Screenshot feature ?
myStphane opened this issue · 5 comments
Could it be possible to have a screenshot feature to capture the current screen with a combination of buttons?
Idea: reserve a memory space (in advance, like save space) to have "some" slot(s) for screenshot(s), and then later retrieve it (& extract it as jpg / png / raw / ... image) in a way like the script "saves_backup.sh" does.
Yes, shouldn't be too hard. Easiest would be to have a static allocation and do a raw frame buffer copy, as the size will be predictable and fixed. JPEG is lossy, and PNG could potentially become large based on the pixel data.
we can also respawn the framebuffer capture over stlink to get some capture.
You can stream the framebuffer in real time to a virtual camera in Linux today, and use it in e.g. obs. It’s not fast but works :). https://github.com/kbeckmann/game-and-watch-retro-go/blob/main/tools/screengrabber.py
use gdb and run :
dump binary memory img1.bin 0x24000000 0x24025800
dump binary memory img2.bin 0x24025800 0x2404B000
will get raw bmp file data but not file header.
Dump that file and finally run:
copy img0.bin/b+img1.bin/b img.bmp
at windows will (img0.bin is a bmp file (320x240 RGB565)'s header) get the screen bmp image file.
img0.bin:
https://drive.google.com/file/d/1czvyuRzgmHeeoLk3bOWI1hpIwXbt2K8O/view
@myStphane I have now implemented the feature.
Screenshots can be captured by pressing PAUSE/SET + GAME. This feature is disabled by default if the external flash is 1MB (stock units), because it takes up 150kB in the external flash.
Screenshots can be downloaded by running make dump_screenshot, and will be saved as a 24-bit RGB PNG.