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     rigid_rect->forces = vec(0.0f, 0.0f);
  74
  75     return rigid_rect;
  76 }
  77
  78 rigid_rect_t *create_rigid_rect_from_stream(FILE *stream)
  79 {
  80     assert(stream);
  81
  82     char color[7];
  83     rect_t rect;
  84
  85     if (fscanf(stream, "%f%f%f%f%6s\n",
  86                &rect.x, &rect.y,
  87                &rect.w, &rect.h,
  88                color) < 0) {
  89         throw_error(ERROR_TYPE_LIBC);
  90         return NULL;
  91     }
  92
  93     return create_rigid_rect(rect, color_from_hexstr(color));
  94 }
  95
  96 void destroy_rigid_rect(rigid_rect_t *rigid_rect)
  97 {
  98     RETURN_LT0(rigid_rect->lt);
  99 }
 100
 101 solid_ref_t rigid_rect_as_solid(rigid_rect_t *rigid_rect)
 102 {
 103     const solid_ref_t ref = {
 104         .tag = SOLID_RIGID_RECT,
 105         .ptr = rigid_rect
 106     };
 107
 108     return ref;
 109 }
 110
 111 void rigid_rect_touches_rect_sides(rigid_rect_t *rigid_rect,
 112                                    rect_t object,
 113                                    int sides[RECT_SIDE_N])
 114 {
 115     rect_object_impact(object, rigid_rect_hitbox(rigid_rect), sides);
 116 }
 117
 118 int rigid_rect_render(const rigid_rect_t *rigid_rect,
 119                       camera_t *camera)
 120 {
 121     return camera_fill_rect(
 122         camera,
 123         rigid_rect_hitbox(rigid_rect),
 124         rigid_rect->color);
 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 opforce_direction = opposing_force_by_sides(sides);
 169
 170     solid_apply_force(
 171         solid,
 172         vec_scala_mult(
 173             vec_neg(vec_norm(opforce_direction)),
 174             vec_length(
 175                 vec_sum(
 176                     rigid_rect->velocity,
 177                     rigid_rect->movement)) * 8.0f));
 178
 179     if (fabs(opforce_direction.x) > 1e-6 && (opforce_direction.x < 0.0f) != ((rigid_rect->velocity.x + rigid_rect->movement.x) < 0.0f)) {
 180         rigid_rect->velocity.x = 0.0f;
 181         rigid_rect->movement.x = 0.0f;
 182     }
 183
 184     if (fabs(opforce_direction.y) > 1e-6 && (opforce_direction.y < 0.0f) != ((rigid_rect->velocity.y + rigid_rect->movement.y) < 0.0f)) {
 185         rigid_rect->velocity.y = 0.0f;
 186         rigid_rect->movement.y = 0.0f;
 187
 188         if (vec_length(rigid_rect->velocity) > 1e-6) {
 189             rigid_rect_apply_force(
 190                 rigid_rect,
 191                 vec_scala_mult(
 192                     vec_neg(rigid_rect->velocity),
 193                     16.0f));
 194         }
 195     }
 196
 197
 198     for (int i = 0; i < 1000 && vec_length(opforce_direction) > 1e-6; ++i) {
 199         rigid_rect->position = vec_sum(
 200             rigid_rect->position,
 201             vec_scala_mult(
 202                 opforce_direction,
 203                 1e-2f));
 204
 205         memset(sides, 0, sizeof(int) * RECT_SIDE_N);
 206         solid_touches_rect_sides(
 207             solid,
 208             rigid_rect_hitbox(rigid_rect),
 209             sides);
 210         opforce_direction = opposing_force_by_sides(sides);
 211     }
 212 }
 213
 214 rect_t rigid_rect_hitbox(const rigid_rect_t *rigid_rect)
 215 {
 216     return rect_from_vecs(
 217         rigid_rect->position,
 218         rigid_rect->size);
 219 }
 220
 221 void rigid_rect_move(rigid_rect_t *rigid_rect,
 222                            vec_t movement)
 223 {
 224     rigid_rect->movement = movement;
 225 }
 226
 227 int rigid_rect_touches_ground(const rigid_rect_t *rigid_rect)
 228 {
 229     return rigid_rect->touches_ground;
 230 }
 231
 232 void rigid_rect_collide_with_lava(rigid_rect_t *rigid_rect,
 233                                   lava_t *lava)
 234 {
 235     assert(rigid_rect);
 236     assert(lava);
 237
 238     rect_t overlap_area = lava_overlap_area(lava, rigid_rect_hitbox(rigid_rect));
 239     rigid_rect->floating = (overlap_area.w * overlap_area.h) / (rigid_rect->size.x * rigid_rect->size.y);
 240 }
 241
 242 void rigid_rect_apply_force(rigid_rect_t * rigid_rect,
 243                             vec_t force)
 244 {
 245     rigid_rect->forces = vec_sum(rigid_rect->forces, force);
 246 }
 247
 248 void rigid_rect_transform_velocity(rigid_rect_t *rigid_rect,
 249                                    mat3x3 trans_mat)
 250 {
 251     rigid_rect->velocity = point_mat3x3_product(rigid_rect->velocity,
 252                                                 trans_mat);
 253 }