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how do you do calculus physics in Assembly like in Donkey Ko
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 Joined: Wed Jun 09, 2010 3:30 am Posts: 9 Location: Melbourne, Australia 
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 how do you do calculus physics in Assembly like in Donkey Kohow do you do calculus physics in Assembly like in Donkey Kong does?
_________________ http://www.rolandszi.com |
| Thu Oct 07, 2010 7:27 am |
 
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Site Admin  Joined: Thu Jan 01, 1970 12:00 am Posts: 251
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The same way you do with C, C++, Java, etc. first you understand the physical model (trajectory in this case), and the create a computer model of it. All my books show this simple example, as do other game development books. So just read one of them on game physics and see for yourself. Then if you want to convert it to ASM then that's a language problem, not a programming problem and you have to be good at ASM.
Andre' |
| Thu Oct 07, 2010 5:12 pm |
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 Joined: Tue Dec 06, 2005 8:01 am Posts: 23 Location: U.S.A.
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Here's a super simple example of ASM Physics, a bouncing ball. Very simple, but enough to get you somewhat started I think. If you can already do that in ASM then just ignore me. ^^
Code: ;Pixel Animation ;8/02/07 ;Ball Bouncing ;By Joe Nesbella start: lda #$00 ;X Position sta $00 lda #$00 ;Y Position sta $01 lda #02 ;Colour sta $03 lda #$0f ;ballx sta $1A ;ballX storage lda #$00 ;ballY sta $1B ;ballY Storage lda #$00 ;ball dir x currently right sta $1C lda #$00 ;ball dir y currently down sta $1D mainLoop: lda #$80 sta $1E jsr delay jmp checkHDir checkHDir: lda $1C ;Load X Dir cmp #$00 ;Going Right? beq checkRight jmp checkLeft ;If not right go left checkVDir: lda $1D ;Load Y DIr cmp #$00 ;Going Down? beq checkDown jmp checkUp delay: dec $1E lda $1E cmp #$00 bne delay rts checkRight: lda $1A ;Load X Coord cmp #$1f bne goRight lda #$01 ;Change Dir to Left sta $1C jmp checkHDir checkLeft: lda $1A ;Load X Coord cmp #$00 bne goLeft lda #$00 ;Change Dir to Right sta $1C jmp checkHDir checkDown: lda $1B ;Load Y Coord cmp #$1f ;Check against bottom of screen bne goDown lda #$01 ;Change to Up sta $1D jmp checkVDir checkUp: lda $1B ;Load Y Coord cmp #$00 ;Check Against Top Of Screen bne goUp lda #$00 ;Change to Down sta $1D jmp checkVDir goRight: ;Erase Pixel First lda $1A ;Load X Coord sta $00 lda $1B ;Load Y Coord sta $01 jsr erasePixel inc $1A ;Increase X Coord 1 lda $1A ;Load X Coord sta $00 jmp checkVDir goLeft: ;Erase Pixel First lda $1A ;Load X Coord sta $00 lda $1B ;Load Y Coord sta $01 jsr erasePixel dec $1A ;Decrease X Coord 1 lda $1A ;Load X Coord sta $00 jmp checkVDir goDown: inc $1B ;Increase Y Coord lda $1B ;Load Y Coord sta $01 jmp drawPixel goUp: dec $1B ;Increase Y Coord lda $1B ;Load Y Coord sta $01 jmp drawPixel drawPixel: ldx $01 ;Load Y Position lda highByte, x sta $0B ;Store High Byte lda lowByte, x sta $0A ;Store Low Byte lda $00 ;Load X Coordinate probably should be adc $0A ;ANDed with 31 to keep on same line sta $0A ;This gives us our complete address lda $03 ;Load the Colour ldx #$00 ;Make sure X offset is 0 sta ($0A, x) ;Get our location jmp mainLoop erasePixel: ldx $01 ;Load Y Position lda highByte, x sta $0B ;Store High Byte lda lowByte, x sta $0A ;Store Low Byte lda $00 ;Load X Coordinate probably should be adc $0A ;ANDed with 31 to keep on same line sta $0A ;This gives us our complete address lda #$00 ;Load the Colour ldx #$00 ;Make sure X offset is 0 sta ($0A, x) ;Get our location rts ;High Byte Y Coordinate Address Lookup highByte: dcb $02, $02, $02, $02, $02, $02, $02, $02 dcb $03, $03, $03, $03, $03, $03, $03, $03 dcb $04, $04, $04, $04, $04, $04, $04, $04 dcb $05, $05, $05, $05, $05, $05, $05, $05 ;Low Byte Y Coordinate Address Lookup lowByte: dcb $00, $20, $40, $60, $80, $A0, $C0, $E0 dcb $00, $20, $40, $60, $80, $A0, $C0, $E0 dcb $00, $20, $40, $60, $80, $A0, $C0, $E0 dcb $00, $20, $40, $60, $80, $A0, $C0, $E0 It's all 6502 ASM (my favorite) code and is designed for the website 6502ASM.com _________________ The wolf and his mate howl, taking solace in the silver moon. Pressing ever foreward to see what the future holds. Mao Mao Games |
