From 4d12f20a6e588e3cf4323260ef7893df5d9220b7 Mon Sep 17 00:00:00 2001
From: hugova <hugova@kth.se>
Date: Mon, 3 Mar 2025 22:08:00 +0100
Subject: [PATCH] A Fix for D that gets the wrong initial value and the branch
 logic in line_* checked for the wrong value. A new proc, line.s that can
 chose whitch line_* to use A small test program in source.s Wrote a smal test
 program in source.s  (all looks good exept line_up_inv)

---
 wip-hugo/macros/16aritmatic.s                 | 45 ++++++-------------
 wip-hugo/routines/memory/line/line.s          | 41 +++++++++++++++++
 .../routines/memory/{ => line}/line_down.s    | 35 +++++++--------
 .../memory/{ => line}/line_down_inv.s         | 27 ++++++-----
 wip-hugo/routines/memory/{ => line}/line_up.s | 29 ++++++------
 .../routines/memory/{ => line}/line_up_inv.s  | 27 ++++++-----
 wip-hugo/run.sh                               |  4 +-
 wip-hugo/source.s                             | 45 ++++++++++++++++++-
 8 files changed, 157 insertions(+), 96 deletions(-)
 create mode 100644 wip-hugo/routines/memory/line/line.s
 rename wip-hugo/routines/memory/{ => line}/line_down.s (75%)
 rename wip-hugo/routines/memory/{ => line}/line_down_inv.s (85%)
 rename wip-hugo/routines/memory/{ => line}/line_up.s (83%)
 rename wip-hugo/routines/memory/{ => line}/line_up_inv.s (85%)

diff --git a/wip-hugo/macros/16aritmatic.s b/wip-hugo/macros/16aritmatic.s
index 8ef0a96..d7e0efb 100755
--- a/wip-hugo/macros/16aritmatic.s
+++ b/wip-hugo/macros/16aritmatic.s
@@ -25,35 +25,18 @@
 	ROL low_
 	ROL hi_
 .endmacro
+;;Se below for some fast 16bit logic
+;;http://6502.org/tutorials/compare_beyond.html
 
-
-;.proc Sub_abs_8 ;return, primary, secondary
-;	LDA primary
-;	SEC
-;	SBC secondary
-;	BPL end_;we got z positive result
-;	LDA secondary
-;	SEC
-;	SBC primary
-;	end_:
-;	STA return
-;.endproc
-;
-;.proc poer ;low, hi, in  ; [low, hi] = [in]^2
-;	LDY in
-;	STY low
-;	LDA #$00
-;	STA hi
-;	;pow:
-;	DEY ; count = count -1
-;	BEQ y_pow_end;
-;	CLC
-;	LDA in
-;	ADC low
-;	STA low
-;	LDA #$00
-;	ADC hi
-;	STA hi
-;	;jmp pow
-;	y_pow_end:
-;.endproc
+;; exampel 4.1.1
+;;Larger then operation. IF a < b then jump to label
+.macro Lag_16 a_low, a_hi, b_low, b_hi, label ; [low, hi] = [low, hi]*2
+    LDA a_hi  ; compare high bytes
+    CMP b_hi
+    BCC label ; if NUM1H < NUM2H then NUM1 < NUM2
+    BNE LABEL ; if NUM1H <> NUM2H then NUM1 > NUM2 (so NUM1 >= NUM2)
+    LDA a_low  ; compare low bytes
+    CMP b_low
+    BCC label ; if NUM1L < NUM2L then NUM1 < NUM2
+    LABEL:
+.endmacro
diff --git a/wip-hugo/routines/memory/line/line.s b/wip-hugo/routines/memory/line/line.s
new file mode 100644
index 0000000..202074c
--- /dev/null
+++ b/wip-hugo/routines/memory/line/line.s
@@ -0,0 +1,41 @@
+.proc line; X_pos =< X_end skall alltid gälla
+    dx = $fe
+    dy = $69
+    ;;dx
+    SEC
+    LDA X_end
+    SBC X_pos
+    STA dx
+
+    SEC
+    LDA Y_pos
+    SBC Y_end
+    STA dy
+    BCC down ;normal  Y_pos < Y_end
+up:; Y_pos > Y_end
+    STA dy
+    CMP dx
+    BCC shallow; dy < dx
+steep:
+    jsr line_up_inv
+    RTS
+shallow: ;dy =< dx
+    jsr line_up
+    RTS
+down:
+    EOR #$ff ; Fix bit underflow
+    STA dy
+    CMP dx
+    BCC shallow_; dy < dx
+steep_:
+    jsr line_down_inv
+    RTS
+shallow_: ;dy < dx
+    jsr line_down
+    RTS
+.endproc
+
+.include "line_down.s"
+.include "line_down_inv.s"
+.include "line_up.s"
+.include "line_up_inv.s"
diff --git a/wip-hugo/routines/memory/line_down.s b/wip-hugo/routines/memory/line/line_down.s
similarity index 75%
rename from wip-hugo/routines/memory/line_down.s
rename to wip-hugo/routines/memory/line/line_down.s
index 9943a61..287b8c2 100644
--- a/wip-hugo/routines/memory/line_down.s
+++ b/wip-hugo/routines/memory/line/line_down.s
@@ -1,5 +1,5 @@
 ;;drawing line from 2 cordinates
-.proc line
+.proc line_down
     ;;#  (X_pos, Y_pos)                                     #
     ;;#                     *                               #
     ;;#                         *                           #
@@ -17,17 +17,6 @@
     V = $0809
     D = $0a0b
 
