From c53631ec2577e869f46d5c5bcc4fb9c7f292e804 Mon Sep 17 00:00:00 2001
From: thrust26 <tjentzsch@yahoo.de>
Date: Fri, 16 Apr 2021 08:33:57 +0200
Subject: [PATCH] slightly improved instructions

---
 QRCodeGen.inc     | 17 ++++++++++-------
 QRCodeGenDemo.asm | 11 ++++++-----
 instructions.txt  | 11 +++++------
 3 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/QRCodeGen.inc b/QRCodeGen.inc
index 361c818..b690347 100644
--- a/QRCodeGen.inc
+++ b/QRCodeGen.inc
@@ -502,8 +502,11 @@ DrawPattern SUBROUTINE
     ldy     .right1
     dey
     dey
-;    bpl     .loopRight      ; unconditional!
-    jmp     .loopRight      ; unconditional!
+  IF QR_OVERLAP
+    jmp     .loopRight
+  ELSE
+    bpl     .loopRight      ; unconditional!
+  ENDIF
 ; } // for right
 .exitDraw
   ENDM
@@ -977,7 +980,11 @@ FormatHi
 ; positions of the 15 type information bits
 FormatX1
     .byte   0, 1, 2, 3, 4, 5, 7, 8
-    .byte   8, 8, 8, 8, 8, 8, 8
+;    ds      7, 8           ; shared
+FormatX2
+    ds      7, 8
+    .byte   QR_SIZE-8, QR_SIZE-7, QR_SIZE-6, QR_SIZE-5
+    .byte   QR_SIZE-4, QR_SIZE-3, QR_SIZE-2, QR_SIZE-1
 FormatY2
     .byte   0, 1, 2, 3, 4, 5, 6
 ;    ds      8, QR_SIZE-9   ; shared
@@ -985,10 +992,6 @@ FormatY1
     ds      8, QR_SIZE-9
     .byte   QR_SIZE-8, QR_SIZE-6, QR_SIZE-5, QR_SIZE-4
     .byte   QR_SIZE-3, QR_SIZE-2, QR_SIZE-1
-FormatX2
-    ds      7, 8
-    .byte   QR_SIZE-8, QR_SIZE-7, QR_SIZE-6, QR_SIZE-5
-    .byte   QR_SIZE-4, QR_SIZE-3, QR_SIZE-2, QR_SIZE-1
   ENDIF ; /QR_SINGLE_MASK = 0 || QR_DIRECT_DRAW = 0
 
 BitMask
diff --git a/QRCodeGenDemo.asm b/QRCodeGenDemo.asm
index 1b7ba70..893b326 100644
--- a/QRCodeGenDemo.asm
+++ b/QRCodeGenDemo.asm
@@ -12,7 +12,7 @@
 ;   + optimize single pattern for space
 ; x support multiple QR code versions
 ; o support multiple QR code levels
-; x try to optimize function pattern (SetPixel)
+; + try to optimize function pattern (SetPixel)
 ; x add logo (does NOT work for such small sizes)
 
 ;---------------------------------------------------------------
@@ -58,6 +58,7 @@ QR_SPRITE_GFX   = 1     ; display playfield or sprite graphics
     ERR
   ENDIF
 
+
 ;===============================================================================
 ; C O N S T A N T S
 ;===============================================================================
@@ -515,14 +516,14 @@ InitDemo SUBROUTINE
     sta     NUSIZ0
     sta     VDELP1
 
-    ldx     #$3f
+    ldx     #$6f
     stx     HMP0
     inx
     stx     HMP1
-    lda     #$a0
+    lda     #$d0
     sta     HMM1
 
-    SLEEP   5
+    SLEEP   4
 
     sta     RESM1
     sta     RESP0
@@ -811,7 +812,7 @@ _QR_TOTAL SET _QR_TOTAL + . - FunctionModulesData
 
     QR_CODE_DATA
 
-    .byte   " QR Code Generator Demo V0.4 - (C)2021 Thomas Jentzsch "
+    .byte   " QR Code Generator Demo V0.5 - (C)2021 Thomas Jentzsch "
 
 ; messages MUST NOT be longer than 26 bytes for version 2, level M!
 MessageTbl
diff --git a/instructions.txt b/instructions.txt
index ed9dca7..9bf279f 100644
--- a/instructions.txt
+++ b/instructions.txt
@@ -22,16 +22,15 @@ Instructions:
 4. Implement two subroutines:
    - GetPixel: checks the pixel at position x (Y), y (X), returns Z = 1 if not set
    - InvertPixel: inverts the pixel at position x (Y), y (X)
+   Note: Both routines MUST NOT change X and Y registers!
 
-5. Add the macros GEN_QR_CODE and QR_CODE_DATA to your code area
+5. Add message text using the START_MSG, n x ADD_MSG_BYTE, STOP_MSG
 
-6. Add message text using the START_MSG, n x ADD_MSG_BYTE, STOP_MSG
+6. Set qrPattern to 0..7 (chosing a mask pattern)
 
-7. Set qrPattern to 0..7 (chosing a mask pattern)
+7. Use the GEN_QR_CODE and QR_CODE_DATA macros
 
-8. Call the GEN_QR_CODE macro
-
-9. Draw the generated QR code bitmap
+8. Draw the generated QR code bitmap
 
 That's all! :)