Completed smarter pathfinding for agressive monsters (#75)

Monsters acting agressive will now path to the player using the A*
algorithm.

Re-did how the project source files are added to the executable.

Author: LiquidityC

CMakeLists.txt

@@ -199,69 +199,6 @@ else ()
 	set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -D__FNAME__=__FILE__")
 endif ()
 
-# PROGRAMS:
-add_executable(breakhack
-	src/main.c
-	src/texture.c
-	src/screenresolution.c
-	src/sprite.c
-	src/sprite_util.c
-	src/util.c
-	src/event.c
-	src/player.c
-	src/save.c
-	src/map.c
-	src/map_lua.c
-	src/camera.c
-	src/timer.c
-	src/roommatrix.c
-	src/position.c
-	src/monster.c
-	src/stats.c
-	src/actiontext.c
-	src/random.c
-	src/time.c
-	src/linkedlist.c
-	src/hashtable.c
-	src/gui.c
-	src/item.c
-	src/item_builder.c
-	src/pointer.c
-	src/gui_button.c
-	src/particle_engine.c
-	src/particle_emitter.c
-	src/menu.c
-	src/collisions.c
-	src/keyboard.c
-	src/input.c
-	src/mixer.c
-	src/io_util.c
-	src/physfsrwops.c
-	src/skillbar.c
-	src/texturecache.c
-	src/skill.c
-	src/projectile.c
-	src/vector2d.c
-	src/map_room_modifiers.c
-	lib/sqlite3/sqlite3.c
-	src/db.c
-	src/settings.c
-	src/actiontextbuilder.c
-	src/animation.c
-	src/trap.c
-	src/artifact.c
-	src/screen.c
-	src/hiscore.c
-	src/object.c
-	src/gui_util.c
-	src/tooltip.c
-	src/tooltip_manager.c
-	src/gamecontroller.c
-	src/effect_util.c
-	${STEAM_SOURCES}
-	)
-set_property(TARGET breakhack PROPERTY C_STANDARD 99)
-
 set(INCLUDE_DIRS
 	${PROJECT_BINARY_DIR}
 	${SDL_INCLUDE_DIR}
@@ -274,11 +211,15 @@ set(INCLUDE_DIRS
 	lib/bh_random/src
 	lib/checksum/src
 )
-
-target_include_directories(breakhack PRIVATE ${INCLUDE_DIRS})
+# PROGRAMS:
+add_executable(${PROJECT_NAME})
+add_subdirectory(src)
+add_subdirectory(lib/sqlite3)
+set_property(TARGET ${PROJECT_NAME} PROPERTY C_STANDARD 99)
+target_include_directories(${PROJECT_NAME} PRIVATE ${INCLUDE_DIRS})
 
 if (NOT MSVC)
-	set_target_properties(breakhack PROPERTIES COMPILE_FLAGS
+	set_target_properties(${PROJECT_NAME} PROPERTIES COMPILE_FLAGS
 		-std=gnu11 -pedantic -Wall -Wextra -Wshadow
 		-Wpointer-arith -Wcast-qual -Wstrict-prototypes
 		-Wmissing-prototypes -Wconversion -Wno-sign-conversion
@@ -297,7 +238,7 @@ endif ()
 # Sqlite has some warnings that I we don't need to see
 set_source_files_properties(lib/sqlite3/sqlite3.c COMPILE_FLAGS -w)
 
-target_link_libraries(breakhack
+target_link_libraries(${PROJECT_NAME}
 	${CMAKE_DL_LIBS} # Sqlite needs DL libs
 	${SDL_LIBRARY}
 	${SDL_IMAGE_LIBRARY}
@@ -310,19 +251,19 @@ target_link_libraries(breakhack
 	)
 
 if (STEAM)
-	target_link_libraries(breakhack
+	target_link_libraries(${PROJECT_NAME}
 		${STEAMWORKS_LIBRARY}
 		steamworks_c_wrapper
 		)
 endif ()
 
