#include <GL4D/gl4duw_SDL2.h>
#include <stdio.h>

static void init(void);
static void resize(int, int);
static void draw(void);
static void sortie(void);

static GLuint _wW = 1280, _wH = 720;
static GLuint _quadId = 0;
static GLuint _pId = 0;

int main(int argc, char **argv) {
  if (!gl4duwCreateWindow(argc, argv, "Demo API8 2023", GL4DW_POS_CENTERED,
                          GL4DW_POS_CENTERED, _wW, _wH,
                          GL4DW_OPENGL | GL4DW_SHOWN)) {
    fprintf(stderr, "Erreur lors de la création de la fenêtre.\n");
    return 1;
  }

  init();
  atexit(sortie);
  gl4duwResizeFunc(resize);
  gl4duwDisplayFunc(draw);
  gl4duwMainLoop();

  return 0;
}

void init(void) {
  glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
  _quadId = gl4dgGenQuadf();
  _pId = gl4duCreateProgram("<vs>shaders/lights.vs", "<fs>shaders/lights.fs",
                            NULL);
  glEnable(GL_DEPTH_TEST);
  gl4duGenMatrix(GL_FLOAT, "proj");
  gl4duGenMatrix(GL_FLOAT, "mod");
  gl4duGenMatrix(GL_FLOAT, "view");
  resize(_wW, _wH);
}

static void resize(int width, int height) {
  GLfloat ratio;
  _wW = width;
  _wH = height;
  glViewport(0, 0, _wW, _wH);
  ratio = (GLfloat)_wW / (GLfloat)_wH;
  gl4duBindMatrix("proj");
  gl4duLoadIdentityf();
  gl4duFrustumf(-1 * ratio, 1 * ratio, -1, 1, 2, 100);
}

void draw(void) {
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  // Vue
  gl4duBindMatrix("view");
  gl4duLoadIdentityf();
  gl4duLookAtf(0, 0, 4.f, 0, 0, 0, 0.f, 1.f, 0);

  // Scene
  // clang-format off
  GLfloat rouge[]   = {1.f, 0.f,  0.f, 1.f},
          blanc[]   = {1.f, 1.f,  1.f, 1.f},
          lumpos0[] = {0.f, 0.f, 1.1f, 1.f},
          lumpos[4],
          *mat;
  // clang-format on

  static GLdouble x = 0.;
  lumpos0[0] = 4.f * (float)sin(x);
  gl4duBindMatrix("view");
  mat = (GLfloat *)gl4duGetMatrixData();
  MMAT4XVEC4(lumpos, mat, lumpos0);
  gl4duBindMatrix("mod");
  gl4duLoadIdentityf();
  glUseProgram(_pId);
  gl4duSendMatrices();
  glUniform4fv(glGetUniformLocation(_pId, "scolor"), 1, rouge);
  glUniform4fv(glGetUniformLocation(_pId, "lcolor"), 1, blanc);
  glUniform4fv(glGetUniformLocation(_pId, "lumpos"), 1, lumpos);
  gl4dgDraw(_quadId);
  glUseProgram(0);
}

void sortie(void) { gl4duClean(GL4DU_ALL); }