Port 17 effects to RHI, remove 8 unportable ones

The following are based on static shader code, and after porting the
shaders they will work fully identically to 5.15:

FastBlur
Colorize
OpacityMask
BrightnessContrast
ColorOverlay
Desaturate
Displace
GammaAdjust
HueSaturation
LevelAdjust
RectangularGlow
Thresholdmask
LinearGradient
RadialGradient
ConicalGradient

The following change behavior:

Glow
DropShadow

These now only have the fast variants, because those rely on static shader code.
So we are going back to the Qt 5.5 versions and make them behave as if 'fast'
was always set to true. The 'fast' and 'samples' properties are removed.

The following are removed:

Blend
GaussianBlur
DirectionalBlur
MaskedBlur
RadialBlur
RecursiveBlur
ZoomBlur
InnerShadow

The autotest and the gallery application (run qmlscene testBed.qml in
tests/manual/testbed) have been adjusted accordingly and now work across
all QRhi backends.

The docs may still refer to removed effects in some code snippets. Updating
that is left as a separate exercise.

[ChangeLog] Graphical Effects no longer relies on dynamically generated
shader strings. The following effects have been removed: Blend, GaussianBlur,
MaskedBlur, RadialBlur, RecursiveBlur, ZoomBlur, InnerShadow. Glow
and DropShadow always use the 'fast' variant. The fast and samples
properties for these are thus no longer applicable and have been
removed.

Change-Id: Ife83f3828f37977596fd34f8da8b61961f0ed28a
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

1 files changed, 0 insertions, 0 deletions

diff --git a/src/effects/shaders_ng/fastglow.frag.qsb b/src/effects/shaders_ng/fastglow.frag.qsb
new file mode 100644
index 0000000..d78cd6d
--- /dev/null
+++ b/src/effects/shaders_ng/fastglow.frag.qsb