OK, like last time, I'm going to anwser myself...

First thing, it is not possible to change the buffer size.
To display something in widescreen mode you have to change the guOrtho or guPerspective to use a different ratio W/H. it will then be rendered in the 640x480 buffer, and then streched back to the TV. And it looks OK.

So I made a few changes in GRRLIB, if you're interested.
First I created 2 global variables called GRRLIB_ScreenWidth and GRRLIB_ScreenHeight, to access it from anywhere in my program (just like rmode before).

So in GRRLIB.h around line 180

GRR_EXTERN  GXRModeObj  *rmode;
GRR_EXTERN  void        *xfb[2]  GRR_INITS(NULL, NULL);
GRR_EXTERN  u32         fb       GRR_INIT(0);
GRR_EXTERN    u16            GRRLIB_ScreenWidth;        //That's new
GRR_EXTERN    u16            GRRLIB_ScreenHeight;        //That's new

In GRRLIB_core.c, line 75

    GRRLIB_ScreenHeight = rmode->xfbHeight;
    GRRLIB_ScreenWidth = rmode->fbWidth;
    
    // 16:9 and 4:3 Screen Adjustment
    if (CONF_GetAspectRatio() == CONF_ASPECT_16_9) {
        rmode->viWidth = 678;
        rmode->viXOrigin = (VI_MAX_WIDTH_NTSC - 678)/2;  // This probably needs to consider PAL
        GRRLIB_ScreenWidth = 16.0f*((f32)rmode->xfbHeight)/9.0f;
    } else {    // 4:3
        mode->viWidth = 672;
        rmode->viXOrigin = (VI_MAX_WIDTH_NTSC - 672)/2;
    }

then around line 150

    guOrtho(perspective, 0, GRRLIB_ScreenHeight, 0, GRRLIB_ScreenWidth, 0, 1000.0f);

Then in GRRLIB_3D.c :
In function GRRLIB_3dMode(...)

    guPerspective(m, fov, (f32)GRRLIB_ScreenWidth/(f32)GRRLIB_ScreenHeight, minDist, maxDist);

In function GRRLIB_2dMode()

    guOrtho(m, 0, GRRLIB_ScreenHeight, 0, GRRLIB_ScreenWidth, 0, 1000.0f);

I haven't checked everything yet. There's probably a few 2D functions that require the screen size. Feel free to complete any modifications that would help solving the wide screen problem.

Also, I've been looking at the ScreenShot function. As it takes image data from the EFB, which is limited to 640x480, it can't be used to created a 853x480 png image. Not with the actual PNGU lib that is. Maybe if someone could come with a nice scaling algorithm...

Last edited by EvilTroopa (2011-01-12 00:44:41)

What happens if you just leave it in widescreen all the time?

If you leave widescreen on a 4:3 screen, the image is compressed on the X axis, as it has 853x480 scaled to 640x480.

do you have to hardcoding 678 into the program?

Actually, I took these values from different forum posts. A guy clamed that it helped to cover most screen overscans, but I haven't noticed anything special on my tv's.
I have tested with 640 and it works perfectly fine.

Why would you have letterbox ? Unless you have some sort of puzzlegame that fits in the screen, you're allowed to show more from the left and right with my solution.
I'd rather have the interface thought to work on both modes than add some aweful black (or whatever color) on the top and bottom.
But hey, you do what you want, my code may not answer all problems.
I'll try to do a few screenshots to show you how I use it

I'm going to try to release a new version of NanoMechas using WideScreen mode to see how it looks.
But the first tries with 3D look fine to me. I'll add some 2D sprites to see if it works too.

Hey BoondokLife !
I haven't made anything on Wii for a while now (huge changes in my life ), but I will eventually come back to Wii dev soon.

To answer shortly, yes you can make a 2D widescreen games. I talked to NoNameNo (or was it Crayon ?) a few months back and he told me he would add the widescreen code I wrote to GRRLIB but I don't know if he had time to do that.

If you simply add the code I wrote above in your files and compile GRRLIB again, you should have widescreen if your Wii is set to widescreen, and 4/3 if it's not.

I'll be back soon with a more details.

See ya!

Last edited by EvilTroopa (2011-10-01 13:34:43)