git.itanic.dy.fi Git - sdl-planets/blob - camera.c

   1 #include <stdio.h>
   2
   3 #include "camera.h"
   4
   5 void init_camera(struct camera *cam)
   6 {
   7         cam->pos.x   = cam->pos.y   = 0;
   8         cam->speed.x = cam->speed.y = 0;
   9         cam->zoom = 1;
  10         cam->zoom_rate = 1;
  11 }
  12
  13 void move_camera(struct camera *cam, const double time)
  14 {
  15         struct vector tmp;
  16
  17         vector_scale(&cam->speed, time / cam->zoom, &tmp);
  18         vector_add(&cam->pos, &tmp, &cam->pos);
  19
  20         cam->zoom *= pow(cam->zoom_rate, time);
  21 }
  22
  23 void print_camera(const struct camera *cam)
  24 {
  25         printf("cam pos (%.2f, %.2f), speed (%.2f, %.2f), zoom (%.2f, %.2f)\n",
  26                cam->pos.x, cam->pos.y, cam->speed.x, cam->speed.y,
  27                cam->zoom, cam->zoom_rate);
  28 }