Implement clearing level in RAM according to End Space effect, supporting up to 4 clearable stages per level; Implement unlocking levels [Commit 1] (#35)

engine/menus/cleared_level_screen.asm

@@ -30,6 +30,8 @@ ClearedLevelScreen:
 	jr z, .loop
 .exit
 	call AddLevelCoinsToBalance
+	call ClearLevel
+	call UnlockLevels
 	ld c, 30
 	jp DelayFrames
 
@@ -58,3 +60,98 @@ AddLevelCoinsToBalance:
 	pop bc
 	farcall GiveCoins
 	ret
+
+ClearLevel:
+	ld a, [wCurSpaceEffect] ; End Space effect byte contains STAGE_*
+	call GetClearedLevelsStageAddress
+	ld b, SET_FLAG
+	ld d, 0
+	ld a, [wCurLevel]
+	ld e, a
+	call FlagAction
+	ret
+
+UnlockLevels:
+	ld hl, LevelUnlockRequirements
+	ld de, wUnlockedLevels - 1
+	ld b, 0
+.next_byte
+	ld c, 8
+	inc de
+	ld a, [de]
+.next_bit
+	srl a
+	push af
+	call nc, .CheckUnlockLevel ; skip if level is already unlocked
+	inc b
+	ld a, b
+	cp NUM_LEVELS
+	jr z, .done
+; advance hl to next level in LevelUnlockRequirements
+.loop
+	ld a, [hli]
+	inc a ; cp $ff
+	jr nz, .loop
+	pop af
+	dec c
+	jr z, .next_byte
+	jr .next_bit
+
+.done
+	pop af
+	ret
+
+; check if the LevelUnlockRequirements[b] at hl for unlocking level b are met.
+; return hl pointing to up to the $ff byte of this LevelUnlockRequirements entry.
+.CheckUnlockLevel:
+	push de
+	push bc
+	ld a, [hl]
+	cp $ff
+	jr z, .reqs_met ; jump if no specific reqs to unlock this level
+	inc hl
+	cp UNLOCK_WHEN_LEVELS_CLEARED
+	jr z, .check_levels_cleared_loop
+	cp UNLOCK_WHEN_NUMBER_OF_LEVELS_CLEARED
+	cp UNLOCK_WHEN_TECHNIQUES_CLEARED
+
+.check_levels_cleared_loop
+	ld a, [hli] ; which level
+	ld e, a
+	inc a ; cp $ff
+	jr z, .reqs_met ; jump when no more required levels and all passed so far
+	ld a, [hli] ; which stage
+	push hl
+	call GetClearedLevelsStageAddress
+	ld b, CHECK_FLAG
+	ld d, 0
+	call FlagAction
+	pop hl
+	jr z, .reqs_not_met ; if this level is not cleared, requirements aren't met
+	jr .check_levels_cleared_loop ; otherwise check next level in list
+
+.reqs_met
+	pop bc
+	pop de
+	ret
+
+.reqs_not_met
+	pop bc
+	pop de
+	ret
+
+; return hl = wClearedLevelsStage* given STAGE_ constant in a
+GetClearedLevelsStageAddress:
+	ld hl, wClearedLevelsStage1
+	cp ES1
+	ret z
+	ld hl, wClearedLevelsStage2
+	cp ES2
+	ret z
+	ld hl, wClearedLevelsStage3
+	cp ES3
+	ret z
+	ld hl, wClearedLevelsStage4
+	ret
+
+INCLUDE "data/levels/levels.asm"

engine/menus/level_selection_menu.asm

@@ -118,6 +118,13 @@ LevelSelectionMenu::
 	jr .main_loop
 
 .enter_level
+	ld a, [wLevelSelectionMenuCurrentLandmark]
+	ld e, a
+	ld d, 0
+	ld hl, LandmarkToLevelTable
+	add hl, de
+	ld a, [hl]
+	ld [wCurLevel], a
 	ld a, [wLevelSelectionMenuCurrentLandmark]
 	call LevelSelectionMenu_GetLandmarkSpawnPoint
 	ld [wDefaultSpawnpoint], a
@@ -521,12 +528,10 @@ LevelSelectionMenu_GetLandmarkName::
 
 LevelSelectionMenu_GetLandmarkSpawnPoint:
 ; Return SPAWN_* (a) of landmark a.
-	push hl
 	ld hl, LevelSelectionMenu_Landmarks + $5
 	ld bc, LevelSelectionMenu_Landmarks.landmark2 - LevelSelectionMenu_Landmarks.landmark1
 	call AddNTimes
 	ld a, [hl]
-	pop hl
 	ret
 
 LevelSelectionMenu_GetValidKeys:
@@ -744,7 +749,7 @@ _LevelSelectionMenuHandleTransition:
 	xor a
 	ret
 
-INCLUDE "data/level_selection_menu.asm"
+INCLUDE "data/levels/level_selection_menu.asm"
 
 LevelSelectionMenuGFX:
 INCBIN "gfx/level_selection_menu/background.2bpp.lz"