-    ;example values ~~~~~ SHOULD BE PRECOMPILED
-    LDA #$00
-    STA X_pos
-    STA Y_pos
-
-    LDA #$90
-    STA X_end
-    LDA #$10
-    STA Y_end
-    ;;~~~~~~~~~~
-
     ;;We need to clear this memory
     LDA #$00
     STA <V
@@ -35,7 +24,7 @@
     STA $FD ; for pixel_draw
 
     ;; V = 2*(dx -dy)
-    ;; where: dy = Y_end - Y_start, dx = X_end - X_start
+    ;; where: dy = Y_end - Y_start, dx = OO - X_start
     LDA Y_end
     SEC
     SBC Y_pos
@@ -53,14 +42,24 @@
     ;dy_2 = dy*2
     mult_16 >dy_2, <dy_2
 
+    ;; D = 2*dy - dx
+    ;; In loop we have that D = D -V
+    ;; So D needs to be at least >=V.
+    ;; V_max = 00000001 11111111
+    ;; For us to work with unsigned numbers we add 00000001 11111111
+    ;; to V and the branch logic to V!
+
     ;;D = 2*dy - dx + 2*255
     ;;Our D is bigger then wikipedia because D is unsigned.
     LDA >dy_2
     STA >D
     LDA <dy_2
     STA <D
-    Add_16 >D, <D, #$00, #$01
+    Add_16 >D, <D, #$ff, #$01
     Sub_16 >D, <D, dx, #$00
+;hihi:
+;jmp hihi
+
 
 for_x:
     jsr pixel_draw
@@ -70,10 +69,9 @@ for_x:
     CPX X_end
     BEQ end
 
-    ;;If D <  %00000001 11111111 <==> >D ==0, then: case_2
-    LDA <D; if <D > 0 then: case_1
-    CMP #$00
-    BEQ case_2
+    ;;If D <  %00000010 00000000:  case_2
+    ;;else case 1.
+    Lag_16 >D, <D, #$00, #$02, case_2
 case_1:
     INC Y_pos
     Sub_16 >D, <D, >V, <V; D = D - V
@@ -82,4 +80,5 @@ case_2:
     Add_16 >D, <D, >dy_2, <dy_2;D = D + 2*dy
     JMP for_x
 end:
+    RTS
 .endproc
diff --git a/wip-hugo/routines/memory/line_down_inv.s b/wip-hugo/routines/memory/line/line_down_inv.s
similarity index 85%
rename from wip-hugo/routines/memory/line_down_inv.s
rename to wip-hugo/routines/memory/line/line_down_inv.s
index 3fd0fec..5ddaf4c 100644
--- a/wip-hugo/routines/memory/line_down_inv.s
+++ b/wip-hugo/routines/memory/line/line_down_inv.s
@@ -1,5 +1,5 @@
 ;;drawing line from 2 cordinates
-.proc line
+.proc line_down_inv
     ;;#  (X_pos, Y_pos)                                     #
     ;;#                     *                               #
     ;;#                         *                           #
@@ -18,14 +18,13 @@
     D = $0a0b
 
