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authorPaul Duncan <pabs@pablotron.org>2019-01-20 10:27:10 -0500
committerPaul Duncan <pabs@pablotron.org>2019-01-20 10:27:10 -0500
commit4b5af8da20f2e35e6cd81a4e7418767e6964e8bc (patch)
tree73729f3c5e07fbd0ee71392b7a9ae843e9f49a61 /src/core
parent2e5ad7027daa0d10453640a617b53fdde4542929 (diff)
downloadsok-4b5af8da20f2e35e6cd81a4e7418767e6964e8bc.tar.bz2
sok-4b5af8da20f2e35e6cd81a4e7418767e6964e8bc.zip
solve: check for corners
Diffstat (limited to 'src/core')
-rw-r--r--src/core/sok-ctx.c163
-rw-r--r--src/core/sok-solve.c13
-rw-r--r--src/core/sok.h4
3 files changed, 85 insertions, 95 deletions
diff --git a/src/core/sok-ctx.c b/src/core/sok-ctx.c
index e278af1..036bf66 100644
--- a/src/core/sok-ctx.c
+++ b/src/core/sok-ctx.c
@@ -183,6 +183,52 @@ pos_find(
return len;
}
+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
+tile_is_corner(
+ const sok_ctx_t * const ctx,
+ const sok_pos_t pos
+) {
+ // right
+ const bool r = ctx_is_wall(ctx, (sok_pos_t) {
+ .x = pos.x + 1,
+ .y = pos.y,
+ });
+
+ // top
+ const bool t = ctx_is_wall(ctx, (sok_pos_t) {
+ .x = pos.x,
+ .y = pos.y - 1,
+ });
+
+ // left
+ const bool l = ctx_is_wall(ctx, (sok_pos_t) {
+ .x = pos.x - 1,
+ .y = pos.y,
+ });
+
+ // bottom
+ const bool b = ctx_is_wall(ctx, (sok_pos_t) {
+ .x = pos.x,
+ .y = pos.y + 1,
+ });
+
+ return (
+ (t && r) || // top-right
+ (t && l) || // top-left
+ (b && l) || // bottom-left
+ (b && r) // bottom-right
+ );
+}
+
static size_t
sok_ctx_count_goals_left(
sok_ctx_t * const ctx
@@ -201,73 +247,29 @@ sok_ctx_count_goals_left(
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;
- * }
- */
+static bool
+sok_ctx_box_is_stuck(
+ const sok_ctx_t * const ctx,
+ const size_t i
+) {
+ return (
+ !tile_is_goal(ctx, ctx->boxes[i]) &&
+ tile_is_corner(ctx, ctx->boxes[i])
+ );
+}
+
+static bool
+sok_ctx_has_stuck_boxes(
+ const sok_ctx_t * const ctx
+) {
+ for (size_t i = 0; i < ctx->level.num_boxes; i++) {
+ if (sok_ctx_box_is_stuck(ctx, i)) {
+ return true;
+ }
+ }
+
+ return false;
+}
void
sok_ctx_init(sok_ctx_t * const ctx, void *user_data) {
@@ -301,7 +303,7 @@ sok_ctx_set_level(
// 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);
+ ctx->is_lost = sok_ctx_has_stuck_boxes(ctx);
// return success
return true;
@@ -329,15 +331,6 @@ tile_is_box(
}
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,
@@ -390,7 +383,7 @@ sok_ctx_move_box(
// 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);
+ ctx->is_lost = sok_ctx_has_stuck_boxes(ctx);
// return success
return true;
@@ -407,14 +400,12 @@ sok_ctx_is_done(
return ctx->num_goals_left == 0;
}
-/*
- * bool
- * sok_ctx_is_lost(
- * const sok_ctx_t * const ctx
- * ) {
- * return ctx->is_lost;
- * }
- */
+bool
+sok_ctx_is_lost(
+ const sok_ctx_t * const ctx
+) {
+ return ctx->is_lost;
+}
bool
sok_ctx_move(
diff --git a/src/core/sok-solve.c b/src/core/sok-solve.c
index 45d227c..0d4e500 100644
--- a/src/core/sok-solve.c
+++ b/src/core/sok-solve.c
@@ -36,13 +36,12 @@ sok_solve_step(
// return failure
return false;
}
-/*
- * // make sure level is solvable
- * if (sok_ctx_is_lost(ctx)) {
- * // return failure
- * return false;
- * }
- */
+
+ // make sure level is solvable
+ if (sok_ctx_is_lost(ctx)) {
+ // return failure
+ return false;
+ }
for (size_t dir = 0; dir < SOK_DIR_LAST; dir++) {
if (!sok_ctx_move(ctx, dir)) {
diff --git a/src/core/sok.h b/src/core/sok.h
index 92fb4e7..d24d22b 100644
--- a/src/core/sok.h
+++ b/src/core/sok.h
@@ -132,7 +132,7 @@ typedef struct {
size_t num_goals_left;
// are there boxes in corners?
- // _Bool is_lost;
+ _Bool is_lost;
// player position
sok_pos_t home;
@@ -149,7 +149,7 @@ void sok_ctx_init(sok_ctx_t * const ctx, void *user_data);
_Bool sok_ctx_set_level(sok_ctx_t * const ctx, const char * const level);
_Bool sok_ctx_is_done(const sok_ctx_t * const);
-// _Bool sok_ctx_is_lost(const sok_ctx_t * const);
+_Bool sok_ctx_is_lost(const sok_ctx_t * const);
_Bool sok_ctx_move(sok_ctx_t * const, const sok_dir_t);
_Bool sok_ctx_undo(sok_ctx_t * const);