+#define PNG_FORMAT_GRAY 0
+#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
+#define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
+#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
+#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
+#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
+#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
+#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
+#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
+
+/* Then the linear 2-byte formats. When naming these "Y" is used to
+ * indicate a luminance (gray) channel.
+ */
+#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
+#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
+#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
+#define PNG_FORMAT_LINEAR_RGB_ALPHA \
+ (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
+
+/* With color-mapped formats the image data is one byte for each pixel, the byte
+ * is an index into the color-map which is formatted as above. To obtain a
+ * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
+ * to one of the above definitions, or you can use one of the definitions below.
+ */
+#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
+#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
+
+/* PNG_IMAGE macros
+ *
+ * These are convenience macros to derive information from a png_image
+ * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
+ * actual image sample values - either the entries in the color-map or the
+ * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
+ * for the pixels and will always return 1 for color-mapped formats. The
+ * remaining macros return information about the rows in the image and the
+ * complete image.
+ *
+ * NOTE: All the macros that take a png_image::format parameter are compile time
+ * constants if the format parameter is, itself, a constant. Therefore these
+ * macros can be used in array declarations and case labels where required.
+ * Similarly the macros are also pre-processor constants (sizeof is not used) so
+ * they can be used in #if tests.
+ *
+ * First the information about the samples.
+ */
+#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
+ (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
+ /* Return the total number of channels in a given format: 1..4 */
+
+#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
+ ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
+ /* Return the size in bytes of a single component of a pixel or color-map
+ * entry (as appropriate) in the image: 1 or 2.
+ */
+
+#define PNG_IMAGE_SAMPLE_SIZE(fmt)\
+ (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
+ /* This is the size of the sample data for one sample. If the image is
+ * color-mapped it is the size of one color-map entry (and image pixels are
+ * one byte in size), otherwise it is the size of one image pixel.
+ */
+
+#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
+ (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
+ /* The maximum size of the color-map required by the format expressed in a
+ * count of components. This can be used to compile-time allocate a
+ * color-map:
+ *
+ * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
+ *
+ * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
+ *
+ * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
+ * information from one of the png_image_begin_read_ APIs and dynamically
+ * allocate the required memory.
+ */
+
+/* Corresponding information about the pixels */
+#define PNG_IMAGE_PIXEL_(test,fmt)\
+ (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
+
+#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
+ PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
+ /* The number of separate channels (components) in a pixel; 1 for a
+ * color-mapped image.
+ */
+
+#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
+ PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
+ /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
+ * image.
+ */
+
+#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
+ /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
+
+/* Information about the whole row, or whole image */
+#define PNG_IMAGE_ROW_STRIDE(image)\
+ (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
+ /* Return the total number of components in a single row of the image; this
+ * is the minimum 'row stride', the minimum count of components between each
+ * row. For a color-mapped image this is the minimum number of bytes in a
+ * row.
+ */
+
+#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
+ (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
+ /* Return the size, in bytes, of an image buffer given a png_image and a row
+ * stride - the number of components to leave space for in each row.
+ */
+
+#define PNG_IMAGE_SIZE(image)\
+ PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
+ /* Return the size, in bytes, of the image in memory given just a png_image;
+ * the row stride is the minimum stride required for the image.
+ */
+
+#define PNG_IMAGE_COLORMAP_SIZE(image)\
+ (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
+ /* Return the size, in bytes, of the color-map of this image. If the image
+ * format is not a color-map format this will return a size sufficient for
+ * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
+ * you don't want to allocate a color-map in this case.
+ */
+
+/* PNG_IMAGE_FLAG_*
+ *
+ * Flags containing additional information about the image are held in the
+ * 'flags' field of png_image.
+ */
+#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
+ /* This indicates the the RGB values of the in-memory bitmap do not
+ * correspond to the red, green and blue end-points defined by sRGB.
+ */
+
+#define PNG_IMAGE_FLAG_FAST 0x02
+ /* On write emphasise speed over compression; the resultant PNG file will be
+ * larger but will be produced significantly faster, particular for large
+ * images. Do not use this option for images which will be distributed, only
+ * used it when producing intermediate files that will be read back in
+ * repeatedly. For a typical 24-bit image the option will double the read
+ * speed at the cost of increasing the image size by 25%, however for many
+ * more compressible images the PNG file can be 10 times larger with only a
+ * slight speed gain.
+ */
+
+#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
+ /* On read if the image is a 16-bit per component image and there is no gAMA
+ * or sRGB chunk assume that the components are sRGB encoded. Notice that
+ * images output by the simplified API always have gamma information; setting
+ * this flag only affects the interpretation of 16-bit images from an
+ * external source. It is recommended that the application expose this flag
+ * to the user; the user can normally easily recognize the difference between
+ * linear and sRGB encoding. This flag has no effect on write - the data
+ * passed to the write APIs must have the correct encoding (as defined
+ * above.)
+ *
+ * If the flag is not set (the default) input 16-bit per component data is
+ * assumed to be linear.
+ *
+ * NOTE: the flag can only be set after the png_image_begin_read_ call,
+ * because that call initializes the 'flags' field.
