diff options
Diffstat (limited to 'engine/overworld/oam.asm')
| -rw-r--r-- | engine/overworld/oam.asm | 99 |
1 files changed, 55 insertions, 44 deletions
diff --git a/engine/overworld/oam.asm b/engine/overworld/oam.asm index b4247257..41360965 100644 --- a/engine/overworld/oam.asm +++ b/engine/overworld/oam.asm @@ -4,25 +4,26 @@ PrepareOAMData: ld a, [wUpdateSpritesEnabled] dec a - jr z, .asm_4b1e + jr z, .updateEnabled cp 0 - 1 ret nz ld [wUpdateSpritesEnabled], a jp HideSprites -.asm_4b1e +.updateEnabled xor a - ld [$ff90], a -.asm_4b21 - ld [$ff8f], a + ld [hOAMBufferOffset], a + +.spriteLoop + ld [hSpriteOffset2], a ld d, wSpriteStateData1 / $100 - ld a, [$ff8f] + ld a, [hSpriteOffset2] ld e, a ld a, [de] ; c1x0 and a - jp z, .asm_4bad + jp z, .nextSprite inc e inc e @@ -31,21 +32,25 @@ PrepareOAMData: cp $ff ; off-screen (don't draw) jr nz, .visible - call Func_4bd1 - jr .asm_4bad + call GetSpriteScreenXY + jr .nextSprite .visible - cp $a0 + cp $a0 ; is the sprite unchanging like an item ball or boulder? jr c, .usefacing + +; unchanging and $f - add $10 - jr .asm_4b48 + add $10 ; skip to the second half of the table which doesn't account for facing direction + jr .next .usefacing and $f -.asm_4b48 + +.next ld l, a +; get sprite priority push de inc d ld a, e @@ -53,15 +58,15 @@ PrepareOAMData: ld e, a ld a, [de] ; c2x7 and $80 - ld [$ff94], a ; temp store sprite priority + ld [hSpritePriority], a ; temp store sprite priority pop de +; read the entry from the table ld h, 0 ld bc, SpriteFacingAndAnimationTable add hl, hl add hl, hl add hl, bc - ld a, [hli] ld c, a ld a, [hli] @@ -70,24 +75,25 @@ PrepareOAMData: ld h, [hl] ld l, a - call Func_4bd1 + call GetSpriteScreenXY - ld a, [$ff90] + ld a, [hOAMBufferOffset] ld e, a ld d, wOAMBuffer / $100 -.tile - ld a, [$ff92] ; temp for sprite Y position + +.tileLoop + ld a, [hSpriteScreenY] ; temp for sprite Y position add $10 ; Y=16 is top of screen (Y=0 is invisible) add [hl] ; add Y offset from table ld [de], a ; write new sprite OAM Y position inc hl - ld a, [$ff91] ; temp for sprite X position + ld a, [hSpriteScreenX] ; temp for sprite X position add $8 ; X=8 is left of screen (X=0 is invisible) add [hl] ; add X offset from table inc e ld [de], a ; write new sprite OAM X position inc e - ld a, [bc] ; read pattern number offset (accomodates orientation (offset 0,4 or 8) and animation (offset 0 or $80)) + ld a, [bc] ; read pattern number offset (accommodates orientation (offset 0,4 or 8) and animation (offset 0 or $80)) inc bc push bc ld b, a @@ -99,55 +105,60 @@ PrepareOAMData: ; Sprites $a and $b have one face (and therefore 4 tiles instead of 12). ; As a result, sprite $b's tile offset is less than normal. cp $b - jr nz, .offset + jr nz, .notFourTileSprite ld a, $a * 12 + 4 - jr .gotoffset + jr .next2 -.offset +.notFourTileSprite ; a *= 12 sla a sla a ld c, a sla a add c -.gotoffset - add b ; which frame + +.next2 + add b ; add the tile offset from the table (based on frame and facing direction) pop bc ld [de], a ; tile id inc hl inc e ld a, [hl] - bit 1, a ; sprite priority - jr z, .fg - ld a, [$ff94] ; facing priority + bit 1, a ; is the tile allowed to set the sprite priority bit? + jr z, .skipPriority + ld a, [hSpritePriority] or [hl] -.fg +.skipPriority inc hl ld [de], a inc e bit 0, a ; OAMFLAG_ENDOFDATA - jr z, .tile + jr z, .tileLoop ld a, e - ld [$ff90], a + ld [hOAMBufferOffset], a -.asm_4bad - ld a, [$ff8f] +.nextSprite + ld a, [hSpriteOffset2] add $10 cp $100 % $100 - jp nz, .asm_4b21 + jp nz, .spriteLoop ; Clear unused OAM. - ld a, [$ff90] + ld a, [hOAMBufferOffset] ld l, a ld h, wOAMBuffer / $100 ld de, $4 ld b, $a0 ld a, [wd736] - bit 6, a + bit 6, a ; jumping down ledge or fishing animation? ld a, $a0 jr z, .clear + +; Don't clear the last 4 entries because they are used for the shadow in the +; jumping down ledge animation and the rod in the fishing animation. ld a, $90 + .clear cp l ret z @@ -155,24 +166,24 @@ PrepareOAMData: add hl, de jr .clear -Func_4bd1: ; 4bd1 (1:4bd1) +GetSpriteScreenXY: ; 4bd1 (1:4bd1) inc e inc e ld a, [de] ; c1x4 - ld [$ff92], a + ld [hSpriteScreenY], a inc e inc e ld a, [de] ; c1x6 - ld [$ff91], a - ld a, $4 + ld [hSpriteScreenX], a + ld a, 4 add e ld e, a - ld a, [$ff92] - add $4 + ld a, [hSpriteScreenY] + add 4 and $f0 ld [de], a ; c1xa (y) inc e - ld a, [$ff91] + ld a, [hSpriteScreenX] and $f0 ld [de], a ; c1xb (x) ret |