;Analog Joys ;----------- ;Analogue Joystick Code ;---------------------- ;By Christos Dimitrakakis (aka Olethros) ;--------------------------------------- ;This code is freely distributable .Comments ;test code for using analogue joysticks ;on port 1 ;seems to work ; ;for the other port, use $DFF012 instead of $DFF014 ;setting up the pins and Paula IO seems to be unnnneeecccessarrry? ;I'd've liked to see an OS-Friendly way to do this... oh well ;Also note that I am not an assembly expert, so any asm ;code used will probably not be the ideal way of doing things. ;|--------------------------------------------------------------| ;| saving of cx,cy,mx,my,nx,ny values | ;| seems to be enough for proper calibration | ;| be careful to use them properly. | ;| | ;| the final calibration stage is a nice easy example of how | ;| to properly use those values | ;| | ;| NOTE: In this example I am adding | ;| 8 measurements together | ;| | ;| Take this under consideration and scale accordingly | ;| if you intend to use AnalogJoyPrefs data for Calibration | ;| | ;|--------------------------------------------------------------| ;HOW TO CONVERT A PC ANALOGUE JOYSTICK(?) ;Well, I dunno the pin assignments from the PC joystick. ;The way I did this: ;(I hope you are adept in things like that. Only danger if you connect 5V to common and ;short your amiga - test with multimeter for max safety) ;Cut the cable and look at the wires. ;Open Up the joystick and look at where they're coming from ;There should be at least one wire coming out from each potentiometer ;Examine the wiring carefully; Find the cable wire corresponding to each potentiometer ;If the two potentiometers have a common wire, then this goes to +5V ;the others go to POTX and POTY ;if they don't (unlikely) then just connect one wire from each pot. to +5V, ;then connect the other 2 wires to POTX and POTY pins as above ;Anyways, my cable was like that: ;GREEN - 5V ;ORANGE - POTX ;BROWN - POTY ;BLACK - COMMON ;WHITE - JOYBUTTON (1?) ;BLUE - JOYBUTTON (2?) ;by the way, especially for driving games, you do NOT want to get raw data from ;the joystick - reasons: ; 1)Jitter ; all potentiometers exhibit jitter, which means noise ; it is quite possible that you have actually listened to ; the effects of jitter the last time you adjusted the ; volume of your aeons-old amp ; 2)Inaccuracy ; Jitter aside, all proportional controllers are inaccurate, ; because of mechanical deficiences (at least mine is) ;Measures: ; ; 1) Averaging ; Averaging in general will considerably improve playability. Try ; continuous averaging for a more immediate and smooth joystick response ; ; 2) Driver (ok Player) aids ; It is important to be able to provide some assistance to the player ; Examples: ; --Logarithmic input - converts linear input to logarithmic, for ; finer control near the centre and more drastic at the edges. ; or you can raise input to a power between 1 and 2 and then scale. ; --Aid Centralize - similar in effect to logarithmic input, this ; creats a dead-zone near the centre, where no input is assumed. ; This could also be implemented by a computer aid that always ; centers the fictional wheel of the car by a small amount ; --Driving Line Aids - A very small, almost tiny help towards ; the perfect driving line can be very helpful without making ; the game too easy. Avoid extremes (ie F1GP) - No-one wants ; to be FORCED on the driving line. ; --Speed-sensitive sensitivity - With this, joystick movements will have ; less effect at higher speeds. ; ; ; Ideally, all these parameters should be user-adjustable... ;if you do not want to wait for a lot of frames to read the joystick ;you can do a continuous average instead ;or a fifo-based accumulator ;(ie get samples and put them in a queue ;each time an item is added to the queue, add its ;value to a variable somewhere. ;every time the queue gets filled up, ;flush the oldest item, WITHOUT FORGETTING TO SUBTRACT ;ITS VALUE FROM THE VARIABLE ;and then push the rest of the items to make room for the ;new value. Note that you can implement a queue as ;a looped Buffer so that you wont have to move all of the ;items everytime a new sample arrives-) .Main_Code Dim xqueue(8) Dim yqueue(8) apoint=8 WbToScreen 0 ShowScreen 0 Window 0,10,10,200,200,$2|$4|$8,"AnalogJoy Calibration",2,1 