Test byte in GCBglcd buffer

[stan cartwright]

Hi all.Sorry to be a nuisance. I want to test if a pixel is lit on a glcd. This code doesn't work. How do I define the start of SSD1306_BufferAlias?
I don't want to copy and change the plot routine, well if I could still plot I would. I'm thinking of modifying the glcd for my own use and just use different inits for different displays but that's not encouraged it seems. Don't see why not. I got to include the glcd anyway so can't see the difference.

#chip 18F25K22, 16
#option explicit
#include <glcd.h>
;
' Define I2C settings - CHANGE PORTS
#define I2C_MODE Master
#define I2C_DATA PORTC.4
#define I2C_CLOCK PORTC.3
#define I2C_DISABLE_INTERRUPTS ON
'Optionally, you can reduce the I2C timings.
#define I2C_BIT_DELAY 0 us
#define I2C_CLOCK_DELAY 0 us
#define I2C_END_DELAY 0 us
; ----- Define GLCD Hardware settings
#define GLCD_TYPE GLCD_TYPE_SSD1306
#define GLCD_I2C_Address 0x78
;
dim pixel as byte
dim pixel_set as byte
dim pixel_x as byte
dim pixel_y as byte
dim ptr as word
;
GLCDCLS
do
line (50,0,50,7,1)
pixel_x=50:pixel_y=0
pixel_lit
;glcdprint (0,30,SSD1306_BufferAlias) ;duplicate definition error
glcdprint (8,0,pixel_set)
glcdprint (60,50,ptr)
if pixel_set=1 Then
  glcdprint (0,20,"pixel set")
Else
  glcdprint (0,20,"pixel clear")
end if

loop
'------
sub pixel_lit
pixel=pixel_y and 7
;
ptr=pixel_y and 0xf8
repeat 4
set c off
rotate ptr left ;x16
end Repeat
ptr=ptr Or pixel_x ;screen byte in buffer

pixel_set=1
repeat pixel
set c off
rotate pixel_set left ;screen byte value of pixel
end repeat

pixel_set=pixel_set And SSD1306_BufferAlias( ptr ) ;where is SSD1306_BufferAlias?
end sub

[Anobium]

This is a relatively simple method to implement.

I already posted on this about a month ago. is this a different ask?

[stan cartwright]

Hi Evan. You mentioned that the arduino c include idea is ad hoc and you want standardisation in GCB and that anyone can use the lib includes for their own ends. That's what I'll do a bit. Seeing it's only a black and white display I could change pset x,y,0 to 2-xor,3-pixel test set/clear. It would then be just SSD1306 glcd driver. I would be portable in that it would work on pic and uno but that's what uno and rpi is,open source on an attempt to standardise. I can see that keeping the x,y,colour format works for all displays the same idea. I'll see again if I can figure out how to use SSD1306_BufferAlias from outside include glcd.

[stan cartwright]

Thanks. My problem is I'm unfamiliar with functions. I only started using sub on the weekend.I got side tracked half way through a robot project. I'll get back to it again. Thanks again.

[Anobium]

For those following along...... I delete the posting with the code. As after speaking offline with Stan i thought has was not going to use the code.

Summary: Turned out that reading of the help, specifically the FAQ helped, and printing numbers and strings needs to use STR(number_variable) and to add spaces to a string to use PAD() or LEFTPAD()

:-)