use dynamic allocation pattern for player bullets

Author: braindigitalis

os/programs/dragonfly.rrbasic

@@ -10,16 +10,15 @@ SPRITELOAD ship3, "/images/dragonfly/ship3.png"
 SPRITELOAD ship4, "/images/dragonfly/ship4.png"
 SPRITELOAD ship_bullet, "/images/dragonfly/ship_bullet.png"
 SPRITELOAD enemy_bullet, "/images/dragonfly/enemy_bullet.png"
-player_bullet_max = 32
+player_bullets = 0
+player_bullet_max = 1
 player_fire_cooldown = 1 ' Starts at one so we dont pick up spurious enter key
 player_fire_delay = 6 ' Rapid fire repeat delay in frames
 DIM player_bullet_x, player_bullet_max
 DIM player_bullet_y, player_bullet_max
 DIM player_bullet_type, player_bullet_max
 DIM player_bullet_vel_x, player_bullet_max
 DIM player_bullet_vel_y, player_bullet_max
-player_bullet_next = 0
-player_bullet_top = 0
 enemy_bullets = 0
 enemy_bullet_max = 1
 DIM enemy_bullet_x, enemy_bullet_max
@@ -69,6 +68,7 @@ REPEAT
     IF VEL_Y < 2 THEN VEL_Y = 2
     PROCundraw_bullets()
     PROCundraw_enemy_bullets()
+    PROCmove_bullets()
     PROCmove_enemy_bullets()
     PROCdraw_bullets()
     PROCdraw_enemy_bullets()
@@ -90,63 +90,75 @@ UNTIL (INKEY$(CHR$(27)) <> "") OR (INKEY$("") = CHR$(27))
 END
 
 DEF PROCalloc_bullet(type, bullet_x, bullet_y, x_vel, y_vel)
-    FOR x = player_bullet_next TO player_bullet_max
-        IF player_bullet_type(x) = 0 THEN
-            PROCclaim_bullet(x, type, bullet_x, bullet_y, x_vel, y_vel)
-            x = player_bullet_next * 255
-        ENDIF
-    NEXT
-    IF player_bullet_next * 255 THEN ENDPROC
-    FOR x = 0 TO player_bullet_next
-        IF player_bullet_type(x) = 0 THEN
-            PROCclaim_bullet(x, type, bullet_x, bullet_y, x_vel, y_vel)
-            x = player_bullet_next * 255
-        ENDIF
-    NEXT
+    player_bullets = player_bullets + 1
+    IF player_bullets > player_bullet_max THEN
+        player_bullet_max = player_bullets
+        REDIM player_bullet_x, player_bullet_max
+        REDIM player_bullet_y, player_bullet_max
+        REDIM player_bullet_type, player_bullet_max
+        REDIM player_bullet_vel_x, player_bullet_max
+        REDIM player_bullet_vel_y, player_bullet_max
+    ENDIF
+
+    player_bullet_x(player_bullets - 1) = bullet_x
+    player_bullet_y(player_bullets - 1) = bullet_y
+    player_bullet_type(player_bullets - 1) = type
+    player_bullet_vel_x(player_bullets - 1) = x_vel
+    player_bullet_vel_y(player_bullets - 1) = y_vel
 ENDPROC
 
-DEF PROCclaim_bullet(x, type, bullet_x, bullet_y, x_vel, y_vel)
-    player_bullet_x(x) = bullet_x
-    player_bullet_y(x) = bullet_y
-    player_bullet_type(x) = type
-    player_bullet_vel_x(x) = x_vel
-    player_bullet_vel_y(x) = y_vel
-    player_bullet_next = x + 1
-    IF player_bullet_next >= player_bullet_max THEN player_bullet_next = 0
-    IF x > player_bullet_top THEN player_bullet_top = x
+DEF PROCfree_bullet(i)
+    POP player_bullet_x, i
+    POP player_bullet_y, i
+    POP player_bullet_type, i
+    POP player_bullet_vel_x, i
+    POP player_bullet_vel_y, i
+
+    player_bullets = player_bullets - 1
+
+    IF player_bullets < 1 THEN
+        player_bullet_max = 1
+    ELSE
+        player_bullet_max = player_bullets
+    ENDIF
+
+    REDIM player_bullet_x, player_bullet_max
+    REDIM player_bullet_y, player_bullet_max
+    REDIM player_bullet_type, player_bullet_max
+    REDIM player_bullet_vel_x, player_bullet_max
+    REDIM player_bullet_vel_y, player_bullet_max
 ENDPROC
 
