optimise memset and pixel draw!

wip-hugo/routines/memory/memset.s

@@ -11,7 +11,7 @@ LDX length +1
 BNE big_set
 JMP small_set
 
-
+LDX length + 1
 big_set: ;sets $ff of memory
         LDY #$ff
         .repeat $ff
@@ -22,7 +22,7 @@ big_set: ;sets $ff of memory
 big_set_end:
         ;;set all hole $ff memory chunks!
         INC A_start + 1
-        DEC length + 1
+        DEX ;; length +1 --
         BEQ small_set
         JMP big_set
 

wip-hugo/routines/pixel/pixel_draw.s

@@ -4,20 +4,6 @@
 .proc pixel_draw; user-procedure :clobbers (A X Y) :clobbers-arguments 0
         .include "pixel.inc"
 
-        ;; Lets clear some memory for later
-        LDA #$00
-	STA btp_mem_pos + 1
-
-calc_byte_to_paint:
-        ;; X = X_pos (mod 8)
-	LDA X_pos
-	AND #%00000111
-	TAX
-
-	;;this is the same as: byte_to_paint = 2^X
-	LDA binary_factor, X;; (see END.s)
-	STA byte_to_paint
-
 	;;FIND position to write byte_to_paint (btp_mem_pos)
 	;; + + + + + >  X
 	;; +
@@ -39,26 +25,33 @@ calc_byte_to_paint:
 	;; We need to remove the last digit if its still there
 	;; same as LSR ASR
 	AND #%11111110
-
 	TAX
-	LDA big_y_offset, X
-	STA btp_mem_pos
-	INX
-	LDA big_y_offset,X
-	STA btp_mem_pos + 1
-
-	;; btp_mem_pos = big_x_offset
+	;; big_y_offset + big_x_offset
+	CLC
+	;;A = big_x_offset
 	LDA #%11111000
 	AND X_pos
-	Add_16 btp_mem_pos, btp_mem_pos +1, A, #$00
+	ADC big_y_offset, X
+	STA btp_mem_pos
+	LDA #$00
+	INX
+	ADC big_y_offset, X
+	STA btp_mem_pos + 1
 
-	;; + smal_y_offset
+	;; + small_y_offset
 	LDA #%00000111 ; A = y (mod 8)
 	AND Y_pos ;; offset to add
 	TAY
 
-	;;Let draw some stuff
-	LDA byte_to_paint ;; note that both bytes are used!
+calc_byte_to_paint: ;; aka small_x_offset
+	LDA X_pos
+	AND #%00000111
+	TAX
+	;;this is the same as: byte_to_paint = 2^X
+	LDA binary_factor, X;; (see END.s)
+	STA byte_to_paint ;; should be removed, here for other code!
+
+draw:	;;Let draw some stuff
 	ORA (btp_mem_pos), Y
 	STA (btp_mem_pos), Y
 	RTS