Install Qwt
Obtain Qwt 6.1 via subversion.
svn checkout svn://svn.code.sf.net/p/qwt/code/branches/qwt-6.1
Edit qwt-6.1/qwtconfig.pri file and comment out following lines by adding '#' sign on beginning each line. It's up to you whether you can leave them as original setup.
QWT_CONFIG += QwtDll
QWT_MATHML += QwtMathML
QWT_CONFIG += QwtDesigner
QWT_CONFIG += QwtExamples
QWT_CONFIG += QwtPlayground
Also edit QWT_INSTALL_PREFIX macro appropriately too.
For MultiArch cross compile, make sure INSTALL_PREFIX point appropriate directory, for example;
QWT_INSTALL_PREFIX = /usr/local/arm-linux-gnueabihf/usr/local/qwt-$$QWT_VERSION-svn
Use "make" for Mac and Linux instead of nmake below.
cd qwt-6.1
qmake qwt.pro
nmake
nmake install
I assume you have C:\Qwt-6.1.3-svn directory, which contains library and header files installed.