Friday 21 November 2014

Using Qt Library templates

The following video shows how to configure a Qt project to create a static library to use in your own projects, the main code for this can be found on github here

The main things you will need to do are in the .pro file as follows

TEMPLATE = lib
CONFIG+=staticlib

If you omit the staticlib it will create a dynamic library and the runtime linker will need to be told where to find your lib.

In the project you intend to use the library in you need to set the LIBS Qt variable passing in the -L[path to lib] and -l lib(s) to link


 For more examples of this see this blog post




Tuesday 4 November 2014

Drawing with Modern OpenGL

The following video demonstrate how modern OpenGL uses Vertex Array Objects to store buffers and generic vertex attributes together for faster drawing.

The first Video shows how the deprecated immediate mode OpenGL version would work as context for why we use Modern OpenGL.

The next videos show the basic framework code using ngl and a simple colour shader. The first demo will then use OpenGL calls to create and display a series of points. The second uses the ngl::VertexArrayObject class to do the same thing. The source code can be found here and suggested man pages are glGenVertexArrays glBindVertexArray glGenBuffers glBufferData glVertexAttribPointer glDrawArrays