#include "../includes/animations.h"

static GLuint _pId = 0;
static GLuint _textTexId = 0;
static GLuint _quadId = 0;

static void init(void);

static void draw(void);

void credits(int state) {
  switch (state) {
  case GL4DH_INIT:
    init();
    break;

  case GL4DH_DRAW:
    draw();
    break;

  default:
    break;
  }
}

static void init(void) {
  _pId = gl4duCreateProgram("<vs>shaders/credits.vs", "<fs>shaders/credits.fs",
                            NULL);
  gl4duGenMatrix(GL_FLOAT, "modview");
  gl4duGenMatrix(GL_FLOAT, "proj");
  _quadId = gl4dgGenQuadf();

  // Charge la police
  TTF_Font *font = NULL;
  if (initFont(&font, "fonts/Instrument.ttf", 100)) {
    exit(1);
  }

  // Ecrit avec la police sur une texture
  if (writeText(&_textTexId, font,
                "                    CRÉDITS\n\n"
                "Concours API8 — 7e édition\n"
                "Font: fontesk et fontsquirrel\n"
                "Audio: beepbox\n"
                "Librairies: GL4D, SDL2 et extensions",
                (SDL_Color){255, 255, 255, 255})) {
    exit(1);
  }

  // Libère la police de la mémoire
  freeFont(font);
}

static void draw(void) {
  glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  static Uint32 t0 = -1;
  GLfloat t, d;
  if (t0 < 0.0f)
    t0 = SDL_GetTicks();
  t = (GLfloat)(SDL_GetTicks() - t0) / 1000.f;
  d = -1.1f + .25f * t;

  GLfloat ratio = (GLfloat)_dims[0] / (GLfloat)_dims[1];
  gl4duBindMatrix("proj");
  gl4duLoadIdentityf();
  gl4duFrustumf(-ratio, ratio, -1, 1, 2, 100);

  gl4duBindMatrix("modview");
  gl4duLoadIdentityf();

  gl4duTranslatef(0.f, d - 1.5f, -2.f);
  glActiveTexture(GL_TEXTURE0);
  glBindTexture(GL_TEXTURE_2D, _textTexId);
  gl4duScalef(1.f, .3f, 1.f);

  glUseProgram(_pId);
  gl4duSendMatrices();

  glUniform1i(glGetUniformLocation(_pId, "inv"), 1);
  glUniform1i(glGetUniformLocation(_pId, "tex"), 0);
  gl4dgDraw(_quadId);

  glUseProgram(0);
}