Refactor shaders into seprate GLSL source files

The default implementation of QSGShaderMaterial::vertexShader() and
fragmentShader() now loads the GLSL source from a list of source files
that can be specified via the setShaderSourceFile() or
setShaderSourceFiles() functions.

Multiple shader source files for each shader stage are supported. Each
source file will be read in the order specified and concatenated
together before being compiled.

The other places where Qt Quick 2 loads shader source code have
been adapted to use the new QSGShaderSourceBuilder, which is also
used internally by QSGMaterial.

This puts Qt Quick 2 into a better state ready to support OpenGL
core profile and to load different shaders based upon OpenGL version,
profile, GPU vendor, platform, etc.

Change-Id: I1a66213c2ce788413168eb48c7bc5317e61988a2
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>

1 files changed, 59 insertions, 2 deletions

diff --git a/src/quick/scenegraph/coreapi/qsgmaterial.cpp b/src/quick/scenegraph/coreapi/qsgmaterial.cpp
index d186823958..686d1438b4 100644
--- a/src/quick/scenegraph/coreapi/qsgmaterial.cpp
+++ b/src/quick/scenegraph/coreapi/qsgmaterial.cpp
@@ -41,9 +41,21 @@
 
 #include "qsgmaterial.h"
 #include "qsgrenderer_p.h"
+#include "qsgmaterialshader_p.h"
+#include <private/qsgshadersourcebuilder_p.h>
 
 QT_BEGIN_NAMESPACE
 
+const char *QSGMaterialShaderPrivate::loadShaderSource(QOpenGLShader::ShaderType type) const
+{
+    QStringList files = m_sourceFiles[type];
+    QSGShaderSourceBuilder builder;
+    Q_FOREACH (const QString &file, files)
+        builder.appendSourceFile(file);
+    m_sources[type] = builder.source();
+    return m_sources[type].constData();
+}
+
 #ifndef QT_NO_DEBUG
 static bool qsg_leak_check = !qgetenv("QML_LEAK_CHECK").isEmpty();
 #endif
@@ -165,14 +177,21 @@ static bool qsg_leak_check = !qgetenv("QML_LEAK_CHECK").isEmpty();
     Creates a new QSGMaterialShader.
  */
 QSGMaterialShader::QSGMaterialShader()
+    : d_ptr(new QSGMaterialShaderPrivate)
+{
+}
+
+QSGMaterialShader::QSGMaterialShader(QSGMaterialShaderPrivate &dd)
+    : d_ptr(&dd)
 {
-    Q_UNUSED(m_reserved);
 }
 
 /*!
-    \fn QSGMaterialShader::~QSGMaterialShader()
     \internal
  */
+QSGMaterialShader::~QSGMaterialShader()
+{
+}
 
 /*!
     \fn char const *const *QSGMaterialShader::attributeNames() const
@@ -194,6 +213,11 @@ QSGMaterialShader::QSGMaterialShader()
 
     The contents returned from this function should never change.
 */
+const char *QSGMaterialShader::vertexShader() const
+{
+    Q_D(const QSGMaterialShader);
+    return d->loadShaderSource(QOpenGLShader::Vertex);
+}
 
 
 /*!
@@ -204,6 +228,11 @@ QSGMaterialShader::QSGMaterialShader()
 
     The contents returned from this function should never change.
 */
+const char *QSGMaterialShader::fragmentShader() const
+{
+    Q_D(const QSGMaterialShader);
+    return d->loadShaderSource(QOpenGLShader::Fragment);
+}
 
 
 /*!
@@ -274,7 +303,35 @@ void QSGMaterialShader::updateState(const RenderState & /* state */, QSGMaterial
 {
 }
 
+/*!
+    Sets the GLSL source file for the shader stage \a type to \a sourceFile. The
+    default implementation of the vertexShader() and fragmentShader() functions
+    will load the source files set by this function.
+
+    This function is useful when you have a single source file for a given shader
+    stage. If your shader consists of multiple source files then use
+    setShaderSourceFiles()
+
+    \sa setShaderSourceFiles(), vertexShader(), fragmentShader()
+ */
+void QSGMaterialShader::setShaderSourceFile(QOpenGLShader::ShaderType type, const QString &sourceFile)
+{
+    Q_D(QSGMaterialShader);
+    d->m_sourceFiles[type] = (QStringList() << sourceFile);
+}
+
+/*!
+    Sets the GLSL source files for the shader stage \a type to \a sourceFiles. The
+    default implementation of the vertexShader() and fragmentShader() functions
+    will load the source files set by this function in the order given.
 
+    \sa setShaderSourceFile(), vertexShader(), fragmentShader()
+ */
+void QSGMaterialShader::setShaderSourceFiles(QOpenGLShader::ShaderType type, const QStringList &sourceFiles)
+{
+    Q_D(QSGMaterialShader);
+    d->m_sourceFiles[type] = sourceFiles;
+}
 
 /*!
     This function is called when the shader is initialized to compile the