Changeset 1343:94416cbd4575

Timestamp:

10/06/09 09:47:34 (10 months ago)

Author:

Howard Butler <hobu.inc@…>

Branch:

default

Message:

implement the ability to create a LASReader with an existing header to override the file's header

Files:

• include/liblas/capi/liblas.h (modified) (1 diff)
• include/liblas/lasheader.hpp (modified) (1 diff)
• include/liblas/lasreader.hpp (modified) (2 diffs)
• python/liblas/core.py (modified) (1 diff)
• python/liblas/file.py (modified) (1 diff)
• python/tests/SRS.txt (modified) (5 diffs)
• src/las_c_api.cpp (modified) (3 diffs)
• src/lasreader.cpp (modified) (4 diffs)

include/liblas/capi/liblas.h

@@ -183 +183 @@
 LAS_DLL LASReaderH LASReader_Create(const char * filename);
 
+/** Creates a LASReaderH object that can be used to read LASHeaderH and 
+ *  LASPointH objects with.  The LASReaderH must not be created with a 
+ *  filename that is opened for read or write by any other API functions.
+ *  @return opaque pointer to a LASReaderH instance.
+ *  @param filename Filename to open for read 
+*/
+LAS_DLL LASReaderH LASReader_CreateWithHeader(  const char * filename, 
+                                                LASHeaderH hHeader);
+
 /** Reads the next available point on the LASReaderH instance.  If no point 
  *  is available to read, NULL is returned.  If an error happens during 

include/liblas/lasheader.hpp

@@ -109 +109 @@
     /// Default constructor.
     /// The default constructed header is configured according to the ASPRS
-    /// LAS 1.1 Specification, point data format set to 0.
+    /// LAS 1.2 Specification, point data format set to 0.
     /// Other fields filled with 0.
     LASHeader();

include/liblas/lasreader.hpp

@@ -68 +68 @@
     LASReader(std::istream& ifs);
 
+    /// User-defined consructor initializes reader with input stream and
+    /// a header to override the values in the file
+    /// @excepion std::runtime_error - on failure state of the input stream.
+    LASReader(std::istream& ifs, LASHeader& header);
+    
     /// Destructor.
     /// @excepion nothrow
@@ -146 +151 @@
     std::vector<LASVariableRecord> m_vlrs;
     
+    bool bCustomHeader;
+    
 };
 

python/liblas/core.py

@@ -169 +169 @@
 las.LASReader_Create.errcheck = check_void
 
+las.LASReader_CreateWithHeader.argtypes = [ctypes.c_char_p, ctypes.c_void_p]
+las.LASReader_CreateWithHeader.restype = ctypes.c_void_p
+las.LASReader_CreateWithHeader.errcheck = check_void
+
 las.LASReader_GetNextPoint.restype=ctypes.c_void_p
 las.LASReader_GetNextPoint.argtypes = [ctypes.c_void_p]

python/liblas/file.py

@@ -76 +76 @@
     def open(self):
         if self._mode == 'r' or self._mode =='rb':
-            self.handle = core.las.LASReader_Create(self.filename)
+            
+            if not self._header:
+                self.handle = core.las.LASReader_Create(self.filename)
+                self._header = lasheader.Header(handle = core.las.LASReader_GetHeader(self.handle))
+            else:
+                self.handle = core.las.LASReader_CreateWithHeader(self.filename, self._header.handle)
+
             self.mode = 0
-            self._header = lasheader.Header(handle = core.las.LASReader_GetHeader(self.handle))
             files['read'].append(self.filename)
             

python/tests/SRS.txt

@@ -67 +67 @@
   ...         f.set_srs(s2)
   ...         p = f.read(0)
-  ...         p.descale(f.header)
   ...         if not s2.vlr_count() == 3: return False
   ...         if not s2.GetVLR(0).recordlength == 64: return False
-  ...         return int(round(p.x)) == -93  and int(round(p.y)) == 90
+  ...         return int(round(p.x)) == -93  and int(round(p.y)) == 42
   ...     return False  
 
@@ -78 +77 @@
   >>> del f
 
-  >>> f = file.File('../test/data/1.2_3.las',mode='r')
-  >>> f.header.data_offset
-  438L
+
+# -93.3515625902 41.5771483954
+
   >>> utm_wkt = """PROJCS["NAD83 / UTM zone 15N",GEOGCS["NAD83",DATUM["North_American_Datum_1983",SPHEROID["GRS 1980",6378137,298.2572221010002,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6269"]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433],AUTHORITY["EPSG","4269"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-93],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AUTHORITY["EPSG","26915"]]"""
 
