Update the shader when devicePixelRatio changes

Task-number: QTBUG-45076
Change-Id: I03de20da2e3f436339dcf48fc7d7d3d11a509577
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

1 files changed, 9 insertions, 1 deletions

diff --git a/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp b/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp
index ffee43852d..102985f2c7 100644
--- a/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp
+++ b/src/quick/scenegraph/qsgdefaultglyphnode_p.cpp
@@ -92,6 +92,7 @@ protected:
     int m_matrix_id;
     int m_color_id;
     int m_textureScale_id;
+    float m_devicePixelRatio;
 
     QFontEngine::GlyphFormat m_glyphFormat;
 };
@@ -121,7 +122,8 @@ void QSGTextMaskShader::initialize()
     m_matrix_id = program()->uniformLocation("matrix");
     m_color_id = program()->uniformLocation("color");
     m_textureScale_id = program()->uniformLocation("textureScale");
-    program()->setUniformValue("dpr", (float) qsg_device_pixel_ratio(QOpenGLContext::currentContext()));
+    m_devicePixelRatio = (float) qsg_device_pixel_ratio(QOpenGLContext::currentContext());
+    program()->setUniformValue("dpr", m_devicePixelRatio);
 }
 
 void QSGTextMaskShader::updateState(const RenderState &state, QSGMaterial *newEffect, QSGMaterial *oldEffect)
@@ -149,6 +151,12 @@ void QSGTextMaskShader::updateState(const RenderState &state, QSGMaterial *newEf
         }
     }
 
+    float devicePixelRatio = (float) qsg_device_pixel_ratio(QOpenGLContext::currentContext());
+    if (m_devicePixelRatio != devicePixelRatio) {
+        m_devicePixelRatio = devicePixelRatio;
+        program()->setUniformValue("dpr", m_devicePixelRatio);
+    }
+
     if (state.isMatrixDirty())
         program()->setUniformValue(m_matrix_id, state.combinedMatrix());
 }