PgDrawText(), PgDrawTextChars()

Draw text

Synopsis:

int PgDrawText( char const *ptr,
                int len,
                PhPoint_t const *pos,
                int flags );

int PgDrawTextv( char const *ptr,
                 int len,
                 PhPoint_t const *pos,
                 int flags );

int PgDrawTextChars( char const *ptr,
                     int len,
                     PhPoint_t const *pos,
                     int flags );

int PgDrawTextCx( void *dc,
                  char const *ptr,
                  int len,
                  PhPoint_t const *pos,
                  int flags );

int PgDrawTextvCx( void *dc,
                   char const *ptr,
                   int len,
                   PhPoint_t const *pos,
                   int flags );

int PgDrawTextCharsCx( void *dc,
                       char const *ptr,
                       int len,
                       PhPoint_t const *pos,
                       int flags );

Description:

Each of these functions builds a command in the draw buffer to draw the text indicated by ptr at location pos, using the font specified in a previous call to PgSetFont().

The len parameter specifies the number of bytes required to store the string. For pure ASCII strings (characters 0 to 127), this is the number of characters. For multibyte strings, len may be larger than the number of characters. For double-byte strings, len is twice the number of characters.

By default, the function assumes that all strings consist of multibyte characters that conform to the ISO/IEC 10646-1 UTF-1 multibyte format. However, if Pg_TEXT_WIDECHAR is set, the function assumes each character is represented by 2 bytes that conform to the ISO/IEC 10646-1 UCS-2 double-byte format.

PgDrawTextChars() assumes that len is the number of characters to draw. Using this number, PgDrawTextChars() determines the number of bytes required to store the string.

In order to:	You can:
Define the color of the text	Use PgSetTextColor(), PgSetTextDither(), or PgSetTextXORColor(),
Mask the text	Use PgSetTextTransPat(),
Fill the extent of the text	Set the background color with PgSetFillColor() or PgSetFillDither() and specify the Pg_BACK_FILL flag to PgDrawText() or PgDrawTextv()
Underline the text	Use PgSetUnderline()

By default, the text is left-aligned (Pg_TEXT_LEFT), and the text is drawn with pos->y as its baseline. You can set flags to a combination of:

Pg_BACK_FILL: Fill the text extent with fill-color parameters.
Pg_TEXT_WIDECHAR: The text is specified as wide characters. Each character is represented by 16 bits.
Pg_TEXT_LEFT: Left align text to pos (text is drawn to the right).
Pg_TEXT_RIGHT: Right align text to pos (text is drawn to the left).
Pg_TEXT_CENTER: Center text horizontally on pos.
Pg_TEXT_TOP: Top align text to pos (text is drawn below).
Pg_TEXT_BOTTOM: Bottom align text to pos (text is drawn above).
Pg_TEXT_MIDDLE: Center text vertically on pos.

Text justification

Text justification relative to the indicated positions.

If you call the "v" forms of these functions, the data isn't physically copied into the draw buffer. Instead, a pointer to the string is stored until the draw buffer is flushed. Make sure you call PgFlush() or PgFlushCx() before you modify the text.

PgDrawText(), PgDrawTextv(), and PgDrawTextChars() work on the current draw context, while you can specify the draw context dc for PgDrawTextCx(), PgDrawTextCxv(), and PgDrawTextCharsCx().

Returns:

0: Success.
-1: The draw buffer is too small to hold the current draw state, the draw command and the data. Increase the size of the draw buffer, or decrease the size of the string.

Examples:

DrawSimpleText() {
    char *s = "Hello World!";
    PhPoint_t p = { 8, 30 };
    char Helvetica18[MAX_FONT_TAG];

    if(PfGenerateFontName("Helvetica", 0, 18,
                          Helvetica18) == NULL) {
        perror("Unable to find font");
    } else {
        PgSetFont( Helvetica18 );
    }
    PgSetTextColor( Pg_WHITE );
    PgDrawText( s, strlen( s ), &p, 0 );
}

The above code draws:

PgDrawText

DrawBackFillText() {
    char *s = "Hello World!";
    PhPoint_t p = { 8, 30 };
    char Helvetica18[MAX_FONT_TAG];

    if(PfGenerateFontName("Helvetica", 0, 18,
                          Helvetica18) == NULL) {
        perror("Unable to find font");
    } else {
        PgSetFont( Helvetica18 );
    }
    PgSetTextColor( Pg_WHITE );
    PgSetFillColor( Pg_PURPLE );
    PgDrawText( s, strlen( s ), &p, Pg_BACK_FILL );
}

The above code draws:

PgDrawText

DrawUnderlineText() {
    char *s = "Hello World!";
    PhPoint_t p = { 8, 30 };
    char Helvetica18[MAX_FONT_TAG];

    if(PfGenerateFontName("Helvetica", 0, 18,
                          Helvetica18) == NULL) {
        perror("Unable to find font");
    } else {
        PgSetFont( Helvetica18 );
    }
    PgSetTextColor( Pg_WHITE );
    PgSetUnderline( Pg_RED, Pg_TRANSPARENT, 0 );
    PgDrawText( s, strlen( s ), &p, 0 );
    PgSetUnderline( Pg_TRANSPARENT, Pg_TRANSPARENT, 0 );
}

The above code draws:

PgDrawText

DrawBackFillUnderlineText() {
    char *s = "Hello World!";
    PhPoint_t p = { 8, 30 };
    char Helvetica18[MAX_FONT_TAG];

    if(PfGenerateFontName("Helvetica", 0, 18,
                          Helvetica18) == NULL) {
        perror("Unable to find font");
    } else {
        PgSetFont( Helvetica18 );
    }
    PgSetTextColor( Pg_WHITE );
    PgSetFillColor( Pg_PURPLE );
    PgSetUnderline( Pg_RED, Pg_TRANSPARENT, 0 );
    PgDrawText( s, strlen( s ), &p, Pg_BACK_FILL );
    PgSetUnderline( Pg_TRANSPARENT, Pg_TRANSPARENT, 0 );
}

The above code draws:

PgDrawText

Classification:

Photon

Safety:
Interrupt handler	No
Signal handler	No
Thread	No

QNX Developer Support

PgDrawText(), PgDrawTextChars()

Synopsis:

Library:

Description:

Returns:

Examples:

Classification:

See also: