Hi Guys

I ran into several problems when trying to work with MegaPOV's postprocess
feature more precicely when trying to use the f_pp_*channel*(x,y,Ref)
functions. At this time the failures where only that the output did not
match the functions i wrote. several parts of the calculations inside the
function blocks seemed to be ignored. for example
"function { 1-4*f_pp_red(x,y,1) }"
leaded to the same result as just
"function { f_pp_red(x,y,1) }"
namely a simple copy of the image. only changes at the parameters of the
function made a change (e.g. -x instead of x).

(This problems did however not occur with Ref=0)


After further simplifing the code i finally ran into a runtime error.

The source that reproduces the error is:
<code>
#version unofficial MegaPOV 1.21;

#include "pprocess.inc"

PP_Init_Alpha_Colors_Outputs()
PP_Init_PP_Alpha_Colors_Outputs()

global_settings {
  post_process {
    function { 1-f_output_red  (x,y) }
    function { 1-f_output_green(x,y) }
    function { 1-f_output_blue (x,y) } //(*)
    function { 1-f_output_alpha(x,y) }
    save_file "step1.png"
  }
  /*post_process {  //<--comment this in
    function { f_pp_red  (x,y,1) }
    function { f_pp_green(x,y,1) }
    function { f_pp_blue (x,y,1) }
    function { f_pp_alpha(x,y,1) }
    save_file "step2.png"
  }*/
}
</code>

When the second block is commented in the render stops at the last line of
the first postprocess step marking the (*) line saying:
"Parse Error:
Runtime error detected in function ''. Function evaluation stack underflow."
The error occurs as well when i use f_pp... with Ref=0 instead of
f_output... in the first post_process block.

Is this a bug? Or am i just making something wrong? Anyone experiences
similar problems? Are there workarounds?

Enlightenment wanted :)
Regards Roman


MegaPov 1.2.1 based on POVRay 3.6.1.msvc7.unofficial-win32
with POVRay 3.6.1.icl8.win32
WindowsXP Home Edition - Build 2600.xpsp_sp2_gdr.050301-1519 : Service Pack
2
Celeron 2.60GHz - 640MB RAM

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