     ;example values ~~~~~ SHOULD BE PRECOMPILED
-    LDA #$00
-    STA X_pos
-    STA Y_pos
-
-    LDA #$40
-    STA X_end
-    LDA #$a0
-    STA Y_end
+    ;LDA #$00
+    ;STA X_pos
+    ;STA Y_pos
+    ;LDA #$40
+    ;STA X_end
+    ;LDA #$a0
+    ;STA Y_end
     ;;~~~~~~~~~~
 
     ;;We need to clear this memory
@@ -59,7 +58,7 @@
     STA >D
     LDA <dx_2
     STA <D
-    Add_16 >D, <D, #$00, #$01
+    Add_16 >D, <D, #$ff, #$01
     Sub_16 >D, <D, dy, #$00
 
 for_y:
@@ -70,10 +69,9 @@ for_y:
     CPY Y_end
     BEQ end
 
-    ;;If D <  %00000001 11111111 <==> >D ==0, then: case_2
-    LDA <D; if <D > 0 then: case_1
-    CMP #$00
-    BEQ case_2
+    ;;If D <  %00000010 00000000:  case_2
+    ;;else case 1.
+    Lag_16 >D, <D, #$00, #$02, case_2
 case_1:
     INC X_pos
     Sub_16 >D, <D, >V, <V; D = D - V
@@ -82,4 +80,5 @@ case_2:
     Add_16 >D, <D, >dx_2, <dx_2;D = D + 2*dx
     JMP for_y
 end:
+    RTS
 .endproc
diff --git a/wip-hugo/routines/memory/line_up.s b/wip-hugo/routines/memory/line/line_up.s
similarity index 83%
rename from wip-hugo/routines/memory/line_up.s
rename to wip-hugo/routines/memory/line/line_up.s
index a667a9c..310d8dd 100644
--- a/wip-hugo/routines/memory/line_up.s
+++ b/wip-hugo/routines/memory/line/line_up.s
@@ -1,5 +1,5 @@
 ;;drawing line from 2 cordinates
-.proc line
+.proc line_up
     ;;#                               *      (X_end, Y_end) #
     ;;#                                                     #
     ;;#                         *                           #
@@ -18,15 +18,14 @@
     V = $0809
     D = $0a0b
 
-    ;example values ~~~~~ SHOULD BE PRECOMPILED
-    LDA #$90
-    STA X_pos
-    STA Y_pos
-
-    LDA #$aa
-    STA X_end
-    LDA #$80
-    STA Y_end
+    ;;example values ~~~~~ SHOULD BE PRECOMPILED
+    ;LDA #$90
+    ;STA X_pos
+    ;STA Y_pos
+    ;LDA #$aa
+    ;STA X_end
+    ;LDA #$80
+    ;STA Y_end
     ;;~~~~~~~~~~
 
     ;;We need to clear this memory
@@ -60,7 +59,7 @@
      STA >D
      LDA <dy_2
      STA <D
-     Add_16 >D, <D, #$00, #$01
+     Add_16 >D, <D, #$ff, #$01
      Sub_16 >D, <D, dx, #$00
 for_x:
     jsr pixel_draw
@@ -70,10 +69,9 @@ for_x:
     CPX X_end
     BEQ end
 
-    ;;If D <  %00000001 11111111 <==> >D ==0, then: case_2
-    LDA <D; if <D > 0 then: case_1
-    CMP #$00
-    BEQ case_2
+    ;;If D <  %00000010 00000000:  case_2
+    ;;else case 1.
+    Lag_16 >D, <D, #$00, #$02, case_2
 case_1:
     DEC Y_pos
     Sub_16 >D, <D, >V, <V; D = D - V
@@ -82,4 +80,5 @@ case_2:
     Add_16 >D, <D, >dy_2, <dy_2;D = D + 2*dy
     JMP for_x
 end:
+    RTS
 .endproc
diff --git a/wip-hugo/routines/memory/line_up_inv.s b/wip-hugo/routines/memory/line/line_up_inv.s
similarity index 85%
rename from wip-hugo/routines/memory/line_up_inv.s
rename to wip-hugo/routines/memory/line/line_up_inv.s
index 394e4ea..cf2aa19 100644
--- a/wip-hugo/routines/memory/line_up_inv.s
+++ b/wip-hugo/routines/memory/line/line_up_inv.s
@@ -1,5 +1,5 @@
 ;drawing line from 2 cordinates
-.proc line
+.proc line_up_inv
     ;;#                                      (X_pos, Y_pos) #
     ;;#                                   *                 #
     ;;#                         *                           #
@@ -18,14 +18,13 @@
     D = $0a0b
 
