Backyard Soccer Will it ever get higher than 20%?
Moderator: ScummVM Team

 Posts: 12
 Joined: Sun Nov 11, 2007 10:42 pm
Backyard Soccer Will it ever get higher than 20%?
Hi, I recently got ScummVM and really want to play Backyard Soccer. However, the completion is at 20% and so it is unplayable. I was wondering if these games are ever revisited, or if it'll just sit this way. Thanks!

 Posts: 12
 Joined: Sun Nov 11, 2007 10:42 pm
If anyone is aware of open source postfix > infix expressions converter, I'd be grateful and will add those U32 opcodes much faster.
I had to use paper and pencil to unwind stacks for all currently implemented U32s, and it takes considerable amount of time.
For the curious ones, postfix expressions which FPU uses are in this form:
2 3 + 5 *
which translates to
(2 + 3) * 5
I.e. it is stackbased.
I know number of infix > postfix converters, particularly implemented in Forth language which uses the latter, but I am not aware about the reverse. Though, to be honest, I did not google for too long.
Eugene
I had to use paper and pencil to unwind stacks for all currently implemented U32s, and it takes considerable amount of time.
For the curious ones, postfix expressions which FPU uses are in this form:
2 3 + 5 *
which translates to
(2 + 3) * 5
I.e. it is stackbased.
I know number of infix > postfix converters, particularly implemented in Forth language which uses the latter, but I am not aware about the reverse. Though, to be honest, I did not google for too long.
Eugene
How complicated are those expressions that are to be converted? I could write a simple Python script to do the conversion for you, if that helps.sev wrote:If anyone is aware of open source postfix > infix expressions converter, I'd be grateful
Well, the FPU itself puts a limitation. Its stack is 8 numbers in depth.
You may find some manually converted expressions in engines/scumm/he/logic_he.cpp file.
For set of FPU commands see Section 1.2.3 here.
I remember this tough example which used whole stack:
Eugene
You may find some manually converted expressions in engines/scumm/he/logic_he.cpp file.
For set of FPU commands see Section 1.2.3 here.
I remember this tough example which used whole stack:
Code: Select all
var18 = (argf[5] + argf[1] + var20) * argf[4] * var10 * 2 +
argf[6] * argf[6] * var28 + argf[4] * argf[4] 
argf[0] * argf[0] * var10 * var10 
argf[5] * argf[0] * var10 * 2 
argf[5] * argf[1] * 2 
argf[1] * argf[1]  argf[5] * argf[5];
Eugene
I see, that's from LogicHEfootball::op_1023.sev wrote:I remember this tough example which used whole stack:
Code: Select all
var18 = (argf[5] + argf[1] + var20) * argf[4] * var10 * 2 + argf[6] * argf[6] * var28 + argf[4] * argf[4]  argf[0] * argf[0] * var10 * var10  argf[5] * argf[0] * var10 * 2  argf[5] * argf[1] * 2  argf[1] * argf[1]  argf[5] * argf[5];
Could you post the corresponding FPU postfix commands that led to this infix C source?
Or, to put it this way: What is the syntax of the input you would feed into my conversion script?
It would be easy to write a script that converts something like "2 3 + 5 *" into "(2 + 3) * 5" (for any stack depth), but I've got the strong feeling that this isn't exactly what you need.
Here goes LogicHEfootball::op_1010() code
But make it work, I'll port it to C and extend desquirr IDA plugin with your algos, so it will be possible to automate this. IDA has all info about constants, addresses, function parameters, etc. I need just the core logic.
Eugene
Code: Select all
mov [esp+4+args1], eax
mov esi, [esp+4+userData]
fild [esp+4+args1] ; Load Integer
add ecx, 46 ; Add
mov [esp+4+userData], ecx
fsubr ds:flt_10019350 ; Subtract Real Reversed
fmul ds:flt_10019390 ; Multiply Real
fstp [esp+4+args1] ; Store Real and Pop
fild [esp+4+userData] ; Load Integer
fld [esp+4+args1] ; Load Real
fmul ds:flt_1001935C ; Multiply Real
fsubp st(1), st ; Subtract Real and Pop
fld [esp+4+args1] ; Load Real
fmul ds:flt_10019368 ; Multiply Real
fmul ds:flt_10019364 ; Multiply Real
fsubr ds:flt_10019348 ; Subtract Real Reversed
fmul ds:flt_10019360 ; Multiply Real
fdivp st(1), st ; Divide Real and Pop
call __ftol ; Call Procedure
push eax
push 108
call [esi+userData.writeVar] ; Indirect Call Near Procedure
fld [esp+0Ch+args1] ; Load Real
call __ftol ; Call Procedure
push eax
push 109
call [esi+userData.writeVar] ; Indirect Call Near Procedure
But make it work, I'll port it to C and extend desquirr IDA plugin with your algos, so it will be possible to automate this. IDA has all info about constants, addresses, function parameters, etc. I need just the core logic.
Eugene
Could this be of any help?
http://multimedia.cx/eggs/barrettsbasi ... areback/
I don't know much about the x87 FPU so bear with me
http://multimedia.cx/eggs/barrettsbasi ... areback/
I don't know much about the x87 FPU so bear with me
Yes, I think so! I had a look at that bb86 program referenced in http://multimedia.cx/eggs/barrettsbasi ... areback/ and it looks promising.john_doe wrote:Could this be of any help?
http://multimedia.cx/eggs/barrettsbasi ... areback/
You can find the download link in this post http://multimedia.cx/eggs/whatrelooks ... ment86937 by Sean Barrett. (Direct download link is: http://nothings.org/remote/bb86.zip)
bb86 parses the FPU commands quite similar to the way I intended to do (but haven't done yet). It comes as Csource. For me, if I'm going to write such a tool from scratch, the hard part of the work would be to figure out what each FPU command does exactly (does it pop or push the stack, etc.). That part is already taken care of in bb86.
sev, please have a look at bb86. Maybe it gives you enough inspiration for the core logic.
I'm already doing it. It's exactly the thing I need.ssdsa wrote:sev, please have a look at bb86. Maybe it gives you enough inspiration for the core logic.
I've extended it a bit, as it does not process many FPU commands, but it's already looks promising.
Eventually I plan to put it inside of desquirr so it could automate the process even more.
Eugene

 Posts: 12
 Joined: Sun Nov 11, 2007 10:42 pm
I don't know if this helps, but I someone deleted one of the files that was installed from Backyard Soccer, and the game ran exactly as it did on ScummVM. Does that mean that if ScummVM accepted more than just the .he0, 2, 4, and 9 files, it would run better? Probably not, but I just wanted to say so, if it helps...