Game Python Postgres with Sound
Introduction
In this part, we continue building a game with Python and Postgres with Sound as part 7 of a multi-part series of lessons where the final result will be a simple 2D graphical top-down-view videogame somewhat like PacMan in that the goal is to acquire powerups while avoiding monsters. We are using Python’s “Arcade” library for its gaming-related functions and methods. We used Postgres to read and write screen and object (player, enemies, obstacles, and power-ups) data. In this lesson we will add sound to give the game more life. In future lessons in this series, we will add various graphics, a “save game” feature, multi-player, and even a screen editor/builder.
Prerequisites
See part 1 through 6, where we learned how to draw a screen, create tables in Postgres for storing and reading screen data and screen objects as Sprites, reading keys to control player movement, added random movements to the monsters, collision detection, and a bit of intelligent player tracking to the monsters. Please study the previous parts of this lesson, starting at Build game with Python and draw a screen.
We will assume you followed the previous parts of this series, we’ll leave out creating the Postgres tables and re-doing the details of setting up a window with Arcade, except in the source code at the bottom of this part seven. So, before the final code at the bottom, we’ll briefly go over some of what we covered in previous parts of the overall lesson.
Random Sprite movement
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | random_compass = random.randint(1, 8) if random_compass == 1: y += 2 if random_compass == 2: x += 2 y += 2 if random_compass == 3: x += 2 if random_compass == 4: x += 2 y -= 2 if random_compass == 5: y -= 2 if random_compass == 6: y -= 2 x -= 2 if random_compass == 7: x -= 2 if random_compass == 8: x -= 2 |
Intelligent Sprite movement
1 2 3 4 5 6 7 8 | if player_y > monster_y: monster_y += 2 if player_x > monster_x: monster_x += 2 if player_y < monster_y: monster_y -= 2 if player_x < monster_x: monster_x -= 2 |
The code above code compares the location cooredinates of the player with the position of a monster. If the monster is above the player, the monster’s “monster_y” value is incremented.
Arcade Sounds with Python
1 | arcade.play_sound("soundfile.mp3") |
Full source code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 | import arcade import psycopg2 import random from flask import Flask from flask import render_template # connect to database t_host = "PostgreSQL database host address" t_port = "5432" t_dbname = "database name" t_user = "database user name" t_pw = "password" db_conn = psycopg2.connect(host=t_host, port=t_port, dbname=t_dbname, user=t_user, password=t_pw) db_cursor = db_conn.cursor() # initialize globals id_screen = 0 t_title = "" i_width = 0 i_height = 0 t_color = "" i_enemy_hit = 0 i_hit_points = 100 i_points = 0 i_lives = 3 t_hit_sound = [] @app.route("/main") def getScreenFromDB(): # Get columns for first row/ # screen using "select top 1" s = "" s += "SELECT TOP 1" s += " id" s += ", t_color" s += ", t_title" s += ", i_height" s += ", i_width" s += " FROM tbl_screens" s += " ORDER BY i_order ASCENDING" try: db_cursor.execute(s) id_screen = db_cursor.fetch("id") t_color_screen = db_cursor.fetch("t_color") t_title = db_cursor.fetch("t_title") i_height = db_cursor.fetch("i_height") i_width = db_cursor.fetch("i_width") except psycopg2.Error as e: t_msg = "SQL error: " + e + "/n SQL: " + s return render_template("error.html", t_msg = t_msg) db_cursor.close def getObjectsFromDB(): # Get objects data from tbl_screens_objects in Postgres s = "" s += "SELECT" s += " id" s += ", t_obj_name" s += ", t_obj_type" s += ", t_obj_img_URL" s += ", i_y" s += ", i_x" s += ", t_color_hit" s += ", t_properties" s += ", t_hit_sound" s += ", t_hit_action" s += ", b_hit_possible" s += ", b_hit_destroys_it" s += ", b_hit_awards" s += ", n_hit_awards" s += ", n_hit_damage" s += " FROM tbl_screens_objects" s += " WHERE (" s += " id_screen = " + id_screen s += ")" s += " ORDER BY i_order" try: db_cursor.execute(s) return db_cursor except psycopg2.Error as e: t_msg = "SQL error: " + e + "/n SQL: " + s return render_template("error.html", t_msg = t_msg) class gameWindow(arcade.Window): def__init__(self, i_width, i_height, t_title, db_cursor): super().