rng optimization

Author: zohassadar

src/gamemode/levelmenu.asm

@@ -165,16 +165,14 @@ levelMenuCheckGoBack:
 shredSeedAndContinue:
         ; seed shredder
 @chooseRandomHole_player1:
-        ldx #$17
-        ldy #$02
+        ldx #rng_seed
         jsr generateNextPseudorandomNumber
         lda rng_seed
         and #$0F
         cmp #$0A
         bpl @chooseRandomHole_player1
 @chooseRandomHole_player2:
-        ldx #$17
-        ldy #$02
+        ldx #rng_seed
         jsr generateNextPseudorandomNumber
         lda rng_seed
         and #$0F

src/gamemodestate/initstate.asm

@@ -103,7 +103,6 @@ gameModeState_initGameState:
         sta currentPiece
         jsr incrementPieceStat
         ldx #rng_seed
-        ldy #$02
         jsr generateNextPseudorandomNumber
         jsr chooseNextTetrimino
         sta nextPiece
@@ -269,8 +268,7 @@ L87E7:  lda generalCounter
         sta vramRow
         lda #$09
         sta generalCounter3
-L87FC:  ldx #$17
-        ldy #$02
+L87FC:  ldx #rng_seed
         jsr generateNextPseudorandomNumber
         lda rng_seed
         and #$07
@@ -289,8 +287,7 @@ L87FC:  ldx #$17
         dec generalCounter3
         jmp L87FC
 
-L8824:  ldx #$17
-        ldy #$02
+L8824:  ldx #rng_seed
         jsr generateNextPseudorandomNumber
         lda rng_seed
         and #$0F

src/modes/tspins.asm

@@ -70,7 +70,6 @@ advanceGameTSpins_actual:
 
 generateNewTSpin:
         ldx #rng_seed
-        ldy #$2
         jsr generateNextPseudorandomNumber
         lda rng_seed
         tax

src/nmi/nmi.asm

@@ -21,7 +21,6 @@ nmi:    pha
         adc frameCounter+1
         sta frameCounter+1
         ldx #rng_seed
-        ldy #$02
         jsr generateNextPseudorandomNumber
         jsr copyCurrentScrollAndCtrlToPPU
         jsr pollControllerButtons

src/playstate/spawnnext.asm

@@ -61,7 +61,6 @@ pickRandomTetrimino:
         bne useNewSpawnID
 @invalidIndex:
         ldx #rng_seed
-        ldy #$02
         jsr generateNextPseudorandomNumber
         lda rng_seed
         and #$07
@@ -152,7 +151,6 @@ pickTetriminoSeed:
         bne @useNewSpawnID
 @invalidIndex:
         ldx #set_seed
-        ldy #$02
         jsr generateNextPseudorandomNumber
         lda set_seed
         and #$07
@@ -174,7 +172,6 @@ pickTetriminoSeed:
 
 setSeedNextRNG:
         ldx #set_seed
-        ldy #$02
         jsr generateNextPseudorandomNumber
         rts
 

src/util/core.asm

@@ -48,19 +48,14 @@ resetScroll:
 
 random10:
         ldx #rng_seed
-        ldy #$02
         jsr generateNextPseudorandomNumber
         ldx #rng_seed
-        ldy #$02
         jsr generateNextPseudorandomNumber
         ldx #rng_seed
-        ldy #$02
         jsr generateNextPseudorandomNumber
         ldx #rng_seed
-        ldy #$02
         jsr generateNextPseudorandomNumber
         ldx #rng_seed
-        ldy #$02
         jsr generateNextPseudorandomNumber
         lda rng_seed
         and #$0F
@@ -249,19 +244,12 @@ copyAddrAtReturnAddressToTmp_incrReturnAddrBy2:
 ;reg x: zeropage addr of seed; reg y: size of seed
 generateNextPseudorandomNumber:
         lda tmp1,x
+        eor tmp2,x
         and #$02
-        sta tmp1
-        lda tmp2,x
-        and #$02
-        eor tmp1
-        clc
-        beq @updateNextByteInSeed
-        sec
-@updateNextByteInSeed:
+        lsr
+        lsr
         ror tmp1,x
-        inx
-        dey
-        bne @updateNextByteInSeed
+        ror tmp2,x
         lda #$00
         adc oneThirdPRNG
         cmp #$03