Implemented basic Wavefront OBJ import. (#90)

Author: c-lipka

changes.txt

@@ -49,6 +49,9 @@ Prior to the release of 3.7.1, the following items still need urgent attention:
 New Features
 ------------
 
+- Basic support for importing Wavefront OBJ files has been added as an extension
+  to the `mesh` primitive.
+
 - The `map_type` keyword now supports the Angular Map projection for light
   probes, popularized by Paul Devebec, as type 7.
 
@@ -109,6 +112,12 @@ For more details on the above new features, see the documentation.
 Changed Behaviour
 -----------------
 
+- The `mesh2` syntax has been absorbed into that of `mesh` (i.e. you can now
+  replace any occurrences of the `mesh2` keyword with `mesh`), to reflect the
+  fact that they are just two syntax variants for one and the same primitive.
+  The old `mesh2` keyword is retained for backward compatibility and, in
+  acknowledgement of its widespread use, remains non-deprecated.
+
 - The `version` pseudo-variable will now evaluate to the effective language
   version at the time the expression is parsed, _except_ when used in a
   `#version` directive, in which case the behaviour remains unchanged.

source/base/fileinputoutput.h

@@ -72,6 +72,7 @@ enum
     POV_File_Text_Macro = POV_File_Text_INC,
     POV_File_Text_INI,
     POV_File_Text_CSV,
+    POV_File_Text_OBJ,
     POV_File_Text_Stream,
     POV_File_Text_User,
     POV_File_Data_DF3,

source/base/fileutil.cpp

@@ -83,6 +83,7 @@ POV_File_Restrictions gPOV_File_Restrictions[POV_File_Count] =
     { true,  false, false, false }, // POV_File_Text_INC
     { true,  false, false, false }, // POV_File_Text_INI
     { true,  true,  false, false }, // POV_File_Text_CSV
+    { true,  true,  false, false }, // POV_File_Text_OBJ
     { true,  false, false, false }, // POV_File_Text_Stream
     { true,  true,  false, false }, // POV_File_Text_User
     { true,  true,  true,  false }, // POV_File_Data_DF3
@@ -128,6 +129,7 @@ POV_File_Extensions gPOV_File_Extensions[POV_File_Count] =
     {{ ".inc",  ".INC",  "",      ""      }}, // POV_File_Text_INC
     {{ ".ini",  ".INI",  "",      ""      }}, // POV_File_Text_INI
     {{ ".csv",  ".CSV",  "",      ""      }}, // POV_File_Text_CSV
+    {{ ".obj",  ".OBJ",  "",      ""      }}, // POV_File_Text_OBJ
     {{ ".txt",  ".TXT",  "",      ""      }}, // POV_File_Text_Stream
     {{ "",      "",      "",      ""      }}, // POV_File_Text_User
     {{ ".df3",  ".DF3",  "",      ""      }}, // POV_File_Data_DF3
@@ -157,6 +159,7 @@ const int gFile_Type_To_Mask [POV_File_Count] =
     NO_FILE,   // POV_File_Text_INC
     NO_FILE,   // POV_File_Text_INI
     NO_FILE,   // POV_File_Text_CSV
+    NO_FILE,   // POV_File_Text_OBJ
     NO_FILE,   // POV_File_Text_Stream
     NO_FILE,   // POV_File_Text_User
     NO_FILE,   // POV_File_Data_DF3

source/base/mathutil.h

@@ -144,6 +144,17 @@ inline T1 RoundDownToMultiple(T1 x, T2 base) { return x - (x % base); }
 template<typename T1, typename T2>
 inline T1 RoundUpToMultiple(T1 x, T2 base) { return RoundDownToMultiple (x + base - 1, base); }
 
+/// Test whether a value is in a given range
+///
+/// This function tests whether the specified value is within the specified interval.
+/// The boundaries are considered part of the interval.
+///
+template<typename T1, typename T2>
+inline bool IsInRange (T1 value, T2 min, T2 max)
+{
+    return (min <= value) && (value <= max);
+}
+
 }
 
 #endif // POVRAY_BASE_MATHUTIL_H

source/base/version.h

@@ -45,7 +45,7 @@
 #define OFFICIAL_VERSION_STRING "3.7.1"
 #define OFFICIAL_VERSION_NUMBER 371
 
-#define POV_RAY_PRERELEASE "alpha.8778710"
+#define POV_RAY_PRERELEASE "x.obj.8787755"
 
 #if (POV_RAY_IS_AUTOBUILD == 1) && ((POV_RAY_IS_OFFICIAL == 1) || (POV_RAY_IS_SEMI_OFFICIAL == 1))
 #ifdef POV_RAY_PRERELEASE