Add support for parameters in QShaderGenerator

Change-Id: Iff8fec51ddbf9b018cb5ec3aff357125134013eb
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

2 files changed, 26 insertions, 8 deletions

diff --git a/src/gui/util/qshadergenerator.cpp b/src/gui/util/qshadergenerator.cpp
index 5d6a05e2a0..52bd275cf7 100644
--- a/src/gui/util/qshadergenerator.cpp
+++ b/src/gui/util/qshadergenerator.cpp
@@ -41,6 +41,22 @@
 
 QT_BEGIN_NAMESPACE
 
+namespace
+{
+    QByteArray replaceParameters(const QByteArray &original, const QShaderNode &node)
+    {
+        auto result = original;
+
+        for (const auto &parameterName : node.parameterNames()) {
+            const auto placeholder = QByteArray(QByteArrayLiteral("$") + parameterName.toUtf8());
+            const auto value = node.parameter(parameterName).toString().toUtf8();
+            result.replace(placeholder, value);
+        }
+
+        return result;
+    }
+}
+
 QByteArray QShaderGenerator::createShaderCode() const
 {
     auto code = QByteArrayList();
@@ -67,7 +83,7 @@ QByteArray QShaderGenerator::createShaderCode() const
 
     for (const auto &node : graph.nodes()) {
         for (const auto &snippet : node.rule(format).headerSnippets) {
-            code << snippet;
+            code << replaceParameters(snippet, node);
         }
     }
 
@@ -93,7 +109,8 @@ QByteArray QShaderGenerator::createShaderCode() const
             const auto variable = QByteArray(QByteArrayLiteral("v") + QByteArray::number(variableIndex));
             line.replace(placeholder, variable);
         }
-        code << QByteArrayLiteral("    ") + line;
+
+        code << QByteArrayLiteral("    ") + replaceParameters(line, node);
     }
 
     code << QByteArrayLiteral("}");
diff --git a/tests/auto/gui/util/qshadergenerator/tst_qshadergenerator.cpp b/tests/auto/gui/util/qshadergenerator/tst_qshadergenerator.cpp
index 655bc94f2c..f64d9458f9 100644
--- a/tests/auto/gui/util/qshadergenerator/tst_qshadergenerator.cpp
+++ b/tests/auto/gui/util/qshadergenerator/tst_qshadergenerator.cpp
@@ -77,12 +77,13 @@ namespace
         auto graph = QShaderGraph();
 
         auto worldPosition = createNode({
-            createPort(QShaderNodePort::Output, "worldPosition")
+            createPort(QShaderNodePort::Output, "value")
         });
-        worldPosition.addRule(openGLES2, QShaderNode::Rule("highp vec3 $worldPosition = worldPosition;",
-                                                           QByteArrayList() << "varying highp vec3 worldPosition;"));
-        worldPosition.addRule(openGL3, QShaderNode::Rule("vec3 $worldPosition = worldPosition;",
-                                                         QByteArrayList() << "in vec3 worldPosition;"));
+        worldPosition.setParameter("name", "worldPosition");
+        worldPosition.addRule(openGLES2, QShaderNode::Rule("highp vec3 $value = $name;",
+                                                           QByteArrayList() << "varying highp vec3 $name;"));
+        worldPosition.addRule(openGL3, QShaderNode::Rule("vec3 $value = $name;",
+                                                         QByteArrayList() << "in vec3 $name;"));
 
         auto texture = createNode({
             createPort(QShaderNodePort::Output, "texture")
@@ -163,7 +164,7 @@ namespace
         graph.addEdge(createEdge(texture.uuid(), "texture", sampleTexture.uuid(), "sampler"));
         graph.addEdge(createEdge(texCoord.uuid(), "texCoord", sampleTexture.uuid(), "coord"));
 
-        graph.addEdge(createEdge(worldPosition.uuid(), "worldPosition", lightFunction.uuid(), "position"));
+        graph.addEdge(createEdge(worldPosition.uuid(), "value", lightFunction.uuid(), "position"));
         graph.addEdge(createEdge(sampleTexture.uuid(), "color", lightFunction.uuid(), "baseColor"));
         graph.addEdge(createEdge(lightIntensity.uuid(), "lightIntensity", lightFunction.uuid(), "lightIntensity"));