I need help to build latest MRIcroGL 1.2, I am building it with lazarus IDE version 2.0.10, I followed all instructions as metal demos installation and python4lazarus package etc, but it is throwing errors below.

mainunit.pas(1583,28) Error: identifier idents no member "PyInt_FromLong"

The same kind of total 8 errors I am getting for PyString_FromString etc.

Please help me what I am missing here. Do I need to install python? I already have it installed version 3.5.0 and I am using 64 bits compiler.

Any help is highly appreciated.

1. Are you trying to build on Windows, Linux or MacOS?

2. If you select to the Projects/ProjectOptions menu item and remove "-dMYPY" from the "Custom Options" does the project compile (albeit without Python).

3. Did you recompile Lazarus using the latest version of the Python-for-Lazarus package (Using the Package/OpenPackageFile menu item):
  https://github.com/Alexey-T/Python-for-Lazarus
Do the examples from that repository compile and run correctly?

Originally posted by Chris Rorden:
I am building for Windows Chris. With project option removing -dMYPY I am getting another set of new errors.

MRIcroGL.lpr(36,1) Error: Can't open object file: ..\static\x86_64-win64\sse\inffast.o

Like this a number of 9 errors like this.

I have built lazarus with Python-for-Lazarus package with this following option.

./lazbuild.exe --build-ide= --add-package lazopenglcontext ../Python-for-Lazarus/python4lazarus/python4lazarus_package.lpk

Please help me to resolve this.

MRIcroGL.lpr(36,1) Error: Can't open object file: ..\static\x86_64-win64\sse\inffast.o

Like this 9 object errors are coming Chris. Please help me to fix this issues.

As noted on the comments where the code failed, when compiling for Windows you have two options:

1. Edit the file "opts.inc" and remove the line:
 {$DEFINE FASTGZ}

The executable will compile and be fully functional, but loading and saving of GZ compressed files will be a bit slower.

2. Download the files from https://github.com/synopse/mORMot and place the 'static' folder in the requested location. In other words, if you have c:\MRIcroGL12\MRIcroGL.lpr you will want a folder c:\static\x86_64-win64\sse\

The executable will compile and be fully functional, loading and saving of GZ compressed files will be accelerated. The included code uses the GPL, so your resulting executable can no longer be shared/sold under the more permissive BSD license.

Okies, Chris. Thanks a lot for the suggestion. I will notify shortly about the result.

It's building now Dear Chris and also running. But, No data file is being loaded, I think it is because of disabling python or opengl, no viewer is coming... which flavour of the version will work with it? please let me know a link of your version, the one that you built successfully..,It shows access violation due to disabling python and static folder changes. What can be done please suggest. Kindly see the image of the error I am getting while loading a data file.

Hmm, I can not replicate your issue. I wonder if this is because the latest SSE code uses new features of the compiler. What happens if you delete line 18 of nifti.pas:
  {$DEFINE SSE}
and recompile. This will provide full functionality, but will not use the faster rescaling. 

Please confirm that your computer works fine with the compiled version here (v1.2.20201102):
  https://github.com/rordenlab/MRIcroGL12/releases
If so, you may need to simply wait for the next stable Lazarus/FPC upgrade, or move your development to trunk. Working with Gareth Moreton, the latest code leverages advances CPU features and also compiles on the upcoming Apple ARM-based Macs. These cutting edge features may make it hard to compile with the current versions of the compiler and IDE. However, they do provide a profound benefit for the users, with many of these functions becoming memory rather than CPU bound.