s/libsok/core/g

1 files changed, 636 insertions, 0 deletions

diff --git a/src/core/sok-ctx.c b/src/core/sok-ctx.c
new file mode 100644
index 0000000..e278af1
--- /dev/null
+++ b/src/core/sok-ctx.c
@@ -0,0 +1,636 @@
+#include <stdbool.h>
+#include <string.h> // memset()
+#include "sok.h"
+
+#define UNUSED(a) ((void) (a))
+
+#define VALID_POS(pos) ( \
+  (pos).x < SOK_LEVEL_MAX_WIDTH && \
+  (pos).y < SOK_LEVEL_MAX_HEIGHT \
+)
+
+#define POINTS_EQUAL(a, b) ( \
+  ((a).x == (b).x) && \
+  ((a).y == (b).y) \
+)
+
+static bool
+ctx_is_wall(
+  const sok_ctx_t * const ctx,
+  const sok_pos_t pos
+) {
+  return ctx->level.walls[pos.y * ctx->level.size.x + pos.x];
+}
+
+static void
+ctx_set_wall(
+  sok_ctx_t * const ctx,
+  const sok_pos_t pos
+) {
+  ctx->level.walls[pos.y * ctx->level.size.x + pos.x] = true;
+}
+
+static void
+ctx_clear_walls(
+  sok_ctx_t * const ctx
+) {
+  memset(ctx->level.walls, 0, SOK_LEVEL_MAX_WIDTH * SOK_LEVEL_MAX_HEIGHT);
+}
+
+static bool
+on_size(
+  const sok_level_parser_t * const parser,
+  const sok_pos_t pos
+) {
+  sok_ctx_t *ctx = (sok_ctx_t*) parser->user_data;
+
+  if (!VALID_POS(pos)) {
+    // size out of bounds
+    return false;
+  }
+
+  // save width and height
+  ctx->level.size = pos;
+
+  // return success
+  return true;
+}
+
+static bool
+on_home(
+  const sok_level_parser_t * const parser,
+  const sok_pos_t pos
+) {
+  sok_ctx_t *ctx = (sok_ctx_t*) parser->user_data;
+
+  if (!VALID_POS(pos)) {
+    // position out of bounds
+    return false;
+  }
+
+  // save start position
+  ctx->level.home = pos;
+
+  // return success
+  return true;
+}
+
+static bool
+on_wall(
+  const sok_level_parser_t * const parser,
+  const sok_pos_t pos
+) {
+  sok_ctx_t *ctx = (sok_ctx_t*) parser->user_data;
+
+  if (!VALID_POS(pos)) {
+    // position out of bounds
+    return false;
+  }
+
+  // save wall
+  ctx_set_wall(ctx, pos);
+
+  // return sucess
+  return true;
+}
+
+static bool
+on_goal(
+  const sok_level_parser_t * const parser,
+  const sok_pos_t pos
+) {
+  sok_ctx_t *ctx = (sok_ctx_t*) parser->user_data;
+
+  if (!VALID_POS(pos)) {
+    // position out of bounds
+    return false;
+  }
+
+  if (ctx->level.num_goals >= SOK_LEVEL_MAX_GOALS - 1) {
+    // too many goals
+    return false;
+  }
+
+  // save goal
+  ctx->level.goals[ctx->level.num_goals++] = pos;
+
+  // return sucess
+  return true;
+}
+
+static bool
+on_box(
+  const sok_level_parser_t * const parser,
+  const sok_pos_t pos
+) {
+  sok_ctx_t *ctx = (sok_ctx_t*) parser->user_data;
+
+  if (!VALID_POS(pos)) {
+    // position out of bounds
+    return false;
+  }
+
+  if (ctx->level.num_boxes >= SOK_LEVEL_MAX_BOXES - 1) {
+    // too many boxes
+    return false;
+  }
+
+  // save box
+  ctx->level.boxes[ctx->level.num_boxes++] = pos;
