I am trying to figure out how I can determine my current absolute location after I have performed a translation and rotation. I am in 2d ortho mode, so hopefully this should simplify things…I’m thinking this may be to do with matrices but I don’t know where to start.
Feedback would be most appreciated.
I had a similar question here recently:
Also, Ortho mode has nothing do with it. You should be applying your translations and rotations to your ModelView matrix, not your projection matrix (i.e. after calling glMatrixMode(GL_MODELVIEW))
Thanks for your reply starman.
I decided not to sleep last night and instead update my knowledge on matrix calculations.
I now understand matrix addition, subtraction, scalar multiplication, matrix multiplication, determinants, inverse matrices, rotation, translation and scaling.
All pretty simple, but new to me.
Anyway, I found that by using the following matrix multiplication I could calculate the eventual x,p point that I was in urgent need to get hold of:
and multiply it against the point I need to translate and rotate (x,y).
Very simple now that I look at it…but only once you know the correct formulae.