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3d Matrix Rotations
Posted: Fri Mar 25, 2005 10:40 pm
by Dreglor
in true axis rotations are made by a matrix
problem is, im not sure how you get x,y,z values out of that i look some stuff on google got some stuff but so far it isn't working..
this is the code i got so far trying this.
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Angle\x = *mfChange\m33Rotation\v3X\x * Angle\x + *mfChange\m33Rotation\v3Y\x * Angle\y + *mfChange\m33Rotation\v3Z\x * Angle\z
Angle\y = *mfChange\m33Rotation\v3X\y * Angle\y + *mfChange\m33Rotation\v3Y\y * Angle\y + *mfChange\m33Rotation\v3Z\y * Angle\z
Angle\z = *mfChange\m33Rotation\v3X\z * Angle\z + *mfChange\m33Rotation\v3Y\z * Angle\y + *mfChange\m33Rotation\v3Z\z * Angle\z
RotateEntity(#k_ObjectEnitiy, OldAngle\x-Angle\x, OldAngle\y-Angle\y, OldAngle\z-Angle\z)
OldAngle\x = Angle\x
OldAngle\y = Angle\y
OldAngle\z = Angle\z
Posted: Thu Mar 31, 2005 11:21 am
by Nells
Well, i don't really know how work your stuff but i see that you use Angle\y in your third line but you've assigned Angle\y at the line before :
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Angle\y = *mfChange\m33Rotation\v3X\y * Angle\y + *mfChange\m33Rotation\v3Y\y * Angle\y + *mfChange\m33Rotation\v3Z\y * Angle\z
Angle\z = *mfChange\m33Rotation\v3X\z * Angle\z + *mfChange\m33Rotation\v3Y\z * Angle\y + *mfChange\m33Rotation\v3Z\z * Angle\z
Posted: Mon Apr 04, 2005 3:47 am
by Dreglor
yeah that is a small typo but the whole thing is wrong to begin with :\
here is the proper way to do it but i need some sort of atan2(y,x) becasue the correct way to get the angles is with this code (which is in c)
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angle_y = D = asin( mat[2]); /* Calculate Y-axis angle */
C = cos( angle_y );
angle_y *= RADIANS;
if ( fabs( C ) > 0.005 ) /* Gimball lock? */
{
trx = mat[10] / C; /* No, so get X-axis angle */
try = -mat[6] / C;
angle_x = atan2( try, trx ) * RADIANS;
trx = mat[0] / C; /* Get Z-axis angle */
try = -mat[1] / C;
angle_z = atan2( try, trx ) * RADIANS;
}
else /* Gimball lock has occurred */
{
angle_x = 0; /* Set X-axis angle to zero */
trx = mat[5]; /* And calculate Z-axis angle */
try = mat[4];
angle_z = atan2( try, trx ) * RADIANS;
}
/* return only positive angles in [0,360] */
if (angle_x < 0) angle_x += 360;
if (angle_y < 0) angle_y += 360;
if (angle_z < 0) angle_z += 360;
and have converted most of it, execpt for the atan2 function...
so if any one can point me to a way to do that function by lib, asm, pb code please point it out for me thanks.
Posted: Mon Apr 04, 2005 8:51 am
by Psychophanta
If you tell me what do ATan2() exactly, i'll give you it in ASM.
Posted: Mon Apr 04, 2005 9:13 am
by Psychophanta
Aha! not needed. Google is magic
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Procedure.l atan2(y.l,x.l)
!fild dword[esp]
!fild dword[esp+4]
!fpatan
result.l
!fistp dword[esp+8]
!mov eax,dword[esp+8]
ProcedureReturn
EndProcedure
;Test it:
Debug atan2(-3,4)
And in FASM macro version:
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!macro atan2 y,x,result{
!fild dword[v_#y]
!fild dword[v_#x]
!fpatan
!fistp dword[v_#result]
!mov eax,dword[v_#result]}
;Test it:
a.l=-3:b.l=5:r.l
!atan2 a,b,r
Debug r.l
I think it is well done.
There are another function in C called atan2f(), which do it with floats:
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Procedure.f atan2f(y.f,x.f)
!fld dword[esp]
!fld dword[esp+4]
!fpatan
EndProcedure
;Test it:
Debug atan2f(-3,5)
And:
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!macro atan2f y,x,result{
!fld dword[v_#y]
!fld dword[v_#x]
!fpatan
!fstp dword[v_#result]}
;Test it:
a.f=-3:b.f=5:r.f
!atan2f a,b,r
Debug r.f
That's it
Posted: Mon Apr 04, 2005 2:31 pm
by Dreglor
THANKS!
yeah, this is in the standard c libs why doesn't pb have it
Posted: Tue Apr 05, 2005 6:30 pm
by Psychophanta
Dreglor wrote:THANKS!
yeah, this is in the standard c libs why doesn't pb have it
Yes, i will request it just now in the request section
Posted: Tue Apr 05, 2005 7:13 pm
by DoubleDutch
And in FASM macro version:
At least somebody doesn't think the macro trick was useless
Posted: Mon Apr 11, 2005 8:46 am
by Psychophanta
DoubleDutch wrote:At least somebody doesn't think the macro trick was useless
hehe! Of course