+
+  // return sucess
+  return true;
+}
+
+static bool
+on_junk(
+  const sok_level_parser_t * const parser,
+  const size_t ofs,
+  const char tile
+) {
+  UNUSED(parser);
+  UNUSED(ofs);
+  UNUSED(tile);
+
+  // TODO
+
+  // return sucess
+  return true;
+}
+
+static const sok_level_parser_cbs_t
+LEVEL_PARSER_CBS = {
+  .on_size = on_size,
+  .on_home = on_home,
+  .on_wall = on_wall,
+  .on_goal = on_goal,
+  .on_box  = on_box,
+  .on_junk = on_junk,
+};
+
+static size_t
+pos_find(
+  const sok_pos_t pos,
+  const sok_pos_t * const set,
+  const size_t len
+) {
+  for (size_t i = 0; i < len; i++) {
+    if (POINTS_EQUAL(pos, set[i])) {
+      return i;
+    }
+  }
+
+  return len;
+}
+
+static size_t
+sok_ctx_count_goals_left(
+  sok_ctx_t * const ctx
+) {
+  const size_t num_boxes = ctx->level.num_boxes;
+  size_t r = 0;
+
+  for (size_t i = 0; i < ctx->level.num_goals; i++) {
+    r += pos_find(
+      ctx->level.goals[i],
+      ctx->boxes,
+      num_boxes
+    ) < num_boxes ? 0 : 1;
+  }
+
+  return r;
+}
+
+/*
+ * static bool
+ * sok_ctx_has_corner_boxes(
+ *   const sok_ctx_t * const ctx
+ * ) {
+ *   for (size_t i = 0; i < ctx->level.num_boxes; i++) {
+ *     // right
+ *     const bool r = ctx_is_wall(ctx, (sok_pos_t) {
+ *       .x = ctx->boxes[i].x + 1,
+ *       .y = ctx->boxes[i].y,
+ *     });
+ *
+ *     // top-right
+ *     const bool tr = ctx_is_wall(ctx, (sok_pos_t) {
+ *       .x = ctx->boxes[i].x + 1,
+ *       .y = ctx->boxes[i].y - 1,
+ *     });
+ *
+ *     // top
+ *     const bool t = ctx_is_wall(ctx, (sok_pos_t) {
+ *       .x = ctx->boxes[i].x,
+ *       .y = ctx->boxes[i].y - 1,
+ *     });
+ *
+ *     // top-left
+ *     const bool tl = ctx_is_wall(ctx, (sok_pos_t) {
+ *       .x = ctx->boxes[i].x - 1,
+ *       .y = ctx->boxes[i].y - 1,
+ *     });
+ *
+ *     // left
+ *     const bool l = ctx_is_wall(ctx, (sok_pos_t) {
+ *       .x = ctx->boxes[i].x - 1,
+ *       .y = ctx->boxes[i].y,
+ *     });
+ *
+ *     // bottom-left
+ *     const bool bl = ctx_is_wall(ctx, (sok_pos_t) {
+ *       .x = ctx->boxes[i].x - 1,
+ *       .y = ctx->boxes[i].y + 1,
+ *     });
+ *
+ *     // bottom
+ *     const bool b = ctx_is_wall(ctx, (sok_pos_t) {
+ *       .x = ctx->boxes[i].x,
+ *       .y = ctx->boxes[i].y + 1,
+ *     });
+ *
+ *     const bool br = ctx_is_wall(ctx, (sok_pos_t) {
+ *       .x = ctx->boxes[i].x + 1,
+ *       .y = ctx->boxes[i].y + 1,
+ *     });
+ *
+ *     if (
+ *       (r && tr && t) || // top-right
+ *       (t && tl && l) || // top-left
+ *       (l && bl && b) || // bottom-left
+ *       (b && br && r)    // bottom-right
+ *     ) {
+ *       // return
+ *       return true;
+ *     }
+ *   }
+ *
+ *   return false;
+ * }
+ */
+
+void
