Split speed physics implementation

patches/rom_map/Bank 90.txt

@@ -8,4 +8,5 @@ $F980 - $FA00: respin.asm
 $FA00 - $FC00: map_progress_maintain.asm (list of cross-area tiles to reveal)
 $FC00 - $FC10: Fake Lava.asm
 $FC10 - $FC20: vanilla_bugfixes.asm
-$FC20 - $FC40: remove_spikesuit.asm
+$FC20 - $FC40: remove_spikesuit.asm
+$FC40 - $FCC0: split_speed.asm

patches/rom_map/RAM.txt

@@ -40,8 +40,9 @@ $7EF4E0-$7EF500: [FREE]
 $7EF500: room map tile graphics pointer (into bank $E4)
 $7EF502-$7EF594: fix_dust_torizo.asm
 $7EF594-$7EF596: fix_transition_bad_tiles.asm
-$7EF596 - vanilla_bugfixes.asm
-$7EF597 - $7EFE00: [FREE]
+$7EF596: vanilla_bugfixes.asm
+$7EF597-$7EF599: split_speed.asm
+$7EF599-$7EFE00: [FREE]
 $7EFE00: map area (copy of $1F5B to be saved to SRAM)
 $7EFE02: map area explored mask
 $7EFE04: copy of $1F5D (to be saved to SRAM for escape autosave)

