asteroids/main.c

#include <math.h>
#include <raylib.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>

#include "bullet.h"
#include "game.h"
#include "ship.h"

#define DRAG -0.001f

void ship_draw(const ship* s)
{
  DrawRectangleV(s->position, s->size, BLACK);
}

void ship_up(ship* s)
{
  Vector2 min = { .x = -1000.0F, .y = -1000.0F };
  Vector2 max = { .x = 1000.0F, .y = 1000.0F };

  Vector2 diff = Vector2Subtract(s->direction, s->position);

  Vector2 accellv = CLITERAL(Vector2){ .x = diff.x, .y = diff.y };
  s->accel = Vector2Add(accellv, s->accel);

  s->accel = Vector2Clamp(s->accel, min, max);
}

void ship_stop(ship* s)
{
  Vector2 min = { .x = 1.0F, .y = 1.0F };
  Vector2 max = { .x = 0.0F, .y = 0.0F };
  s->accel.y -= 0.0001F;
  s->accel.x -= 0.0001F;
  s->accel = Vector2Clamp(s->accel, min, max);
}

void ship_update(game* g, ship* s)
{
  Vector2 drag = { .x = DRAG * s->velocity.x, .y = DRAG * s->velocity.y };

  float x = cosf(s->angle);
  float y = sinf(s->angle);

  Vector2 polar = CLITERAL(Vector2){ .x = x, .y = y };
  Vector2 pos = Vector2Add(s->position, polar);

  float x1 = 100 * cosf(s->angle);
  float y1 = 100 * sinf(s->angle);

  Vector2 polar1 = CLITERAL(Vector2){ .x = x1, .y = y1 };
  Vector2 pos1 = Vector2Add(s->position, polar1);

  s->direction.x = pos.x;
  s->direction.y = pos.y;

  s->velocity.x += s->accel.x * g->dt;
  s->velocity.y += s->accel.y * g->dt;
  s->velocity = Vector2Add(s->velocity, drag);

  s->position.x += s->velocity.x * g->dt;
  s->position.y += s->velocity.y * g->dt;

  DrawLine(s->position.x, s->position.y, pos1.x, pos1.y, RED);
}

void ship_fire(game* g, ship* s)
{
  // Vector2 min = { .x = -300.0f, .y = -300.0f };
  // Vector2 max = { .x = 300.0f, .y = 300.0f };
  if (g->bullets_fired >= MAX_BULLETS) {
    g->bullets_fired = 0;
    // g->active_bullets -= 1;
  }
  float current_fire = GetFrameTime();
  float allowed_fire = 0.0002;
  if (current_fire > allowed_fire) {
    Vector2 diff = Vector2Subtract(s->direction, s->position);

    Vector2 accellv = CLITERAL(Vector2){ .x = diff.x, .y = diff.y };
    g->bullets[g->bullets_fired].accel
      = Vector2Zero();  // Vector2Scale(diff,3000);//Vector2Add(accellv, s->accel);

    g->bullets[g->bullets_fired].position = s->position;
    g->bullets[g->bullets_fired].radius = 5.0F;
    g->bullets[g->bullets_fired].velocity = Vector2Scale(diff, 3000);
    g->bullets[g->bullets_fired].active = true;

    g->bullets_fired++;
    g->active_bullets += 1;
    g->last_fire = GetFrameTime();
  }
}

void bullets_draw(game* g, bullet* b)
{
  if (b->active) {
    DrawCircle(b->position.x, b->position.y, b->radius, RED);
  }
}

void bullets_update(game* g, bullet* b)
{
  if (b->active) {
    b->velocity.x += b->accel.x * g->dt;
    b->velocity.y += b->accel.y * g->dt;

    b->position.x += b->velocity.x * g->dt;
    b->position.y += b->velocity.y * g->dt;

    b->velocity = Vector2ClampValue(b->velocity, -3000, 3000);

    if (b->position.x > (GetScreenWidth() - b->radius)
        || b->position.y > (GetScreenHeight() - b->radius)) {
      b->active = false;
      g->active_bullets -= 1;
    }

    if (b->position.x < b->radius || b->position.y < b->radius) {
      b->active = false;
      g->active_bullets -= 1;
    }

    // DrawLine(g->s.position.x, g->s.position.y, b->direction.x, b->direction.y, GREEN);
  }
}

void process_inputs(game* g)
{
  if (IsKeyDown(KEY_W)) {
    ship_up(&g->s);
  } else {
    ship_stop(&g->s);
  }
  if (IsKeyDown(KEY_D)) {
    g->s.angle += 1.0F * g->dt;
  }
  if (IsKeyDown(KEY_A)) {
    g->s.angle -= 1.0F * g->dt;
  }

  if (IsKeyDown(KEY_SPACE)) {
    ship_fire(g, &g->s);
  }
}

void text(const game* g)
{
  char ind[256] = { 0 };
  sprintf(ind,
          "ship position %fx%f\nship speed %fx%f\nship accel %fx%f\nangle: "
          "%f\ndirection %fx%f\nbullets fired %zu\nactive bullets %zu",
          g->s.position.x, g->s.position.y, g->s.velocity.x, g->s.velocity.y, g->s.accel.x,
          g->s.accel.y, g->s.angle, g->s.direction.x, g->s.direction.y, g->bullets_fired,
          g->active_bullets);
  DrawText(ind, 10, 10, 20, BLACK);
}

int main(void)
{
  InitWindow(1820, 900, "Hello World");

  ship s1 = { 0 };
  s1.position.x = 910.0F;
  s1.position.y = 450.0F;

  s1.size.x = 10.0F;
  s1.size.y = 10.0F;
  s1.angle = 3 * PI / 2;

  game g;
  g.s = s1;

  memset(g.bullets, 0, MAX_BULLETS);

  while (!WindowShouldClose()) {
    BeginDrawing();
    ClearBackground(WHITE);

    for (size_t i = 0; i < MAX_BULLETS; i++) {
      bullets_draw(&g, &g.bullets[i]);
      bullets_update(&g, &g.bullets[i]);
    }

    ship_draw(&g.s);
    ship_update(&g, &g.s);
    text(&g);
    process_inputs(&g);
    EndDrawing();

    g.dt = GetFrameTime();
  }

  return (0);
}