use a more gradual ramp up for speed

geometric instead of arithmetic progression, via a lookup table

1 files changed, 15 insertions, 4 deletions

diff --git a/main.s b/main.s
index 705a9f1..7819d39 100644
--- a/main.s
+++ b/main.s
@@ -106,7 +106,7 @@ clrmem:
   LDA #$04
   LDX #$01
   STA head_y, x
-  LDA #35
+  LDA #20
   STA frame_skip
 
   ; Second wait for vblank, PPU is ready after this
@@ -370,9 +370,9 @@ eat_apple:
   STX length
   AND #$07
   BNE +
-  LDX frame_skip
-  DEX
-  STX frame_skip
+  LDX length
+  LDA speed.w, x
+  STA frame_skip
 + JSR new_apple
 
 end_game_loop:
@@ -699,6 +699,17 @@ game_background_middle: ; {{{
 game_background_bottom: ; {{{
   .asc "       '----------------:       "
 ; }}}
+speed: ; {{{
+  .db 20,20,20,19,19,19,19,19,19,19,18,18,18,18,18,18,18,17,17,17,17,17,17,17,
+  .db 17,16,16,16,16,16,16,16,16,16,15,15,15,15,15,15,15,15,15,14,14,14,14,14,
+  .db 14,14,14,14,13,13,13,13,13,13,13,13,13,13,13,12,12,12,12,12,12,12,12,12,
+  .db 12,12,11,11,11,11,11,11,11,11,11,11,11,11,10,10,10,10,10,10,10,10,10,10,
+  .db 10,10,10,10,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+  .db 8,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
+  .db 6,6,6,6,6,6,6,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,4,4,
+  .db 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,3,3,3,3,
+  .db 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3
+; }}}
 ; }}}
   .orga $FFFA    ;first of the three vectors starts here
 ; interrupt vectors {{{