From 02029c9da6a208be01f23e84404594bdaa76b221 Mon Sep 17 00:00:00 2001
From: dpethes <dejvu@email.cz>
Date: Tue, 14 Oct 2014 01:57:58 +0200
Subject: [PATCH] hob parser: properly distinguish between quad and triangle
 faces

---
 doc/file_hob_spec.txt     |  7 +++----
 hob_parser/hob_parser.pas | 17 ++++++++---------
 2 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/doc/file_hob_spec.txt b/doc/file_hob_spec.txt
index 5fd9f51..2461b1f 100644
--- a/doc/file_hob_spec.txt
+++ b/doc/file_hob_spec.txt
@@ -61,16 +61,15 @@ NOF * face block
   4B int face count FC
   FC * face
   {
-    4B int ?    
+    4B int face flags? if bit 3 is set, the face is a quad, otherwise triangle
     1B int 46/49/4B
     1B int 51/71
     1B int 0C
     1B int block size / 4: A = 40B, 9 = 36, etc.
     2B int zero?
     2B int texture/material index?
-    4x 2B vertex indices, relative to the face group
-        -if the last index is zero, the face is most probably a triangle
-    x bytes until block size
+    4x 2B vertex indices, relative to the face group. The last index is zero in triangle faces 
+    x bytes until block size: most probably texture coordinates and some other stuff?
   }
 }
 
diff --git a/hob_parser/hob_parser.pas b/hob_parser/hob_parser.pas
index c53f75a..5419e01 100644
--- a/hob_parser/hob_parser.pas
+++ b/hob_parser/hob_parser.pas
@@ -8,7 +8,7 @@ uses
 
 type
   THobFace = record
-      dw1: integer;
+      flags: integer;
       b1, b2, b3: byte;
       bsize: byte;
       ftype: byte; //3 - tri, 4 - quad
@@ -84,7 +84,7 @@ begin
   SetLength(group.faces, group.face_count);
   for i := 0 to group.face_count - 1 do begin
       file_pos := f.Position;
-      face.dw1 := f.ReadDWord;  //?
+      face.flags := f.ReadDWord;  //?
       face.b1 := f.ReadByte;  //46/49/4B
       face.b2 := f.ReadByte;  //51/71
       face.b3 := f.ReadByte;  //0C
@@ -105,18 +105,17 @@ begin
       for k := 0 to unknown - 1 do
           buf[k] := f.ReadByte;
 
-      //face type: don't know how to distinguish between quad and triangle, so hack:
-      //if last vertex index is 0, consider this to be a triangle, quad otherwise.
-      //Breaks faces that really use the 0 vertex.
-      if face.indices[3] = 0 then
-          face.ftype := 3
+      //face type: quad or triangle
+      if face.flags and %1000 > 0 then
+          face.ftype := 4
       else
-          face.ftype := 4;
+          face.ftype := 3;
 
       group.faces[i] := face;
 
       if DumpFaces then begin
-          write(face.dw1:8, face.b1:3, face.b2:3, face.b3:3, face.bsize:3);
+          if face.ftype = 3 then write('t') else write('q');
+          write(face.flags:5, face.b1:3, face.b2:3, face.b3:3, face.bsize:3);
           write(' ti: ', face.tex_index);
           write(' coords: ');
           for k := 0 to 3 do