_selectpalette

Description

Selects a graphics palette for CGA.

#include <graph.h>

short __far _selectpalette( short number );

Remarks

The _selectpalette function works only under the video modes _MRES4COLOR, _MRESNOCOLOR, and _ORESCOLOR. A CGA palette consists of a selectable background color (Color 0) and three set colors. Under the _MRES4COLOR mode, the number argument selects one of the four predefined palettes shown in Table R.6.

Table R.6 _MRES4COLOR Palette Colors

The _MRESNOCOLOR video mode is used with black-and-white displays, producing palettes consisting of various shades of gray. It will also produce color when used with a color display. The number of palettes available depends upon whether a CGA or EGA hardware package is employed. Under a CGA configuration, only the palettes shown in Table R.7 are available. Note that although four palette numbers are listed, palettes 0 and 1 are identical, as are palettes 2 and 3.

Table R.7 _MRESNOCOLOR Mode CGA Palette Colors

Under the EGA configuration, the three palettes shown in Table R.8 are available in the _MRESNOCOLOR video mode. Note that although four palette numbers are listed, palettes 1 and 3 are identical.

Table R.8 _MRESNOCOLOR Mode EGA Palette Colors

You can use the _ORESCOLOR high resolution video mode for the Olivetti graphics adapters found in most Olivetti computers and in the AT&T 6300 series computers. In _ORESCOLOR mode, an argument number in the range 0–15 selects one of the colors listed in Table R.9. The background color is always black in this mode.

Table R.9 _ORESCOLOR Mode Colors

Return Value

The function returns the value of the previous palette. There is no error return.

Compatibility

Standards:None

16-Bit:DOS

32-Bit:None

See Also

_getvideoconfig, _remappalette, _setbkcolor, _setvideomode

Example

/* SELPAL.C: This program changes the current CGA palette. */

#include <stdio.h>

#include <stdlib.h>

#include <conio.h>

#include <graph.h>

long bkcolor[8] = { _BLACK, _BLUE, _GREEN, _CYAN,

_RED, _MAGENTA, _BROWN, _WHITE };

char *bkname [] = { "BLACK", "BLUE", "GREEN", "CYAN",

"RED", "MAGENTA", "BROWN", "WHITE" };

void main( void )

{

int i, j, k;

if ( !_setvideomode( _MRES4COLOR ) )

{

printf( "No palettes available" );

exit( 1 );

}

for( i = 0; i < 4; i++ ) /* Palette loop */

{

_selectpalette( i );

for( k = 0; k < 8; k++ ) /* Background color loop */

{

_clearscreen( _GCLEARSCREEN );

_setbkcolor( bkcolor[k] );

_settextposition( 1, 1 );

printf( "Background: %s\tPalette: %d", bkname[k], i );

for( j = 1; j < 4; j++ ) /* Foreground color loop */

{

_setcolor( j );

_ellipse( _GFILLINTERIOR, 100, j * 30, 220, 80 + (j * 30) );

}

_getch();

}

}

_setvideomode( _DEFAULTMODE );

exit( 0 );

}