ilmbase_half.README

Instructions for bringing in a new version of half
---------------------------------------------------------------

Current version: ilmbase-2.3.0
Source can be found at: https://github.com/openexr/openexr/tree/master/IlmBase/Half

1. Build IlmBase from source. We don't actually need to built libraries, but the 
   build generates some header files that we need to copy into our source code.

2. Copy in the new files from source
    ```
    cp openexr/IlmBase/Half/half.h ilmbase_half.h
    cp openexr/IlmBase/Half/half.cpp ilmbase_half.cpp
    cp openexr/IlmBase/Half/halfLimits.h ilmbase_halfLimits.h
    cp openexr/IlmBase/Half/eLut.h ilmbase_eLut.h
    cp openexr/IlmBase/Half/toFloat.h ilmbase_toFloat.h
    ```

3. Apply the patch file.
    ```
    patch -s -p0 < ilmbase_half.patch
    ```

How to update the patchfile
--------------------------------
If you need to manually make some edits, and thus need to 
generate a new patch file, run the following commands

```
diff -ruN openexr/IlmBase/Half/half.cpp ilmbase_half.cpp > ilmbase_half.patch
diff -ruN openexr/IlmBase/Half/half.h ilmbase_half.h >> ilmbase_half.patch
diff -ruN openexr/IlmBase/Half/halfLimits.h ilmbase_halfLimits.h >> ilmbase_half.patch
```