platform: POV35b6 on PII233 128 MB with NT4 SP6

I found below script returns "Float expected but vector or color
expression found." for fourth line.

#local A=array[1]{<0,1,2,3,4>}
#local L=A[0].x;
#warning str(A[0].x,0,-1)
#warning str(L,0,-1)

It's present in beta 2 and not work for any operator at lines 2 and 3:
y, red, green, u, v, transmit, etc.

ABX

Post a reply to this message

This makes it work, so it probably gives a hint about what's going on:

#local A=array[1]{<0,1,2,3,4>}
#local L=(A[0].x);
#warning str(A[0].x,0,-1)
#warning str(L,0,-1)


  (My guess is that the parser stops at the ] and then somehow the .x is
lost... The parentheses force the parser to parse everything inside them
before it can assign any value to L, thus making it work.)

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

Post a reply to this message

news:r87attcjuq76avf6ms2j7hbp3h5dm35omd@4ax.com...
> platform: POV35b6 on PII233 128 MB with NT4 SP6
>
> I found below script returns "Float expected but vector or color
> expression found." for fourth line.
>
> #local A=array[1]{<0,1,2,3,4>}
> #local L=A[0].x;
> #warning str(A[0].x,0,-1)
> #warning str(L,0,-1)
>
> It's present in beta 2 and not work for any operator at lines 2 and 3:
> y, red, green, u, v, transmit, etc.
>
> ABX


IIRC this is an old one.  I found this in the doc :

in "6.1.5.5  Common Color Pitfalls"


--- quote---
Finally there is another problem which arises when using color dot operators
in #declare or #local directives. Consider the directive:
 #declare MyColor = rgb <0.75, 0.5, 0.75>;
 #declare RedAmt = MyColor.red;

Now RedAmt should be a float but unfortunately it is a color. POV-Ray looks
at the first keyword after the equals to try to guess what type of
identifier you want. It sees the color identifier MyColor and assumes you
want to declare a color. It then computes the float value as 0.75 then
promotes that into rgbft<0.75,0.75,0.75,0.75,0.75>. It would take a major
rewrite to fix this problem so we're just warning you about it. Any of the
following work-arounds will work properly.
 #declare RedAmt = 0.0+MyColor.red;
 #declare RedAmt = 1.0*MyColor.red;
 #declare RedAmt = (MyColor.red);
---end of quote---


I did not find anything more enlightening, but I admit I searched rather
hastily. I remember the problem (or something rather similar) discussed
somewhere in the pov newsgroups (at least a year ago...)



Povingly


Philippe

Post a reply to this message