 if (MSVC)
-	set_target_properties(breakhack PROPERTIES LINK_FLAGS_DEBUG "/SUBSYSTEM:CONSOLE /NODEFAULTLIB:MSVCRTD")
-	set_target_properties(breakhack PROPERTIES COMPILE_DEFINITIONS_DEBUG "_CONSOLE")
-	set_target_properties(breakhack PROPERTIES LINK_FLAGS_RELWITHDEBINFO "/SUBSYSTEM:CONSOLE")
-	set_target_properties(breakhack PROPERTIES COMPILE_DEFINITIONS_RELWITHDEBINFO "_CONSOLE")
-	set_target_properties(breakhack PROPERTIES LINK_FLAGS_RELEASE "/SUBSYSTEM:WINDOWS /NODEFAULTLIB:MSVCRTD")
-	set_target_properties(breakhack PROPERTIES LINK_FLAGS_MINSIZEREL "/SUBSYSTEM:WINDOWS")
+	set_target_properties(${PROJECT_NAME} PROPERTIES LINK_FLAGS_DEBUG "/SUBSYSTEM:CONSOLE /NODEFAULTLIB:MSVCRTD")
+	set_target_properties(${PROJECT_NAME} PROPERTIES COMPILE_DEFINITIONS_DEBUG "_CONSOLE")
+	set_target_properties(${PROJECT_NAME} PROPERTIES LINK_FLAGS_RELWITHDEBINFO "/SUBSYSTEM:CONSOLE")
+	set_target_properties(${PROJECT_NAME} PROPERTIES COMPILE_DEFINITIONS_RELWITHDEBINFO "_CONSOLE")
+	set_target_properties(${PROJECT_NAME} PROPERTIES LINK_FLAGS_RELEASE "/SUBSYSTEM:WINDOWS /NODEFAULTLIB:MSVCRTD")
+	set_target_properties(${PROJECT_NAME} PROPERTIES LINK_FLAGS_MINSIZEREL "/SUBSYSTEM:WINDOWS")
 endif (MSVC)
 
 # TESTS:
@@ -344,6 +285,11 @@ IF (CMOCKA_FOUND AND NOT OSX AND NOT CLANG)
 	target_link_libraries(test_hashtable ${CMOCKA_LIBRARY})
 	add_test(test_hashtable test_hashtable)
 
+	add_executable(test_pos_heap test/test_pos_heap.c src/pos_heap.c src/util.c)
+	target_include_directories(test_pos_heap PRIVATE ${INCLUDE_DIRS})
+	target_link_libraries(test_pos_heap ${CMOCKA_LIBRARY})
+	add_test(test_pos_heap test_pos_heap)
+
 	add_executable(test_input test/test_input.c src/input.c src/keyboard.c)
 	target_include_directories(test_input PRIVATE ${INCLUDE_DIRS})
 	target_link_libraries(test_input
@@ -413,7 +359,7 @@ endif ()
 include(InstallRequiredSystemLibraries)
 
 if (NOT STEAM)
-	INSTALL(TARGETS breakhack
+	INSTALL(TARGETS ${PROJECT_NAME}
 		COMPONENT Release
 		RUNTIME DESTINATION bin/
 	)
@@ -422,7 +368,7 @@ if (NOT STEAM)
 		DESTINATION share/breakhack/
 	)
 else ()
-	INSTALL(TARGETS breakhack
+	INSTALL(TARGETS ${PROJECT_NAME}
 		COMPONENT Release
 		RUNTIME DESTINATION .
 	)
@@ -432,7 +378,7 @@ else ()
 	)
 endif ()
 
-set(CPACK_INSTALL_CMAKE_PROJECTS "${PROJECT_BINARY_DIR};breakhack;Release;.")
+set(CPACK_INSTALL_CMAKE_PROJECTS "${PROJECT_BINARY_DIR};${PROJECT_NAME};Release;.")
 set(CPACK_PACKAGE_NAME "BreakHack")
 set(CPACK_PACKAGE_VENDOR "OliveShark")
 set(CPACK_PACKAGE_DESCRIPTION_FILE "${CMAKE_CURRENT_SOURCE_DIR}/README.md")
@@ -444,9 +390,9 @@ set(CPACK_PACKAGE_VERSION_PATCH ${breakhack_PATCH_VERSION})
 set(CPACK_PACKAGE_INSTALL_DIRECTORY "BreakHack")
 set(CPACK_PACKAGE_CHECKSUM "MD5")
 if (WIN32)
-	set(CPACK_PACKAGE_FILE_NAME "breakhack-${CPACK_PACKAGE_VERSION_MAJOR}.${CPACK_PACKAGE_VERSION_MINOR}.${CPACK_PACKAGE_VERSION_PATCH}-win32")
+	set(CPACK_PACKAGE_FILE_NAME "${PROJECT_NAME}-${CPACK_PACKAGE_VERSION_MAJOR}.${CPACK_PACKAGE_VERSION_MINOR}.${CPACK_PACKAGE_VERSION_PATCH}-win32")
 else ()
-	set(CPACK_PACKAGE_FILE_NAME "breakhack-${CPACK_PACKAGE_VERSION_MAJOR}.${CPACK_PACKAGE_VERSION_MINOR}.${CPACK_PACKAGE_VERSION_PATCH}")
+	set(CPACK_PACKAGE_FILE_NAME "${PROJECT_NAME}-${CPACK_PACKAGE_VERSION_MAJOR}.${CPACK_PACKAGE_VERSION_MINOR}.${CPACK_PACKAGE_VERSION_PATCH}")
 endif ()
 if (STEAM)
 	set(CPACK_INCLUDE_TOPLEVEL_DIRECTORY OFF)
@@ -455,7 +401,7 @@ endif ()
 
