nothing to do */
+ while (sp < ep)
+ *dp++ = *sp, sp += 2;
- else /* if (row_info->bit_depth == 16) */
- {
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */
- sp += 8; dp += 6;
- for (i = 1; i < row_width; i++)
- {
- /* This could be (although png_memcpy is probably slower):
- png_memcpy(dp, sp, 6);
- sp += 8;
- dp += 6;
- */
-
- *dp++ = *sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- sp += 2;
- }
- }
+ row_info->pixel_depth = 8;
+ }
- else
- {
- /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */
- for (i = 0; i < row_width; i++)
- {
- /* This could be (although png_memcpy is probably slower):
- png_memcpy(dp, sp, 6);
- sp += 8;
- dp += 6;
- */
-
- sp += 2;
- *dp++ = *sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- *dp++ = *sp++;
- }
- }
+ else if (row_info->bit_depth == 16)
+ {
+ if (at_start) /* Skip initial filler */
+ sp += 2;
+ else /* Skip initial channel and, for sp, the filler */
+ sp += 4, dp += 2;
- row_info->pixel_depth = 48;
- row_info->rowbytes = row_width * 6;
- }
- row_info->channels = 3;
+ while (sp < ep)
+ *dp++ = *sp++, *dp++ = *sp, sp += 3;
+
+ row_info->pixel_depth = 16;
}
- else if ((row_info->color_type == PNG_COLOR_TYPE_GRAY ||
- (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
- (flags & PNG_FLAG_STRIP_ALPHA))) &&
- row_info->channels == 2)
- {
- if (row_info->bit_depth == 8)
- {
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- /* This converts from GX or GA to G */
- for (i = 0; i < row_width; i++)
- {
- *dp++ = *sp++;
- sp++;
- }
- }
+ else
+ return; /* bad bit depth */
- else
- {
- /* This converts from XG or AG to G */
- for (i = 0; i < row_width; i++)
- {
- sp++;
- *dp++ = *sp++;
- }
- }
+ row_info->channels = 1;
- row_info->pixel_depth = 8;
- row_info->rowbytes = row_width;
- }
+ /* Finally fix the color type if it records an alpha channel */
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ row_info->color_type = PNG_COLOR_TYPE_GRAY;
+ }
- else /* if (row_info->bit_depth == 16) */
- {
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- /* This converts from GGXX or GGAA to GG */
- sp += 4; dp += 2;
- for (i = 1; i < row_width; i++)
- {
- *dp++ = *sp++;
- *dp++ = *sp++;
- sp += 2;
- }
- }
+ /* RGBA, RGBX, XRGB cases */
+ else if (row_info->channels == 4)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ if (at_start) /* Skip initial filler */
+ ++sp;
+ else /* Skip initial channels and, for sp, the filler */
+ sp += 4, dp += 3;
- else
- {
- /* This converts from XXGG or AAGG to GG */
- for (i = 0; i < row_width; i++)
- {
- sp += 2;
- *dp++ = *sp++;
- *dp++ = *sp++;
- }
- }
+ /* Note that the loop adds 3 to dp and 4 to sp each time. */
+ while (sp < ep)
+ *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2;
- row_info->pixel_depth = 16;
- row_info->rowbytes = row_width * 2;
+ row_info->pixel_depth = 24;
+ }
+
+ else if (row_info->bit_depth == 16)
+ {
+ if (at_start) /* Skip initial filler */
+ sp += 2;
+ else /* Skip initial channels and, for sp, the filler */
+ sp += 8, dp += 6;
+
+ while (sp < ep)
+ {
+ /* Copy 6 bytes, skip 2 */
+ *dp++ = *sp++, *dp++ = *sp++;
+ *dp++ = *sp++, *dp++ = *sp++;
+ *dp++ = *sp++, *dp++ = *sp, sp += 3;
}
- row_info->channels = 1;
+
+ row_info->pixel_depth = 48;
}
- if (flags & PNG_FLAG_STRIP_ALPHA)
- row_info->color_type = (png_byte)(row_info->color_type &
- ~PNG_COLOR_MASK_ALPHA);
+ else
+ return; /* bad bit depth */
+
+ row_info->channels = 3;
+
+ /* Finally fix the color type if it records an alpha channel */
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ row_info->color_type = PNG_COLOR_TYPE_RGB;
}
+
+ else
+ return; /* The filler channel has gone already */
+
+ /* Fix the rowbytes value. */
+ row_info->rowbytes = dp-row;
}
#endif
@@ -703,11 +652,16 @@ png_get_user_transform_ptr(png_const_structp png_ptr)
}
#endif
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
png_uint_32 PNGAPI
png_get_current_row_number(png_const_structp png_ptr)
{
+ /* See the comments in png.h - this is the sub-image row when reading and
+ * interlaced image.
+ */
if (png_ptr != NULL)
return png_ptr->row_number;
+
return PNG_UINT_32_MAX; /* help the app not to fail silently */
}
@@ -718,6 +672,7 @@ png_get_current_pass_number(png_const_structp png_ptr)
return png_ptr->pass;
return 8; /* invalid */
}
+#endif /* PNG_USER_TRANSFORM_INFO_SUPPORTED */
#endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
PNG_WRITE_USER_TRANSFORM_SUPPORTED */
#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
generated by cgit v0.12 at 2024-11-11 01:42:51 (GMT)