Add more more minute optimisations of circle draw

wip-hugo/routines/circle/circle.inc

@@ -7,7 +7,7 @@
         t2    = $E1
         X_rel = radius
         Y_rel = $E2
-        temp = $E3
+        Y_copy = $E3
         temp_ = $E4
         temo__ = $E5
         byte_to_paint_qaa = byte_to_paint

wip-hugo/routines/circle/circle.s

@@ -33,7 +33,7 @@ draw_center_px_in_circle:
 draw_lower_px_in_circle:
         CLC
         LDA Y_pos
-        STA temp
+        STA temp_
         ADC radius
         STA Y_pos
 
@@ -48,7 +48,7 @@ draw_lower_px_in_circle:
 
         Sub_16 btp_mem_pos_qdb, btp_mem_pos_qdb +1, #$08, #$00
 
-        LDA temp
+        LDA temp_
         STA Y_pos
 draw_right_px_in_circle:
         CLC

wip-hugo/routines/circle/circle_help.s

@@ -6,13 +6,13 @@
 
         ;;We have named the parts of the circle as such.
         ;;               |
-        ;;      qbb      |      qab
+        ;;      qbb (7)  |      qab (8)
         ;;               |
         ;;   qba (2)     |         qaa (1)
         ;;---------------X-----------------> X
-        ;;   qca         |         qda
+        ;;   qca (4)     |         qda (3)
         ;;               |
-        ;;      qcb      |      qdb
+        ;;      qcb (5)  |      qdb (6)
         ;;               |
         ;;               v Y
 
@@ -57,7 +57,7 @@ end_calculation:
 
 ;; Lets draw all half-quatrons of the circle. This draws only 8 pixels per iteration.
 ;; Note that I have the draw_qxx in listed pairs. Each pair chair the same Y-register :)
-STY temp
+STY Y_copy
 draw_qaa:
         LDA byte_to_paint ;A byte containing a single 1. Coresponds to X position in the chunk.
         ORA (btp_mem_pos), Y
@@ -65,19 +65,35 @@ draw_qaa:
 draw_qba: ;;mirror_technique
         LDX byte_to_paint
 	LDA inverse_factor_value, X;; (see END.s)
-	STA temp___
+	TAX
         ORA (btp_mem_pos_qba), Y
         STA (btp_mem_pos_qba), Y
+draw_qda:; y is inverted
+
+        ;; invert Y, this is shared with qca
+        LDA #$07
+        SBC Y_copy
+        TAY
+
+        LDA byte_to_paint
+        ORA (btp_mem_pos_qda), Y
+        STA (btp_mem_pos_qda), Y
+
+draw_qca: ;;mirror technique
+
+        TXA
+        ORA (btp_mem_pos_qca), Y
+        STA (btp_mem_pos_qca), Y
+
 draw_qcb:; xy swoped
-        LDX temp___
         LDA log, X
         TAY
 
         ;;modify X_pos
-        LDX temp
+        LDX Y_copy
        	LDA binary_factor, X; (see END.s)
-        TAX
 
+        TAX
         ORA (btp_mem_pos_qcb), Y
         STA (btp_mem_pos_qcb), Y
 
@@ -106,25 +122,9 @@ draw_qab:; xy swoped + mirroring
         ORA (btp_mem_pos_qab), Y
         STA (btp_mem_pos_qab), Y
 
-draw_qda:; y is inverted
-
-        ;; invert Y, this is shared with qca
-        LDA #$07
-        SBC temp
-        TAY
-
-        LDA byte_to_paint
-        ORA (btp_mem_pos_qda), Y
-        STA (btp_mem_pos_qda), Y
-
-draw_qca: ;;mirror technique
-
-        LDA temp___
-	ORA (btp_mem_pos_qca), Y
-        STA (btp_mem_pos_qca), Y
 
 ;;Recover the Y value (we changed it because evrything is inverted)
-        LDY temp
+LDY Y_copy
 
 increment_y_pos:
         INC Y_rel ; y++