#include "posteffectmodule.h"
#include "framebuffer.h"
#include "glassert.h"
#include "texture.h"
#include "shader.h"

const GLfloat PostEffectModule::vertices[] = {
    0.0f, 1.0f, 0.0f,
    1.0f, 1.0f, 0.0f,
    1.0f, 0.0f, 0.0f,
    1.0f, 0.0f, 0.0f,
    0.0f, 0.0f, 0.0f,
    0.0f, 1.0f, 0.0f
};

PostEffectModule::PostEffectModule(int width, int height)
{
    inputFBO = new FrameBuffer();
    Texture* tex;
    // Color buffer
    tex = new Texture(GL_RGBA, GL_RGBA, width, height);
    tex->setFiltering(GL_NEAREST);
    inputFBO->addTexture(tex, GL_COLOR_ATTACHMENT1);

    // Depth buffer
    tex = new Texture(GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT, width, height, GL_FLOAT);
    tex->setFiltering(GL_NEAREST);
    inputFBO->addTexture(tex, GL_DEPTH_ATTACHMENT);

    inputFBO->initColorAttachments();

    outputFBO = FrameBuffer::screen;

    // set up vao
    glAssert(glGenVertexArrays(1, &vao));
    glAssert(glBindVertexArray(vao));
    glAssert(glGenBuffers(1, &vbo));
    glAssert(glBindBuffer(GL_ARRAY_BUFFER, vbo));
    glAssert(glBufferData(GL_ARRAY_BUFFER, 6 * sizeof(GLfloat), vertices, GL_STATIC_DRAW));
    glAssert(glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(float)*3, NULL));
    glAssert(glEnableVertexAttribArray(0));
}

PostEffectModule::~PostEffectModule()
{
    glAssert(glDeleteVertexArrays(1, &vao));
    glAssert(glDeleteBuffers(1, &vbo));
    delete(inputFBO);
}

void PostEffectModule::renderGL(Camera* myCamera, Scene* scene)
{
    if(shader != NULL)
    {
        shader->bind();
        shader->bindInteger(colorLocation, COLOR_BUFFER);
        shader->bindInteger(depthLocation, DEPTH_BUFFER);

        outputFBO->bindFBO();

        inputFBO->getTexture(COLOR_BUFFER)->bind(COLOR_BUFFER);
        inputFBO->getTexture(DEPTH_BUFFER)->bind(DEPTH_BUFFER);

        glAssert(glBindVertexArray(vao));
        glAssert(glDrawArrays(GL_TRIANGLES, 0, 36));
    }
}

void PostEffectModule::setShader(Shader* myShader)
{
    shader = myShader;
    colorLocation = shader->getLocation("colorSampler");
    depthLocation = shader->getLocation("depthSampler");
}