Changes on brushes memory management, in preparation for Issue 362

git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1699 416bcca6-2ee7-4201-b75f-2eb2f807beb1

src/brush.h

@@ -111,9 +111,16 @@ void Capture_brush_with_lasso(int vertices, short * points,short clear);
 
 
 ///
-/// Changes the Brush size, discarding its previous content.
-/// @return 0 OK, 1 Failed
-byte Realloc_brush(word new_brush_width, word new_brush_height);
+/// Changes the Brush size.
+/// @return 0 on success, non-zero on failure (memory?).
+/// @param new_brush: Optionally, you can provide an already allocated new
+///        brush - otherwise, this function performs the allocation.
+/// @param old_brush: If the caller passes NULL, this function will free the old
+///        pixel data. If the caller provides the address of a (free) byte
+///        pointer, the function will make it point to the original pixel data,
+///        in this case it will be the caller's responsibility to free() it
+///        (after transferring pixels to Brush, usually).
+byte Realloc_brush(word new_brush_width, word new_brush_height, byte *new_brush, byte **old_brush);