@class wxDataOutputStream
This class provides functions that write binary data types in a portable
- way. Data can be written in either big-endian or little-endian format,
- little-endian being the default on all architectures.
+ way.
+
+ Data can be written in either big-endian or little-endian format,
+ little-endian being the default on all architectures but BigEndianOrdered()
+ can be used to change this. The default format for the floating point types
+ is 80 bit "extended precision" unless @c wxUSE_APPLE_IEEE was turned off
+ during the library compilation, in which case extended precision is not
+ available at all. You can call UseBasicPrecisions() to change this and
+ use the standard IEEE 754 32 bit single precision format for floats and
+ standard 64 bit double precision format for doubles. This is recommended
+ for the new code for better interoperability with other software that
+ typically uses standard IEEE 754 formats for its data, the use of extended
+ precision by default is solely due to backwards compatibility.
If you want to write data to text files (or streams) use wxTextOutputStream
instead.
@param stream
The output stream.
@param conv
- Charset conversion object object used to encoding Unicode strings
+ Charset conversion object used to encoding Unicode strings
before writing them to the stream in Unicode mode (see
WriteString() for a detailed description). Note that you must not
destroy @a conv before you destroy this wxDataOutputStream
order.
*/
void BigEndianOrdered(bool be_order);
-
+
/**
Returns the current text conversion class used for
writing strings.
*/
wxMBConv *GetConv() const;
- /**
+ /**
Sets the text conversion class used for writing strings.
*/
void SetConv( const wxMBConv &conv );
-
+
+ /**
+ Disables the use of extended precision format for floating point
+ numbers.
+
+ This method disables the use of 80 bit extended precision format for
+ the @c float and @c double values written to the stream, which is used
+ by default (unless @c wxUSE_APPLE_IEEE was set to @c 0 when building
+ the library, in which case the extended format support is not available
+ at all and this function does nothing).
+
+ After calling it, @c float values will be written out in one of IEEE
+ 754 "basic formats", i.e. 32 bit single precision format for floats and
+ 64 bit double precision format for doubles.
+
+ @since 2.9.5
+ */
+ void UseBasicPrecisions();
+
+ /**
+ Explicitly request the use of extended precision for floating point
+ numbers.
+
+ This function allows the application code to explicitly request the use
+ of 80 bit extended precision format for the floating point numbers.
+ This is the case by default but using this function explicitly ensures
+ that the compilation of code relying on producing the output stream
+ using extended precision would fail when using a version of wxWidgets
+ compiled with @c wxUSE_APPLE_IEEE==0 and so not supporting this format
+ at all.
+
+ @since 2.9.5
+ */
+ void UseExtendedPrecision();
+
/**
Writes the single byte @a i8 to the stream.
*/
void Write8(wxUint8 i8);
/**
- Writes an array of bytes to the stream. The amount of bytes to write is
+ Writes an array of bytes to the stream. The number of bytes to write is
specified with the @a size variable.
*/
void Write8(const wxUint8* buffer, size_t size);
*/
void Write16(wxUint16 i16);
/**
- Writes an array of 16 bit unsigned integer to the stream. The amount of
+ Writes an array of 16 bit unsigned integer to the stream. The number of
16 bit unsigned integer to write is specified with the @a size variable.
*/
void Write16(const wxUint16* buffer, size_t size);
*/
void Write32(wxUint32 i32);
/**
- Writes an array of 32 bit unsigned integer to the stream. The amount of
+ Writes an array of 32 bit unsigned integer to the stream. The number of
32 bit unsigned integer to write is specified with the @a size variable.
*/
void Write32(const wxUint32* buffer, size_t size);
*/
void Write64(wxUint64 i64);
/**
- Writes an array of 64 bit unsigned integer to the stream. The amount of
+ Writes an array of 64 bit unsigned integer to the stream. The number of
64 bit unsigned integer to write is specified with the @a size variable.
*/
void Write64(const wxUint64* buffer, size_t size);
/**
- Writes the double @a f to the stream using the IEEE format.
+ Writes the float @a f to the stream.
+
+ If UseBasicPrecisions() had been called, the value is written out using
+ the standard IEEE 754 32 bit single precision format. Otherwise, this
+ method uses the same format as WriteDouble(), i.e. 80 bit extended
+ precision representation.
+
+ @since 2.9.5
*/
- void WriteDouble(double f);
+ void WriteFloat(float f);
+
/**
- Writes an array of double to the stream. The amount of double to write is
- specified with the @a size variable.
+ Writes an array of float to the stream. The number of floats to write is
+ specified by the @a size variable.
+
+ @since 2.9.5
+ */
+ void WriteFloat(const float* buffer, size_t size);
+
+ /**
+ Writes the double @a d to the stream.
+
+ The output format is either 80 bit extended precision or, if
+ UseBasicPrecisions() had been called, standard IEEE 754 64 bit double
+ precision.
