Hello! I'm trying to implement bloom to my OpenGL game but I'm a bit confused. I want to create a second color attachment for saving the scene highlights. I'm using multisampled textures and have no idea how to do this.

Do I need to create two multi sampled color attachments? Two multisampledTextures like below?

glGenTextures(1, &multisampledTexture);
glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, multisampledTexture);
glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGB, width, height, GL_TRUE);
glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, multisampledTexture, 0);

I'm completely lost and don't know how to do this :( I don't want to know how to accomplish the bloom effect, just need to do now how to save 2 color attachments that are multisampled.

I'll show share my implementation below if it helps. Thanks!

glBindFramebuffer(GL_FRAMEBUFFER, 0);
glGenFramebuffers(1, &m_framebuffer);
glBindFramebuffer(GL_FRAMEBUFFER, m_framebuffer);

// Multisampled Color Attachment
glGenTextures(1, &multisampledTexture);
glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, multisampledTexture);
glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGB, width, height, GL_TRUE);
glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, multisampledTexture, 0);


glGenRenderbuffers(1, &m_rbo);
glBindRenderbuffer(GL_RENDERBUFFER, m_rbo);
glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_DEPTH24_STENCIL8, width, height);
glBindRenderbuffer(GL_RENDERBUFFER, 0);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, m_rbo);

if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
    std::cout << "ERROR::FRAMEBUFFER:: Framebuffer is not complete!" << std::endl;
glBindFramebuffer(GL_FRAMEBUFFER, 0);
//

glGenFramebuffers(1, &m_intermediateFBO);
glBindFramebuffer(GL_FRAMEBUFFER, m_intermediateFBO);

glGenTextures(1, &m_resolvedTexture);
glBindTexture(GL_TEXTURE_2D, m_resolvedTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_resolvedTexture, 0);

if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
    std::cout << "ERROR::FRAMEBUFFER:: Intermediate framebuffer is not complete!" << std::endl;
glBindFramebuffer(GL_FRAMEBUFFER, 0);