/*
  author: Miloslav Ciz
  license: CC0
*/

#include <SDL2/SDL.h>
#include <stdio.h>
#include <math.h>

#define S3L_PRESET_EMBEDDED

#define S3L_PIXEL_FUNCTION drawPixel

#define S3L_RESOLUTION_X 640
#define S3L_RESOLUTION_Y 480

#define S3L_COMPUTE_DEPTH 1
#define S3L_PERSPECTIVE_CORRECTION 1
#define S3L_NEAR_CLAMPING 1

#include "small3dlib.h"

#include "house.h"

int32_t offScreenPixels = 0;
const S3L_Unit ver[] = { S3L_CUBE_VERTICES };
const S3L_Index tri[] = { S3L_CUBE_TRIANGLES };
const S3L_Unit tex_coords[] = { S3L_CUBE_TEXCOORDS(16) };

S3L_Model3D models[2];
S3L_Scene scene;

int8_t keys[256];

const uint8_t testTexture[] =
{
  2,2,2,0,0,0,2,2,2,2,0,0,0,2,2,2,
  2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,
  2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,
  0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,
  0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,
  2,0,0,0,0,1,1,1,1,1,0,0,0,0,0,2,
  2,0,0,0,0,1,1,0,0,0,0,0,0,0,0,2,
  2,0,0,0,0,1,1,0,0,0,0,0,0,0,0,2,
  2,0,0,0,0,1,1,0,0,0,0,0,0,0,0,2,
  0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,
  0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,
  0,0,2,2,0,0,0,0,0,0,0,0,1,1,0,0,
  2,0,2,2,0,0,0,0,0,0,0,0,1,1,0,2,
  2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,
  2,2,2,0,0,0,2,2,2,2,0,0,0,2,2,2
};

uint32_t pixels[S3L_RESOLUTION_X * S3L_RESOLUTION_Y];

uint32_t frame = 0;

void clearScreen()
{
  memset(pixels,0,S3L_RESOLUTION_X * S3L_RESOLUTION_Y * sizeof(uint32_t));
}

static inline void setPixel(int x, int y, uint8_t red, uint8_t green, uint8_t blue)
{
  if (x < 0 || x >= S3L_RESOLUTION_X || y < 0 || y >= S3L_RESOLUTION_Y)
    return;

  uint32_t r = red & 0x000000FF;
  r = r << 24;

  uint32_t g = green & 0x000000FF;
  g = g << 16;

  uint32_t b = blue & 0x000000FF;
  b = b << 8;

  pixels[y * S3L_RESOLUTION_X + x] = r | g | b;
}

uint8_t texturePixel(int32_t u, int32_t v)
{
  u %= 16;
  v %= 16;

  return testTexture[v * 16 + u];
}

void drawPixel(S3L_PixelInfo *p)
{
  if (p->x < 0 || p ->x >= S3L_RESOLUTION_X || p->y < 0 || p->y >= S3L_RESOLUTION_Y)
  {
    offScreenPixels++;
    return;
  }

  S3L_Unit u, v;
  const S3L_Unit *coords;

  coords = tex_coords + p->triangleID * 6;

  u = S3L_interpolateBarycentric(
    0,
    0,
    15,
    p->barycentric0, p->barycentric1, p->barycentric2);

  v = S3L_interpolateBarycentric(
    0,
    15,
    0,
    p->barycentric0, p->barycentric1, p->barycentric2);
/*
  u = S3L_interpolateBarycentric(
    coords[0],
    coords[2],
    coords[4],
    p->barycentric0, p->barycentric1, p->barycentric2);

  v = S3L_interpolateBarycentric(
    coords[1],
    coords[3],
    coords[5],
    p->barycentric0, p->barycentric1, p->barycentric2);
*/
  uint8_t col = texturePixel(u,v);
  uint8_t dep = (p->depth / 5000.0) * 255;

  setPixel(p->x,p->y,col * 120,dep,(2 - col) * 120);

//setPixel(p->x,p->y,sss, (p->triangleID * 37) % 255 ,128);

//setPixel(p->x,p->y,p->modelID * 64,p->modelID * 128,255);

//  setPixel(p->x,p->y,p->barycentric0 / ((float) S3L_FRACTIONS_PER_UNIT) * 255,p->barycentric1 / ((float) S3L_FRACTIONS_PER_UNIT) * 255,p->barycentric2 / ((float) S3L_FRACTIONS_PER_UNIT) * 255);
}

S3L_Transform3D modelTransform;
S3L_DrawConfig conf;

void draw()
{
  S3L_newFrame();

  offScreenPixels = 0;

  clearScreen();

  uint32_t f = frame;

  scene.models[0].transform.rotation.z = f * 0.1;
  scene.models[0].transform.rotation.x = f * 0.3;

