ELEC2645 (2019/20) / Mbed 2 deprecated ELEC2645_Project_mc18hal_v2

Helios Lyons 201239214

Dependencies:   mbed

Brief

My aim for this project was to create a FRDM K64F adapted version of the classic Space Invaders by Tomohiro Nishikado. The game itself has a number of clear features to implement;

  • Left to right movement for the player 'canon'
  • A fixed amount of player lives
  • Firing mechanics for both canon and invaders (hence collision systems)
  • Random firing from remaining invaders
  • Wave based combat

My own addition to these established ideas was Boss waves, featuring a single, larger sprite which fires at a faster interval than previous waves. The addition of a movement system using a basic for loop, as opposed to a velocity based system, will enhance the nostalgic feel of the game.

https://os.mbed.com/media/uploads/helioslyons/screenshot_2020-05-27_at_06.12.00.png

Gameplay

Movement is controlled with the joystick, moving the canon left or right. Fire by pressing A. Invaders spawn at set positions, but randomly fire at a set interval, which is higher for boss waves. Time is taken during each wave, and displayed at wave intervals, and if the play wins.

Controls are shown on the Gamepad below: (attribution: Craig A. Evans, ELEC2645 University of Leeds)

https://os.mbed.com/media/uploads/helioslyons/screenshot_2020-05-27_at_06.20.18.png

Diff: Invaders/Army.cpp

Revision:
7:5fe9ac6522c5
Parent:
6:e3a1bfbb1627
Child:
8:ec4199484adf
--- a/Invaders/Army.cpp	Tue Apr 14 14:09:33 2020 +0000
+++ b/Invaders/Army.cpp	Fri Apr 17 13:52:37 2020 +0000
@@ -15,7 +15,7 @@
 
 void Army::create_army()
 {
-    Invader army[3][3];
+    Invader Army[3][3];
 
     int i, n;
     for(i=0; i < 4; i++) {
@@ -36,18 +36,19 @@
 void Army::start_pos(int rowX, int rowY)
 {
     int tempX = rowX;
+    _move_left = true;
     
     for (int i = 0; i < 4; i++){ // Loop through each row and assign start_pos
         army[i][0].set_pos(rowX, rowY); // Based on X and Y inputs
         rowX += 13; // 2 above standard Invader width of 11
         } 
-    rowX = temp;
+    rowX = tempX;
     rowY += 10;
     for (int i = 0; i < 4; i++){
         army[i][1].set_pos(rowX, rowY);
         rowX +=13;
         }
-    rowX = temp;
+    rowX = tempX;
     rowY += 10;
     for (int i = 0; i < 4; i++){
         army[i][2].set_pos(rowX, rowY);
@@ -55,7 +56,94 @@
         }
 }
 
-void Army::move_army(int move_distance)
+void Army::move_army(int x_distance, int y_distance) // REPLACE WITH FSM AFTER BASIC FUNCTIONALITY TEST
 {
-    _move_distance = move_distance;
+    _x_distance = x_distance;
+    _y_distance = y_distance;
+    
+    int left_X = 0;
+    int right_X = 80;
+    int bot_Y = 0;
+    int top_Y = 80;
+    
+    // find leftmost, rightmost, top and bottom invaders
+    // less invaders means more room to cover (also speed up)
+    
+    for (int i = 3; i < 0; i--) {
+        for (int n = 3; n < 0; n--) {
+            int tempX = army[n][i].get_x_pos();
+            int tempY = army[n][i].get_y_pos();
+            
+            if (tempX < left_X) {
+                left_X = tempX;
+                }
+            else if (tempX > right_X) {
+                right_X = tempX;
+                }
+                
+            if (tempY < top_Y) {
+                top_Y = tempY;
+                }
+            else if (tempY > bot_Y) {
+                bot_Y = tempY;
+                }
+            }
+        }
+            
+            
+    if (_move_left == true) { // if moving left
+        if (left_X < 12) { // check if edge will be reached, if so change direction
+                _move_left = false;
+                if(bot_Y > 50) { 
+                    // if lowest Y point is below 50, move up
+                        for (int i = 3; i < 0; i--) {
+                            for (int n = 3; n < 0; n--) {
+                                army[i][n].set_pos(army[i][n].get_x_pos(), army[i][n].get_y_pos() - _y_distance);
+                                }
+                            }
+                    }
+                else { // else move down
+                    for (int i = 3; i < 0; i--) {
+                            for (int n = 3; n < 0; n--) {
+                                army[i][n].set_pos(army[i][n].get_x_pos(), army[i][n].get_y_pos() + _y_distance);
+                                }
+                            }
+                    }
+            }
+        else { // if edge is not near to being reached, move left
+            for (int i = 3; i < 0; i--) {
+                for (int n = 3; n < 0; n--) {
+                    army[i][n].set_pos(army[i][n].get_x_pos() - _x_distance, army[i][n].get_y_pos());
+                    }
+                } 
+        }
+    }
+    
+    else {
+        if (right_X > 65) { // if rightmost invader is further than X = 65, change direction
+            _move_left = true;
+            
+            if (bot_Y > 50) { // if lowest invader is below Y = 50, go up
+                for (int i = 3; i < 0; i--) {
+                    for (int n = 3; n < 0; n--) {
+                        army[i][n].set_pos(army[i][n].get_x_pos(), army[i][n].get_y_pos() - _y_distance);
+                        }
+                    }
+            }
+            else { // otherwise go down
+                for (int i = 3; i < 0; i--) {
+                    for (int n = 3; n < 0; n--) {
+                            army[i][n].set_pos(army[i][n].get_x_pos(), army[i][n].get_y_pos() + _y_distance);
+                        }
+                    }
+            }
+        }
+        else { // if edge is not near to being reached, move right
+            for (int i = 3; i < 0; i--) {
+                    for (int n = 3; n < 0; n--) {
+                            army[i][n].set_pos(army[i][n].get_x_pos() + _x_distance, army[i][n].get_y_pos() + _y_distance);
+                        }
+                    }
+            }
+    }
 }