Add a core profile file selector to OpenGL ShaderEffect

Similarly to what we do with "hlsl" in the D3D12 backend, we can use
"glslcore" to provide a file-based alternative to the GraphcsInfo or
OpenGLInfo-based conditions in the fragmentShader and vertexShader
properties. This is particularly useful in a few places inside Qt,
for example Quick Controls, that have to cater to all possiblities.

Change-Id: I5d89e7b1534afbc323a663869bab7796bd1a337d
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

2 files changed, 14 insertions, 2 deletions

diff --git a/src/quick/items/qquickopenglshadereffect.cpp b/src/quick/items/qquickopenglshadereffect.cpp
index f65062ae38..b77a7830ff 100644
--- a/src/quick/items/qquickopenglshadereffect.cpp
+++ b/src/quick/items/qquickopenglshadereffect.cpp
@@ -53,6 +53,7 @@
 
 #include <QtQml/qqmlfile.h>
 #include <QtCore/qsignalmapper.h>
+#include <QtCore/qfileselector.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -325,7 +326,16 @@ void QQuickOpenGLShaderEffectCommon::updateShader(QQuickItem *item, Key::ShaderT
     // A qrc or file URL means the shader source is to be read from the specified file.
     QUrl srcUrl(QString::fromUtf8(source.sourceCode[shaderType]));
     if (!srcUrl.scheme().compare(QLatin1String("qrc"), Qt::CaseInsensitive) || srcUrl.isLocalFile()) {
-        const QString fn = QQmlFile::urlToLocalFileOrQrc(srcUrl);
+        if (!fileSelector) {
+            fileSelector = new QFileSelector(item);
+            // There may not be an OpenGL context accessible here. So rely on
+            // the window's requestedFormat().
+            if (item->window()
+                    && item->window()->requestedFormat().profile() == QSurfaceFormat::CoreProfile) {
+                fileSelector->setExtraSelectors(QStringList() << QStringLiteral("glslcore"));
+            }
+        }
+        const QString fn = fileSelector->select(QQmlFile::urlToLocalFileOrQrc(srcUrl));
         QFile f(fn);
         if (f.open(QIODevice::ReadOnly | QIODevice::Text)) {
             source.sourceCode[shaderType] = f.readAll();
diff --git a/src/quick/items/qquickopenglshadereffect_p.h b/src/quick/items/qquickopenglshadereffect_p.h
index bc60ba1e83..062eedd744 100644
--- a/src/quick/items/qquickopenglshadereffect_p.h
+++ b/src/quick/items/qquickopenglshadereffect_p.h
@@ -66,6 +66,7 @@ QT_BEGIN_NAMESPACE
 
 class QSGContext;
 class QSignalMapper;
+class QFileSelector;
 class QQuickOpenGLCustomMaterialShader;
 
 // Common class for QQuickOpenGLShaderEffect and QQuickCustomParticle.
@@ -74,7 +75,7 @@ struct Q_QUICK_PRIVATE_EXPORT QQuickOpenGLShaderEffectCommon
     typedef QQuickOpenGLShaderEffectMaterialKey Key;
     typedef QQuickOpenGLShaderEffectMaterial::UniformData UniformData;
 
-    QQuickOpenGLShaderEffectCommon(QObject *host) : host(host) { }
+    QQuickOpenGLShaderEffectCommon(QObject *host) : host(host), fileSelector(nullptr) { }
     ~QQuickOpenGLShaderEffectCommon();
     void disconnectPropertySignals(QQuickItem *item, Key::ShaderType shaderType);
     void connectPropertySignals(QQuickItem *item, Key::ShaderType shaderType);
@@ -95,6 +96,7 @@ struct Q_QUICK_PRIVATE_EXPORT QQuickOpenGLShaderEffectCommon
     QVector<UniformData> uniformData[Key::ShaderTypeCount];
     QVector<QSignalMapper *> signalMappers[Key::ShaderTypeCount];
     QString parseLog;
+    QFileSelector *fileSelector;
 };