ATan() possible?

[AnonymousTipster]

I have come to a snag in my current project which requires an ATan function. I don't think that this can be solved by a simple array of numbers like sin and cos. There 'seems' to be sceFpuSin and sceFpuCos, but I can't see a sceFpuATan function. I couldn't see a function like this in the PSPSDK, and was wondering if somebody can think of a solution to this.

Thanks.

[nol33t]

use the math lib ( #include<math.h> and -lm at the link )

see also http://forums.ps2dev.org/viewtopic.php?p=19341#19341

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Mathematical Library Functions                           atan(3M)

NAME
     atan - arc tangent function

SYNOPSIS
     cc [ flag ... ] file ... -lm [ library ... ]
     #include <math.h>

     double atan&#40;double x&#41;;

DESCRIPTION
     The atan&#40;&#41; function computes the principal value of the  arc
     tangent of x.

[Treat]

http://en.wikipedia.org/wiki/Taylor_ser ... _functions

[AnonymousTipster]

Well, the compiler is finding s_atan.c (newlib/libm/math/s_atan.c), but it gives me lots of undefined referrences to '__adddf3' and '__muldf3'. I have #include <Math.h> and have put -lm for my linker. I think it is also finding the s_atan.o, which has been precompiled. It must be something simple, but i'm not sure what i'm doing wrong.

[ector]

Avoid double precision math on the PSP as it is likely to be dog slow because of the lack of double precision floating point hardware. It has a fast single precision FPU though, not to speak of the VFPU which still has not been publically documented..

[pixel]

Missing -lgcc, obviously.

[AnonymousTipster]

I've put the -lgcc in, and that stops the errors, but the compiler complains : psp-ld: cannot find -lgcc.

[pixel]

Something's wrong with your toolchain then. Look if the libgcc.a file is in the toolchain directory. If yes, the toolchain is misplaced, and you need a -L on the command line to specify the path to libgcc.a. If no, your toolchain is fucked up and there's nothing I can do about it.

[mrbrown]

Well, you could just tell him to link with psp-gcc and not psp-ld, since that's what we've told everyone else who has the same problem.

[pixel]

Aaaahhh, indeed, I didn't see he was using psp-ld and not psp-gcc...

[AnonymousTipster]

Well, the main part of my .sh file looks like this:

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psp-gcc -g -c hellopsp.c
psp-gcc -g -c AnTi2D.c
psp-gcc -g -c -xassembler -O -o startup.o startup.S
psp-gcc -O0 startup.o hellopsp.o AnTi2D.o  -lgcc -lm -M -Ttext 8900000 -q -o  out > hellopsp.map

Whearas it looked like:

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psp-gcc -g -c hellopsp.c
psp-gcc -g -c AnTi2D.c
psp-gcc -g -c -xassembler -O -o startup.o startup.S
psp-ld -O0 startup.o hellopsp.o AnTi2D.o  -lgcc -lm -M -Ttext 8900000 -q -o  out > hellopsp.map

When there was the -lgcc not found error.
With the new script, I am getting 'linker input file not used because linking not done'.
I haven't used cygwin and gcc before, so any help will be appreciated, and thanks for being understanding.

[mrbrown]

Switch to PSPSDK and all of these problems will go away.

http://wiki.ps2dev.org/psp:programming_faq

[AnonymousTipster]

Ok, thanks, I'll get onto porting it after my first release.