FrameBuffer.cpp

#include "FrameBuffer.h"

FrameBuffer::FrameBuffer(uint32_t width, uint32_t height)
    : depthTexture(0), depthBuffer(0), colourTexture(0), width(width), height(height) {
    glGenFramebuffers(1, &framebufferID);
}

void FrameBuffer::addColourTexture() {
    bind();
    glGenTextures(1, &colourTexture);

    glBindTexture(GL_TEXTURE_2D, colourTexture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    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, GL_TEXTURE_2D, colourTexture, 0);

    // Isn't necessary at the moment but I feel like it should be
    // GLenum DrawBuffers[1] = {GL_COLOR_ATTACHMENT0};
    // glDrawBuffers(1, DrawBuffers); // "1" is the size of DrawBuffers

    unbind();
}

void FrameBuffer::addDepthTexture() {
    bind();
    glGenTextures(1, &depthTexture);

    glBindTexture(GL_TEXTURE_2D, depthTexture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT32, width, height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_REF_TO_TEXTURE);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depthTexture, 0);

    unbind();
}

void FrameBuffer::addDepthBuffer() {
    bind();
    glGenRenderbuffers(1, &depthBuffer);
    glBindRenderbuffer(GL_RENDERBUFFER, depthBuffer);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, width, height);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthBuffer);
    unbind();
}

bool FrameBuffer::isOkay() {
    bind();
    bool result = true;
    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
        result = false;
    }
    unbind();
    return result;
}

GLuint FrameBuffer::getColourTexture() {
    return colourTexture;
}

GLuint FrameBuffer::getDepthTexture() {
    return depthTexture;
}

GLuint FrameBuffer::getDepthBuffer() {
    return depthBuffer;
}

int FrameBuffer::getWidth() {
    return width;
}

int FrameBuffer::getHeight() {
    return height;
}

void FrameBuffer::bind() {
    glBindFramebuffer(GL_FRAMEBUFFER, framebufferID);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glViewport(0, 0, width, height);
}

void FrameBuffer::unbind() {
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
}