Error with line drawing

[josuah]

Thank you to @rezolf who submitted that detailed reproducer
https://discord.com/channels/963222352534048818/1129289344834883594/1129353768346079342

This can be reproduced with the latest firmware release from Brilliant as below:

import display

#  a X on the display, and some more line drawing

# Left Down to Right Up
l1 = display.Line(0,0,639,399, display.GREEN)
# Left Up to Right Down
l2 = display.Line(0, 399, 639, 0, display.GREEN)
#  Vertical middle 
l3 = display.Line(319,0,319,399, display.RED)
#  Horzontal middle 
l4 = display.Line(0,199,639,199, display.RED)

# draw Left down to Right up (works)
display.show(l1)

# draw Left Up, Right down (works)
display.show(l2)

# draw X, (Fails, Nothing on screen)
display.show(l1,l2)

# Left Down to Right Up and Vertical (Works)
display.show(l1,l3)

# Left Down to Right Up and Horizontal (Fails, on lower part of screen)
display.show(l1,l4)

I will try to provide equivalent raw libvgr2d calls today.

[josuah]

This under ongoing debugging through this patch: #16.

[josuah]

[EDIT: this is all due to the vgrs.py tool made that ignored the 16x resolution and blending, this has been fixed since then. This message can be ignored.]

original message

# draw Left down to Right up (works)
display.show(l1)

Looking fine, maybe a bit too thick at the bottom...

---

# draw Left Up, Right down (works)
display.show(l2)

Looking fine, maybe a few lines missing at the bottom...

---

# draw X, (Fails, Nothing on screen)
display.show(l1,l2)

Looking mostly fine, although the top-right part of the 'X' is offset by what seems to be the line thickness of the left branch of the 'X', and overflows (as seen on the top left corner having the tip of the top right branch).

---

# Left Down to Right Up and Vertical (Works)
display.show(l1,l3)

Here we can clearly see the offset.

---

# Left Down to Right Up and Horizontal (Fails, on lower part of screen)
display.show(l1,l4)

This bug might be unrelated, maybe some bug in my software renderer for RVGR...

[josuah]

# draw Left down to Right up (works)
display.show(l1)

Looking fine.

---

# draw Left Up, Right down (works)
display.show(l2)

Looking fine.

---

# draw X, (Fails, Nothing on screen)
display.show(l1,l2)

Looking fine on simulation, although the top-right part of the 'X' is possibly a bit too far off the right edge?
[EDIT: apparently not]

---

# Left Down to Right Up and Vertical (Works)
display.show(l1,l3)

Looking fine.

---

# Left Down to Right Up and Horizontal (Fails, on lower part of screen)
display.show(l1,l4)

(mind that the photo is turned upside down)