__init__(width, height, title, resizable=false) self.set_location(100, 100) # Give our window a background color. arcade.set_background_color(arcade.color.t_color_screen) self.player_x = 100 self.player_y = 200 self.player_speed = 250 self.right = false self.left = false self.up = false self.down = false # Initialize a spritelist to track objects like walls. # This type of object only stops player motion. self.ListSpriteObjects = arcade.SpriteList() # Initialize a spritelist to track monsters/enemies. # These objects cause damage to i_hit_points. self.ListSpriteEnemies = arcade.SpriteList() # Initialize a spritelist to track powerups. # These objects give points to the player when a collision occurs. self.ListSpritePowerUps = arcade.SpriteList() # Get data from the database into the 3 lists above. i = 0 for each db_row in db_cursor: id_screen = db_row.fetch("id") t_obj_name.append(db_row.fetch("t_obj_name")) t_obj_type.append(db_row.fetch("t_obj_type")) t_obj_img_URL = db_row.fetch("t_obj_img_URL") i_y = db_row.fetch("i_y") i_x = db_row.fetch("i_x") t_properties.append(db_row.fetch("t_properties")) t_color_hit.append(db_row.fetch("t_color_hit")) # Notice the slightly different syntax here: # Instead of placing the value from the database straight into our array via append, # we are setting each t_hit_sound item (matched to corresponding object) # to be an actual sound object to be played later in our code below. t_hit_sound.append(arcade.load_sound(db_row.fetch("t_hit_sound"))) t_hit_action.append(db_row.fetch("t_hit_action")) b_hit_possible.append(db_row.fetch("b_hit_possible")) b_hit_destroys_it.append(db_row.fetch("b_hit_destroys_it")) b_hit_awards.append(db_row.fetch("b_hit_awards")) n_hit_awards.append(db_row.fetch("n_hit_awards")) n_hit_damage.append(db_row.fetch("n_hit_damage")) # draw the current sprite in db_row if t_object_type == "obstacle": self.SpriteObject = arcade.Sprite(t_object_image_URL, i_x, i_y) # add current obstacle to growing list of Sprites (SpriteList) self.ListSpriteObjects.append(self.SpriteObject) elif t_object_type == "enemy": self.SpriteObstacle = arcade.Sprite(t_object_image_URL, i_x, i_y) # add current enemy (sprite) to growing list of Sprites (SpriteList) self.SpriteEnemies.append(self.SpriteObject) elif t_object_type == "powerup": self.SpriteObstacle = arcade.Sprite(t_object_image_URL, i_x, i_y) # add current PowerUp to growing list of Sprites (SpriteList) self.SpritePowerUps.append(self.SpriteObject) elif t_object_type == "Player": self.SpritePlayer = arcade.Sprite(t_object_image_URL, i_x, i_y) # increment the counter i += 1 def enemyMovement(): # Iterate through enemy sprites. # In this case, there are only 2 enemies but we designed this so # you can add as many as you want to add to the database. # THEN we give them a random direction out of eight # possible directions. # FINALLY we add our new-for-this-part "intelligent" direction to # the random one. for currentSprite in self.ListSpriteEnemies: x = currentSprite.position[0] y = currentSprite.position[1] # Random movement direction = random.randint(1, 8) if direction == 1: y += 2 if direction == 2: x += 2 y += 2 if direction == 3: x += 2 if direction == 4: x += 2 y -= 2 if direction == 5: y -= 2 if direction == 6: y -= 2 x -= 2 if direction == 7: x -= 2 if direction == 8: x -= 2 y += 2 # NEW "intelligent" movement. if