  S3L_drawScene(scene);

  if (offScreenPixels > 0)
    printf("offscreen pixels: %d\n",offScreenPixels);
}

int main()
{
  SDL_Window *window = SDL_CreateWindow("test", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, S3L_RESOLUTION_X, S3L_RESOLUTION_Y, SDL_WINDOW_SHOWN); 
  SDL_Renderer *renderer = SDL_CreateRenderer(window,-1,0);
  SDL_Texture *texture = SDL_CreateTexture(renderer,SDL_PIXELFORMAT_RGBX8888, SDL_TEXTUREACCESS_STATIC, S3L_RESOLUTION_X, S3L_RESOLUTION_Y);
  SDL_Surface *screenSurface = SDL_GetWindowSurface(window);
  SDL_Event event;

  S3L_initCamera(&scene.camera);

  scene.camera.transform.translation.z = -S3L_FRACTIONS_PER_UNIT * 2;
  scene.modelCount = 2;
  scene.models = models;

  scene.models[0].vertices = ver;
  scene.models[0].vertexCount = S3L_CUBE_VERTEX_COUNT; 
  scene.models[0].triangles = tri;
  scene.models[0].triangleCount = S3L_CUBE_TRIANGLE_COUNT;
  S3L_initTransoform3D(&(scene.models[0].transform));
  S3L_initDrawConfig(&(scene.models[0].config));
  scene.models[0].transform.translation.x = S3L_FRACTIONS_PER_UNIT;

//  scene.models[1] = scene.models[0];
//  scene.models[1].transform.translation.x = 0.5 * S3L_FRACTIONS_PER_UNIT;

  scene.models[1] = house;
  S3L_initTransoform3D(&(scene.models[1].transform));
  S3L_initDrawConfig(&(scene.models[1].config));
  scene.models[1].transform.translation.y = -1 * S3L_FRACTIONS_PER_UNIT;
  scene.models[1].transform.translation.z = 4 * S3L_FRACTIONS_PER_UNIT;

//  scene.camera.transform.translation.x = S3L_FRACTIONS_PER_UNIT;
//  scene.camera.transform.translation.y = S3L_FRACTIONS_PER_UNIT;

  S3L_initTransoform3D(&modelTransform);
  S3L_initDrawConfig(&conf);

  int running = 1;

  for (int i = 0; i < 256; ++i)
    keys[i] = 0;

  while (running)
  {
    draw();
    SDL_UpdateTexture(texture,NULL,pixels,S3L_RESOLUTION_X * sizeof(uint32_t));

    int code = 0;

    while (SDL_PollEvent(&event))
    {
      switch (event.type)
      {
        case SDL_QUIT:
          running = 0;
          break;

        case SDL_KEYDOWN:
          code = 'a' + event.key.keysym.scancode - SDL_SCANCODE_A;

          if (code >= 0 && code <= 255)
            keys[code] = 1;

          break;

        case SDL_KEYUP:
          code = 'a' + event.key.keysym.scancode - SDL_SCANCODE_A;

          if (code >= 0 && code <= 255)
            keys[code] = 0;

          break;

        default:
          break;
      }
    }

    S3L_Vec4 camF, camR, camU;
    int step = 10;
 
    S3L_rotationToDirections(
      scene.camera.transform.rotation,
      step,
      &camF,
      &camR,
      &camU);

    if (keys['w'])
      S3L_vec3Add(&scene.camera.transform.translation,camF);

    if (keys['s'])
      S3L_vec3Sub(&scene.camera.transform.translation,camF);

    if (keys['d'])
      S3L_vec3Add(&scene.camera.transform.translation,camR);

    if (keys['a'])
      S3L_vec3Sub(&scene.camera.transform.translation,camR);

    if (keys['c'])
      S3L_vec3Add(&scene.camera.transform.translation,camU);

    if (keys['x'])
      S3L_vec3Sub(&scene.camera.transform.translation,camU);

    if (keys['q'])
      scene.camera.transform.rotation.y -= 1;

    if (keys['e'])
      scene.camera.transform.rotation.y += 1;

    if (keys['r'])
      scene.camera.transform.rotation.x -= 1;

    if (keys['t'])
      scene.camera.transform.rotation.x += 1;

    if (keys['f'])
      scene.camera.transform.rotation.z -= 1;

    if (keys['g'])
      scene.camera.transform.rotation.z += 1;

    SDL_RenderClear(renderer);
    SDL_RenderCopy(renderer,texture,NULL,NULL);
    SDL_RenderPresent(renderer);

    frame++;
  }

  return 0;
}