+sok_ctx_init(sok_ctx_t * const ctx, void *user_data) {
+  memset(ctx, 0, sizeof(sok_ctx_t));
+  ctx->user_data = user_data;
+}
+
+bool
+sok_ctx_set_level(
+  sok_ctx_t * const ctx,
+  const char * const str
+) {
+
+  // clear level
+  ctx->level.num_goals = 0;
+  ctx->level.num_boxes = 0;
+  ctx_clear_walls(ctx);
+
+  // parse level
+  sok_level_parser_t parser;
+  sok_level_parser_init(&parser, &LEVEL_PARSER_CBS, ctx);
+  if (!sok_level_parser_parse(&parser, str, strlen(str))) {
+    // return failure
+    return false;
+  }
+
+  // init moves, player, and boxes
+  ctx->num_moves = 0;
+  ctx->home = ctx->level.home;
+  memcpy(ctx->boxes, ctx->level.boxes, ctx->level.num_boxes * sizeof(sok_pos_t));
+
+  // count number of goals left and check whether there are
+  ctx->num_goals_left = sok_ctx_count_goals_left(ctx);
+  // ctx->is_lost = sok_ctx_is_lost(ctx);
+
+  // return success
+  return true;
+}
+
+static bool
+tile_is_floor(
+  const sok_ctx_t * const ctx,
+  const sok_pos_t pos
+) {
+  return (
+    (pos.x < SOK_LEVEL_MAX_WIDTH - 1) &&
+    (pos.y < SOK_LEVEL_MAX_HEIGHT - 1) &&
+    !ctx_is_wall(ctx, pos)
+  );
+}
+
+static bool
+tile_is_box(
+  const sok_ctx_t * const ctx,
+  const sok_pos_t pos
+) {
+  const size_t num_boxes = ctx->level.num_boxes;
+  return pos_find(pos, ctx->boxes, num_boxes) < num_boxes;
+}
+
+static bool
+tile_is_goal(
+  const sok_ctx_t * const ctx,
+  const sok_pos_t pos
+) {
+  const size_t num_goals = ctx->level.num_goals;
+  return pos_find(pos, ctx->level.goals, num_goals) < num_goals;
+}
+
+static bool
+sok_ctx_push_move(
+  sok_ctx_t * const ctx,
+  const sok_dir_t dir,
+  const bool is_push
+) {
+  if (ctx->num_moves >= SOK_CTX_MAX_MOVES - 1) {
+    return false;
+  }
+
+  ctx->moves[ctx->num_moves].pos = ctx->home;
+  ctx->moves[ctx->num_moves].dir = dir;
+  ctx->moves[ctx->num_moves].is_push = is_push;
+  ctx->num_moves++;
+
+  return true;
+}
+
+static bool
+sok_ctx_pop_move(
+  sok_ctx_t * const ctx,
+  sok_move_t * const ret
+) {
+  if (!ctx->num_moves) {
+    // return failure
+    return false;
+  }
+
+  // decriment moves
+  ctx->num_moves--;
+
+  if (ret) {
+    // save popped move
+    *ret = ctx->moves[ctx->num_moves];
+  }
+
+  // return success
+  return true;
+}
+
+static bool
+sok_ctx_move_box(
+  sok_ctx_t * const ctx,
+  const sok_pos_t old_pos,
+  const sok_pos_t new_pos
+) {
+  const size_t num_boxes = ctx->level.num_boxes,
+               box_ofs = pos_find(old_pos, ctx->boxes, num_boxes);
+
+  if (box_ofs < num_boxes) {
+    // update box and goal count
+    ctx->boxes[box_ofs] = new_pos;
+    ctx->num_goals_left = sok_ctx_count_goals_left(ctx);
+    // ctx->is_lost = sok_ctx_has_corner_boxes(ctx);
+
+    // return success
+    return true;
+  }
+
+  // return failure
+  return false;
+}
