asteroids/main.c

#include <stdio.h>
#include <math.h>
#include "raylib.h"
#include "raymath.h"

#define DRAG -0.001f

typedef struct ship_t
{
    Vector2 position;
    Vector2 velocity;
    Vector2 accel;
    Vector2 size;
    float angle;
} ship;

typedef struct game_g
{
    ship s;
    float dt;
} game;

game g;

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

void ship_up(ship *s)
{

    Vector2 min = {.x = 0.0f, .y = 1.0f};
    Vector2 max = {.x = 0.0f, .y = -1.0f};

    float x = cosf(s->angle);
    float y = sinf(s->angle);
    Vector2 polar = CLITERAL(Vector2){.x = x, .y = y};

    s->accel.y -= 0.3f; // * pos.y;
    s->accel = Vector2Clamp(s->accel, min, max);
    
}

void ship_stop(ship *s)
{

    Vector2 min = {.x = 1.0, .y = 1.0};
    Vector2 max = {.x = 0.0, .y = 0.0};
    s->accel.y -= 0.0001f;
    s->accel = Vector2Clamp(s->accel, min, max);

}

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

    s->velocity = Vector2Add(s->velocity, s->accel);
    s->velocity = Vector2Add(s->velocity, drag);

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

    float x = 100 * cosf(s->angle);
    float y = 100 * sinf(s->angle);
    Vector2 polar = CLITERAL(Vector2){.x = x, .y = y};
    // polar = Vector2Normalize(polar);
    Vector2 pos = Vector2Add(s->position, polar);
    // pos = Vector2Normalize(pos);
    // printf("polar (%f,%f)\n", pos.x, pos.y);
    DrawLine(s->position.x, s->position.y, pos.x, pos.y, RED);
}

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;
    }
}

void text(const game *g)
{
    char ind[256] = {0};
    sprintf(ind, "ship position %f\nship speed %f\nship accel %f\nangle: %f\n", g->s.position.y, g->s.velocity.y, g->s.accel.y, g->s.angle);
    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;

    g.s = s1;

    while (!WindowShouldClose())
    {
        BeginDrawing();
        ClearBackground(WHITE);
        process_inputs(&g);
        ship_draw(&g.s);
        ship_update(&g.s);
        text(&g);
        EndDrawing();

        g.dt = GetFrameTime();
    }

    return (0);
}