BSP Loader | RLE Dekompression, bits in Byte Array

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	marcelkroener Betreff: BSP Loader \| RLE Dekompression, bits in Byte Array	So, Mai 25, 2008 21:30 Antworten mit Zitat
Hi. Ich verzweifel leider wieder an einem Problem mit meinem BSP Loader. Das Sichtbarkeits System scheint zu funktionieren, das Dekomprimieren der Daten noch nicht ganz. Ich habe C Code zum dekomprimieren eines bit arrays in ein Byte array. Ich weis nicht genau ob ich ihn richtig übersetzt habe. Beschreibung: The rest of the visibility lump is the actual visibility information. For every cluster the visibility state (either visible or occluded) is stored for every other cluster in the world. Clusters are always visible from within themselves. Because this is such a massive amount of data, this array is stored as a bit vector (one bit per element) and 0's are run-length-encoded. Here's an example of a C-routine to decompress the PVS into a byte array (this was adapted from the "Quake Specifications" document): C Code: Code: [AUSKLAPPEN] [EINKLAPPEN] int v = offset; memset(cluster_visible, 0, num_clusters); for (int c = 0; c < num_clusters; v++) { if (pvs_buffer[v] == 0) { v++; c += 8 * pvs_buffer[v]; } else { for (uint8 bit = 1; bit != 0; bit = 2, c++) { if (pvs_buffer[v] & bit) { cluster_visible[c] = 1; } } } } Hier mein BB Code: Code:* [AUSKLAPPEN] [EINKLAPPEN] Function lump_visiblity() bf=FilePos(file) debug("---------- Vis Data (Lump 4) ----------") num_clusters=ReadInt(file) cluster_count = num_clusters ; debug("Num Clusters: "+num_clusters) Dim visiblity_offset(num_clusters-1,1) Dim visiblity_buffer(num_clusters-1) Dim visiblity(num_clusters^2-1) For i=0 To num_clusters-1 visiblity_offset(i,0)=ReadInt(file) ;PVS offset visiblity_offset(i,1)=ReadInt(file) ;PAS offset debug("Cluster "+i+": PVS offset "+visiblity_offset(i,0)+" \| PAS offset: "+visiblity_offset(i,1)) Next debug("") debug("..::Visiblity Data::..") For i=0 To num_clusters-1 SeekFile(file,bf+visiblity_offset(i,0)) visiblity_buffer(i)=ReadByte(file) debug(i+" :"+visiblity_buffer(i)) Next For i=0 To num_clusters-1 ;Decompress Visdata into a byte Array debug("Cluster "+i+":") c=0 v=i ;start at cluster 0 While c<num_clusters If visiblity_buffer(v) = 0 Then v=v+1 DebugLog "v: "+v+" \| c: "+c skip = 8 * visiblity_buffer(v) debug("Skipped "+skip+" Clusters!") c=c+skip Else buffer = visiblity_buffer(v) bit=1 While Not bit=0 If (buffer And bit) Then visiblity(c+inum_clusters)=1 EndIf bit=bit Shl 1 If bit > $FF Then bit = 0 ; c=c+1 Wend EndIf v=v+1 Wend Next ;For i=0 To num_clusters^2-1 ;debug("Vis: "+visiblity(i)) ;Next visiblity_count=i debug("") End Function ich bekomme ein "Array Index out of bounds" beim überspringen von Clustern. (Zeile: skip = 8 visiblity_buffer(v)) Ich habe den Code vom ganzen visiblity Lump gepostet, vieleicht liegt mein Fehler doch woanders. (artikel & erklärung zum dateiformat: http://www.geocities.com/cofrdrbob/bspformat.html) mfg mk

marcelkroener

Betreff: BSP Loader | RLE Dekompression, bits in Byte Array

So, Mai 25, 2008 21:30
Antworten mit Zitat

Hi.
Ich verzweifel leider wieder an einem Problem mit meinem BSP Loader.
Das Sichtbarkeits System scheint zu funktionieren, das Dekomprimieren der Daten noch nicht ganz.
Ich habe C Code zum dekomprimieren eines bit arrays in ein Byte array.
Ich weis nicht genau ob ich ihn richtig übersetzt habe.

Beschreibung:
The rest of the visibility lump is the actual visibility information. For every cluster the visibility state (either visible or occluded) is stored for every other cluster in the world. Clusters are always visible from within themselves. Because this is such a massive amount of data, this array is stored as a bit vector (one bit per element) and 0's are run-length-encoded. Here's an example of a C-routine to decompress the PVS into a byte array (this was adapted from the "Quake Specifications" document):
C Code:
Code: [AUSKLAPPEN]

int v = offset;

memset(cluster_visible, 0, num_clusters);

for (int c = 0; c < num_clusters; v++) {

if (pvs_buffer[v] == 0) {
v++;
c += 8 * pvs_buffer[v];
} else {
for (uint8 bit = 1; bit != 0; bit *= 2, c++) {
if (pvs_buffer[v] & bit) {
cluster_visible[c] = 1;
}
}
}

}

Hier mein BB Code:

Code: [AUSKLAPPEN]

Function lump_visiblity()
bf=FilePos(file)
debug("---------- Vis Data (Lump 4) ----------")
num_clusters=ReadInt(file)
cluster_count = num_clusters ;
debug("Num Clusters: "+num_clusters)
Dim visiblity_offset(num_clusters-1,1)
Dim visiblity_buffer(num_clusters-1)
Dim visiblity(num_clusters^2-1)
For i=0 To num_clusters-1
   visiblity_offset(i,0)=ReadInt(file) ;PVS offset
   visiblity_offset(i,1)=ReadInt(file) ;PAS offset
   debug("Cluster "+i+": PVS offset "+visiblity_offset(i,0)+" | PAS offset: "+visiblity_offset(i,1))
Next
debug("")
debug("..::Visiblity Data::..")
For i=0 To num_clusters-1
   SeekFile(file,bf+visiblity_offset(i,0))
   visiblity_buffer(i)=ReadByte(file)
   debug(i+" :"+visiblity_buffer(i))
Next

For i=0 To num_clusters-1 ;Decompress Visdata into a byte Array
debug("Cluster "+i+":")
c=0
v=i ;start at cluster 0
While c<num_clusters
   If visiblity_buffer(v) = 0 Then
      v=v+1
      DebugLog "v: "+v+" | c: "+c
      skip = 8 * visiblity_buffer(v)
      debug("Skipped "+skip+" Clusters!")
      c=c+skip
   Else
      buffer = visiblity_buffer(v)
      bit=1
      While Not bit=0
         If (buffer And bit) Then
            visiblity(c+i*num_clusters)=1
         EndIf
         bit=bit Shl 1
         If bit > $FF Then bit = 0 ;
         c=c+1
      Wend
   EndIf
   v=v+1
Wend
Next

;For i=0 To num_clusters^2-1
   ;debug("Vis: "+visiblity(i))
;Next

visiblity_count=i
debug("")
End Function

ich bekomme ein "Array Index out of bounds" beim überspringen von Clustern.
(Zeile: skip = 8 * visiblity_buffer(v))
Ich habe den Code vom ganzen visiblity Lump gepostet, vieleicht liegt mein Fehler doch woanders.

(artikel & erklärung zum dateiformat: http://www.geocities.com/cofrdrbob/bspformat.html)

mfg mk