Affine Utilities

[pramsey]

With an 'affine' type, it would be possible to create some cool affine utilities

ST_AffineCalculate(point, point) => affine (translate)
ST_AffineCalculate(line, line) => affine(scale/rotate/translate/shear)
ST_AffineTranslate(affine, point) => affine with added translation
ST_AffineRotate(affine, angle) => affine with added rotation
ST_AffineScale(affine, point) => affine with added scale
ST_AffineInvert(affine) => affine the carries out reverse of input

[pramsey]

Oh, and of course

ST_Affine(geometry, affine) => geometry

[komzpa]

Can it be made compatible with opengl matrices?

Would be cool to have a chain of functions that can take screen geometry and camera view and transform both into a shape that ST_Intersects with everything that needs fetching into screen, although it needs some more thought.

[pramsey]

I think doing a projection from 3-space to x/y is possible, with a normal to the screen, a normal to the projection plan and a camera locations/direction. But... I'm not sure how useful it would be :)