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I tried compiling my SDL app for NaCl (mostly just for fun).

I was able to get the SDL test app running on Chrome, but I could not find instructions to compile SDL_image for NaCl to get my own app to compile.

Are there instructions somewhere that I could follow?

Hello,

SDL_image, ttf and mixer are working with NaCL.
only a small patch need to be done on their files "config.sub"

(Like on SDL lib, see https://hg.libsdl.org/SDL/rev/ae720d61d14d)

I guess it should be somehow generated, but I don't know how.

Cheers,
Sylvain


On Mon, Jul 7, 2014 at 10:18 AM, ollika wrote:



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Sylvain Becker
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I just updated SDL_image, SDL_mixer, SDL_net, and SDL_ttf with the nacl config.sub changes.

Thanks!


On Mon, Jul 7, 2014 at 2:50 AM, Sylvain Becker wrote:

Thanks!
I got everything to compile with some fiddling. My app is currently crashing on load, but I'm sure that it's my fault (because I haven't looked into how to load files files with nacl yet).

I thought I'd put some notes from my adventures so far.

Obviously all this needs to be cleaned up and automated, but here is a quick and dirty way to compile SDL and SDL_image for PNaCl (on linux):

1) Preparing NACL
Download and install nacl (I installed nacl to ~/nacl_sdk/)
Set the environment var that points to the nacl installation:
export NACL_SDK_ROOT=/home/me/nacl_sdk/pepper_35

2) Compiling SDL (in your SDL dir):
export CFLAGS="-I$NACL_SDK_ROOT/include -I$NACL_SDK_ROOT/include/pnacl"
export CC="$NACL_SDK_ROOT/toolchain/linux_pnacl/bin/pnacl-clang"
export AR="$NACL_SDK_ROOT/toolchain/linux_pnacl/bin/pnacl-ar"
export LD="$NACL_SDK_ROOT/toolchain/linux_pnacl/bin/pnacl-ar"
export RANLIB="$NACL_SDK_ROOT/toolchain/linux_pnacl/bin/pnacl-ranlib"
./configure --host=pnacl
make

3) Compiling SDL_image (in your SDL_image dir):
Nacl comes with precompiled libz, libpng and libjpeg but they are in a separate "ports" folder.
I added the paths manually here to make configure find them. For some reason adding the path to CFLAGS did not work, so I added it directly to the command. Also I had to add LIBS=-lm to get configure to accept libpng.

In addition SDL_image needs to know about SDL.

export SDL2_CONFIG=<path to your sdl>/SDL
export CFLAGS="-I$NACL_SDK_ROOT/include -I$NACL_SDK_ROOT/include/pnacl -I<path to your sdl>/SDL/include"
export LDFLAGS="-L$NACL_SDK_ROOT/ports/lib/newlib_pnacl/Release"
export CC="$NACL_SDK_ROOT/toolchain/linux_pnacl/bin/pnacl-clang -I$NACL_SDK_ROOT/ports/include"
export LIBS=-lm
./configure --host=pnacl
make

Compiling the test program for SDL image fails, but I got the libSDL2_image.a out OK so it doesn't really matter.

4) Compiling my app
I copied the test program from SDL/test/nacl/ to myproject/nacl/.
I created myproject/nacl/lib and copied all the SDL libs there (libSDL2.a libSDL2_image.a libSDL2main.a)

I did some edits to the Makefile copied from sdl test:
Point NACL_SDK_ROOT to your nacl installation:
NACL_SDK_ROOT ?= /home/suikkari/nacl/nacl_sdk/pepper_35

I added the image libs (and removed test). This order worked for me (order matters):
LIBS = SDL2_image SDL2 ppapi_simple SDL2main SDL2 png tiff jpeg z $(DEPS) ppapi_gles2 ppapi_cpp ppapi pthread

I created a new variable containing the extra libs:
EXTRA_LIB_PATHS = -L$(NACL_SDK_ROOT)/ports/lib/newlib_pnacl/$(CONFIG) -L./lib

and modified the linking line a bit to use it:
$(call LOG,LINK,$$@,$(PNACL_LINK) -o $$@ $(2) $(PNACL_LDFLAGS) $(foreach path,$(5),-L$(path)/pnacl/$(CONFIG)) $(EXTRA_LIB_PATHS) $(foreach lib,$(3),-l$(lib)) $(6))

(There must be a better way to define library search paths. Surely. Also I assume there is some way to nicely link to the ports libs that are included with nacl, but I did not find it with a quick search.):

Now replace the sources list with your source files and run make (Assuming the same environment variables that were defined for compiling SDL_image are still defined):
make

5) Done. There should be a pexe file somewhere in myproject/nacl/pnacl.

There are still some steps to see the app in your browser but those should be easier to figure out. Like I said, my app is still crashing on startup. So I'm not 100% sure if this works, but I'm pretty sure it should. I could try with some simpler program, but I haven't had the time to do that yet.

Thanks for sharing! You can open Chrome's Dev Console and see if you get any information there before the crash, and you can also use GDB's remote debugging (it's a PITA to get right though ): https://developer.chrome.com/native-client/devguide/devcycle/debugging


2014-07-08 10:54 GMT-03:00 ollika:




--
Gabriel.

Ollika,

On my side, there was almost not modification to build my app for NaCl.
The most annoying trouble was chrome on linux that wasn't working correctly.

I had to use the "google-chrome-beta" package.
I would double-check that the "test examples" are working !

Cheers,
Sylvain




On Tue, Jul 8, 2014 at 4:18 PM, Gabriel Jacobo wrote:



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Sylvain Becker
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