Fix projection of distance field text and shader compliance

We were ignoring the projection matrix when calculating the
alpha range of the distance field algorithm. In Qt Quick this
is not necessary since there is no depth in the scene, but
in 3D of course it became very obvious as the text moved
closer to the camera.

Note that there is still an issue visible when combining a
scaling model matrix with proximity to the camera, but since
this is a clear improvement, I commit it by itself and defer
the other problem to a follow-up patch.

Second note: This also fixes a bug where the texture width and
height was not cast to float, which is not according to spec and
will break on some drivers.

Task-number: QT3DS-3343
Change-Id: Iddf00614c307ffc73119ecb37a4dfbb52dad78b1
Reviewed-by: Jere Tuliniemi <jere.tuliniemi@qt.io>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

0 files changed, 0 insertions, 0 deletions