cube-game-plus-plus/client/rendering/Framebuffer.cpp

#include <iostream>

#include "Framebuffer.h"
#include "client/Utils.h"

Framebuffer::Framebuffer(u32 width, u32 height, u32 mode) : mode(mode), buffer(0), valid(false)
{
    glGenFramebuffers(1, &buffer);
    glBindFramebuffer(GL_FRAMEBUFFER, buffer);
    
    GLuint attachments[4];
    u32 counter = 0;
    
    if(mode & POSITION) // position texture
    {
        glGenTextures(1, &(textures[0]));
        glBindTexture(GL_TEXTURE_2D, textures[0]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F, width, height, 0, GL_RGB, GL_FLOAT, nullptr);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + counter, GL_TEXTURE_2D, textures[0], 0); 
        attachments[counter] = GL_COLOR_ATTACHMENT0 + counter;
        counter++;
    }
      
    if(mode & NORMAL) // normal texture
    {
        glGenTextures(1, &(textures[1]));
        glBindTexture(GL_TEXTURE_2D, textures[1]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, width, height, 0, GL_RGB, GL_FLOAT, nullptr);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + counter, GL_TEXTURE_2D, textures[1], 0);  
        attachments[counter] = GL_COLOR_ATTACHMENT0 + counter;
        counter++;
    }
    
    if(mode & COLOR) // color texture
    {
        glGenTextures(1, &(textures[2]));
        glBindTexture(GL_TEXTURE_2D, textures[2]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + counter, GL_TEXTURE_2D, textures[2], 0);  
        attachments[counter] = GL_COLOR_ATTACHMENT0 + counter;
        counter++;
    }
    
    if(mode & RED) // single color channel texture
    {
        glGenTextures(1, &textures[3]);
        glBindTexture(GL_TEXTURE_2D, textures[3]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_R32F, width, height, 0, GL_RGB, GL_FLOAT, nullptr);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + counter, GL_TEXTURE_2D, textures[3], 0);  
        attachments[counter] = GL_COLOR_ATTACHMENT0 + counter;
        counter++;
    }
    
    if(mode & DEPTH24_STENCIL8) // depth texture
    {
        glGenTextures(1, &textures[4]);
        glBindTexture(GL_TEXTURE_2D, textures[4]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_STENCIL, width, height, 0, GL_DEPTH_STENCIL, GL_UNSIGNED_INT_24_8, nullptr);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_TEXTURE_2D, textures[4], 0);
    }
    
    glDrawBuffers(counter, attachments);   
    
    if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
    {
	std::cout << "frame buffer is not complete\n";
        return;
    }
    valid = true;
}

Framebuffer::~Framebuffer()
{
    glDeleteFramebuffers(1, &buffer);
    for(GLuint& texture : textures)
    {
        glDeleteTextures(1, &texture);
    }
}

bool Framebuffer::isValid() const
{
    return valid;
}

void Framebuffer::bind() const
{
    glBindFramebuffer(GL_FRAMEBUFFER, buffer);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
}

void Framebuffer::resize(u32 width, u32 height) const
{
    if(mode & POSITION) // position texture
    {
        glBindTexture(GL_TEXTURE_2D, textures[0]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, width, height, 0, GL_RGB, GL_FLOAT, nullptr);
    }
    if(mode & NORMAL) // normal texture
    {
        glBindTexture(GL_TEXTURE_2D, textures[1]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, width, height, 0, GL_RGB, GL_FLOAT, nullptr);
    }
    if(mode & COLOR) // color texture
    {
        glBindTexture(GL_TEXTURE_2D, textures[2]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
    }
    if(mode & RED) // single color channel texture
    {
        glBindTexture(GL_TEXTURE_2D, textures[3]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width, height, 0, GL_RGB, GL_FLOAT, nullptr);
    }
    if(mode & DEPTH24_STENCIL8) // depth texture
    {
        glBindTexture(GL_TEXTURE_2D, textures[4]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH24_STENCIL8, width, height, 0, GL_DEPTH_STENCIL, GL_UNSIGNED_INT_24_8, nullptr);
    }
}

void Framebuffer::bindPositionTexture(u32 textureUnit) const
{
    glActiveTexture(GL_TEXTURE0 + textureUnit);
    glBindTexture(GL_TEXTURE_2D, textures[0]);
}

void Framebuffer::bindNormalTexture(u32 textureUnit) const
{
    glActiveTexture(GL_TEXTURE0 + textureUnit);
    glBindTexture(GL_TEXTURE_2D, textures[1]);
}

void Framebuffer::bindColorTexture(u32 textureUnit) const
{
    glActiveTexture(GL_TEXTURE0 + textureUnit);
    glBindTexture(GL_TEXTURE_2D, textures[2]);
}

void Framebuffer::bindRedTexture(u32 textureUnit) const
{
    glActiveTexture(GL_TEXTURE0 + textureUnit);
    glBindTexture(GL_TEXTURE_2D, textures[3]);
}

void Framebuffer::bindDepthTexture(u32 textureUnit) const
{
    glActiveTexture(GL_TEXTURE0 + textureUnit);
    glBindTexture(GL_TEXTURE_2D, textures[4]);
}