+
+bool
+sok_ctx_is_done(
+  const sok_ctx_t * const ctx
+) {
+  return ctx->num_goals_left == 0;
+}
+
+/*
+ * bool
+ * sok_ctx_is_lost(
+ *   const sok_ctx_t * const ctx
+ * ) {
+ *   return ctx->is_lost;
+ * }
+ */
+
+bool
+sok_ctx_move(
+  sok_ctx_t * const ctx,
+  const sok_dir_t dir
+) {
+  if (ctx->num_moves >= SOK_CTX_MAX_MOVES - 1) {
+    // no more move slots available
+    return false;
+  }
+
+  const sok_pos_t ps[2] = {{
+    .x = ctx->home.x + ((dir == SOK_DIR_LEFT) ? -1 : ((dir == SOK_DIR_RIGHT) ? 1 : 0)),
+    .y = ctx->home.y + ((dir == SOK_DIR_UP) ? -1 : ((dir == SOK_DIR_DOWN) ? 1 : 0))
+  }, {
+    .x = ctx->home.x + ((dir == SOK_DIR_LEFT) ? -2 : ((dir == SOK_DIR_RIGHT) ? 2 : 0)),
+    .y = ctx->home.y + ((dir == SOK_DIR_UP) ? -2 : ((dir == SOK_DIR_DOWN) ? 2 : 0))
+  }};
+
+  const bool can_move = (
+    (dir == SOK_DIR_UP) ? (ctx->home.y > 0) :
+    ((dir == SOK_DIR_DOWN) ? (ctx->home.y < SOK_LEVEL_MAX_HEIGHT - 1) :
+    ((dir == SOK_DIR_LEFT) ? (ctx->home.x > 0) :
+    ((dir == SOK_DIR_RIGHT) ? (ctx->home.x < SOK_LEVEL_MAX_WIDTH - 1) :
+    false
+  ))));
+
+  const bool can_push = (
+    (dir == SOK_DIR_UP) ? (ctx->home.y > 1) :
+    ((dir == SOK_DIR_DOWN) ? (ctx->home.y < SOK_LEVEL_MAX_HEIGHT - 2) :
+    ((dir == SOK_DIR_LEFT) ? (ctx->home.x > 1) :
+    ((dir == SOK_DIR_RIGHT) ? (ctx->home.x < SOK_LEVEL_MAX_WIDTH - 2) :
+    false
+  ))));
+
+  if (
+    can_move &&
+    tile_is_floor(ctx, ps[0]) &&
+    !tile_is_box(ctx, ps[0])
+  ) {
+    // push move
+    if (!sok_ctx_push_move(ctx, dir, false)) {
+      return false;
+    }
+
+    // update position
+    ctx->home.x += (dir == SOK_DIR_LEFT) ? -1 : ((dir == SOK_DIR_RIGHT) ? 1 : 0);
+    ctx->home.y += (dir == SOK_DIR_UP) ? -1 : ((dir == SOK_DIR_DOWN) ? 1 : 0);
+
+    // return success
+    return true;
+  } else if (
+    can_push &&
+    tile_is_floor(ctx, ps[0]) &&
+    tile_is_box(ctx, ps[0]) &&
+    tile_is_floor(ctx, ps[1]) &&
+    !tile_is_box(ctx, ps[1])
+  ) {
+    // push move
+    if (!sok_ctx_push_move(ctx, dir, true)) {
+      return false;
+    }
+
+    // move box
+    if (!sok_ctx_move_box(ctx, ps[0], ps[1])) {
+      return false;
+    }
+
+    // update position
+    ctx->home.x += (dir == SOK_DIR_LEFT) ? -1 : ((dir == SOK_DIR_RIGHT) ? 1 : 0);
+    ctx->home.y += (dir == SOK_DIR_UP) ? -1 : ((dir == SOK_DIR_DOWN) ? 1 : 0);
+
+
+    // return success
+    return true;
+  }
+
+  // return failure
+  return false;
+}
+
+bool
+sok_ctx_undo(
+  sok_ctx_t * const ctx
+) {
+  sok_move_t move;
+  if (!sok_ctx_pop_move(ctx, &move)) {
+    // return failure
+    return false;
+  }
+
+  if (move.is_push) {
+    const sok_pos_t box_pos = {
+      .x = move.pos.x + ((move.dir == SOK_DIR_LEFT) ? -2 : ((move.dir == SOK_DIR_RIGHT) ? 2 : 0)),