 if(UNIX)
 	set(CPACK_GENERATOR TGZ ZIP)
-	set(CPACK_STRIP_FILES breakhack)
+	set(CPACK_STRIP_FILES ${PROJECT_NAME})
 	set(CPACK_SOURCE_STRIP_FILES "")
 elseif(WIN32)
 	set(CPACK_NSIS_ENABLE_UNINSTALL_BEFORE_INSTALL ON)

lib/sqlite3/CMakeLists.txt

@@ -0,0 +1,3 @@
+file(GLOB_RECURSE SOURCE_FILES CONFIGURE_DEPENDS *.c)
+
+target_sources(${PROJECT_NAME} PRIVATE ${SOURCE_FILES})

src/CMakeLists.txt

@@ -0,0 +1,7 @@
+file(GLOB SOURCE_FILES CONFIGURE_DEPENDS *.c)
+
+if (STEAM)
+	file(GLOB SOURCE_FILES CONFIGURE_DEPENDS steam/*.c)
+endif ()
+
+target_sources(${PROJECT_NAME} PRIVATE ${SOURCE_FILES})

src/defines.h

@@ -92,7 +92,7 @@ typedef int64_t		Sint64;
 typedef uint64_t	Uint64;
 
 typedef enum Direction_t {
-	UP, DOWN, LEFT, RIGHT
+	UP, DOWN, LEFT, RIGHT, INVALID
 } Direction;
 
 typedef enum GameMode {

src/monster.c

@@ -37,6 +37,7 @@
 #include "trap.h"
 #include "object.h"
 #include "mixer.h"
+#include "pos_heap.h"
 
 static void
 monster_set_sprite_clip_for_current_state(Monster *m)
@@ -371,67 +372,117 @@ monster_drunk_walk(Monster *m, RoomMatrix *rm)
 	}
 }
 
+/**
+ * \brief Get the first move in the provided path
+ */
+static Direction
+find_first_in_path(const Position *from, const Position *dest, const Position *start)
+{
+	Position current = *dest;
+	Position next = *dest;
+	while (!position_equals(&next, start)) {
+		current = next;
+		next = from[current.x + current.y * MAP_ROOM_WIDTH];
+	}
+
+	Vector2d dir = { current.x - next.x, current.y - next.y };
+	if (dir.x > 0)
+		return RIGHT;
+	else if (dir.x < 0)
+		return LEFT;
+	else if (dir.y > 0)
+		return DOWN;
+	else
+		return UP;
+}
+
+/* Manhattan distance */
+#define MDIST(p1, p2) abs(p1.x - p2.x) + abs(p1.y - p2.y)
+
+/**
+ * \brief A* path finding algorithm
+ *
+ * This is a basic A* algorithm implementation usinga heap for the open_set.
+ * The pathing will avoid dangerous, lethal and blocked tiles but not tiles
+ * with monsters on so there can still be some stacking there.
+ */
 static Direction
-get_optimal_move_towards(Monster *m, RoomMatrix *rm, const Position *dest)
+get_optimal_move_towards(Monster *m, RoomMatrix *rm, const Position dest)
 {
+	Direction ret_val = INVALID;
 	int x_dist, y_dist;
-	Position mPos;
+	const Position start = position_to_matrix_coords(&m->sprite->pos);
+	const Vector2d directions[] = {
+		VECTOR2D_UP,
+		VECTOR2D_DOWN,
+		VECTOR2D_LEFT,
+		VECTOR2D_RIGHT,
+	};
 
