reduse linedraw cpu cyckles before the loop

wip-hugo/routines/line/line_down.s

@@ -22,9 +22,8 @@
         SEC
         LDA dx
         SBC dy
+        Mult_16 A, V +1
         STA V
-        Mult_16 V, V +1
-
         ;dy_2 = dy*2
         Mult_16 dy_2, dy_2 +1 ;>dy_2 = dy (same address)
 
@@ -39,9 +38,21 @@
         ;; and to its branch logic later in the loop.
 
         ;;D = 2*dy - dx + 2*255
-        Mov_16 D, D + 1, dy_2, dy_2 + 1
+        LDA dy_2
-        Add_16 D, D + 1, #$ff, #$01, !
+        ADC #$ff
-        Sub_16 D, D + 1, dx, #$00
+        TAX
+        LDA dy + 1
+        ADC #$01
+        TAY
+
+        SEC
+        TXA
+        SBC dx
+        STA D
+        TYA
+        SBC #$00
+        STA D + 1
+
 selfmod:
         ;; Self modifying code. Makes LDA and SBC instructions each take 1 cycle less.
         ;; You can remove this if you run the loop without # at dy_2 and V.

wip-hugo/routines/line/line_down_inv.s

@@ -19,15 +19,25 @@
         SEC
         LDA dy
         SBC dx
+        Mult_16 A, V + 1
         STA V
-        Mult_16 V, V + 1
 
         Mult_16 dx_2, dx_2 + 1
 
-        Mov_16 D, D + 1, dx_2, dx_2 + 1
+        LDA dx_2
-        Add_16 D, D + 1, #$ff, #$01, !
+        ADC #$ff
-        Sub_16 D, D + 1, dy, #$00
+        TAX
+        LDA dx + 1
+        ADC #$01
+        TAY
 
+        SEC
+        TXA
+        SBC dy
+        STA D
+        TYA
+        SBC #$00
+        STA D + 1
 
 selfmod:
         LDA dx_2

wip-hugo/routines/line/line_up.s

@@ -21,14 +21,25 @@
         SEC
         LDA dx
         SBC dy
+        Mult_16 A, V + 1
         STA V
-        Mult_16 V, V + 1
-
         Mult_16 dy_2, dy_2 + 1
 
-        Mov_16 D, D + 1, dy_2, dy_2 + 1
+
-        Add_16 D, D + 1, #$ff, #$01, !
+        LDA dy_2
-        Sub_16 D, D + 1, dx, #$00
+        ADC #$ff
+        TAX
+        LDA dy + 1
+        ADC #$01
+        TAY
+
+        SEC
+        TXA
+        SBC dx
+        STA D
+        TYA
+        SBC #$00
+        STA D + 1
 
 selfmod:
         LDA dy_2

wip-hugo/routines/line/line_up_inv.s

@@ -20,14 +20,25 @@
         SEC
         LDA dy
         SBC dx
+        Mult_16 A, V + 1
         STA V
-        Mult_16 V, V + 1
 
         Mult_16 dx_2, dx_2 + 1
 
-        Mov_16 D, D + 1, dx_2, dx_2 + 1
+        LDA dx_2
-        Add_16 D, D + 1, #$ff, #$01, !
+        ADC #$ff
-        Sub_16 D, D + 1, dy, #$00
+        TAX
+        LDA dx + 1
+        ADC #$01
+        TAY
+
+        SEC
+        TXA
+        SBC dy
+        STA D
+        TYA
+        SBC #$00
+        STA D + 1
 
 selfmod:
         LDA dx_2