osgMyGUI: add support for layers to insert custom rendering state

components/myguiplatform/myguirendermanager.cpp

@@ -45,6 +45,9 @@ namespace osgMyGUI
 
 class Drawable : public osg::Drawable {
     osgMyGUI::RenderManager *mParent;
+    osg::ref_ptr<osg::StateSet> mStateSet;
+
+public:
 
     // Stage 0: update widget animations and controllers. Run during the Update traversal.
     class FrameUpdate : public osg::Drawable::UpdateCallback
@@ -101,6 +104,10 @@ class Drawable : public osg::Drawable {
     virtual void drawImplementation(osg::RenderInfo &renderInfo) const
     {
         osg::State *state = renderInfo.getState();
+
+        state->pushStateSet(mStateSet);
+        state->apply();
+
         state->disableAllVertexArrays();
         state->setClientActiveTextureUnit(0);
         glEnableClientState(GL_VERTEX_ARRAY);
@@ -113,6 +120,13 @@ class Drawable : public osg::Drawable {
         {
             const Batch& batch = *it;
             osg::VertexBufferObject *vbo = batch.mVertexBuffer;
+
+            if (batch.mStateSet)
+            {
+                state->pushStateSet(batch.mStateSet);
+                state->apply();
+            }
+
             osg::Texture2D* texture = batch.mTexture;
             if(texture)
                 state->applyTextureAttribute(0, texture);
@@ -135,12 +149,20 @@ class Drawable : public osg::Drawable {
             }
 
             glDrawArrays(GL_TRIANGLES, 0, batch.mVertexCount);
+
+            if (batch.mStateSet)
+            {
+                state->popStateSet();
+                state->apply();
+            }
         }
 
         glDisableClientState(GL_VERTEX_ARRAY);
         glDisableClientState(GL_TEXTURE_COORD_ARRAY);
         glDisableClientState(GL_COLOR_ARRAY);
 
+        state->popStateSet();
+
         state->unbindVertexBufferObject();
         state->dirtyAllVertexArrays();
         state->disableAllVertexArrays();
@@ -161,10 +183,17 @@ public:
         osg::ref_ptr<FrameUpdate> frameUpdate = new FrameUpdate;
         frameUpdate->setRenderManager(mParent);
         setUpdateCallback(frameUpdate);
+
+        mStateSet = new osg::StateSet;
+        mStateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
+        mStateSet->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
+        mStateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
+        mStateSet->setMode(GL_BLEND, osg::StateAttribute::ON);
     }
     Drawable(const Drawable &copy, const osg::CopyOp &copyop=osg::CopyOp::SHALLOW_COPY)
         : osg::Drawable(copy, copyop)
         , mParent(copy.mParent)
+        , mStateSet(copy.mStateSet)
         , mWriteTo(0)
         , mReadFrom(0)
     {
@@ -180,6 +209,9 @@ public:
         // need to hold on to this too as the mVertexBuffer does not hold a ref to its own array
         osg::ref_ptr<osg::UByteArray> mArray;
 
+        // optional
+        osg::ref_ptr<osg::StateSet> mStateSet;
+
         size_t mVertexCount;
     };
 
@@ -321,6 +353,7 @@ RenderManager::RenderManager(osgViewer::Viewer *viewer, osg::Group *sceneroot, R
   , mUpdate(false)
   , mIsInitialise(false)
   , mInvScalingFactor(1.f)
+  , mInjectState(NULL)
 {
     if (scalingFactor != 0.f)
         mInvScalingFactor = 1.f / scalingFactor;
@@ -364,12 +397,6 @@ void RenderManager::initialise()
     camera->setViewMatrix(osg::Matrix::identity());
     camera->setRenderOrder(osg::Camera::POST_RENDER);
     camera->setClearMask(GL_NONE);
-    osg::StateSet *state = new osg::StateSet;
-    state->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
-    state->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
-    state->setMode(GL_BLEND, osg::StateAttribute::ON);
-    state->setAttribute(new osg::BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA));
-    geode->setStateSet(state);
     geode->setCullingActive(false);
     camera->addChild(geode.get());
 
@@ -418,10 +445,17 @@ void RenderManager::doRender(MyGUI::IVertexBuffer *buffer, MyGUI::ITexture *text
         if (batch.mTexture->getDataVariance() == osg::Object::DYNAMIC)
             mDrawable->setDataVariance(osg::Object::DYNAMIC); // only for this frame, reset in begin()
     }
+    if (mInjectState)
+        batch.mStateSet = mInjectState;
 
     mDrawable->addBatch(batch);
 }
 
+void RenderManager::setInjectState(osg::StateSet* stateSet)
+{
+    mInjectState = stateSet;
+}
+
 void RenderManager::end()
 {
 }

components/myguiplatform/myguirendermanager.hpp

@@ -20,6 +20,7 @@ namespace osg
     class Group;
     class Camera;
     class RenderInfo;
+    class StateSet;
 }
 
 namespace osgMyGUI
@@ -48,6 +49,8 @@ class RenderManager : public MyGUI::RenderManager, public MyGUI::IRenderTarget
 
     float mInvScalingFactor;
 
+    osg::StateSet* mInjectState;
+
     void destroyAllResources();
 
 public:
@@ -95,6 +98,9 @@ public:
     /** @see IRenderTarget::doRender */
     virtual void doRender(MyGUI::IVertexBuffer *buffer, MyGUI::ITexture *texture, size_t count);
 
+    /** specify a StateSet to inject for rendering. The StateSet will be used by future doRender calls until you reset it to NULL again. */
+    void setInjectState(osg::StateSet* stateSet);
+
     /** @see IRenderTarget::getInfo */
     virtual const MyGUI::RenderTargetInfo& getInfo() { return mInfo; }