src/dying_rect.c

   1 #include <assert.h>
   2 #include <SDL2/SDL.h>
   3
   4 #include "./lt.h"
   5 #include "./error.h"
   6 #include "./dying_rect.h"
   7
   8 struct dying_rect_t
   9 {
  10     lt_t *lt;
  11
  12     vec_t position;
  13     vec_t size;
  14     color_t color;
  15     Uint32 duration;
  16     Uint32 time_passed;
  17 };
  18
  19 dying_rect_t *create_dying_rect(rect_t rect,
  20                                 color_t color,
  21                                 Uint32 duration)
  22 {
  23     lt_t *lt = create_lt();
  24     if (lt == NULL) {
  25         return NULL;
  26     }
  27
  28     dying_rect_t *dying_rect = PUSH_LT(lt, malloc(sizeof(dying_rect_t)), free);
  29     if (dying_rect == NULL) {
  30         throw_error(ERROR_TYPE_LIBC);
  31         RETURN_LT(lt, NULL);
  32     }
  33
  34     dying_rect->lt = lt;
  35     dying_rect->position = vec(rect.x, rect.y);
  36     dying_rect->size = vec(rect.w, rect.h);
  37     dying_rect->color = color;
  38     dying_rect->duration = duration;
  39     dying_rect->time_passed = 0;
  40
  41     return dying_rect;
  42 }
  43
  44 void destroy_dying_rect(dying_rect_t *dying_rect)
  45 {
  46     assert(dying_rect);
  47     RETURN_LT0(dying_rect->lt);
  48 }
  49
  50 /* TODO(#109): Dying Rect animation is too boring */
  51 int dying_rect_render(const dying_rect_t *dying_rect,
  52                       SDL_Renderer *renderer,
  53                       const camera_t *camera)
  54 {
  55     assert(dying_rect);
  56     assert(renderer);
  57     assert(camera);
  58
  59     const float scale = 1.0f - (float) dying_rect->time_passed / (float) dying_rect->duration;
  60     const vec_t center = vec_sum(
  61         dying_rect->position,
  62         vec_scala_mult(
  63             dying_rect->size,
  64             0.5f));
  65     const vec_t scaled_size =
  66         vec_scala_mult(dying_rect->size, scale);
  67     const vec_t scaled_position =
  68         vec_sum(center, vec_scala_mult(scaled_size, -0.5f));
  69
  70     return camera_fill_rect(
  71         camera,
  72         renderer,
  73         rect_from_vecs(scaled_position, scaled_size),
  74         dying_rect->color);
  75 }
  76
  77 int dying_rect_update(dying_rect_t *dying_rect,
  78                       Uint32 delta_time)
  79 {
  80     assert(dying_rect);
  81     assert(delta_time > 0);
  82
  83     if (!dying_rect_is_dead(dying_rect)) {
  84         dying_rect->time_passed = dying_rect->time_passed + delta_time;
  85     }
  86
  87     return 0;
  88 }
  89
  90 int dying_rect_is_dead(const dying_rect_t *dying_rect)
  91 {
  92     assert(dying_rect);
  93     return dying_rect->time_passed >= dying_rect->duration;
  94 }