Own gadgets with banks - chapter ][

BlitzPlus Forums/BlitzPlus Tutorials/Own gadgets with banks - chapter ][

CS_TBL

(Posted 2005) [#1]

Here's another tutorial for own gadgets, much in line with the other one. I'm bad with names, so I called this draw-object a M33P :)

Run the code below, and notice that when you put the whole lot of functions in includefiles, you don't need anything else to know. No declarations, no global variables (thank heavens!), no nothing. Just create it, use it, and release it when done.

In a nutshell the basics of this method:

* All variables, images, gadgets etc. go into banks.
* There is a 'create' function
* There is an 'update' function
* There is an 'event' function
* There is a 'free' function
* It's recommended to have banks in banks to allow for expansion without messing-up the bank-structure
* It's recommended to have special gadgetbanks, imagebanks etc.
* Images, gadgets, banks etc. are all 1 int
* Objects like these can be created and free'd locally

One might argue to use consts for the adresses.. that's up to you.. I'm comfy without them..

; Bank tutorial, by CS_TBL
;
; purpose: Demonstrating how to create programs using banks for variable-storage
;

app=CreateWindow("Bank tutorial 'M33P' - By CS_TBL",0,0,640,480)
Global quit


; let's create some m33ps ..

m33p1=CreateM33P(32,32,256,128,app) ; x,y,w,h,parent

m33p2=CreateM33P(32,200,192,96,app) ; x,y,w,h,parent

m33p3=CreateM33P(300,32,320,256,app) ; x,y,w,h,parent

m33p4=CreateM33P(332,320,80,80,app) ; x,y,w,h,parent

Repeat
	Delay 2
	WaitEvent()
	If EventID()=$803 quit=True

	evM33P(m33p1)
	evM33P(m33p2)
	evM33P(m33p3)
	evM33P(m33p4)

Until quit

FreeM33P(m33p1)
FreeM33P(m33p2)
FreeM33P(m33p3)
FreeM33P(m33p4)

End

Function evM33P(bank)
	; security..
	If Not bank Break "No bank given in evM33P()"

	; first extract what we need first.. if the mouse is not on the canvas, there's no need to extract the rest yet
	panel=PeekInt(bank,0)
	gadgets=PeekInt(bank,4)
	canvas=PeekInt(gadgets,0)
	button=PeekInt(gadgets,8)
	images=PeekInt(bank,8)
	image=PeekInt(images,0)

	If EventSource()=canvas
		; extract more variables
		titlecanvas=PeekInt(gadgets,4)
		r=PeekByte(bank,12)
		g=PeekByte(bank,13)
		b=PeekByte(bank,14)
		drawR=PeekByte(bank,21)
		drawG=PeekByte(bank,22)
		drawB=PeekByte(bank,23)
		w=GadgetWidth(canvas)
		h=GadgetHeight(canvas)
		LMD=PeekByte(bank,16)
		
		If EventID()=$205 ; canvasenter
			PokeByte bank,15,1
			updateM33P(bank)
		EndIf
		
		If EventID()=$203 ; canvasmove
			PokeByte bank,15,1
			updateM33P(bank)
		EndIf
		
		If EventID()=$206 ; canvasleave
			PokeByte bank,15,0
			updateM33P(bank)
		EndIf

		If EventID()=$201
			If EventData()=1
				LMD=1
				oldx=EventX():PokeShort bank,17,oldx
				oldy=EventY():PokeShort bank,19,oldy
				PokeByte bank,16,LMD
			EndIf
		EndIf
		
		If EventID()=$202
			If EventData()=1
				LMD=0
				PokeByte bank,16,LMD
			EndIf
		EndIf

		If LMD
			x=EventX()
			y=EventY()
			
			If x<0 x=0      ; clip to canvas
			If x>w-1 x=w-1  ;
			If y<0 y=0      ;
			If y>h-1 y=h-1  ;
			
			oldx=PeekShort(bank,17)
			oldy=PeekShort(bank,19)
			
			SetBuffer ImageBuffer(image)
				Color drawR,drawG,drawB
				Line oldx,oldy,x,y
			SetBuffer DesktopBuffer()
			
			PokeShort bank,17,x
			PokeShort bank,19,y
		EndIf
		
	EndIf

	If EventSource()=button
		SetBuffer ImageBuffer(image)
			Cls
		SetBuffer DesktopBuffer()
		updateM33P(bank)
		ActivateGadget panel
	EndIf

	colorcanvas=PeekInt(gadgets,12)
	If EventSource()=colorcanvas
		If EventID()=$201
		
			drawR=PeekByte(bank,21)
			drawG=PeekByte(bank,22)
			drawB=PeekByte(bank,23)
			
			RequestColor(drawR,drawG,drawB)
	
			PokeByte bank,21,RequestedRed()
			PokeByte bank,22,RequestedGreen()
			PokeByte bank,23,RequestedBlue()
			
			updateM33P(bank)
		EndIf
	EndIf

End Function

Function CreateM33P(x,y,w,h,parent)

	; some security here first:
	If Not parent Break "No parent given in CreateM33P()"
	If w<64 w=64
	If h<40 h=40
	; now we have proper dimensions for our panel