     ;example values ~~~~~ SHOULD BE PRECOMPILED
-    LDA #$60
-    STA X_pos
-    STA Y_pos
-
-    LDA #$50
-    STA X_end
-    LDA #$90
-    STA Y_end
+    ;LDA #$60
+    ;STA X_pos
+    ;STA Y_pos
+    ;LDA #$50
+    ;STA X_end
+    ;LDA #$90
+    ;STA Y_end
     ;;~~~~~~~~~~
 
     ;We need to clear this memory
@@ -59,7 +58,7 @@
     STA >D
     LDA <dx_2
     STA <D
-    Add_16 >D, <D, #$00, #$01
+    Add_16 >D, <D, #$ff, #$01
     Sub_16 >D, <D, dy, #$00
 for_y:
     jsr pixel_draw
@@ -69,10 +68,9 @@ for_y:
     CPY Y_end
     BEQ end
 
-    ;;If D <  %00000001 11111111 <==> >D ==0, then: case_2
-    LDA <D; if <D > 0 then: case_1
-    CMP #$00
-    BEQ case_2
+    ;;If D <  %00000010 00000000:  case_2
+    ;;else case 1.
+    Lag_16 >D, <D, #$00, #$02, case_2
 case_1:
     DEC X_pos
     Sub_16 >D, <D, >V, <V; D = D - V
@@ -81,4 +79,5 @@ case_2:
     Add_16 >D, <D, >dx_2, <dx_2;D = D + 2*dy
     JMP for_y
 end:
+    RTS
 .endproc
diff --git a/wip-hugo/run.sh b/wip-hugo/run.sh
index 3f9534c..df1ccb2 100755
--- a/wip-hugo/run.sh
+++ b/wip-hugo/run.sh
@@ -1,4 +1,4 @@
 # !/bin/bash
-pkill -f pulseaudio
 killall x64sc ; cl65 -o file.prg -u __EXEHDR__ -t c64 -C c64-asm.cfg source.s && nohup flatpak run net.sf.VICE -windowypos 0 -windowxpos 960 -windowwidth 945 -windowheight 720 file.prg  </dev/null &>/dev/null &
-#https://vice-emu.sourceforge.io/vice_7.html
+sleep 2
+rm source.o
diff --git a/wip-hugo/source.s b/wip-hugo/source.s
index 21017ef..8cf7114 100755
--- a/wip-hugo/source.s
+++ b/wip-hugo/source.s
@@ -1,9 +1,50 @@
 .include "STARTUP.s"
 .include "macros/16aritmatic.s"
-.include "routines/memory/line_up_inv.s"
+
+    X_end = $04
+    Y_end = $05
+    X_pos = $FC
+    Y_pos = $FB
+
+    ;;for testing stuff
+    Y_pos_ = $0D
+    X_pos_ = $0E
+    Y_end_ = $10
+    X_end_ = $11
+
+    LDA #$d0
+    STA X_pos_
+    LDA #$60
+    STA Y_pos_
+    LDA #$ff
+    STA X_end_
+    LDA #$0
+    STA Y_end_
+
+@loop:
+    LDA Y_pos_
+    STA Y_pos
+    LDA X_pos_
+    STA X_pos
+    LDA Y_end_
+    STA Y_end
+    LDA X_end_
+    STA X_end
+
+    jsr line
+    INC Y_end_
+    LDA Y_end_
+    CMP #$bb
+    BEQ loop
+    jmp @loop
+loop:
+    jmp loop
+
+
+
 
 loop_:
 jmp loop_
-
 .include "routines/memory/memory_rec.s"
 .include "routines/memory/pixel_draw.s"
+.include "routines/memory/line/line.s"