#include "ShadowMap.h"

ShadowMap::ShadowMap(vec2 size, vec2 pixelOffset){
    m_size = size;
    m_pixelOffset = pixelOffset;

    glGenTextures(1, &m_texture);
    glBindTexture(GL_TEXTURE_2D, m_texture);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_R_TO_TEXTURE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_FUNC, GL_LEQUAL);
    glTexParameteri(GL_TEXTURE_2D, GL_DEPTH_TEXTURE_MODE, GL_INTENSITY);

    glTexImage2D(GL_TEXTURE_2D,
                 0,
                 GL_DEPTH_COMPONENT,
                 GLsizei(m_size.x),
                 GLsizei(m_size.y),
                 0,
                 GL_DEPTH_COMPONENT,
                 GL_UNSIGNED_BYTE,
                 NULL);

    glBindTexture(GL_TEXTURE_2D, 0);

    glGenFramebuffers(1, &m_fbo); // FBO erstellen
    glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);

    glDrawBuffer(GL_NONE);
    glReadBuffer(GL_NONE);

    glFramebufferTexture2D(GL_FRAMEBUFFER,
                           GL_DEPTH_ATTACHMENT,
                           GL_TEXTURE_2D,
                           m_texture,
                           0);

    if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE){
        cerr<<"Framebuffer could not be initalized!"<<endl;
    }

    glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

ShadowMap::~ShadowMap(){
    glDeleteBuffers(1, &m_texture);
    glDeleteBuffers(1, &m_fbo);

    delete &m_size;
    delete &m_pixelOffset;
}

void ShadowMap::updateTexture(vec2 v){
    m_size = v;

    glBindTexture(GL_TEXTURE_2D, m_texture);

    glTexImage2D(GL_TEXTURE_2D,
                 0,
                 GL_DEPTH_COMPONENT,
                 GLsizei(m_size.x),
                 GLsizei(m_size.y),
                 0,
                 GL_DEPTH_COMPONENT,
                 GL_UNSIGNED_BYTE,
                 NULL);

    glBindTexture(GL_TEXTURE_2D, 0);
}

void ShadowMap::updateTexture(float x, float y){
    updateTexture(vec2(x, y));
}

void ShadowMap::setPixelOffset(vec2 v){
    m_pixelOffset = v;
}

void ShadowMap::setPixelOffset(float x, float y){
    setPixelOffset(vec2(x, y));
}

GLuint ShadowMap::getTextureID(){
    return m_texture;
}

GLuint ShadowMap::getFBO(){
    return m_fbo;
}

vec2 ShadowMap::getTextureSize(){
    return m_size;
}

float ShadowMap::getTextureWidth(){
    return m_size.x;
}

float ShadowMap::getTextureHeight(){
    return m_size.y;
}

vec2 ShadowMap::getPixelOffset(){
    return m_pixelOffset;
}