Clears a screen or bitmap.

Err ClearBitmap (Item ioreq, Item scr_bm, Bitmap *bmPtr, int32 rgbValue)

Sets all pixels in the screen or bitmap to the specified rgbValue. Uses SetVRAMPages() for fast operation.

The rgbValue is a pair of RGB555 values packed into a 32-bit word. If you don't want simple black (zero), use the MakeRGB15Pair() macro to create this value from separate red, green, and blue values.

For best performance, pass a non-zero IOreq parameter and a bitmap pointer instead of a screen or bitmap item. This will avoid LookupItem() and CreateIOReq() calls that would otherwise be made internally.

• ioreq IOReq item obtained from GetVRAMIOReq(), or zero to have an IOReq created and deleted internally during the call.

• scr_bm Screen or Bitmap item number. May be zero if a Bitmap pointer is provided.

• bmPtr Bitmap pointer. May be NULL if a Screen or Bitmap item is provided.

• rgbValue Color value to store into all screen or bitmap pixels.

Returns zero on success or a negative error code.

Library call implemented in lib3do.lib.

lib3do.lib, displayutils.h