6502 QR Code Generator - (C)2021 Thomas Jentzsch

Instructions:

1. Include QRCodeGen.inc into the code area of your own code

2. Define the following constants:
   - QR_VERSION  = 1..3	; QR code size (21, 25, 29)
   - QR_LEVEL    = 0..3	; error correction levels L, M, Q, H
   - QR_PADDING  = 0|1	; add padding bytes add the end of test message text
   - QR_GENERATE = 0|1	; generate Reed-Solomon ECC generator polynomial on-the-fly
                        ;   else use built-in table

3. Define memory for code generation and displayed bitmap:
   - qrTmpVars 	    ds 9
   - qrData 	    ds QR_TOTAL
   - qrPattern 	    ds 1
   - qrGenerator    ds QR_DEGREE (only required if QR_GENERATE = 1)
   - bitmap         depends on platform

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)

5. Add the macros GEN_QR_CODE and QR_CODE_DATA to your code area

6. Add message text using the START_MSG, n x ADD_MSG_BYTE, STOP_MSG

7. Set qrPattern to 0..7 (chosing a mask pattern)

8. Call the GEN_QR_CODE macro

9. Draw the generated QR code bitmap

That's all! :)