@@ -88 +87 @@
   >>> s_utm = srs.SRS()
   >>> s_utm.wkt = utm_wkt
+
+  >>> f = file.File('../test/data/1.2_3.las',mode='r')
+  >>> dd_header = f.header
+  >>> utm_header = f.header
+  >>> del f
+
+  >>> utm_header.offset
+  [0.0, 0.0, 0.0]
+  >>> utm_header.offset = [offset+1.0/0.000001 for offset in utm_header.offset]
+  >>> utm_header.offset
+  [1000000.0, 1000000.0, 1000000.0]
+  >>> utm_header.scale = [0.000001,0.000001,0.000001]
+  >>> utm_header.srs = s_utm
+  
+  >>> dd_header.scale = [0.000001,0.000001,0.000001]
+  >>> dd_header.srs = s_dd
+  
+  >>> f = file.File('../test/data/1.2_3.las',mode='r', header = utm_header)
+  >>> f.header.data_offset
+  438L
+  >>> f.header.scale
+  [9.9999999999999995e-07, 9.9999999999999995e-07, 9.9999999999999995e-07]
   >>> p = f.read(0)
   >>> origx, origy = p.x, p.y
@@ -95 +116 @@
   True
   >>> p = f.read(0)
-  >>> p.descale(f.header)
   >>> p.x, p.y
-  (-92.999999999999972, 89.999999999999972)
-  >>> dd_header = f.header
-  >>> dd_header.scale = [0.000001,0.000001,0.000001]
-  >>> dd_header.srs = s_dd
+  (-93.350000000000009, 41.57)
+  
+  
+
   >>> f_project = file.File('junk_srs_project.las',mode='w',header=dd_header)
   >>> dd_header.srs.proj4
@@ -113 +133 @@
   >>> s_utm.wkt = utm_wkt
   >>> p3 = f3.read(1)
-  >>> p3.x, p3.y
-  (-92.999999000000003, 89.999999000000003)
+  >>> int(round(p3.x)), int(round(p3.y))
+  (-93, 42)
   >>> p3 = f3.read(0)
-  >>> p3.x,p3.y
-  (-92.999999000000003, 89.999999000000003)
+  >>> int(round(p3.x)), int(round(p3.y))
+  (-93, 42)
 
   >>> import os

src/las_c_api.cpp

@@ -182 +182 @@
 }
 
+std::istream* OpenInput(std::string filename) 
+{
+    std::ios::openmode const mode = std::ios::in | std::ios::binary;
+    std::istream* istrm = 0;
+    if (compare_no_case(filename.c_str(),"STDIN",5) == 0)
+    {
+        istrm = &std::cin;
+    }
+    else 
+    {
+        istrm = new std::ifstream(filename.c_str(), mode);
+    }
+    
+    if (!istrm->good())
+    {
+        delete istrm;
+        throw std::runtime_error("Reading stream was not able to be created");
+        exit(1);
+    }
+    return istrm;
+}
+
 LAS_DLL LASReaderH LASReader_Create(const char* filename) 
 
@@ -188 +210 @@
 
     try {
-        std::ios::openmode const mode = std::ios::in | std::ios::binary;
-        std::istream* istrm;
-        if (compare_no_case(filename,"STDIN",5) == 0)
-        {
-            istrm = &std::cin;
-        }
-        else 
-        {
-            istrm = new std::ifstream(filename, mode);
-        }
         
-        if (!istrm->good())
-        {
-            delete istrm;
-            throw std::runtime_error("Reading stream was not able to be created");
-        }
+        std::istream* istrm = OpenInput(std::string(filename));
         return (LASReaderH) new LASReader(*istrm);
 
@@ -213 +221 @@
      }
 
-    
+}
+
+LAS_DLL LASReaderH LASReader_CreateWithHeader(  const char* filename,
+                                                LASHeaderH hHeader) 
+
+{
+    VALIDATE_LAS_POINTER1(filename, "LASReader_CreateWithHeader", NULL);
+    VALIDATE_LAS_POINTER1(hHeader, "LASReader_CreateWithHeader", NULL);
+
+    try {
+        
+        std::istream* istrm = OpenInput(std::string(filename));
+        
+        LASHeader* header = ((LASHeader*) hHeader);
+        return (LASReaderH) new LASReader(*istrm, *header);
+
+    
+    } catch (std::exception const& e)
+     {
+         LASError_PushError(LE_Failure, e.what(), "LASReader_Create");
+         return NULL;
+     }
+
 }
 

src/lasreader.cpp

@@ -56 +56 @@
 
 LASReader::LASReader(std::istream& ifs) :
-    m_pimpl(detail::ReaderFactory::Create(ifs))
+    m_pimpl(detail::ReaderFactory::Create(ifs)),
+    bCustomHeader(false)
 {
 
@@ -62 +63 @@
 }
 
+LASReader::LASReader(std::istream& ifs, LASHeader& header) :
+    m_pimpl(detail::ReaderFactory::Create(ifs)),
+    bCustomHeader(false)
+{
+    m_header = header;
+    bCustomHeader = true;
+    Init();
+}
 LASReader::~LASReader()
 {
@@ -112 +121 @@
 
 void LASReader::Init()
-{    
+{   
+    // Copy our existing header in case we have already set a custom 
+    // one.  We will use this instead of the one from the file if 
+    // the constructor with the header was used.
+    LASHeader custom_header(m_header);
+
     bool ret = m_pimpl->ReadHeader(m_header);
     if (!ret)
@@ -123 +137 @@
     m_pimpl->ReadGeoreference(m_header);
     m_pimpl->Reset(m_header);
+    
+    if (bCustomHeader) {
+        custom_header.SetDataOffset(m_header.GetDataOffset());
+        m_header = custom_header;
+    }
 }