-	mPos = position_to_matrix_coords(&m->sprite->pos);
+	PHeap open_set;
 
-	unsigned int currentScore = 100;
-	unsigned int chosenDirection = UP;
-
-	for (unsigned int i = 0; i < 4; ++i) {
-		Position next = mPos;
-		unsigned int nextScore = 0;
-
-		switch (i) {
-			case UP:
-				next.y -= 1;
-				break;
-			case DOWN:
-				next.y += 1;
-				break;
-			case LEFT:
-				next.x -= 1;
-				break;
-			case RIGHT:
-				next.x += 1;
-				break;
-		}
+	uint16_t gScore[MAP_ROOM_WIDTH * MAP_ROOM_HEIGHT];
+	uint16_t fScore[MAP_ROOM_WIDTH * MAP_ROOM_HEIGHT];
 
-		if (position_equals(&next, dest)) {
-			chosenDirection = (Direction) i;
-			break;
-		}
+	memset(gScore, 0xFF, sizeof(gScore));
+	memset(fScore, 0xFF, sizeof(fScore));
+
+	Position from[MAP_ROOM_WIDTH * MAP_ROOM_HEIGHT];
+	bool visited[MAP_ROOM_WIDTH * MAP_ROOM_HEIGHT] = { false };
+	const size_t WIDTH = MAP_ROOM_WIDTH;
 
-		if (!position_in_roommatrix(&next))
-			continue;
+	/* Pre-allocate all the space we'll need and add start node */
+	pheap_init(&open_set, MAP_ROOM_WIDTH * MAP_ROOM_HEIGHT);
+	pheap_insert(&open_set, start, MDIST(start, dest));
+	visited[start.x + start.y * WIDTH] = true;
 
-		x_dist = abs(next.x - dest->x);
-		y_dist = abs(next.y - dest->y);
+	gScore[start.x + start.y * WIDTH] = 0;
+	fScore[start.x + start.y * WIDTH] = MDIST(start, dest);
 
-		if (rm->spaces[next.x][next.y].occupied
-		    || rm->spaces[next.x][next.y].lethal
-		    || rm->spaces[next.x][next.y].trap) {
-			nextScore += 50;
+	while (open_set.size > 0) {
+		Position current = pheap_pop(&open_set);
+		if (position_equals(&current, &dest)) {
+			ret_val = find_first_in_path(from, &dest, &start);
+			goto out;
 		}
 
-		nextScore += x_dist > y_dist ? x_dist : y_dist;
-		if (nextScore < currentScore) {
-			currentScore = nextScore;
-			chosenDirection = (Direction) i;
+		for (size_t i = 0; i < 4; i++) {
+			Position next = {
+				current.x + directions[i].x,
+				current.y + directions[i].y,
+			};
+
+			if (!position_equals(&next, &dest)) {
+				if (!position_in_roommatrix(&next)
+				    || rm->spaces[next.x][next.y].occupied
+				    || rm->spaces[next.x][next.y].lethal
+				    || rm->spaces[next.x][next.y].trap) {
+					continue;
+				}
+			}
+
+			uint32_t temp_score = 1 + gScore[current.x + current.y * WIDTH];
+			if (temp_score < gScore[next.x + next.y * WIDTH]) {
+				from[next.x + next.y * WIDTH] = current;
+				gScore[next.x + next.y * WIDTH] = temp_score;
+				fScore[next.x + next.y * WIDTH] = temp_score + MDIST(next, dest);
+				if (!visited[next.x + next.y * WIDTH]) {
+					visited[next.x + next.y * WIDTH] = true;
+					pheap_insert(&open_set, next, fScore[next.x + next.y * WIDTH]);
+				}
+			}
 		}
 	}
 
-	return chosenDirection;
+out:
+	pheap_destroy(&open_set);
+	return ret_val;
 }
 
 static void
 monster_agressive_walk(Monster *m, RoomMatrix *rm)
 {
-	unsigned int chosenDirection = get_optimal_move_towards(m, rm, &rm->playerRoomPos);
+	unsigned int chosenDirection = get_optimal_move_towards(m, rm, rm->playerRoomPos);
 
 	switch (chosenDirection) {
 		case UP:
@@ -446,6 +497,9 @@ monster_agressive_walk(Monster *m, RoomMatrix *rm)
 		case RIGHT:
 			move(m, rm, VECTOR2D_RIGHT);
 			break;
+		case INVALID:
+		default:
+			break;
 	}
 }