some refactorings for cleanup

.gitignore

@@ -6,4 +6,5 @@ graphics1
 ham1
 intuition1
 openwin
-ostest
+ostest
+main

scrolling_tricks/Makefile

@@ -2,7 +2,7 @@ ASM=vasmm68k_mot
 ASM_FLAGS = -Fhunk -devpac
 .SUFFIXES = .o .asm .c
 
-CC=vc +kick13
+CC=vc +aos68k
 CFLAGS=-c99 -I$(NDK_INC) -DDEBUG
 
 all: main

scrolling_tricks/README.md

@@ -1,9 +1,13 @@
 # Scrolling Tricks
 
 This is a project to rework the Aminet Scrolling Tricks by Georg Steger into a
-version that works on all Amiga OS releases from 1.3 and has
-higher reuse. The ScrollingTricks tutorial has tremendous learning
-value, but requires at least AmigaOS3.0 to run
+version that has higher internal reuse, is smaller and compiles with
+VBCC. The purpose is mainly to better understand the algorithms
+
+# System Requirements
+
+This software requires V39 libraries and therefore only runs on the
+3.x releases or greater of AmigaOS
 
 ## Original source
 

scrolling_tricks/main.c

@@ -107,35 +107,12 @@ struct FetchInfo
 
 /********************* COMPATIBILITY ***********************/
 
-/*
- * AllocBitMap() is V39, provide a version here, that works on all AmigaOS versions
- * Older releases, unfortunately have to do the initialization in a more lengthy way
- */
-struct BitMap *alloc_bitmap(ULONG sizex, ULONG sizey, ULONG depth, ULONG flags,
-                             struct BitMap *friend_bitmap)
-{
-    return AllocBitMap(sizex, sizey, depth, flags, friend_bitmap);
-}
-
-/* FreeBitMap() is V39, provide a version here that works on all AmigaOS versions */
-void free_bitmap(struct BitMap *bitmap)
-{
-    FreeBitMap(bitmap);
-}
-
-/*
-  GetBitMapAttr() is V39, provide a version here that works on all AmigaOS versions
-  On older revisions, we simply read the bitmap structure
-*/
 ULONG is_bitmap_interleaved(struct BitMap *bitmap)
 {
     return (GetBitMapAttr(bitmap, BMA_FLAGS) & BMF_INTERLEAVED) == BMF_INTERLEAVED;
 }
 
-/* Encapsulation of the FindDisplayInfo()/GetDisplayInfo() functions which
-   don't exist in 1.x OS releases, in that case, we can simply return INVALID_ID
- */
-static ULONG get_mode_id_os3()
+static ULONG get_mode_id_os3(void)
 {
     ULONG modeid = INVALID_ID;
 	struct DimensionInfo diminfo;
@@ -149,7 +126,7 @@ static ULONG get_mode_id_os3()
     return modeid;
 }
 
-ULONG get_mode_id()
+ULONG get_mode_id(void)
 {
     ULONG modeid;
 
@@ -182,12 +159,12 @@ static void Cleanup(char *msg)
 
 	if (ScreenBitmap) {
 		WaitBlit();
-        free_bitmap(ScreenBitmap);
+        FreeBitMap(ScreenBitmap);
 	}
 
 	if (BlocksBitmap) {
 		WaitBlit();
-		free_bitmap(BlocksBitmap);
+		FreeBitMap(BlocksBitmap);
 	}
 
 	if (Map) free(Map);
@@ -254,11 +231,11 @@ static void OpenBlocks(void)
 {
 	LONG l;
 
-	if (!(BlocksBitmap = alloc_bitmap(BLOCKSWIDTH,
-                                      BLOCKSHEIGHT,
-                                      BLOCKSDEPTH,
-                                      BMF_STANDARD | BMF_INTERLEAVED,
-                                      0)))	{
+	if (!(BlocksBitmap = AllocBitMap(BLOCKSWIDTH,
+                                     BLOCKSHEIGHT,
+                                     BLOCKSDEPTH,
+                                     BMF_STANDARD | BMF_INTERLEAVED,
+                                     0)))	{
 		Cleanup("Can't alloc blocks bitmap!");
 	}
 
@@ -282,14 +259,13 @@ static void OpenBlocks(void)
 	blocksbuffer = BlocksBitmap->Planes[0];
 }
 
-// V36: OpenScreenTags()
 static void OpenDisplay(void)
 {
 	ULONG				modeid;
 	LONG				bmflags;
 
-	if (!(ScreenBitmap = alloc_bitmap(BITMAPWIDTH,BITMAPHEIGHT + 3,BLOCKSDEPTH,
-                                      BMF_STANDARD | BMF_INTERLEAVED | BMF_CLEAR,0))) {
+	if (!(ScreenBitmap = AllocBitMap(BITMAPWIDTH,BITMAPHEIGHT + 3,BLOCKSDEPTH,
+                                     BMF_STANDARD | BMF_INTERLEAVED | BMF_CLEAR,0))) {
 		Cleanup("Can't alloc screen bitmap!");
 	}
 	frontbuffer = ScreenBitmap->Planes[0];
@@ -379,7 +355,7 @@ static void InitCopperlist(void)
 
 /******************* SCROLLING **********************/
 
-static void DrawBlock(LONG x,LONG y,LONG mapx,LONG mapy)
+static void DrawBlock(LONG x, LONG y, LONG mapx, LONG mapy)
 {
 	UBYTE block;