Checking for Sprite in WIMP sprite pool.

Is there an easy way of looking for a given sprite name in the WIMP sprite pool without failing hard if not found?

Use SWI Wimp_SpriteOp which is basically OS_SpriteOp with the sprite area address (R1) filled in by the Wimp.

Minor correction – XWimp_SpriteOp so if the sprite doesn’t exist, the call will return with the V flag set (and R0 pointing to an error block). Easy to check the V flag and know that the call failed.

If you just want to know whether or not the sprite exists, the usual way is to read its info and see if that fails. In C with OSLib

static osbool objutil_test_sprite(char *sprite)
{
	if (sprite == NULL)
		return FALSE;

	return xwimpspriteop_read_sprite_info(sprite, NULL, NULL, NULL, NULL) == NULL;
}

and in BASIC

DEF FNtypes_sprite_from_type(filetype%)
LOCAL sprite$, flags%

REM Discard out of bounds types immediately.

IF filetype% < 0 OR filetype% > &FFF THEN = "file_xxx"

REM Try the type's sprite, and fall back if it doesn't exist.

sprite$ = "file_" + RIGHT$("000" + STR$~(filetype%), 3)

SYS "XWimp_SpriteOp", 40,,sprite$ TO ;flags%
IF flags% AND 1 THEN sprite$ = "file_xxx"

=sprite$