patches/src/split_speed.asm

@@ -0,0 +1,197 @@
+!bank_90_free_space_start = $90FC40
+!bank_90_free_space_end = $90FCC0
+
+!bank_91_free_space_start = $91F7F4
+!bank_91_free_space_end = $91F88C
+
+!equipped_items = $09A2
+!fake_shinecharge = $7EF597
+
+; bitmask for equipped items ($09A2) and collected items ($09A4):
+!blue_booster = $0040
+!spark_booster = $0080
+!speed_booster = $2000
+!any_booster = !blue_booster|!spark_booster|!speed_booster
+
+; Accelerate Samus' animation with any booster item:
+org $908502
+    bit #!any_booster
+
+; Increase Samus' dash counter with any booster item:
+org $90855B
+    bit #!any_booster
+
+; Raise dash speed cap from $2.0 to $7.0 with any booster item:
+org $90978C
+    bit #!any_booster
+
+; When only Spark Booster is equipped, lose speed when jumping or falling:
+; This caps Samus' dash speed to $2.0, resets dash counter to zero, and remove echoes.
+org $909919 : jsr hook_jump
+org $91E901 : jsr hook_fall
+
+; Apply speedy jump height with Blue Booster or Speed Booster:
+org $90991C : bit #!blue_booster|!speed_booster   ; regular jump
+org $9099A9 : bit #!blue_booster|!speed_booster   ; wall jump
+
+; Graphical change to not show Samus as blue when running with Spark Booster:
+org $91D9EA
+    jsr hook_speed_boosting
+
+; Graphical change to show fake shinecharge palette:
+org $91DAE3
+    jsr hook_shinecharge_palette
+
+; Prevent shinespark from happening with fake shinecharge, and reset dash counter 
+; (to ensure you still have to wait out the fake shinecharge for temp blue):
+org $91F564 : jsr hook_normal_jump_spark
+org $91F571 : jsr hook_normal_jump_spark
+
+; When running with only Blue Booster is equipped, replace shinecharge with "fake shinecharge".
+; This flashes blue instead of white and does not allow a shinespark.
+; Shinecharging using a blue suit still gives a real shinecharge.
+org $91F7C1
+    jsr hook_shinecharge
+
+; When only Blue Booster is equipped, disable speed echoes when having dash speed:
+org $90EEE7
+    jsr hook_update_speed_echoes
+
+org !bank_91_free_space_start
+
+
+hook_speed_boosting:
+    ; If case of any item combination other than exactly Spark Booster, behave like vanilla:
+    lda !equipped_items
+    and #!any_booster
+    cmp #!spark_booster
+    bne .vanilla
+
+    ; If Samus does not have running momentum, behave like vanilla (e.g. to be able to show blue suit):
+    lda $0B3C  ; Samus running momentum flag
+    beq .vanilla
+
+    ; If Samus is running with Spark Booster, don't show blue:
+    lda #$0000
+    rts
+
+.vanilla:
+    ; Vanilla behavior: show blue palette if dash counter = 4
+    lda $0B3E
+    rts
+
+hook_shinecharge_palette:
+    ; load vanilla palette
+    lda !fake_shinecharge
+    beq .vanilla
+    lda fake_shinecharge_palette_table,x
+    rts
+.vanilla:
+    lda $DB10,x
+    rts
+
+hook_shinecharge:
+    lda !equipped_items
+    and #!any_booster
+    cmp #!blue_booster
+    bne .vanilla
+
+    ; If Samus does not have running momentum, behave like vanilla;
+    ; e.g. to be able to shinecharge with blue suit:
+    lda $0B3C  ; Samus running momentum flag
+    beq .vanilla
+
+    lda #$0001  ; fake shinecharge
+    bra .done
+.vanilla:
+    lda #$0000  ; regular shinecharge
+.done:
+    sta !fake_shinecharge
+    lda #$0001  ; run hi-jacked instruction
+    rts
+
+fake_shinecharge_palette_table:
+    dw .no_suit, .varia_suit, .gravity_suit
+.no_suit:
+    dw $9B20, $9B40, $9B60, $9B80, $9B60, $9B40
+.varia_suit:
+    dw $9D20, $9D40, $9D60, $9D80, $9D60, $9D40
+.gravity_suit:
+    dw $9FA0, $9F20, $9F40, $9F60, $9F40, $9F20
+
+hook_normal_jump_spark:
+    lda !fake_shinecharge
+    beq .skip
+
+    ; If attempting to activate a "fake shinecharge", clear the dash counter.
+    ; This makes it so you still have to wait out the fake shinecharge when doing temporary blue,
+    ; or the blue is lost.
+    lda #$0000
+    sta $0B3E
+    rts
+.skip:
+    lda $0A68   ; run hi-jacked instruction
+    rts
+
+
+hook_fall:
+    jsl spark_booster_lose_speed
+    lda $0a1e  ; run hi-jacked instruction
+    rts
+
+assert pc() <= !bank_91_free_space_end
+
+org !bank_90_free_space_start
+
+spark_booster_lose_speed:
+    ; If either Blue Booster or Speed Booster is equipped, skip the speed clamp/loss.
+    lda !equipped_items
+    bit #!blue_booster|!speed_booster
+    bne .skip_speed_clamp
+
+    ; If Samus does not have running momentum, skip the speed clamp/loss (to avoid interfering with blue suit).
+    lda $0B3C  ; Samus running momentum flag
+    beq .skip_speed_clamp
+
+    ; Set speed echoes to merge back into Samus
+    lda #$FFFF
+    sta $0AAE
+
+    stz $0b3e   ; Clear dash counter
+
+    ; Clamp extra run speed to $2.0:
+    lda $0b42
+    cmp #$0002
+    bcc .skip_speed_clamp
+    lda #$0002
+    sta $0b42
+    stz $0b44
+
+    lda #$0000
+    rtl
+.skip_speed_clamp:
+    lda $09a2   ; run hi-jacked instruction (relevant only where called by hook_jump)
+    rtl
+
+hook_jump:
+    jsl spark_booster_lose_speed
+    rts
+
+hook_update_speed_echoes:
+    lda !equipped_items
+    and #!any_booster
+    cmp #!blue_booster
+    bne .vanilla
+
+    ; If Samus does not have running momentum, show echoes as normal (so they can appear with blue suit).
+    lda $0B3C  ; Samus running momentum flag
+    beq .vanilla
+
+.hide_echoes
+    lda #$0000
+    rts
+.vanilla:
+    lda $0b3e  ; run hi-jacked instruction
+    rts
+
+assert pc() <= !bank_90_free_space_end

rust/maprando/src/patch.rs

@@ -650,6 +650,9 @@ impl Patcher<'_> {
             patches.push("load_blue_suit");
         }
 
+        // TODO: make this conditional on setting:
+        // patches.push("split_speed");
+
         for patch_name in patches {
             let patch_path = patches_dir.join(patch_name.to_string() + ".ips");
             apply_ips_patch(self.rom, &patch_path)?;