+ */
+ void WriteDouble(double d);
+
+ /**
+ Writes an array of double to the stream. The number of doubles to write is
+ specified by the @a size variable.
*/
void WriteDouble(const double* buffer, size_t size);
@class wxDataInputStream
This class provides functions that read binary data types in a portable
- way. Data can be read in either big-endian or little-endian format,
- little-endian being the default on all architectures.
+ way.
+
+ Please see wxDataOutputStream for the discussion of the format expected by
+ this stream on input, notably for the floating point values.
If you want to read data from text files (or streams) use wxTextInputStream
instead.
@param stream
The input stream.
@param conv
- Charset conversion object object used to decode strings in Unicode
+ Charset conversion object used to decode strings in Unicode
mode (see ReadString() for a detailed description). Note that you
must not destroy @a conv before you destroy this wxDataInputStream
instance!
*/
void BigEndianOrdered(bool be_order);
-
/**
Returns the current text conversion class used for
reading strings.
*/
wxMBConv *GetConv() const;
-
+
/**
Reads a single byte from the stream.
*/
wxUint8 Read8();
/**
- Reads bytes from the stream in a specified buffer. The amount of bytes
+ Reads bytes from the stream in a specified buffer. The number of bytes
to read is specified by the @a size variable.
*/
void Read8(wxUint8* buffer, size_t size);
wxUint16 Read16();
/**
Reads 16 bit unsigned integers from the stream in a specified buffer.
- The amount of 16 bit unsigned integers to read is specified by the
+ The number of 16 bit unsigned integers to read is specified by the
@a size variable.
*/
void Read16(wxUint16* buffer, size_t size);
wxUint32 Read32();
/**
Reads 32 bit unsigned integers from the stream in a specified buffer.
- The amount of 32 bit unsigned integers to read is specified by the
+ The number of 32 bit unsigned integers to read is specified by the
@a size variable.
*/
void Read32(wxUint32* buffer, size_t size);
wxUint64 Read64();
/**
Reads 64 bit unsigned integers from the stream in a specified buffer.
- The amount of 64 bit unsigned integers to read is specified by the
+ The number of 64 bit unsigned integers to read is specified by the
@a size variable.
*/
void Read64(wxUint64* buffer, size_t size);
/**
- Reads a double (IEEE encoded) from the stream.
+ Reads a float from the stream.
+
+ Notice that if UseBasicPrecisions() hadn't been called, this function
+ simply reads a double and truncates it to float as by default the same
+ (80 bit extended precision) representation is used for both float and
+ double values.
+
+ @since 2.9.5
+ */
+ float ReadFloat();
+
+ /**
+ Reads float data from the stream in a specified buffer.
+
+ The number of floats to read is specified by the @a size variable.
+
+ @since 2.9.5
+ */
+ void ReadFloat(float* buffer, size_t size);
+
+ /**
+ Reads a double from the stream.
+
+ The expected format is either 80 bit extended precision or, if
+ UseBasicPrecisions() had been called, standard IEEE 754 64 bit double
+ precision.
*/
double ReadDouble();
+
/**
- Reads double data (IEEE encoded) from the stream in a specified buffer.
- The amount of doubles to read is specified by the @a size variable.
+ Reads double data from the stream in a specified buffer.
+
+ The number of doubles to read is specified by the @a size variable.
*/
void ReadDouble(double* buffer, size_t size);
In Unicode build of wxWidgets, the fuction first reads multibyte
(char*) string from the stream and then converts it to Unicode using
the @e conv object passed to constructor and returns the result as
- wxString. You are responsible for using the same convertor as when
+ wxString. You are responsible for using the same converter as when
writing the stream.
@see wxDataOutputStream::WriteString()
*/
wxString ReadString();
- /**
+ /**
Sets the text conversion class used for reading strings.
*/
void SetConv( const wxMBConv &conv );
+
+ /**
+ Disables the use of extended precision format for floating point
+ numbers.
+
+ This method disables the use of 80 bit extended precision format for
+ the @c float and @c double values read from the stream, which is used
+ by default (unless @c wxUSE_APPLE_IEEE was set to @c 0 when building
+ the library, in which case the extended format support is not available
+ at all and this function does nothing).
+
+ After calling it, @c float values will be expected to appear in one of
+ IEEE 754 "basic formats", i.e. 32 bit single precision format for
+ floats and 64 bit double precision format for doubles in the input.
+
+ @since 2.9.5
+ */
+ void UseBasicPrecisions();
+
+ /**
+ Explicitly request the use of extended precision for floating point
+ numbers.
+
+ This function allows the application code to explicitly request the use
+ of 80 bit extended precision format for the floating point numbers.
+ This is the case by default but using this function explicitly ensures
+ that the compilation of code relying on reading the input containing
+ numbers in extended precision format would fail when using a version of
+ wxWidgets compiled with @c wxUSE_APPLE_IEEE==0 and so not supporting
+ this format at all.
+
+ @since 2.9.5
+ */
+ void UseExtendedPrecision();
};
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