chriscamacho / gles2framework Goto Github PK

Hi,

Not an issue, but a question.
I'm learning OpenGL and can't stop playing with the Rpi, so I was really happy to find your helper library for fonts support :-)

I would like to draw a video overlay, i.e.
_ render a video using omxplayer (layer 0)
_ draw an Opengl and render it to a dispmanx layer to make an overlay

I'm currently trying to customize testFreetypeGlesPi to make the overlay background transparent.
Using dispmanx, I'm able to display png pictures with transparency, I would expect that I just need to make the texture's background transparent.
Although I can control the background color, I fail to make it transparent.

My changes are:

in makeNativeWindow():

• VC_DISPMANX_ALPHA_T alpha = {
  DISPMANX_FLAGS_ALPHA_FIXED_ALL_PIXELS,255,0 };

• VC_DISPMANX_ALPHA_T alpha = { DISPMANX_FLAGS_ALPHA_FROM_SOURCE,255,0 };

in main()

• glClearColor(R, G, B, 1);

• glClearColor(R, G, B, 0);

... so it seems that I've missed something.
Any idea? Could you give me some hints?

Thanks!

I have just installed Raspbian on my Raspberry Pi. Could you point how to install all the dependencies and what are the commands to compile and run gles2framework examples?

sudo apt-get install git
sudo apt-get install libpng-dev
sudo apt-get install libode-dev
...

git clone https://github.com/chriscamacho/gles2framework.git
cd gles2framework
make

I've got this error : http://d.pr/i/yEvR

Hi Chris,
your framework-examples are compiling fine with $C_INCLUDE_PATH=/opt/vc/include on raspberry pi but nothing happens when they are executed, I just get my command line back again; any hints for that issue?
Thanks a lot

The following little patch is needed in order to build this with libpng 1.4 or never.
The function in question has been marked as deprecated since version 1.0.18.

Here is more info from the version 1.4.0 announce file.

m. The function png_set_gray_1_2_4_to_8() was removed. It has been
deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with
png_set_expand_gray_1_2_4_to_8() because the former function also
expanded palette images.

Here is the little patch that is needed to make this work on """""nonstable""""""
distros. (Arch, Gentoo):

diff --git a/src/support.c b/src/support.c
index ea48c86..80d93a5 100644
--- a/src/support.c
+++ b/src/support.c
@@ -294,7 +294,7 @@ int loadPNG(const char *filename)
if (colourType == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png_ptr);
if (colourType == PNG_COLOR_TYPE_GRAY && bitDepth < 8)

•           png_set_gray_1_2_4_to_8(png_ptr);
  

•           png_set_expand_gray_1_2_4_to_8(png_ptr);
  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
          png_set_tRNS_to_alpha(png_ptr);
  

Hello,
This looks like a nice project, especially for its ultra lightweight windowing/input that includes a no-X code path. However, I couldn't find its license and would ask you to correct this. Code without a license is essentially proprietary and cannot be reused for anything public. If you don't have a license in mind, I'd suggest MIT, which I prefer for my own stuff these days (it allows broader usage than the GPL).