#include "text.h"

Text::Text(const std::string& text, int x, int y, int size) : m_text(text), m_x(x), m_y(y), m_size(size), m_length(text.length())
{
    glGenBuffers(1, &m_vbo_vertices);
    glGenBuffers(1, &m_vbo_uvs);
}

void Text::draw()
{
    std::vector<glm::vec2> vertices;
    std::vector<glm::vec2> uvs;

    for (unsigned int i = 0; i < m_length; i++)
    {
        glm::vec2 v_up_left = glm::vec2(m_x + i * m_size, m_y + m_size);
        glm::vec2 v_up_right = glm::vec2(m_x + i * m_size + m_size, m_y + m_size);
        glm::vec2 v_down_right = glm::vec2(m_x + i * m_size + m_size, m_y);
        glm::vec2 v_down_left = glm::vec2(m_x + i * m_size, m_y);

        vertices.push_back(v_up_left);
        vertices.push_back(v_down_left);
        vertices.push_back(v_up_right);

        vertices.push_back(v_down_right);
        vertices.push_back(v_up_right);
        vertices.push_back(v_down_left);

        char character = m_text.at(i);

        float uv_x = (character % 16) / 16.0f;
        float uv_y = (character / 16) / 16.0f;

        glm::vec2 u_up_left = glm::vec2(uv_x, 1.0f - uv_y);
        glm::vec2 u_up_right = glm::vec2(uv_x + 1.0f / 16.0f, 1.0f - uv_y);
        glm::vec2 u_down_right = glm::vec2(uv_x + 1.0f / 16.0f, 1.0f - (uv_y + 1.0f / 16.0f));
        glm::vec2 u_down_left = glm::vec2(uv_x, 1.0f - (uv_y + 1.0f / 16.0f));

        uvs.push_back(u_up_left);
        uvs.push_back(u_down_left);
        uvs.push_back(u_up_right);

        uvs.push_back(u_down_right);
        uvs.push_back(u_up_right);
        uvs.push_back(u_down_left);
    }

    glBindBuffer(GL_ARRAY_BUFFER, m_vbo_vertices);
    glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(glm::vec2), &vertices[0], GL_STATIC_DRAW);
    glBindBuffer(GL_ARRAY_BUFFER, m_vbo_uvs);
    glBufferData(GL_ARRAY_BUFFER, uvs.size() * sizeof(glm::vec2), &uvs[0], GL_STATIC_DRAW);

    this->getMaterial()->getShader()->bind();
    this->getMaterial()->bindAttributes();
    this->getMaterial()->getDiffuseTexture()->bind(0);
    this->getMaterial()->getShader()->setUniform1i("diffuseTexture", 0);

    glEnableVertexAttribArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, m_vbo_vertices);
    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, nullptr);

    glEnableVertexAttribArray(1);
    glBindBuffer(GL_ARRAY_BUFFER, m_vbo_uvs);
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, nullptr);

    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    glDrawArrays(GL_TRIANGLES, 0, vertices.size());
    glDisable(GL_BLEND);


    glDisableVertexAttribArray(0);
    glDisableVertexAttribArray(1);

    this->getMaterial()->getShader()->unbind();
    this->getMaterial()->getDiffuseTexture()->unbind();
}

Text::~Text()
{
    glDeleteBuffers(1, &m_vbo_vertices);
    glDeleteBuffers(1, &m_vbo_uvs);
}