player_y > y: y += 2 if player_x > x: x += 2 if player_y < y: y -= 2 if player_x < x: x -= 2 # Set the current monster's location on screen. currentSprite.set_position(x, y) def on_draw(self): self.SpritePlayer.draw() self.ListSpriteObjects.draw() self.ListSpriteEnemies.draw() self.ListSpritePowerUps.draw() def on_update(self, delta_time): # Delta_time is last time the # same function was used; We use this # to scale movement speed with speed of processing. if self.right = true: self.player_x += self.player_speed * delta_time if self.left = true: self.player_x -= self.player_speed * delta_time if self.up = true: self.player_y += self.player_speed * delta_time if self.down = true: self.player_y -= self.player_speed * delta_time # Set a new location based on the player's x and y coordinates: self.SpritePlayer.set_position(self.player_x, self.player_y) # Move all enemy Sprites. enemyMovement() # Update Sprite Lists: self.ListSpriteObjects.update() self.ListSpriteEnemies.update() self.ListSpritePowerUps.update() # Did the user hit a monster? i = 0 for SpriteEnemy in self.ListSpriteEnemies: b_collision = arcade.check_for_collision(SpriteEnemy, self.SpritePlayer) if b_collision == true: i_enemy_hit = i i_hit_points -= n_hit_damage[i_enemy_hit] # Graphical changes (like explosion or something) code # to show crash will go here in later lesson. # NEW: arcade.play_sound(t_hit_sound[i]) if i_hit_points < 1: i_lives -= 1 if i_lives < 1: # Dead - Next part we will build code to handle this. # For now, the player lives forever. i_hit_points = 100 i +=1 # Did the user run into a power-up? i = 0 for SpritePowerUp in self.ListSpritePowerUps: b_collision = arcade.check_for_collision(SpritePowerUp, self.SpritePlayer) if b_collision == true: i_pu_hit = i i_points += n_hit_awards[i_pu_hit] # Graphics and code to show # powerup hit will go here. # NEW: arcade.play_sound(t_hit_sound[i]) i +=1 # Did the user collide with another type of obstacle? i = 0 for SpritePowerUp in self.ListSpritePowerUps: b_collision = arcade.check_for_collision(SpritePowerUp, self.SpritePlayer) if b_collision == true: # half player movement self.right = false self.left = false self.up = false self.down = false # Graphics code to show object collision # here in a future part of this lesson. # NEW: arcade.play_sound(t_hit_sound[i]) # increment the counter. i += 1 def on_key_press(self, symbol, modifiers): # When a key is pressed: # Tracking only the four arrow keys # NOTE: We are careful to NOT use elif here # because we want to allow diagonal movement. if symbol == arcade.key.right: self.right = true if symbol == arcade.key.left: self.left = true if symbol == arcade.key.up: self.up = true if symbol == arcade.key.down: self.down = true def on_key_release(self, symbol, modifiers): # When a key is released: if symbol == arcade.key.right: self.right = false if symbol == arcade.key.left: self.left = false if symbol == arcade.key.up: self.up = false if symbol == arcade.key.down: self.down = false Def main(): # Primary module getScreenFromDB() db_cursor = getObjectsFromDB() gameWindow(i_width, i_height, t_title, db_cursor) enemyMovement() arcade.run() |
Conclusion
In this part 7, we continued building a game with Python and Postgres with sound added, as part of a multi-part bunch of lessons where the final result will be a basic 2D graphical top-view game; think Pac Man. We are using Python’s Arcade library for gaming-type features. We are using Python’s “Arcade” library for its gaming-related functions and methods. We used PostgreSQL to read and write screenS and objects, including player, enemies, obstacles, and power-ups. In this lesson we will add sound to make the game more interesting. In future lessons we will add various graphics, a “save game” feature, multi-player, and a screen editor.
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