Remove qtgraphicaleffects sources and add note about its state in Qt 6HEADdev

Add a README.md mentioning the documentation on where the ported
effects can be found, as well as how to check out the Qt5 branch.

Pick-to: 6.2
Fixes: QTBUG-95757
Change-Id: Ib47c7e73f8622c8e287df0f74c6f16a5113b357e
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 0 insertions, 26 deletions

diff --git a/src/effects/shaders_ng/brightnesscontrast.frag b/src/effects/shaders_ng/brightnesscontrast.frag
deleted file mode 100644
index c9ae173..0000000
--- a/src/effects/shaders_ng/brightnesscontrast.frag
+++ /dev/null
@@ -1,26 +0,0 @@
-#version 440
-
-layout(location = 0) in vec2 qt_TexCoord0;
-layout(location = 0) out vec4 fragColor;
-
-layout(std140, binding = 0) uniform buf {
-    // qt_Matrix and qt_Opacity must always be both present
-    // if the built-in vertex shader is used.
-    mat4 qt_Matrix;
-    float qt_Opacity;
-    float brightness;
-    float contrast;
-};
-
-layout(binding = 1) uniform sampler2D source;
-
-void main()
-{
-    vec4 pixelColor = texture(source, qt_TexCoord0);
-    pixelColor.rgb /= max(1.0/256.0, pixelColor.a);
-    float c = 1.0 + contrast;
-    float contrastGainFactor = 1.0 + c * c * c * c * step(0.0, contrast);
-    pixelColor.rgb = ((pixelColor.rgb - 0.5) * (contrastGainFactor * contrast + 1.0)) + 0.5;
-    pixelColor.rgb = mix(pixelColor.rgb, vec3(step(0.0, brightness)), abs(brightness));
-    fragColor = vec4(pixelColor.rgb * pixelColor.a, pixelColor.a) * qt_Opacity;
-}