Raspberry Pi 3 Graphics

[seanshpark]

Have problem with RPi3 graphics from console,

• Run SDL_Init() but doesn't work and no error message
• Want to use EGL but get failed to add service - already in use

[seanshpark]

Comment out this line in /boot/config.txt

# dtoverlay=vc4-kms-v3d

Save, reboot and try again.

googling showed that currently it's an experimental OpenGL driver.

[seanshpark]

SDL2 build from source

sudo apt-get install libudev-dev

../configure --prefix=/opt/rpi \
--disable-pulseaudio --disable-esd --disable-video-mir \
--disable-video-wayland --disable-video-x11 --without-x \
--disable-video-opengl --disable-video-vulkan \
--enable-video-opengles --enable-video-opengles1 \
--enable-video-opengles2 \
--enable-video-rpi \
--enable-video-directfb

make
sudo make install

set environment to rpi

export SDL_VIDEODRIVER=rpi

[seanshpark]

Existing issues

• Screen resolution doesn't change with Window size
• Key input doesn't go to SDL
  • Keyboard connected with USB works
    • if executed from terminal then key pressed is sent to the console and not eaten up by the program.

[seanshpark]

Read https://elinux.org/Raspberry_Pi_VideoCore_APIs

[seanshpark]

With DirectFB, export SDL_VIDEODRIVER=directfb

DirectFB/fbdev/vt: Unable to restore VT mode!!!

--> it's called when shutdown. https://github.com/djbclark/directfb-core-DirectFB/blob/master/systems/fbdev/vt.c

DFBResult
dfb_vt_shutdown( bool emergency )

Another error right before this:

Direct/Thread: Started 'VT Switcher' (-1) [CRITICAL OTHER/OTHER 0/0]
[1434: 0.000] --> Caught signal 1 (sent by the kernel)

Run again with second virtual console by pressing ALT-F2.

• Now it seems to work in all virtual console but blank
• Display info reports 640x480 @ 0Hz, wrong.
• Renderer creation fails

[seanshpark]

$ cat ~/.directfbrc
mode=1024x768
depth=16
pixelformat=RGB16

Changes resolution , still no rectangle

[seanshpark]

One solution is to change video resolution at boot time. edit /boot/config.txt and change settings;

hdmi_group=2
hdmi_mode=16

This will change to 1024x768 60Hz

• https://elinux.org/RPiconfig#Video_mode_options

set video to RPi

export SDL_VIDEODRIVER=rpi

Run the program.

[seanshpark]

There exist a program that can change resolution

• http://www.cpmspectrepi.uk/raspberry_pi/MoinMoinExport/OptimisedDisplaySettings.html
• https://www.raspberrypi.org/forums/viewtopic.php?t=162837

Change to 1024x768 60Hz

tvservice -e "DMT 16"

Change to prefered, (default?)

tvservice -p

or

tvservice -e "DMT 82"

Problem: screen is on but blank, nothing is shown. Chaging to another virtual screen (ALT-Fx) solves.

• hack:

  fbset -depth 24 && fbset -depth 32

[seanshpark]

Added to https://github.com/seanshpark/help/wiki/Graphics page.