Correct implementation of DeviceSource resize

previous commit was bad...

DeviceSource.cpp

@@ -384,13 +384,14 @@ void DeviceSource::setDevice(const std::string &devicename)
 
         pipeline << " ! videoconvert";
 
-        dettach();
+        // resize render buffer
+        if (renderbuffer_)
+            renderbuffer_->resize(best.width, best.height);
 
         // open gstreamer
         stream_->open( pipeline.str(), best.width, best.height);
         stream_->play(true);
 
-
         // will be ready after init and one frame rendered
         ready_ = false;
     }

FrameBuffer.cpp

@@ -171,6 +171,31 @@ glm::vec3 FrameBuffer::resolution() const
     return glm::vec3(attrib_.viewport.x, attrib_.viewport.y, 0.f);
 }
 
+void FrameBuffer::resize(int width, int height)
+{
+    if (framebufferid_) {
+        if (attrib_.viewport.x != width || attrib_.viewport.y != height)
+        {
+            // de-init
+            glDeleteFramebuffers(1, &framebufferid_);
+            framebufferid_ = 0;
+
+            if (intermediate_framebufferid_)
+                glDeleteFramebuffers(1, &intermediate_framebufferid_);
+            intermediate_framebufferid_ = 0;
+            if (textureid_)
+                glDeleteTextures(1, &textureid_);
+            textureid_ = 0;
+            if (intermediate_textureid_)
+                glDeleteTextures(1, &intermediate_textureid_);
+            intermediate_textureid_ = 0;
+
+            // change resolution
+            attrib_.viewport = glm::ivec2(width, height);
+        }
+    }
+}
+
 void FrameBuffer::begin(bool clear)
 {
     if (!framebufferid_)

FrameBuffer.h

@@ -69,6 +69,7 @@ public:
     inline uint width() const { return attrib_.viewport.x; }
     inline uint height() const { return attrib_.viewport.y; }
     glm::vec3 resolution() const;
+    void resize(int width, int height);
     float aspectRatio() const;
     std::string info() const;
 

Source.cpp

@@ -425,14 +425,6 @@ void Source::render()
     }
 }
 
-void Source::dettach()
-{
-    // replace renderbuffer_
-    if (renderbuffer_)
-        delete renderbuffer_;
-    renderbuffer_ = nullptr;
-}
-
 void Source::attach(FrameBuffer *renderbuffer)
 {
     // invalid argument

Source.h

@@ -246,7 +246,6 @@ protected:
     // NB: rendershader_ is applied at render()
     FrameBuffer *renderbuffer_;
     void attach(FrameBuffer *renderbuffer);
-    void dettach() ;
 
     // the rendersurface draws the renderbuffer in the scene
     // It is associated to the rendershader for mixing effects