Made it work on Raspberry PI 3 Model B
This is an update of eglonx for Raspberry pi. This fixes crashes on start up and a pixel swapping error on the software conversion to 565 for drawing on to the X window. Also added more complete handling of X window mouse and expose events.
Fixed startup crash by replacing this:
Ximage = XGetImage(Xdsp, Xwin, 0, 0, Xgwa.width, Xgwa.height, AllPlanes, ZPixmap);
with
char *buf = (char *)malloc(Xgwa.width*Xgwa.height*2);
Ximage = XCreateImage(Xdsp,
DefaultVisual(Xdsp, DefaultScreen(Xdsp)),
DefaultDepth(Xdsp, DefaultScreen(Xdsp)),
ZPixmap, 0, buf, Xgwa.width, Xgwa.height, 16, 0);
And added this on exit:
bcm_host_deinit();
Paul
Demo of Raspbery Pi OpenGL ES rendering to X window posted to raspberrypi.org forums by @teh_orph at http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=6488
Converted to c from c++, added Makefile. Tested on Raspbian.
to run type
cd pi-eglonx
make
./eglonx
Post by @teh_orph
Hello guys,
Quick proof-of-concept: hardware accelerated 3D in an X window.
You do not need any fancy X server to make this work. The code provided
below only works in a 16-bit 5/6/5 screen though.
Brief summary:
- I took this code: http://wiki.maemo.org/SimpleGL_example
- replaced the eglCreateWindowSurface with eglCreatePixmapSurface
- replaced the swap buffers with a glReadPixels and an XPutImage
Since everything's done in X, all window hiding stuff works fine. You can
run multiple EGL programs too. (In the video I run the same program twice -
no sharing is being done between them if you're wondering!)
http://www.youtube.com/watch?v=l0i55EndDZQ
CAVEATS:
- eglCreatePixmapSurface seems to be ill-documented for the Broadcom 3D EGL
API. Figuring out what to put as the pixmap argument appears to be guesswork!
- X is currently invisible in 24/32-bit mode, and I can't get the pixmap to run
in 16-bit mode. So I *in software* glReadPixels the image in 32-bit mode, and
then convert to 5/6/5 by hand...this is of course slow. Once it's figured out
how to make either a 16-bit pixmap or get 32-bit X working, no conversion will
be required.
NB: glReadPixels is powered by the hardware's DMA functionality once the GPU
is flushed. The X server it is running on in the video has DMA-enabled blitting,
so - assuming the 32->16 conversion is omitted - the whole process would be
powered by DMA.