| Wed Oct 20, 2010 12:28 am |
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 Joined: Sat Nov 21, 2009 6:16 pm Posts: 10
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Jinroh wrote: Here's a super simple example of ASM Physics, a bouncing ball. Very simple, but enough to get you somewhat started I think. If you can already do that in ASM then just ignore me. ^^ Code: ;Pixel Animation ;8/02/07 ;Ball Bouncing ;By Joe Nesbella start: lda #$00 ;X Position sta $00 lda #$00 ;Y Position sta $01 lda #02 ;Colour sta $03 lda #$0f ;ballx sta $1A ;ballX storage lda #$00 ;ballY sta $1B ;ballY Storage lda #$00 ;ball dir x currently right sta $1C lda #$00 ;ball dir y currently down sta $1D mainLoop: lda #$80 sta $1E jsr delay jmp checkHDir checkHDir: lda $1C ;Load X Dir cmp #$00 ;Going Right? beq checkRight jmp checkLeft ;If not right go left checkVDir: lda $1D ;Load Y DIr cmp #$00 ;Going Down? beq checkDown jmp checkUp delay: dec $1E lda $1E cmp #$00 bne delay rts checkRight: lda $1A ;Load X Coord cmp #$1f bne goRight lda #$01 ;Change Dir to Left sta $1C jmp checkHDir checkLeft: lda $1A ;Load X Coord cmp #$00 bne goLeft lda #$00 ;Change Dir to Right sta $1C jmp checkHDir checkDown: lda $1B ;Load Y Coord cmp #$1f ;Check against bottom of screen bne goDown lda #$01 ;Change to Up sta $1D jmp checkVDir checkUp: lda $1B ;Load Y Coord cmp #$00 ;Check Against Top Of Screen bne goUp lda #$00 ;Change to Down sta $1D jmp checkVDir goRight: ;Erase Pixel First lda $1A ;Load X Coord sta $00 lda $1B ;Load Y Coord sta $01 jsr erasePixel inc $1A ;Increase X Coord 1 lda $1A ;Load X Coord sta $00 jmp checkVDir goLeft: ;Erase Pixel First lda $1A ;Load X Coord sta $00 lda $1B ;Load Y Coord sta $01 jsr erasePixel dec $1A ;Decrease X Coord 1 lda $1A ;Load X Coord sta $00 jmp checkVDir goDown: inc $1B ;Increase Y Coord lda $1B ;Load Y Coord sta $01 jmp drawPixel goUp: dec $1B ;Increase Y Coord lda $1B ;Load Y Coord sta $01 jmp drawPixel drawPixel: ldx $01 ;Load Y Position lda highByte, x sta $0B ;Store High Byte lda lowByte, x sta $0A ;Store Low Byte lda $00 ;Load X Coordinate probably should be adc $0A ;ANDed with 31 to keep on same line sta $0A ;This gives us our complete address lda $03 ;Load the Colour ldx #$00 ;Make sure X offset is 0 sta ($0A, x) ;Get our location jmp mainLoop erasePixel: ldx $01 ;Load Y Position lda highByte, x sta $0B ;Store High Byte lda lowByte, x sta $0A ;Store Low Byte lda $00 ;Load X Coordinate probably should be adc $0A ;ANDed with 31 to keep on same line sta $0A ;This gives us our complete address lda #$00 ;Load the Colour ldx #$00 ;Make sure X offset is 0 sta ($0A, x) ;Get our location rts ;High Byte Y Coordinate Address Lookup highByte: dcb $02, $02, $02, $02, $02, $02, $02, $02 dcb $03, $03, $03, $03, $03, $03, $03, $03 dcb $04, $04, $04, $04, $04, $04, $04, $04 dcb $05, $05, $05, $05, $05, $05, $05, $05 ;Low Byte Y Coordinate Address Lookup lowByte: dcb $00, $20, $40, $60, $80, $A0, $C0, $E0 dcb $00, $20, $40, $60, $80, $A0, $C0, $E0 dcb $00, $20, $40, $60, $80, $A0, $C0, $E0 dcb $00, $20, $40, $60, $80, $A0, $C0, $E0 It's all 6502 ASM (my favorite) code and is designed for the website 6502ASM.com Jinroh, Check out: http://www.google.com/url?sa=t&source=w ... kWAZPddsXA Almost the same instructions I bet you would not need much training to program the 9s12 too.  |
| Wed Oct 20, 2010 1:36 pm |
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Joined: Wed Jun 09, 2010 3:30 am Posts: 9 Location: Melbourne, Australia
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most engines use newtonian physics modelling I suppose.
_________________ http://www.rolandszi.com |
| Tue Nov 09, 2010 6:29 am |
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