	

	; We make a description of the bank here:
	; ---------------------------------------
	; adres		size	description
	;
	; 00		04		panel
	; 04		04		gadgetbank	(seperate bank, so it can grow with gadgets without messing up this M33P-bank)
	; 08		04		imagebank	(I just decided we need various images :)
	; 12		01		title R
	; 13		01		title G
	; 14		01		title B
	; 15		01		active
	; 16		01		LMD (required for drawing)
	; 17		02		oldx
	; 19		02		oldy
	; 21		01		draw R
	; 22		01		draw G
	; 23		01		draw B

	; for the moment our bank has a size of 24 (adresses 0..23 when reading bytes)
	; I could've chosen to put the panel inside the gadgetsbank, I didn't .. you can .., I figured I always need a
	; panel anyway, and the seperate gadgetbank is here solely so it can expanded without ruining the m33p-bank..


	bank=CreateBank(24)
	
	panel=CreatePanel(x,y,w,h,parent): PokeInt bank,0,panel
	images=CreateBank(4) :	PokeInt bank,8,images

	PokeByte bank,12,160 ; title R
	PokeByte bank,13,160 ; title G
	PokeByte bank,14,255 ; title B
	PokeByte bank,15,0   ; active
	PokeByte bank,21,255 ; draw R
	PokeByte bank,22,255 ; draw G
	PokeByte bank,23,255 ; draw B


	; let's create a new list, for the gadgets.

	; ---------------------------------------
	; adres		size	description
	;
	; 00		04		canvas
	; 04		08		canvas (title)
	; 08		04		clearbutton
	; 12		04		colorcanvas

	; so.. a size of 16
	gadgets=CreateBank(16): PokeInt bank,4,gadgets

	PokeInt gadgets, 0,CreateCanvas(0,16,w-32,h-16,panel)
	PokeInt gadgets, 4,CreateCanvas(0,0,w-32,16,panel)
	PokeInt gadgets, 8,CreateButton("CLS",w-32,0,32,24,panel)
	PokeInt gadgets,12,CreateCanvas(2+w-32,2+24,32-4,24-4,panel)

	; let's create 1 image  (ok ok, so I decided M33P is a mini-drawtool :)

	PokeInt images,0,CreateImage(w-32,h-16)

	updateM33P(bank) ; draw it for the very first time!

	Return bank
	
End Function

Function updateM33P(bank)

	; security..
		If Not bank Break "No bank given in updateM33P()"

	; extract the variables we need..
	
	gadgets=PeekInt(bank,4)
	canvas=PeekInt(gadgets,0)
	colorcanvas=PeekInt(gadgets,12)
	titlecanvas=PeekInt(gadgets,4)
	r=PeekByte(bank,12)
	g=PeekByte(bank,13)
	b=PeekByte(bank,14)
	drawR=PeekByte(bank,21)
	drawG=PeekByte(bank,22)
	drawB=PeekByte(bank,23)
	active=PeekByte(bank,15)
	w=GadgetWidth(canvas)
	h=GadgetHeight(canvas)
	images=PeekInt(bank,8)
	image=PeekInt(images,0)

	SetBuffer CanvasBuffer(titlecanvas)

		If active
			ClsColor r,g,b
		Else
			ClsColor r/2,g/2,b/2
		EndIf
		Cls
		
		Color r/3,g/3,b/3
		For t=0 To 15 Step 2
			Rect 0,t,w,1,False
		Next
	FlipCanvas titlecanvas

	SetBuffer CanvasBuffer(canvas)
		DrawBlock image,0,0
	FlipCanvas canvas
	
	SetBuffer CanvasBuffer(colorcanvas)
		ClsColor drawR,drawG,drawB:Cls
		drawR=(drawR+128) Mod 256
		drawG=(drawG+128) Mod 256
		drawB=(drawB+128) Mod 256
		Color drawR,drawG,drawB
		Rect 0,0,28,20,False
	FlipCanvas colorcanvas
End Function

Function FreeM33P(bank)

	; security..
	If Not bank Break "No bank given in FreeM33P()"


	gadgets=PeekInt(bank,4)
	
	b=BankSize(gadgets) ; only free gadgets if there are gadgets anyway..
	If b
		For t=0 To b-1 Step 4 ; step 4, because gadgets, images, banks etc. are stored in INT values (= 4 bytes)
			g=PeekInt(gadgets,t)
			If g FreeGadget g ; perhaps we freed a gadget earlier? No need to free it now then...
		Next
	EndIf

	images=PeekInt(bank,8)
	
	b=BankSize(images) ; only free images if there are images anyway..
	If b
		For t=0 To b-1 Step 4
			i=PeekInt(images,t)
			If i FreeImage i ; perhaps we freed an image earlier? No need to free it now then...
		Next
	EndIf

	FreeGadget PeekInt(bank,0) ; let's not forget the panel..

	FreeBank bank ; an last but not least... the m33p itself.

End Function

Function Break(s$)
	Notify s$
	SetBuffer DesktopBuffer()
	End
End Function

m33p ^_^