-DEF PROCundraw_bullets()
-    FOR x = 0 TO player_bullet_top
-        IF player_bullet_type(x) <> 0 THEN
-            RECTANGLE player_bullet_x(x) - 4, player_bullet_y(x) - 4, player_bullet_x(x) + 48, player_bullet_y(x) + 48
-            player_bullet_x(x) = player_bullet_x(x) + player_bullet_vel_x(x)
-            player_bullet_y(x) = player_bullet_y(x) + player_bullet_vel_y(x)
-            IF (player_bullet_x(x) < 0) OR (player_bullet_y(x) < 0) OR (player_bullet_x(x) > GRAPHICS_WIDTH) OR (player_bullet_y(x) > GRAPHICS_HEIGHT) THEN
-                player_bullet_type(x) = 0
-            ENDIF
-        ENDIF
-    NEXT
-    E = FALSE
+DEF PROCmove_bullets()
+    i = 0
+    done = FALSE
     REPEAT
-        IF player_bullet_top = 0 THEN
-            E = TRUE
+        IF i >= player_bullets THEN
+            done = TRUE
         ELSE
-            IF player_bullet_type(player_bullet_top) <> 0 THEN
-                E = TRUE
+            player_bullet_x(i) = player_bullet_x(i) + player_bullet_vel_x(i)
+            player_bullet_y(i) = player_bullet_y(i) + player_bullet_vel_y(i)
+
+            IF (player_bullet_x(i) < -48) OR (player_bullet_y(i) < -48) OR (player_bullet_x(i) > GRAPHICS_WIDTH + 48) OR (player_bullet_y(i) > GRAPHICS_HEIGHT + 48) THEN
+                PROCfree_bullet(i)
             ELSE
-                player_bullet_top = player_bullet_top - 1
-                IF player_bullet_top = 0 THEN E = TRUE
+                i = i + 1
             ENDIF
         ENDIF
-    UNTIL E = TRUE
+    UNTIL done = TRUE
+ENDPROC
+
+DEF PROCundraw_bullets()
+    IF player_bullets = 0 THEN ENDPROC
+    FOR i = 0 TO player_bullets - 1
+        RECTANGLE player_bullet_x(i) - 4, player_bullet_y(i) - 4, player_bullet_x(i) + 48, player_bullet_y(i) + 48
+    NEXT
 ENDPROC
 
 DEF PROCdraw_bullets()
-    FOR x = 0 TO player_bullet_top
-        IF player_bullet_type(x) <> 0 THEN
-            PLOT ship_bullet, player_bullet_x(x), player_bullet_y(x)
-        ENDIF
+    IF player_bullets = 0 THEN ENDPROC
+    FOR i = 0 TO player_bullets - 1
+        PLOT ship_bullet, player_bullet_x(i), player_bullet_y(i)
     NEXT
 ENDPROC
 
@@ -206,12 +218,14 @@ DEF PROCmove_enemy_bullets()
 ENDPROC
 
 DEF PROCdraw_enemy_bullets()
+    IF enemy_bullets = 0 THEN ENDPROC
     FOR i = 0 TO enemy_bullets - 1
         PLOT enemy_bullet, enemy_bullet_x(i), enemy_bullet_y(i)
     NEXT
 ENDPROC
 
 DEF PROCundraw_enemy_bullets()
+    IF enemy_bullets = 0 THEN ENDPROC
     FOR i = 0 TO enemy_bullets - 1
         RECTANGLE enemy_bullet_x(i) - 4, enemy_bullet_y(i) - 4, enemy_bullet_x(i) + 48, enemy_bullet_y(i) + 48
     NEXT