src/game/level/player/rigid_rect.c

   1 #include <SDL2/SDL.h>
   2 #include <assert.h>
   3 #include <stdio.h>
   4
   5 #include "color.h"
   6 #include "game/level/boxes.h"
   7 #include "game/level/solid.h"
   8 #include "rigid_rect.h"
   9 #include "system/error.h"
  10 #include "system/lt.h"
  11
  12
  13
  14 struct rigid_rect_t {
  15     lt_t *lt;
  16     vec_t position;
  17     vec_t velocity;
  18     vec_t movement;
  19     vec_t size;
  20     color_t color;
  21     int touches_ground;
  22     float floating;
  23     vec_t forces;
  24 };
  25
  26 static const vec_t opposing_rect_side_forces[RECT_SIDE_N] = {
  27     { .x = 1.0f,  .y =  0.0f  },  /* RECT_SIDE_LEFT = 0, */
  28     { .x = -1.0f, .y =  0.0f  },  /* RECT_SIDE_RIGHT, */
  29     { .x = 0.0f,  .y =  1.0f, },  /* RECT_SIDE_TOP, */
  30     { .x = 0.0f,  .y = -1.0f, }   /* RECT_SIDE_BOTTOM, */
  31 };
  32
  33 static vec_t opposing_force_by_sides(int sides[RECT_SIDE_N])
  34 {
  35     vec_t opposing_force = {
  36         .x = 0.0f,
  37         .y = 0.0f
  38     };
  39
  40     for (rect_side_t side = 0; side < RECT_SIDE_N; ++side) {
  41         if (sides[side]) {
  42             vec_add(
  43                 &opposing_force,
  44                 opposing_rect_side_forces[side]);
  45         }
  46     }
  47
  48     return opposing_force;
  49 }
  50
  51 rigid_rect_t *create_rigid_rect(rect_t rect, color_t color)
  52 {
  53     lt_t *lt = create_lt();
  54
  55     if (lt == NULL) {
  56         return NULL;
  57     }
  58
  59     rigid_rect_t *rigid_rect = PUSH_LT(lt, malloc(sizeof(rigid_rect_t)), free);
  60     if (rigid_rect == NULL) {
  61         throw_error(ERROR_TYPE_LIBC);
  62         RETURN_LT(lt, NULL);
  63     }
  64
  65     rigid_rect->lt = lt;
  66     rigid_rect->position = vec(rect.x, rect.y);
  67     rigid_rect->velocity = vec(0.0f, 0.0f);
  68     rigid_rect->movement = vec(0.0f, 0.0f);
  69     rigid_rect->size = vec(rect.w, rect.h);
  70     rigid_rect->color = color;
  71     rigid_rect->touches_ground = 0;
  72     rigid_rect->floating = 0.0f;
  73
  74     return rigid_rect;
  75 }
  76
  77 rigid_rect_t *create_rigid_rect_from_stream(FILE *stream)
  78 {
  79     assert(stream);
  80
  81     char color[7];
  82     rect_t rect;
  83
  84     if (fscanf(stream, "%f%f%f%f%6s\n",
  85                &rect.x, &rect.y,
  86                &rect.w, &rect.h,
  87                color) < 0) {
  88         throw_error(ERROR_TYPE_LIBC);
  89         return NULL;
  90     }
  91
  92     return create_rigid_rect(rect, color_from_hexstr(color));
  93 }
  94
  95 void destroy_rigid_rect(rigid_rect_t *rigid_rect)
  96 {
  97     RETURN_LT0(rigid_rect->lt);
  98 }
  99
 100 solid_ref_t rigid_rect_as_solid(rigid_rect_t *rigid_rect)
 101 {
 102     const solid_ref_t ref = {
 103         .tag = SOLID_RIGID_RECT,
 104         .ptr = rigid_rect
 105     };
 106
 107     return ref;
 108 }
 109
 110 void rigid_rect_touches_rect_sides(rigid_rect_t *rigid_rect,
 111                                    rect_t object,
 112                                    int sides[RECT_SIDE_N])
 113 {
 114     rect_object_impact(object, rigid_rect_hitbox(rigid_rect), sides);
 115 }
 116
 117 int rigid_rect_render(const rigid_rect_t *rigid_rect,
 118                       const camera_t *camera)
 119 {
 120     return camera_fill_rect(
 121         camera,
 122         rigid_rect_hitbox(rigid_rect),
 123         rigid_rect->color);
 124
 125 }
 126
 127 int rigid_rect_update(rigid_rect_t * rigid_rect,
 128                       float delta_time)
