Fix distorted text with subpixel matrix translation

We would pixel-align native text *before* applying the
model-view matrix, which would cause GL_NEAREST artifacts to
show up when the text was positioned at a subpixel offset in
some cases. Instead, we pixel-align the coordinates after mapping
them to the view frustum, but before applying the projection to the
screen.

To make it easier to modify the buffer layout for the shaders the
next time, this also adds some constants for offsets.

[ChangeLog][Text] Fixed an issue where text using NativeRendering
would look slightly skewed if it was inside a parent that had
been positioned at a subpixel offset.

Fixes: QTBUG-96112
Fixes: QTBUG-83626
Task-number: QTBUG-55638
Change-Id: Ifb785ad5830093df94afc75a7bc288e24ca7aa38
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
(cherry picked from commit b21948f5e811ce1b7abf065bc48af61a231e86f4)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/quick/scenegraph/shaders_ng/textmask.frag b/src/quick/scenegraph/shaders_ng/textmask.frag
index 518d5c965f..ed8da4cd30 100644
--- a/src/quick/scenegraph/shaders_ng/textmask.frag
+++ b/src/quick/scenegraph/shaders_ng/textmask.frag
@@ -6,7 +6,8 @@ layout(location = 0) out vec4 fragColor;
 layout(binding = 1) uniform sampler2D _qt_texture;
 
 layout(std140, binding = 0) uniform buf {
-    mat4 matrix;
+    mat4 modelViewMatrix;
+    mat4 projectionMatrix;
     vec4 color;
     vec2 textureScale;
     float dpr;