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

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

// Initialize
static void init(void);

// Draw
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();

  // Font
  char *text = "                    CRÉDITS\n\n"
               "Concours API8 — 7 édition\n"
               "Font: fontesk et fontsquirrel\n"
               "Librairies: GL4D, SDL2 et extensions";
  char *fontName = "fonts/Instrument.ttf";

  SDL_Color c = {255, 255, 255, 255};
  SDL_Surface *d, *s;
  TTF_Font *font = NULL;

  if (TTF_Init() == -1) {
    fprintf(stderr, "Erreur TTF : %s\n", TTF_GetError());
    exit(2);
  }

  glGenTextures(1, &_textTexId);
  glBindTexture(GL_TEXTURE_2D, _textTexId);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

  if (!(font = TTF_OpenFont(fontName, 100))) {
    fprintf(stderr, "Erreur TTF : %s\n", TTF_GetError());
    exit(2);
  }

  if ((d = TTF_RenderUTF8_Blended_Wrapped(font, text, c, 0)) == NULL) {
    TTF_CloseFont(font);
    fprintf(stderr, "Erreur TTF : RenderText\n");
    exit(2);
  }

  assert((s = SDL_CreateRGBSurface(0, d->w, d->h, 32, R_MASK, G_MASK, B_MASK,
                                   A_MASK)));
  SDL_BlitSurface(d, NULL, s, NULL);
  SDL_FreeSurface(d);

  glBindTexture(GL_TEXTURE_2D, _textTexId);
  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, s->w, s->h, 0, GL_RGBA,
               GL_UNSIGNED_BYTE, s->pixels);

  SDL_FreeSurface(s);
  TTF_CloseFont(font);
  glBindTexture(GL_TEXTURE_2D, 0);
}

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, -2.f);
  glActiveTexture(GL_TEXTURE0);
  glBindTexture(GL_TEXTURE_2D, _textTexId);
  gl4duScalef(.5f, .1f, .5f);

  glUseProgram(_pId);
  gl4duSendMatrices();

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

  glUseProgram(0);
}