 129 {
 130     assert(rigid_rect);
 131
 132     rigid_rect->touches_ground = 0;
 133
 134     /* TODO(#207): rigid_rect floating in lava is broken */
 135     rigid_rect->velocity = vec_sum(
 136         rigid_rect->velocity,
 137         vec_scala_mult(
 138             rigid_rect->forces,
 139             delta_time));
 140
 141     rigid_rect->position = vec_sum(
 142         rigid_rect->position,
 143         vec_scala_mult(
 144             vec_sum(
 145                 rigid_rect->velocity,
 146                 rigid_rect->movement),
 147             delta_time));
 148
 149     rigid_rect->forces = vec(0.0f, 0.0f);
 150
 151     return 0;
 152 }
 153
 154 void rigid_rect_collide_with_solid(rigid_rect_t * rigid_rect,
 155                                    solid_ref_t solid)
 156 {
 157     assert(rigid_rect);
 158     assert(rigid_rect != solid.ptr);
 159
 160     int sides[RECT_SIDE_N] = { 0, 0, 0, 0 };
 161
 162     solid_touches_rect_sides(solid, rigid_rect_hitbox(rigid_rect), sides);
 163
 164     if (sides[RECT_SIDE_BOTTOM]) {
 165         rigid_rect->touches_ground = 1;
 166     }
 167
 168     vec_t opposing_force = opposing_force_by_sides(sides);
 169
 170     for (int i = 0; i < 1000 && vec_length(opposing_force) > 1e-6; ++i) {
 171         rigid_rect->position = vec_sum(
 172             rigid_rect->position,
 173             vec_scala_mult(
 174                 opposing_force,
 175                 1e-2f));
 176
 177         if (fabs(opposing_force.x) > 1e-6 && (opposing_force.x < 0.0f) != ((rigid_rect->velocity.x + rigid_rect->movement.x) < 0.0f)) {
 178             rigid_rect->velocity.x = 0.0f;
 179             rigid_rect->movement.x = 0.0f;
 180         }
 181
 182         if (fabs(opposing_force.y) > 1e-6 && (opposing_force.y < 0.0f) != ((rigid_rect->velocity.y + rigid_rect->movement.y) < 0.0f)) {
 183             rigid_rect->velocity.y = 0.0f;
 184             rigid_rect->movement.y = 0.0f;
 185         }
 186
 187         memset(sides, 0, sizeof(int) * RECT_SIDE_N);
 188         solid_touches_rect_sides(
 189             solid,
 190             rigid_rect_hitbox(rigid_rect),
 191             sides);
 192         opposing_force = opposing_force_by_sides(sides);
 193     }
 194 }
 195
 196 rect_t rigid_rect_hitbox(const rigid_rect_t *rigid_rect)
 197 {
 198     return rect_from_vecs(
 199         rigid_rect->position,
 200         rigid_rect->size);
 201 }
 202
 203 void rigid_rect_move(rigid_rect_t *rigid_rect,
 204                            vec_t movement)
 205 {
 206     rigid_rect->movement = movement;
 207 }
 208
 209 int rigid_rect_touches_ground(const rigid_rect_t *rigid_rect)
 210 {
 211     return rigid_rect->touches_ground;
 212 }
 213
 214 void rigid_rect_collide_with_lava(rigid_rect_t *rigid_rect,
 215                                   lava_t *lava)
 216 {
 217     assert(rigid_rect);
 218     assert(lava);
 219
 220     rect_t overlap_area = lava_overlap_area(lava, rigid_rect_hitbox(rigid_rect));
 221     rigid_rect->floating = (overlap_area.w * overlap_area.h) / (rigid_rect->size.x * rigid_rect->size.y);
 222 }
 223
 224 void rigid_rect_apply_force(rigid_rect_t * rigid_rect,
 225                             vec_t force)
 226 {
 227     rigid_rect->forces = vec_sum(rigid_rect->forces, force);
 228 }
 229
 230 void rigid_rect_transform_velocity(rigid_rect_t *rigid_rect,
 231                                    mat3x3 trans_mat)
 232 {
 233     rigid_rect->velocity = point_mat3x3_product(rigid_rect->velocity,
 234                                                 trans_mat);
 235 }