RP2040 DVI Zooming bitmap

[jposada202020]

CircuitPython version

Adafruit CircuitPython 8.1.0-beta.1-36-g7d02bff6b on 2023-04-20; Adafruit Feather RP2040 DVI with rp2040

Code/REPL

import board
import displayio
from bitmaptools import draw_line
display = board.DISPLAY
group = displayio.Group()

palette = displayio.Palette(1)
palette[0] = 0xFFFFFF

a2 = displayio.Group(x=0, y=0, scale=1)
a2bitmap = displayio.Bitmap(300, 300, 2)
tile2 = displayio.TileGrid(a2bitmap, pixel_shader=palette, x=0, y=0)
draw_line(a2bitmap, 1, 1, 1, 300, 1)
draw_line(a2bitmap, 1, 1, 200, 200, 1,)
a2.append(tile2)
group.append(a2)

display.show(group)

Behavior

Description

So Not sure if my display resolution is all wrong, but I should get 640x480? If it is my mistake, sorry :).
However this script works fine in the Pyportal Titano https://github.com/jposada202020/CircuitPython_uplot/blob/main/examples/uplot_readme_example.py
But with the DVI is blown-up and some of the plots could not be seen.

Additional information

No response

[dglaude]

Just sharing what this code give on my SONY Bravia TV. What was your question?

[dglaude]

First thank you for your piece of code, I could not have progress without reading your code.

I changed a few things to let you check your screen rendering.
First I make the bitmap exactly the size of the DISPLAY.
a2bitmap = displayio.Bitmap(display.width, display.height, 2)

Then I draw a boarder one pixel inside.
Finally I use a sleep loop to stay in the program and not exit in the REPL.

import time

import board
import displayio
from bitmaptools import draw_line
display = board.DISPLAY

group = displayio.Group()

palette = displayio.Palette(1)
palette[0] = 0xFFFFFF

a2 = displayio.Group(x=0, y=0, scale=1)
a2bitmap = displayio.Bitmap(display.width, display.height, 2)

tile2 = displayio.TileGrid(a2bitmap, pixel_shader=palette, x=0, y=0)

draw_line(a2bitmap, 1, 1, 1, display.height-2, 1)
draw_line(a2bitmap, 1, 1, display.width-2, 1, 1)
draw_line(a2bitmap, display.width-2, 1, display.width-2, display.height-2, 1)
draw_line(a2bitmap, 1, display.height-2, display.width-2, display.height-2, 1)

draw_line(a2bitmap, 1, 1, display.height-2, display.height-2, 1)

a2.append(tile2)
group.append(a2)

display.show(group)

while True:
    time.sleep(1)

[dglaude]

And the result:

[dglaude]

I know your mistake, you expect 640x480... and that is the output resolution after pixel doubling, you only have 320x240 in the frame buffer.
I know it from listening to "Ask an Engineer" or "Show and Tell", I am not sure where this is documented in writing.

[jposada202020]

Thank you. Thats explain a lot. Happily will close this 😇. Will test later. Thank you for the info @dglaude . I guess I will need to learn more about this. 🥳

[jposada202020]

@dglaude Thank you