SceneFBO.cpp

Go to the documentation of this file.

#include "Application.hpp"


SceneFBO::SceneFBO(Application* app, uvec2 const & size)
    : m_app(app)
    , m_size(size)
{
    glGenRenderbuffers(1, &m_rb);
    glGenTextures(1, &m_texScene);
    glGenTextures(1, &m_texId);
    glGenFramebuffers(1, &m_fbo);
    
    glBindTexture(GL_TEXTURE_2D, m_texId);
    {
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    }
    glBindTexture(GL_TEXTURE_2D, 0);
    
    glBindTexture(GL_TEXTURE_2D, m_texScene);
    {
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    }
    glBindTexture(GL_TEXTURE_2D, 0);
    
    resize(m_size);

    glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
    {
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, m_rb);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_texScene, 0);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, m_texId, 0);
        
        GLuint buffers[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 };
        glDrawBuffers(2, buffers);
        
        glReadBuffer(GL_COLOR_ATTACHMENT1);

        GLenum e = glCheckFramebufferStatus(GL_FRAMEBUFFER);
        if (e != GL_FRAMEBUFFER_COMPLETE)
            cerr << "ERROR: fbo not complete" << endl;
    }
    glBindFramebuffer(GL_FRAMEBUFFER, 0);

}

SceneFBO::~SceneFBO()
{
    glDeleteFramebuffers(1, &m_fbo);
    glDeleteRenderbuffers(1, &m_rb);
    glDeleteTextures(1, &m_texScene);
    glDeleteTextures(1, &m_texId);
}

void SceneFBO::draw(double time, double timeDelta)
{
    glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
    {
        glClearColor(0,0,0,0);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        
        DrawArgs args(time,
                      timeDelta,
                      &(m_app->getWindow().getProjection()),
                      &(m_app->getCamera().getView()));

        m_app->getSceneGraph().draw(args);
    }
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

void SceneFBO::resize(vec2 const & size)
{
    m_size = size;
    
    glBindRenderbuffer(GL_RENDERBUFFER, m_rb);
    {
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, m_size.x, m_size.y);
    }
    glBindRenderbuffer(GL_RENDERBUFFER, 0);

    glBindTexture(GL_TEXTURE_2D, m_texScene);
    {
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, m_size.x, m_size.y, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
    }
    glBindTexture(GL_TEXTURE_2D, 0);
     
    glBindTexture(GL_TEXTURE_2D, m_texId); 
    {
        glTexImage2D(GL_TEXTURE_2D, 0, GL_ID_FORMAT, m_size.x, m_size.y, 0, GL_RED_INTEGER, GL_ID_TYPE, nullptr);
    }
    glBindTexture(GL_TEXTURE_2D, 0); 

    glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
    {
        glFramebufferParameteri(GL_FRAMEBUFFER, GL_FRAMEBUFFER_DEFAULT_WIDTH, m_size.x);
        glFramebufferParameteri(GL_FRAMEBUFFER, GL_FRAMEBUFFER_DEFAULT_HEIGHT, m_size.y);
        
        GLenum e = glCheckFramebufferStatus(GL_FRAMEBUFFER);
        if (e != GL_FRAMEBUFFER_COMPLETE)
            cerr << "ERROR: fbo not complete" << endl;
    }
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

void SceneFBO::readIds(OUT id_t* target, uvec2 const center, uint const distance)
{
    auto _x = (int)center.x - (int)distance;
    auto _y = (int)center.y - (int)distance;

    glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
    {
        glReadPixels(_x,_y,distance*2, distance*2, GL_RED_INTEGER, GL_ID_TYPE, target);
    }
    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    
    // outside: left
    for (size_t x = 0; (int)x < -_x; x++)
        for (size_t y = 0; y < 2*distance; y++)
            target[y * 2 * distance + x] = (id_t)0;
    
    
    // outside: right
    for (size_t x = 4*distance - _x + m_size.x; x < 2*distance; x++)
        for (size_t y = 0; y < 2*distance; y++)
            target[y * 2 * distance + x] = (id_t)0;
    
    // outside: top
    for (size_t x = 0; x < 2*distance; x++)
        for (size_t y = 0; (int)y < -_y; y++)
            target[y * 2 * distance + x] = (id_t)0;

    // outside: bottom
    for (size_t x = 0; x < 2*distance; x++)
        for (size_t y = 4*distance - _y + m_size.y; y < (2*distance); y++)
            target[y * 2 * distance + x] = (id_t)0;
}
void SceneFBO::readAllIds(OUT id_t* target)
{   
    glBindTexture(GL_TEXTURE_2D, m_texId); 
    {
        glGetTexImage(GL_TEXTURE_2D, 0, GL_RED_INTEGER, GL_ID_TYPE, target);
    }
    glBindTexture(GL_TEXTURE_2D, 0);
}
void SceneFBO::bindIdTexture(GLuint target)
{
    glActiveTexture(GL_TEXTURE0 + target);
    glBindTexture(GL_TEXTURE_2D, m_texId);
}
void SceneFBO::bindSceneTexture(GLuint target)
{
    glActiveTexture(GL_TEXTURE0 + target);
    glBindTexture(GL_TEXTURE_2D, m_texScene);
}