From 35d9188e8122d652b015058e6d74a941cf7796d5 Mon Sep 17 00:00:00 2001 From: "Peter Helcmanovsky (Ped)" Date: Sun, 9 Feb 2020 10:55:34 +0100 Subject: [PATCH] Part 8: player controls: left+right and jump+fall mechanics Walking on platforms, falling down off the ledge, jumping, staying within play-field, detecting when falling from too high (will just disable controls for 1s in this version). No ladder mechanics yet (will be part 9) --- SpecBong.asm | 249 ++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 179 insertions(+), 70 deletions(-) diff --git a/SpecBong.asm b/SpecBong.asm index cf3aa55..4e3cbd5 100644 --- a/SpecBong.asm +++ b/SpecBong.asm @@ -164,6 +164,11 @@ InitBallsLoop: ld (ix+S_SPRITE_4B_ATTR.y),206 ; near bottom of paper area ld (ix+S_SPRITE_4B_ATTR.mrx8),0 ; clear pal offset, mirrors, rotate, x8 ld (ix+S_SPRITE_4B_ATTR.vpat),$80 + 2 ; pattern "2" (player + ;DEBUG position for testing the jump+fall mechanics + ld (ix+S_SPRITE_4B_ATTR.x),32+100 + ld (ix+S_SPRITE_4B_ATTR.y),32 + ld a,255 + ld (Player1SafeLandingY),a ; main loop of the game GameLoop: @@ -379,90 +384,177 @@ GetPlatformPosUnder: ;------------------------------------------------------------------------------------- ; "AI" subroutines + ;------------------------------------------------------------------------------------- + ; Part 8 - player controls: left+right and jump+fall mechanics + Player1MoveByControls: - ; update "cooldown" of fire button to allow it only once per 10 frames - ld a,(Player1FireCoolDown) + ; update "cooldown" of controls if there's some delay needed + ld a,(Player1ControlsCoolDown) sub 1 ; SUB to update also carry flag adc a,0 ; clamp the value to 0 to not go -1 - ld (Player1FireCoolDown),a - ; just DEBUG: up/down/left/right over whole screen, fire changing animation frame + ld (Player1ControlsCoolDown),a + ret nz ; don't do anything with player during "cooldown" ld ix,SprPlayer + ; calculate nearest platform at x-3 and x+3 + ld l,(ix+S_SPRITE_4B_ATTR.x) + ld a,l + sub 3 ; not caring about edge cases, only works for expected X values + ld (ix+S_SPRITE_4B_ATTR.x),a ; posX-3 + call GetPlatformPosUnder + sub 16 ; player wants platform at +16 from player.Y + ld h,a + ld a,l + add a,3 + ld (ix+S_SPRITE_4B_ATTR.x),a + call GetPlatformPosUnder + sub 16 ; player wants platform at +16 from player.Y + ld (ix+S_SPRITE_4B_ATTR.x),l ; restore posX + cp h + jr nc,.keepHigherPlatform + ld h,a +.keepHigherPlatform: + ; H = -16 + min(PlatformY[-3], PlatformY[+3]), C = extras of right platform, L = posX + ld a,(Player1JumpIdx) + or a + jr z,.notInTableJump +.doTheTableJumpFall: + ; table jump/fall .. keep doing it until landing (no controls accepted) + ld e,a + ld d,high PlayerJumpYOfs ; address of current DeltaY + cp 255 + adc a,0 ; increment it until it will reach 255, then keep 255 + ld (Player1JumpIdx),a + ; adjust posX by jump direction (3 of 4 frames) + ld a,(TotalFrames) + and 3 + jr z,.skipJumpPosXupdate + ld a,(Player1JumpDir) + call .updateXPosAplusL +.skipJumpPosXupdate: + ; adjust posY by jump/fall table + ld a,(de) ; deltaY for current jumpIdx + add a,(ix+S_SPRITE_4B_ATTR.y) + cp h ; compare with platform Y + jr z,.didLand + jr nc,.didLand + ; still falling + ld (ix+S_SPRITE_4B_ATTR.y),a + ret +.didLand: + ld (ix+S_SPRITE_4B_ATTR.y),h ; land *at* platform precisely + xor a + ld (Player1JumpIdx),a ; next frame do