+      .y = move.pos.y + ((move.dir == SOK_DIR_UP) ? -2 : ((move.dir == SOK_DIR_DOWN) ? 2 : 0)),
+    };
+
+    sok_ctx_move_box(ctx, box_pos, ctx->home);
+  }
+
+  // update position
+  ctx->home = move.pos;
+
+  // return success
+  return true;
+}
+
+bool sok_ctx_walk(
+  const sok_ctx_t * const ctx,
+  const sok_ctx_walk_cbs_t * const cbs,
+  void * const data
+) {
+  if (!cbs) {
+    return false;
+  }
+
+  if (cbs->on_size) {
+    // emit size
+    if (!cbs->on_size(ctx, ctx->level.size, data)) {
+      return false;
+    }
+  }
+
+  if (cbs->on_walls_start && !cbs->on_walls_start(ctx, data)) {
+    return false;
+  }
+
+  if (cbs->on_wall) {
+    // walk walls
+    for (size_t i = 0; i < (ctx->level.size.x * ctx->level.size.y); i++) {
+      const sok_pos_t pos = {
+        .y = i / ctx->level.size.x,
+        .x = i % ctx->level.size.x,
+      };
+
+      if (ctx_is_wall(ctx, pos)) {
+        // emit wall
+        if (!cbs->on_wall(ctx, pos, data)) {
+          return false;
+        }
+      }
+    }
+  }
+
+  if (cbs->on_walls_end && !cbs->on_walls_end(ctx, data)) {
+    return false;
+  }
+
+  if (cbs->on_goals_start && !cbs->on_goals_start(ctx, data)) {
+    return false;
+  }
+
+  if (cbs->on_goal) {
+    // walk goals
+    for (size_t i = 0; i < ctx->level.num_goals; i++) {
+      const bool has_player = POINTS_EQUAL(ctx->level.goals[i], ctx->home);
+      const bool has_box = tile_is_box(ctx, ctx->level.goals[i]);
+
+      // emit goal
+      if (!cbs->on_goal(ctx, ctx->level.goals[i], has_player, has_box, data)) {
+        return false;
+      }
+    }
+  }
+
+  if (cbs->on_goals_end && !cbs->on_goals_end(ctx, data)) {
+    return false;
+  }
+
+  if (cbs->on_boxes_start && !cbs->on_boxes_start(ctx, data)) {
+    return false;
+  }
+
+  if (cbs->on_home) {
+    const bool has_goal = tile_is_goal(ctx, ctx->home);
+
+    // emit home
+    if (!cbs->on_home(ctx, ctx->home, has_goal, data)) {
+      return false;
+    }
+  }
+
+  if (cbs->on_box) {
+    // walk boxes
+    for (size_t i = 0; i < ctx->level.num_boxes; i++) {
+      const bool has_goal = tile_is_goal(ctx, ctx->boxes[i]);
+
+      // emit box
+      if (!cbs->on_box(ctx, ctx->boxes[i], has_goal, data)) {
+        return false;
+      }
+    }
+  }
+
+  if (cbs->on_boxes_end && !cbs->on_boxes_end(ctx, data)) {
+    return false;
+  }
+
+  if (cbs->on_moves_start && !cbs->on_moves_start(ctx, data)) {
+    return false;
+  }
+
+  if (cbs->on_move) {
+    // walk moves
+    for (size_t i = 0; i < ctx->num_moves; i++) {
+      // emit move
+      if (!cbs->on_move(ctx, ctx->moves[i], data)) {
+        return false;
+      }
+    }
+  }
+
+  if (cbs->on_moves_end && !cbs->on_moves_end(ctx, data)) {
+    return false;
+  }
+
+  // return success
+  return true;
+}