changed format to screen fbo for a more explicit and safe one

forwardmodule.h

@@ -18,7 +18,7 @@ class ForwardModule : public Module
 public:
     ForwardModule() :
         shaderSources(NULL),
-        renderTarget(FrameBuffer::getScreen())
+        renderTarget(FrameBuffer::screen)
     {}
 
     virtual void renderGL(Camera* myCamera, Scene* scene);
@@ -47,7 +47,7 @@ private:
     ShaderSource* shaderSources;
     std::vector<Shader*> shaders;
     std::vector<unsigned int> flags;
-    FrameBuffer* renderTarget;
+    const FrameBuffer* renderTarget;
 
     void lightPass(Camera* myCamera, Scene* scene, Light* light, unsigned int type);
 };

framebuffer.cpp

@@ -2,11 +2,10 @@
 #include "texture.h"
 #include "glassert.h"
 
-FrameBuffer::FrameBuffer(bool isNULL)
+const FrameBuffer* FrameBuffer::screen = new FrameBuffer(0);
+
+FrameBuffer::FrameBuffer()
 {
-    if(isNULL)
-        fbo = 0;
-    else
     glAssert(glGenFramebuffers(1, &fbo));
 }
 
@@ -17,33 +16,35 @@ FrameBuffer::~FrameBuffer()
 }
 
 void FrameBuffer::addTexture(Texture* tex, GLenum attachment)
+{
+    if(fbo != 0)
     {
         textures.push_back(tex);
         bindFBO();
         glAssert(glFramebufferTexture2D(GL_FRAMEBUFFER, attachment, tex->getTarget(), tex->getId(), 0));
         attachments.push_back(attachment);
     }
+}
 
 void FrameBuffer::initGL()
+{
+    if(fbo != 0)
     {
         bindFBO();
         glAssert(glDrawBuffers(attachments.size(), attachments.data()));
     }
+}
 
-void FrameBuffer::bindFBO()
+void FrameBuffer::bindFBO() const
 {
     glAssert(glBindFramebuffer(GL_FRAMEBUFFER, fbo));
 }
 
 Texture* FrameBuffer::getTexture(int texId)
 {
+    if(fbo != 0)
         return textures[texId];
+    else
+        return NULL;
 }
 
-FrameBuffer* FrameBuffer::getScreen()
-{
-    static FrameBuffer* screen = NULL;
-    if(screen == NULL)
-        screen = new FrameBuffer(true);
-    return screen;
-}

framebuffer.h

@@ -8,19 +8,23 @@ class Texture;
 
 class FrameBuffer
 {
+private:
+    FrameBuffer(int id) : fbo(id) {}
+
 protected:
     GLuint fbo;
     std::vector<Texture*> textures;
     std::vector<GLuint> attachments;
+
 public:
-    FrameBuffer(bool isNULL = false);
+    FrameBuffer();
     ~FrameBuffer();
     void addTexture(Texture* tex, GLenum attachment);
     void initGL();
 
-    void bindFBO();
+    void bindFBO() const;
     Texture* getTexture(int texId);
-    static FrameBuffer* getScreen();
+    static const FrameBuffer* screen;
 };
 
 #endif // FRAMEBUFFER_H