: mWidth(width), mHeight(height)

{

// 1) Create a framebuffer object

glGenFramebuffers(1, &mFBO);

// 2) Bind the framebuffer object

glBindFramebuffer(GL_FRAMEBUFFER, mFBO);

// Now we need to create the texture which will contain the RGB output of our shader.

// This code is very classic :

// The texture we're going to render to

glGenTextures(1, &mTexture);

checkGLError();

// "Bind" the newly created texture : all future texture functions will modify this texture

glBindTexture(GL_TEXTURE_2D, mTexture);

checkGLError();

// Give an empty image to OpenGL ( the last "0" )

//glTexImage2D(GL_TEXTURE_2D, 0, GL_R32F, mWidth, mHeight, 0, GL_RED, GL_FLOAT, 0);

glTexImage2D(GL_TEXTURE_2D, 0, GL_R32F, mWidth, mHeight, 0, GL_LUMINANCE, GL_FLOAT, 0);

checkGLError();

// Poor filtering. Needed !

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

checkGLError();

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); //GL_CLAMP);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); //GL_CLAMP);

checkGLError();

// 3) Attach a texture to the FBO

glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTexture, 0);

checkGLError();

// Set the list of draw buffers.

//GLenum DrawBuffers[2] = {GL_COLOR_ATTACHMENT0, 0};

//glDrawBuffers(1, DrawBuffers); // "1" is the size of DrawBuffers

//checkGLError();

// Always check that our framebuffer is ok

assert(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE);

Release();

// Activate the framebuffer

glBindFramebuffer(GL_FRAMEBUFFER, mFBO);

checkGLError();

// Disable the framebuffer

glBindFramebuffer(GL_FRAMEBUFFER, 0);

checkGLError();

{

glBindTexture(GL_TEXTURE_2D, target);

checkGLError();

glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_R32F, 0, 0, mWidth, mHeight, 0);

checkGLError();

glBindTexture(GL_TEXTURE_2D, 0);

checkGLError();