+ */
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+/* READ APIs
+ * ---------
+ *
+ * The png_image passed to the read APIs must have been initialized by setting
+ * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
+ */
+#ifdef PNG_STDIO_SUPPORTED
+PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
+ const char *file_name));
+ /* The named file is opened for read and the image header is filled in
+ * from the PNG header in the file.
+ */
+
+PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
+ FILE* file));
+ /* The PNG header is read from the stdio FILE object. */
+#endif /* PNG_STDIO_SUPPORTED */
+
+PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
+ png_const_voidp memory, png_size_t size));
+ /* The PNG header is read from the given memory buffer. */
+
+PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
+ png_const_colorp background, void *buffer, png_int_32 row_stride,
+ void *colormap));
+ /* Finish reading the image into the supplied buffer and clean up the
+ * png_image structure.
+ *
+ * row_stride is the step, in byte or 2-byte units as appropriate,
+ * between adjacent rows. A positive stride indicates that the top-most row
+ * is first in the buffer - the normal top-down arrangement. A negative
+ * stride indicates that the bottom-most row is first in the buffer.
+ *
+ * background need only be supplied if an alpha channel must be removed from
+ * a png_byte format and the removal is to be done by compositing on a solid
+ * color; otherwise it may be NULL and any composition will be done directly
+ * onto the buffer. The value is an sRGB color to use for the background,
+ * for grayscale output the green channel is used.
+ *
+ * background must be supplied when an alpha channel must be removed from a
+ * single byte color-mapped output format, in other words if:
+ *
+ * 1) The original format from png_image_begin_read_from_* had
+ * PNG_FORMAT_FLAG_ALPHA set.
+ * 2) The format set by the application does not.
+ * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
+ * PNG_FORMAT_FLAG_LINEAR *not* set.
+ *
+ * For linear output removing the alpha channel is always done by compositing
+ * on black and background is ignored.
+ *
+ * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
+ * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
+ * image->colormap_entries will be updated to the actual number of entries
+ * written to the colormap; this may be less than the original value.
+ */
+
+PNG_EXPORT(238, void, png_image_free, (png_imagep image));
+ /* Free any data allocated by libpng in image->opaque, setting the pointer to
+ * NULL. May be called at any time after the structure is initialized.
+ */
+#endif /* PNG_SIMPLIFIED_READ_SUPPORTED */
+
+#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+/* WRITE APIS
+ * ----------
+ * For write you must initialize a png_image structure to describe the image to
+ * be written. To do this use memset to set the whole structure to 0 then
+ * initialize fields describing your image.
+ *
+ * version: must be set to PNG_IMAGE_VERSION
+ * opaque: must be initialized to NULL
+ * width: image width in pixels
+ * height: image height in rows
+ * format: the format of the data (image and color-map) you wish to write
+ * flags: set to 0 unless one of the defined flags applies; set
+ * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
+ * values do not correspond to the colors in sRGB.
+ * colormap_entries: set to the number of entries in the color-map (0 to 256)
+ */
+PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
+ const char *file, int convert_to_8bit, const void *buffer,
+ png_int_32 row_stride, const void *colormap));
+ /* Write the image to the named file. */
+
+PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
+ int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
+ const void *colormap));
+ /* Write the image to the given (FILE*). */
+
+/* With both write APIs if image is in one of the linear formats with 16-bit
+ * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
+ * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
+ * encoded PNG file is written.
+ *
+ * With color-mapped data formats the colormap parameter point to a color-map
+ * with at least image->colormap_entries encoded in the specified format. If
+ * the format is linear the written PNG color-map will be converted to sRGB
+ * regardless of the convert_to_8_bit flag.
+ *
+ * With all APIs row_stride is handled as in the read APIs - it is the spacing
+ * from one row to the next in component sized units (1 or 2 bytes) and if
+ * negative indicates a bottom-up row layout in the buffer.
+ *
+ * Note that the write API does not support interlacing or sub-8-bit pixels.
+ */
+#endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */
+/*******************************************************************************
+ * END OF SIMPLIFIED API
+ ******************************************************************************/
+
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+PNG_EXPORT(242, void, png_set_check_for_invalid_index,
+ (png_structrp png_ptr, int allowed));
+# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
+ png_const_infop info_ptr));
+# endif
+#endif /* CHECK_FOR_INVALID_INDEX */
+
+/*******************************************************************************
+ * IMPLEMENTATION OPTIONS
+ *******************************************************************************
+ *
+ * Support for arbitrary implementation-specific optimizations. The API allows
+ * particular options to be turned on or off. 'Option' is the number of the
+ * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
+ * by the PNG_OPTION_ defines below.
+ *
+ * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
+ * are detected at run time, however sometimes it may be impossible
+ * to do this in user mode, in which case it is necessary to discover
+ * the capabilities in an OS specific way. Such capabilities are
+ * listed here when libpng has support for them and must be turned
+ * ON by the application if present.
+ *
+ * SOFTWARE: sometimes software optimizations actually result in performance
+ * decrease on some architectures or systems, or with some sets of
+ * PNG images. 'Software' options allow such optimizations to be
+ * selected at run time.
+ */
+#ifdef PNG_SET_OPTION_SUPPORTED
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
+#endif
+#define PNG_OPTION_NEXT 2 /* Next option - numbers must be even */
projects / wxWidgets.git / blobdiff