POV-Ray

fix submitted as change #4990

It seems to work (with source from #5066) but I have the following observations:

1. the previewed mozaic is one pixel short (at least on linux): at iteration with size x, we can still see the border (one pixel width) of the iteration with size*2. (and from starting grid, the black layout): is it an intended effect ?
(see attached picture)

2. There is a side effect on the reported statistics (or actually ?) for the number of threads used to perform the rendering.

With +sp64 +ep16 +H1025 +W1025:

Photon Time:      0 hours  0 minutes  0 seconds (0.190 seconRender Time:
Photon Time:      0 hours  0 minutes  0 seconds (0.189 seconds)
            using 21 thread(s) with 0.216 CPU-seconds total
Radiosity Time:   No radiosity
Trace Time:       0 hours  4 minutes  5 seconds (245.113 seconds)
            using 72 thread(s) with 2882.681 CPU-seconds total

POV-Ray finished

With +H1025 +W1025:
Render Time:

Photon Time:      0 hours  0 minutes  0 seconds (0.190 seconds)
            using 21 thread(s) with 0.216 CPU-seconds total
Radiosity Time:   No radiosity
Trace Time:       0 hours  4 minutes  1 seconds (241.207 seconds)
            using 18 thread(s) with 2852.969 CPU-seconds total

POV-Ray finished

With +sp256 +ep16 +H1025 +W1025:
Render Time:

Photon Time:      0 hours  0 minutes  0 seconds (0.189 seconds)
            using 21 thread(s) with 0.217 CPU-seconds total
Radiosity Time:   No radiosity
Trace Time:       0 hours  4 minutes  3 seconds (243.261 seconds)
            using 72 thread(s) with 2866.325 CPU-seconds total

With +sp32 +ep16 +H1025 +W1025:
Render Time:

Photon Time:      0 hours  0 minutes  0 seconds (0.190 seconds)
            using 21 thread(s) with 0.216 CPU-seconds total
Radiosity Time:   No radiosity
Trace Time:       0 hours  4 minutes  3 seconds (243.193 seconds)
            using 54 thread(s) with 2878.677 CPU-seconds total

POV-Ray finished

So it seems the number of working Threads are accumulated/multiplied by the number of steps on the mozaic.
(and maybe +sp256 is maxed out to a lower value)
As the threads used for the mozaic are probably ended before actually rendering the remaining picture, it's a bit of a lie: there probably was never 72 simultaneous threads alive...
(My default +WT is 18, YMMV)

   imperfect_mozaic.png (145.3 KiB)

Corrected 1 pixel error with change #5099

Preview is now fine with beta 39.
(from sources via perforce)

I would like to suggest to close.