regular AI (no more jump table) + ld (ix+S_SPRITE_4B_ATTR.vpat),$80+4 ; landing sprite + ld a,4 ; keep landing sprite for 4 frames + ld (Player1ControlsCoolDown),a + ; check if landing was too hard + ld a,(Player1SafeLandingY) + cp h + ret nc + ; lands too hard, "die" - just disable controls for 1s for now + ld a,50 + ld (Player1ControlsCoolDown),a + ret + +.notInTableJump: + ; H = -16 + min(PlatformY[-3], PlatformY[+3]), C = extras of right platform, L = posX + ; if landing pattern, turn it into normal pattern + ld a,(ix+S_SPRITE_4B_ATTR.vpat) + cp $80+4 + jr nz,.notLandingSprite + ld (ix+S_SPRITE_4B_ATTR.vpat),$80 ; reset sprite to 0 +.notLandingSprite: + ;TODO if ladder pattern, do the ladder AI + ; if regular pattern, do regular movement handling + ; check if stands at platform +-1px (and align with platform) + ld a,(ix+S_SPRITE_4B_ATTR.y) + sub h + adc a,0 ; turn -1/0/+1 into 0/+1 + cp 2 + jr c,.almostAtPlatform + ; too much above platform, turn it into freefall (table jump) + xor a + ld (Player1JumpDir),a + ld a,low PlayerFallYOfs + jr .doTheTableJumpFall ; and do the first tick of fall this frame already + +.almostAtPlatform: + ld (ix+S_SPRITE_4B_ATTR.y),h ; place him precisely at platform + ; refresh safe landing Y + ld a,18 + add a,h + ld (Player1SafeLandingY),a ld a,(Player1Controls) ld b,a ; keep control bits around in B for simplicity - ; HL = current X coordinate (9 bit) - ld l,(ix+S_SPRITE_4B_ATTR.x) - ld h,(ix+S_SPRITE_4B_ATTR.mrx8) - ld c,h ; preserve current mirrorX + bit JOY_BIT_FIRE,b + jr z,.notJumpPressed + ; start a new jump sequence + ld a,$80+3 ; jump pattern + visible + ld (ix+S_SPRITE_4B_ATTR.vpat),a + xor a + bit JOY_BIT_LEFT,b + jr z,.noLeftJump + dec a +.noLeftJump: bit JOY_BIT_RIGHT,b - jr z,.notGoingRight - inc hl - inc hl ; X += 2 - res 3,c ; mirrorX=0 (face right) -.notGoingRight: + jr z,.noRightJump + inc a +.noRightJump: + ld (Player1JumpDir),a + ld a,low PlayerJumpYOfs + jp .doTheTableJumpFall ; and do the first tick of jump this frame already + +.notJumpPressed: +/* TODO + if up/down is pressed { + near ladder +-Npx -> switch to ladder pattern, adjust Y -> end + else reset dir controls + continue (stands) + } +*/ + ; C = extras of right platform, L = posX, B = user controls bit JOY_BIT_LEFT,b jr z,.notGoingLeft - dec hl - dec hl ; X -= 2 - set 3,c ; mirrorX=1 (face left) + ; move left + set 3,(ix+S_SPRITE_4B_ATTR.mrx8) ; set MirroX flag (to face left) + ld a,(TotalFrames) + and 3 + jr z,.animateRunPattern ; one frame out of 4 don't move but animate (0.75px speed) + ld a,-1 + jr .updateXPosAplusL + .notGoingLeft: - ; sanitize HL to values range 32..272 (16px sprite fully visible in PAPER area) - ld de,32 - ; first clear top bits of H to keep only "x8" bit of it (remove mirrors/rot/pal data) - rr h ; Fcarry = x8 - ld h,0 - rl h ; x8 back to H, Fcarry=0 (for sbc) - sbc hl,de - add hl,de ; Fc=1 when HL is 0..31 - jr nc,.XposIs32plus - ex de,hl ; for 0..31 reset the Xpos=HL=32 -.XposIs32plus: ; (there was "272" constant in previous part => bug, now fixed) - ld de,32+256-16+1 ; 273 - first position when sprite has one px in border - or a ; Fc=0 - sbc hl,de - add hl,de ; Fc=1 when HL is 32..272 - jr c,.XposIsValid - ex de,hl - dec hl ; for 273+ reset the Xpos=HL=272 -.XposIsValid: - ; store the sanitized X post and new mirrorX to player sprite values - ld a,c - and ~1 ; clear x8 bit (preserves only mirror/rotate/...) - or h ; merge x8 back - ld (ix+S_SPRITE_4B_ATTR.x),l - ld (ix+S_SPRITE_4B_ATTR.mrx8),a - ; vertical movement - ld a,(ix+S_SPRITE_4B_ATTR.y) - bit JOY_BIT_UP,b - jr z,.notGoingUp - dec a - dec a ; Y -= 2 - cp 32 ; sanitize right here - jr nc,.notGoingUp - ld a,32 ; 0..31 -> Y=32 -.notGoingUp: - bit JOY_BIT_DOWN,b - jr z,.notGoingDown - inc a - inc a ; Y += 2 - cp 32+192-16+1 ; sanitize right here (209+ is outside of PAPER area) - jr c,.notGoingDown - ld a,32+192-16 ; 209..255 -> Y=208 (was 207 in previous part = bug) -.notGoingDown: - ld (ix+S_SPRITE_4B_ATTR.y),a - ; change through all 64 sprite patterns when pressing fire - bit JOY_BIT_FIRE,b - ret z ; Player1 movement done - no fire button - ld a,(Player1FireCoolDown) - or a - ret nz ; check "cooldown" of fire, ignore button if still cooling down - ld a,10 - ld (Player1FireCoolDown),a ; set new "cooldown" if pattern will change + bit JOY_BIT_RIGHT,b + jr z,.notGoingRight + ; move right + res 3,(ix+S_SPRITE_4B_ATTR.mrx8) ; reset MirroX flag (to face right) + ld a,(TotalFrames) + and 3 + jr z,.animateRunPattern ; one frame out of 4 don't move but animate (0.75px speed) + ld a,+1 + jr .updateXPosAplusL + +.animateRunPattern: + ; animate pattern 0..3 frames (in case he holds left or right) (if not, it will be zeroed) ld a,(ix+S_SPRITE_4B_ATTR.vpat) inc a - and ~64 ; force the pattern to stay 0..63 and keep +128 for "visible" + and %1'0'000011 ; force pattern to stay 0..3 (+visible flag) ld (ix+S_SPRITE_4B_ATTR.vpat),a ret +.notGoingRight: + ; not going anywhere + ld (ix+S_SPRITE_4B_ATTR.vpat),$80 ; reset to frame 0 + ret + +.updateXPosAplusL: + add a,l ; add A and L to get final posX + cp 32 + ret c ; way too left, don't update + cp 32+192-16+1 + ret nc ; way too right, don't update + ld (ix+S_SPRITE_4B_ATTR.x),a ; valid X: 32..32+192-16 + ret + SnowballsAI: ld ix,SprSnowballs ld de,S_SPRITE_4B_ATTR @@ -613,8 +705,14 @@ CollisionFxCount: ; count the dynamically created extra FX sprites dis ; bits encoding inputs as Kempston/MD: https://wiki.specnext.dev/Kempston_Joystick Player1Controls: DB 0 -Player1FireCoolDown: +Player1ControlsCoolDown: + DB 0 +Player1JumpIdx: ; when non-zero, player is jumping (and it is index to PlayerJumpYOfs table) DB 0 +Player1JumpDir: + DB 0 ; -1/0/+1 depending if the jump has direction or not +Player1SafeLandingY: + DB 0 ; last known safe landing Y (will be +18 to current Y when *at* platform) ; reserve full 128 sprites 4B type (this demo will not use 5B type sprites) ALIGN 256 ; aligned at 256B boundary w/o particular reason (yet) @@ -671,6 +769,17 @@ PlatformsCollisionData: ; the Y-coord of platforms are in sprite coordinates DB 97, 1, 156, 1, 214, 1, 255, 0, 255, 0, 255, 0, 255, 0, 255, 0 PlatformsCollisionDataEnd: + ; this is 32B table which should precisely fit at the end of 256B page + ; i.e. at $xxE0..$xxFF addresses - it will be used by the code to stay at last item +PlayerJumpYOfs: + DB -2, -2, -2, -1, -1, -1, -1, -1 + DB -1, -1, -1, 0, -1, 0, -1, 0 + DB 0, 0, 0, 1, 0, 1, 0, 1 + DB 1, 1, 1, 1 +PlayerFallYOfs: ; first item of free-fall w/o jump + DB 1, 1, 1, 2 ; last item to be used repeatedly + ASSERT low $ == 0 ; did reach end of aligned 256B block? + ;------------------------------------------------------------------------------------- ; reserve area for stack at $B800..$BFFF region ORG $B800