oxx.w=0 oyy.w=0 mx.w=0 my.w=0 nx.w=0 ny.w=0 sx.w=0 sy.w=0 Window 1,70,170,360,60,2|4|$800,"",2,1 WBox 0,0,360,60,1 WBox 1,1,359,59,2 WBox 2,2,358,58,0 WLocate 12,12:NPrint "CENTER JOYSTICK AND PRESS A MOUSE BUTTON" While Joyb(0)=0 xx.w=0:x.w=0 yy.w=0:y.w=0 For n=1 To 8 VWait MOVE.w $dff014,d0 MOVE.b d0,d1 LSR.w #8,d0 MOVE.b #1,$dff034 PutReg d0,y.w PutReg d1,x.w cx+x cy+y Next n WLocate 10,22 Print cx,":",cy," " cx=0:cy=0 Wend xx.w=0:x.w=0 yy.w=0:y.w=0 For n=1 To 16 VWait MOVE.w $dff014,d0 MOVE.b d0,d1 LSR.w #8,d0 MOVE.b #1,$dff034 PutReg d0,y.w PutReg d1,x.w cx+x cy+y ; MOVE.w #1,$dff034 ;move.w #65281,$dff034 Next n cx/2 cy/2 WCls WBox 0,0,360,60,1 WBox 1,1,359,59,2 WBox 2,2,358,58,0 WLocate 36,4 NPrint "NOW WIGGLE THE JOYSTICK AROUND" WLocate 24,14 NPrint "UNTIL THE CURSOR FITS IN THE BOX" WLocate 48,24 NPrint "THEN PRESS A MOUSE BUTTON" Use Window 0 WindowOutput 0 WBox 50,50,150,150,2 Format "+00.00" mx.w=0 my.w=0 nx.w=0 ny.w=0 xx.w=0:yy.w=0 Repeat x.w=0 y.w=0 For n=1 To 1 VWait ;this code should ALWAYS run on type 5 interrupt ;unless 100% positive that game loop runs ;in time < 1 frame MOVE.w $dff014,d0 ;get Port1 POT MOVE.b d0,d1 ;move lower byte (X) to d1 LSR.w #8,d0 ;shift 8 - now Y is in lower byte ;(perhaps the MOVE/LSR combo could ;be replaced with a bitfield instruction?) MOVE.b #1,$dff034 ;dump the capacitors! ;almost immediately after the VBLANK ;must read POTX/POTY first, though PutReg d0,y.w ;put the stuff into place PutReg d1,x.w xx+x-xqueue(apoint) ;add them yy+y-yqueue(apoint) xqueue(apoint)=x yqueue(apoint)=y apoint+1 If apoint>8 Then apoint=1 Next n rx.w=xx-cx ry.w=yy-cy mx=Max(mx,rx) my=Max(my,ry) nx=Min(nx,rx) ny=Min(ny,ry) If rx>0 Then Cfx=mx Else Cfx=-nx If ry>0 Then Cfy=my Else Cfy=-ny CalX=10*rx/Cfx CalY=10*ry/Cfy WLocate 1,1 NPrint "X:",CalX," Y:",CalY," " WCircle ox,oy,3,0 ox=5*CalX+100:oy=5*CalY+100 WCircle ox,oy,3,1 WCircle 100,100,4,3 Until Joyb(1)=1 OR Joyb(0)=1 Format "00000" ;NOW SAVE THE PREFS choose=RTEZRequest("AnalogJoyPrefs","Calibration Complete","SAVE|USE|CANCEL") If choose=1 If Exists("ENVARC:") If Exists("ENVARC:AnalogJoy.prefs") KillFile("ENVARC:AnalogJoy.prefs") EndIf If WriteFile(0,"ENVARC:AnalogJoy.prefs") FileOutput 0 Gosub write_data CloseFile 0 DefaultOutput EndIf EndIf EndIf If choose<>0 If Exists("ENV:") If Exists("ENV:AnalogJoy.prefs") KillFile("ENV:AnalogJoy.prefs") EndIf If WriteFile(0,"ENV:AnalogJoy.prefs") FileOutput 0 Gosub write_data CloseFile 0 DefaultOutput EndIf EndIf EndIf Use Window 0 InnerCls Gosub write_data MouseWait End ;What follows is the proposed stanard for files ;related to analogue joysticks ;look at accompanying docs for more info on the standard .write_data NPrint "ANALOGJOYPREFS" NPrint "1.0" NPrint "TYPE" NPrint "STANDARD_PORT1" NPrint "CX" NPrint cx NPrint "CY" NPrint cy NPrint "MX" NPrint mx NPrint "MY" NPrint my NPrint "NX" NPrint nx NPrint "NY" NPrint ny NPrint "END" Return .Appendix ;Appendix ;-------- ;Standard code for analog Joys using above var names ;--------------------------------------------------- ;(NOTE: CODE UNTESTED) ;InitBank(0,32,65536) ;BuffOffset.b=14 ;JoyBuff.l=Bank(0) ;location of the joybuffer ;avx.w=0 ;avy.w=0 ; ;SetInt 5 ; GetReg a0,JoyxBuff ;this asm code implements a continuous ; ;average using a small buffer and a pointer ; GetReg d2,BuffOffset ;to store the temporary data ; ; GetReg d3,avx ; GetReg d4,avy ; ; ; CLR.w d0 ;clear those so that we can ; CLR.l d1 ;do word addition later ; ; MOVE.w $dff014,d0 ;get Port1 POT ; MOVE.b d0,d1 ;move lower byte (X) to d1 ; LSR.w #8,d0 ;shift 8 - now Y is in lower byte ; MOVE.b #1,$dff034 ;dump the capacitors! ; ; SUB.w (a0,d2.b),d3 ;sub the last values ; SUB.w 16(a0,d2.b),d4 ;in the queue ; ; MOVE.w d1,(a0,d2.b) ;place the new values in the queue ; ADD.w d1,d3 ;and add them ; MOVE.w d0,16(a0,d2.b) ;code slightly optimized for pipelining :) -yeah ; ADD.w d0,d4 ; ; SUBI.b #2,d2 ;decrease counter ; BGE end_read_loop ;alternatively use: ; MOVE.b #14,d2 ;ADDI.b #2,d2:AND.b #15,d2 ; ;end_read_loop: ; ; PutReg d3,avx ;put things back so we can read them again ; PutReg d4,avy ; PutReg d2,BuffOffset ; ;End SetInt ; ;xx+x ;rx.w=xx-cx ;ry.w=yy-cy ; ;If rx>0 Then Cfx=mx Else Cfx=-nx ;If ry>0 Then Cfy=my Else Cfy=-ny ; ;CalX=10*rx/Cfx ;CalY=10*ry/Cfy ;-------------------------------------------------------