examples/flight/flight.cpp

#include <string>
#include <string.h>
#include <memory>
#include <cstdlib>

#include "graphics/mode7.hpp"


#include "flight.hpp"

using namespace blit;

const uint16_t screen_width = 160;
const uint16_t screen_height = 120;

// extra space allocated to take mipmaps
// mipmaps are stored as Pen since they're the blended result of scaling the paletted image data
uint8_t __sprites[(128 * 128) + (64 * 128 * sizeof(Pen))] __SECTION__(".ss");

// storage for the water spritesheet
uint8_t __water[64 * 64] __SECTION__(".ss");

/* create surfaces */
SpriteSheet *sprites;
SpriteSheet *water;

Map map(Rect(0, 0, 128, 128));

struct object {
  Vec2 pos;
  uint8_t type;

  object(Vec2 pos, uint8_t type) : pos(pos), type(type) {}
};

std::vector<object> objects;

static Vec2 vel(0, 0);
static float angle = -15.0f * (M_PI / 180.0f);
Vec2 pos(512, 512);

float map_size = 128;
float fov = 95.0f * (M_PI / 180.0f);
float far = 500.0f;
float near = 10.0f;

float deg2rad(float a) {
  return a * (M_PI / 180.0f);
}

float rad2deg(float r) {
  return r * (180.0f / M_PI);
}

void init() {
  map.add_layer("ground", layer);
  map.layers["ground"].transforms = layer_transforms;

  // Load our map sprites into the __sprites space we've reserved
  sprites = SpriteSheet::load(packed_data, __sprites);
  sprites->generate_mipmaps(3);

  water = SpriteSheet::load(water_packed_data, __water);

  // extract information about objects from the map data
  Point p;
  for (p.y = 0; p.y < 128; p.y++) {
    for (p.x = 0; p.x < 128; p.x++) {
      int16_t tid = map.layers["ground"].tile_at(p);
      if (tid == 27) {
        objects.emplace_back(
          Vec2(p.x * 8 + 4, p.y * 8 + 4),
          1
        );
      }
      if (tid == 28) {
        objects.emplace_back(
          Vec2(p.x * 8 + 4, p.y * 8 + 4),
          2
        );
      }
      if (tid == 29) {
        objects.emplace_back(
          Vec2(p.x * 8 + 4, p.y * 8 + 4),
          3
        );
      }
      if (tid == 30) {
        objects.emplace_back(
          Vec2(p.x * 8 + 4, p.y * 8 + 4),
          4
        );
      }
    }
  }
}

void render(uint32_t time_ms) {
  static int tick_count = 0; tick_count++;

  screen.alpha = 255;
  screen.mask = nullptr;
  screen.pen = Pen(99, 155, 255);
  screen.rectangle(Rect(0, 0, 160, 50));

  screen.pen = Pen(91, 110, 225);
  screen.rectangle(Rect(0, 50, 160, 120 - 50));
  uint32_t ms_start = now();

  Rect vp(0, 50, 160, 120 - 50);
  
  screen.alpha = 55;

  screen.blit(water, Rect(0, 0, 64, 64), Point(0, 50));

  mode7(&screen, sprites, &map.layers["ground"], fov, angle, pos, near, far, vp);

  for (auto o : objects) {
    Vec2 vo = (o.pos - pos);
    vo.normalize();
    Vec2 forward(0, -1);
    forward *= Mat3::rotation(angle);

    // TODO: provide a "is_point_in_frustrum" check
    if(forward.dot(vo) > 0) { // check if object is in front of us
      Vec2 vs = world_to_screen(o.pos, fov, angle, pos, near, far, vp);
      float dist = (o.pos - pos).length();
      int alpha = ((500 - dist) / 500) * 255;
      screen.alpha = alpha;
      Rect sr(120, 112, 8, 16);
      screen.blit(sprites, sr, vs - Point(4, 15));
    }
  }
  uint32_t ms_end = now();

  // Orientation debug info
  screen.alpha = 255;
  screen.pen = Pen(255, 255, 255);
  screen.text("N: " + std::to_string(int(near)) + " - F:" + std::to_string(int(far)), minimal_font, Rect(0, 0, 100, 10));
  screen.text("X: " + std::to_string(int(pos.x)) + " - Y:" + std::to_string(int(pos.y)), minimal_font, Rect(0, 10, 100, 10));
  screen.text("A: " + std::to_string(int(rad2deg(angle))), minimal_font, Rect(0, 20, 100, 10));

  // draw the mini map
  screen.alpha = 200;
  screen.pen = Pen(0, 0, 0, 100);
  screen.rectangle(Rect(160 - 64, 120 - 64, 64, 64));
  Vec2 mmp;
  for (mmp.y = 0; mmp.y < 64; mmp.y++) {
    for (mmp.x = 0; mmp.x < 64; mmp.x++) {
      Point tp = mmp * 2.0f;
      
      int16_t tile_id = map.layers["ground"].tile_at(tp) - 1;

      if (tile_id != -1) {
        Point sp(
          (tile_id & 0b1111),
          (tile_id / 16)
        ); // sprite sheet coordinates

        Pen *spr = (Pen *)sprites->mipmaps[2]->data;
        Pen *mmv = &spr[sp.x + sp.y * 16];
        screen.pen = *mmv;
        screen.pixel(mmp + Vec2(160 - 64, 120 - 64));
      }
    }
  }
  
  Vec2 mmpos = (pos / 16.0f) + Vec2(160 - 64, 120 - 64);
  screen.pen = Pen(255, 255, 255);
  screen.pixel(mmpos);

  Vec2 mtpos = (Vec2(400, 400) / 16.0f) + Vec2(160 - 64, 120 - 64);
  screen.pen = Pen(0, 255, 255);
  screen.pixel(mtpos);

  Vec2 forward(0, -10);
  forward *= Mat3::rotation(angle);
  screen.pen = Pen(255, 255, 255, 100);
  screen.line(mmpos, mmpos + forward);

  // draw FPS meter
  screen.alpha = 255;
  screen.pen = Pen(255, 255, 255, 100);
  screen.rectangle(Rect(1, 120 - 10, 12, 9));
  screen.pen = Pen(255, 255, 255, 200);
  std::string fms = std::to_string(ms_end - ms_start);
  screen.text(fms, minimal_font, Rect(3, 120 - 9, 10, 16));

  int block_size = 4;
  for (uint32_t i = 0; i < (ms_end - ms_start); i++) {
    screen.pen = Pen(i * 5, 255 - (i * 5), 0);
    screen.rectangle(Rect(i * (block_size + 1) + 1 + 13, screen.bounds.h - block_size - 1, block_size, block_size));
  }
}

void update(uint32_t time) {
  static float angle_delta = 0.0f;

  if (pressed(Button::DPAD_LEFT))  { angle_delta += 0.1f; }
  if (pressed(Button::DPAD_RIGHT)) { angle_delta -= 0.1f; }
  if (pressed(Button::DPAD_UP))    { vel.y += 0.2f; }
  if (pressed(Button::DPAD_DOWN))  { vel.y -= 0.2f; }

  angle += deg2rad(angle_delta);   
  Mat3 r = Mat3::rotation(angle);    
  pos = pos - (vel * r);

  if (pressed(Button::A)) {
    far = far + (far * 0.025f);
  }
  if (pressed(Button::B)) {
    far = far - (far * 0.025f);
  }

  if (pressed(Button::X)) {
    fov = fov + (fov * 0.025f);
  }
  if (pressed(Button::Y)) {
    fov = fov - (fov * 0.025f);
  }

  angle_delta *= 0.95f;
  vel *= 0.95f;

}