+#ifdef const
+ /* zlib.h sometimes #defines const to nothing, undo this. */
+# undef const
+#endif
+
+/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
+ * with older builds.
+ */
+#if ZLIB_VERNUM < 0x1260
+# define PNGZ_MSG_CAST(s) png_constcast(char*,s)
+# define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
+#else
+# define PNGZ_MSG_CAST(s) (s)
+# define PNGZ_INPUT_CAST(b) (b)
+#endif
+
+/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
+ * can handle at once. This type need be no larger than 16 bits (so maximum of
+ * 65535), this define allows us to discover how big it is, but limited by the
+ * maximuum for png_size_t. The value can be overriden in a library build
+ * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
+ * lower value (e.g. 255 works). A lower value may help memory usage (slightly)
+ * and may even improve performance on some systems (and degrade it on others.)
+ */
+#ifndef ZLIB_IO_MAX
+# define ZLIB_IO_MAX ((uInt)-1)
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+/* The type of a compression buffer list used by the write code. */
+typedef struct png_compression_buffer
+{
+ struct png_compression_buffer *next;
+ png_byte output[1]; /* actually zbuf_size */
+} png_compression_buffer, *png_compression_bufferp;
+
+#define PNG_COMPRESSION_BUFFER_SIZE(pp)\
+ (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
+#endif
+
+/* Colorspace support; structures used in png_struct, png_info and in internal
+ * functions to hold and communicate information about the color space.
+ *
+ * PNG_COLORSPACE_SUPPORTED is only required if the application will perform
+ * colorspace corrections, otherwise all the colorspace information can be
+ * skipped and the size of libpng can be reduced (significantly) by compiling
+ * out the colorspace support.
+ */
+#ifdef PNG_COLORSPACE_SUPPORTED
+/* The chromaticities of the red, green and blue colorants and the chromaticity
+ * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
+ */
+typedef struct png_xy
+{
+ png_fixed_point redx, redy;
+ png_fixed_point greenx, greeny;
+ png_fixed_point bluex, bluey;
+ png_fixed_point whitex, whitey;
+} png_xy;
+
+/* The same data as above but encoded as CIE XYZ values. When this data comes
+ * from chromaticities the sum of the Y values is assumed to be 1.0
+ */
+typedef struct png_XYZ
+{
+ png_fixed_point red_X, red_Y, red_Z;
+ png_fixed_point green_X, green_Y, green_Z;
+ png_fixed_point blue_X, blue_Y, blue_Z;
+} png_XYZ;
+#endif /* COLORSPACE */
+
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+/* A colorspace is all the above plus, potentially, profile information,
+ * however at present libpng does not use the profile internally so it is only
+ * stored in the png_info struct (if iCCP is supported.) The rendering intent
+ * is retained here and is checked.
+ *
+ * The file gamma encoding information is also stored here and gamma correction
+ * is done by libpng, whereas color correction must currently be done by the
+ * application.
+ */
+typedef struct png_colorspace
+{
+#ifdef PNG_GAMMA_SUPPORTED
+ png_fixed_point gamma; /* File gamma */
+#endif
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+ png_xy end_points_xy; /* End points as chromaticities */
+ png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */
+ png_uint_16 rendering_intent; /* Rendering intent of a profile */
+#endif
+
+ /* Flags are always defined to simplify the code. */
+ png_uint_16 flags; /* As defined below */
+} png_colorspace, * PNG_RESTRICT png_colorspacerp;
+
+typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
+
+/* General flags for the 'flags' field */
+#define PNG_COLORSPACE_HAVE_GAMMA 0x0001
+#define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002
+#define PNG_COLORSPACE_HAVE_INTENT 0x0004
+#define PNG_COLORSPACE_FROM_gAMA 0x0008
+#define PNG_COLORSPACE_FROM_cHRM 0x0010
+#define PNG_COLORSPACE_FROM_sRGB 0x0020
+#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
+#define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */
+#define PNG_COLORSPACE_INVALID 0x8000
+#define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags))
+#endif /* COLORSPACE || GAMMA */
projects / wxWidgets.git / blobdiff