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Hi everyone,

I've just started a closed beta for my game based on SDL 2 (2.0.3) and one of the testers reported a very weird behaviour when running the game on a Samsung S3 (Android 4.3).

Basically every colour is turned into red as showed in the pics you can find here:
http://imgur.com/a/dvris

The most weird thing is that if he takes a screenshot the images come up with the right colours.

I did some digging on Google and found other games suffer the same bug, for example:
http://openxcom.org/forum/index.php/topic,1864.msg16802.html#msg16802


That guy was experiencing this problem on a Galaxy Note 10.1 which has a Mali-400MP4 as GPU, the same used by the S3. My game works fine on a Sony Xperia U with a Mali-400 instead. So it seems to be very specific to that particular GPU.


Any idea how to fix this?


Thanks

--
Davide Coppola

email:
website: http://www.davidecoppola.com



blog: http://blog.davidecoppola.com


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This is a known issue, take a look at Bugzilla for a few workarounds.

2015-09-04 12:42 GMT-03:00 Davide Coppola:




--
Gabriel.

Thank you Gabriel.

For future reference the related bug report is: https://bugzilla.libsdl.org/show_bug.cgi?id=2291


I haven't tried any workaround yet, but I will post my results here and on Bugzilla.


Cheers


--
Davide Coppola

email:
website: http://www.davidecoppola.com



blog: http://blog.davidecoppola.com


[/url] [url=http://www.linkedin.com/in/davidecoppola] [url=http://www.twitter.com/vivaladav][/url]

I had this issue on a samsung device. I was able to solve it by adding this code before my window create call.

    SDL_GetDisplayMode(0, 0, &sdpm);
    i_width = sdpm.w;
    i_height = sdpm.h;


    SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 5);
    SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 6);
    SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5);


    window = SDL_CreateWindow(title, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, i_width, i_height, SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN);



You can also try 8, 8, 8 if 5,6,5 doesn't work for you.


On Sat, Sep 5, 2015 at 2:59 AM, Davide Coppola wrote:

I wonder why SDL requests a R3 G3 B2 (8-bit) system GL framebuffer by default in the first place. I’d expect SDL to default to at least 5,6,5 (16-bit) – sane systems will probably just give back 16 or 24/32 bit when 8 bit is requested, in any case.

Ryan / Sam: would you object to changing the default RGB bit sizes that SDL requests for the system GL framebuffer from 3,3,2 to 5,6,5?


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I always thought that the default size of the rgb bitfields depended on system capabilities.



On Sat, Sep 5, 2015 at 12:27 PM, Alex Szpakowski wrote:

SDL requests an R3G3B2-sized color framebuffer by default: https://hg.libsdl.org/SDL/file/6d6a972746b3/src/video/SDL_video.c#l2669

But systems are allowed to actually use larger sizes than what was requested (and they definitely do in practice.) The 3-3-2 request just seems to screw up colors on some Android devices.

I confirm that calling SDL_GL_SetAttribute for the 3 colour channels fixed the problem.

This was happening on a Samsung S3 running Android 4.3, but not on one running Android 4.4.


As Alex suggested, I agree it would be sensible to set the default values to 565.


On 5 September 2015 at 20:38, Alex Szpakowski wrote:




--
Davide Coppola

email:
website: http://www.davidecoppola.com



blog: http://blog.davidecoppola.com


[/url] [url=http://www.linkedin.com/in/davidecoppola] [url=http://www.twitter.com/vivaladav][/url]

I'd rather set the default values based on underlying hardware capabilities.

On my system for example the preferred format is 8888


On Mon, Sep 7, 2015 at 9:44 AM, Davide Coppola wrote:

yes, that would be definitely better!

I didn't look at the code though and I was assuming the default values were used when the proper capabilities are not recognized or properly handled by SDL (as it seems to happen for this, still unfixed, bug).


On 7 September 2015 at 17:47, Raymond Jennings wrote:




--
Davide Coppola

email:
website: http://www.davidecoppola.com



blog: http://blog.davidecoppola.com


[/url] [url=http://www.linkedin.com/in/davidecoppola] [url=http://www.twitter.com/vivaladav][/url]