[E-Penguin]

Not being an artist, I want to generate some shapes for a game programatically. Drawing them each time on a bitmap then displaying seems to work fine but slowly, so I thought I'd draw to a temporary BitMap, then GetAShape and blit that.

I thought I'd start off simple and draw a red circle on a standard double-buffered display.

Whenever I get to the bit about blitting my shape, WinUAE dies with HALT3. Which I think is memory related?

However I don't see what I'm doing wrong. Is it me?

Using WinUAE ver 3.6.1 64bit with standard A1200 config.

;; Play nicely with WB
WBStartup

;; Everything is a WORD unless otherwise stated
DEFTYPE .w

;; Set up a palette with 4 colours, black red green blue
InitPalette 0,4
PalRGB 0,0,0,0,0
PalRGB 0,1,15,00,00
PalRGB 0,2,00,15,00
PalRGB 0,3,00,00,15

;; Set up a CopList, low-res, 2 bitplane
InitCopList 0,$002

;; Temporary bitmap for creating shapes
#BM_DRAW = 9
BitMap #BM_DRAW,320,256,2
Use BitMap #BM_DRAW

;; Draw a 10x10 circle centred on 5,5
Circle 5, 5, 5, 5, 1

;; Get a shape
#SH_1 = 1
GetaShape #SH_1,0,0,10,10 

;; GO BLITZ MODE
BLITZ

;; Not entirely sure what these do but needed to control the screen
CreateDisplay 0
DisplayPalette 0,0

;; Let's start doing double buffering
dp = 0

;; Allocate the two bitmaps
#BM_DISP1 = 0
#BM_DISP2 = 1
BitMap #BM_DISP1,320,256,2
BitMap #BM_DISP2,320,256,2

;; Start off with DISP1
dp = #BM_DISP1

;; Do until mouse press
While Joyb(0)=0
	;; Select a BitMap to use
	Use BitMap dp
	
	;; Wipe out everything
	Cls 0
	
	;; Blit
	Blit #SH_1, 0, 0, 0
	
	;; Display it
	VWait
    DisplayBitMap 0,dp
	
	;; Swap over the display BitMap
	dp = 1 - dp	
	
Wend

End