circuitpython/tests/extmod/framebuf_blit.py
Damien George b15348415e extmod/modframebuf: Add support for blit'ing read-only data.
Currently the `FrameBuffer.blit(buf, x, y)` method requires the `buf`
argument to be another `FrameBuffer`, which is quite restrictive because it
doesn't allow blit'ing read-only memory/data.

This commit extends `blit()` to allow the `buf` argument to be a tuple or
list of the form:

    (buffer, width, height, format[, stride])

where `buffer` can be anything with the buffer protocol and may be
read-only, eg `bytes`.

Also, the palette argument to `blit()` may be of the same form.

The form of this tuple/list was chosen to be the same as the signature of
the `FrameBuffer` constructor (that saves quite a bit of code size doing it
that way).

Signed-off-by: Damien George <damien@micropython.org>
2025-06-04 02:40:45 +10:00

68 lines
1.4 KiB
Python

# Test FrameBuffer.blit method.
try:
import framebuf
except ImportError:
print("SKIP")
raise SystemExit
def printbuf():
print("--8<--")
for y in range(h):
for x in range(w):
print("%02x" % buf[(x + y * w)], end="")
print()
print("-->8--")
w = 5
h = 4
buf = bytearray(w * h)
fbuf = framebuf.FrameBuffer(buf, w, h, framebuf.GS8)
fbuf2 = framebuf.FrameBuffer(bytearray(4), 2, 2, framebuf.GS8)
fbuf2.fill(0xFF)
# Blit another FrameBuffer, at various locations.
for x, y in ((-1, -1), (0, 0), (1, 1), (4, 3)):
fbuf.fill(0)
fbuf.blit(fbuf2, x, y)
printbuf()
# Blit a bytes object.
fbuf.fill(0)
image = (b"\x10\x11\x12\x13", 2, 2, framebuf.GS8)
fbuf.blit(image, 1, 1)
printbuf()
# Blit a bytes object that has a stride.
fbuf.fill(0)
image = (b"\x20\x21\xff\x22\x23\xff", 2, 2, framebuf.GS8, 3)
fbuf.blit(image, 1, 1)
printbuf()
# Blit a bytes object with a bytes palette.
fbuf.fill(0)
image = (b"\x00\x01\x01\x00", 2, 2, framebuf.GS8)
palette = (b"\xa1\xa2", 2, 1, framebuf.GS8)
fbuf.blit(image, 1, 1, -1, palette)
printbuf()
# Not enough elements in the tuple.
try:
fbuf.blit((0, 0, 0), 0, 0)
except ValueError:
print("ValueError")
# Too many elements in the tuple.
try:
fbuf.blit((0, 0, 0, 0, 0, 0), 0, 0)
except ValueError:
print("ValueError")
# Bytes too small.
try:
fbuf.blit((b"", 1, 1, framebuf.GS8), 0, 0)
except ValueError:
print("ValueError")