Re: [Inkscape-devel] Windows Compilation 0.91pre1

On 22-6-2014 20:22, Partha Bagchi wrote:

On Sun, Jun 22, 2014 at 10:22 AM, Liam White <inkscapebrony@...400... mailto:inkscapebrony@...400...> wrote:

    There is no standardized way of determining what OS you are
    compiling for. However, _WIN32 seems more common than WIN32.
    See, e.g. here:
    http://sourceforge.net/p/predef/wiki/OperatingSystems/
    So, we should be able to change all WIN32 to _WIN32 and
    improve compatibility.
    The standard Windows build system (btool/build.xml) explicitly
    defines WIN32 in config.h.

That's correct. Also note that Microsoft's compiler does /not
/define __WIN32__, so we should stop checking for that as well.

    About M_PI, <2geom/angle.h> defines it if it is not already
    defined. If there are many other constants needed (Liam
    mentioned sqrt(2)), we could add <geom/constants.h> file to
    collect all those. Regardless, I think you cannot escape
    modifying the source code, or temporarily adding the missing
    defines to the gcc cmdline.


Looks like we need, at a bare minimum:
M_PI
M_PI_2
M_SQRT2 (this is the default zoom factor in Inkscape)
Although defining others
<http://msdn.microsoft.com/en-us/library/4hwaceh6.aspx> would be
great, too.

These are actually defined and if you don't compile with C++11 then you can get away with it.

My suggestion would be either

#define _USE_MATH_DEFINES #include <cmath>

right at the top or

or |const double pi= boost::math::constants::pi<double>();| Moreover, simply collecting them in geom/constants.h may not cover all since M_PI is used in other places as well such as widgets and tools?

Yes, so these files should include geom/constants.h. The point is to localize the code that does this non-standard stuff, so it is easily changed later on if needs be.

regards, Johan