Re: [Vala] How to bitwise math and implement a jagged array in Vala?

[Thomas F Steinhauer <tom_steinhauer hotmail com>]

I tried your code as you suggested however that did not work. I guess 
the real question that I am asking here is has anyone successfully 
generated a Checker board type texture with OpenGL and Vala and 
displayed it on a cube or square. That is the code that I really need. 
It seems that because Vala does not supported "jagged" arrays that this 
is not possible or did I miss something in the reading somewhere?

Thanks
Tom

On 07/02/2013 01:09 PM, Evan Nemerson wrote:
> On Tue, 2013-07-02 at 06:36 -0500, Thomas F Steinhauer wrote:
> > Dear members I am new here and I have a couple of questions and they are
> > are all centered around this piece of code I found online:
> >
> >   1. /*  Create checkerboard texture  */
> >   2. #define checkImageWidth 64
> >   3. #define checkImageHeight 64
> >   4. static GLubyte checkImage[checkImageHeight][checkImageWidth][4];
> >   5. static GLuint texName;
> >   6. void makeCheckImage(void)
> >   7. {
> >   8.     int i, j, c;
> >   9.
> > 10.     for (i = 0; i < checkImageHeight; i++) {
> > 11.        for (j = 0; j < checkImageWidth; j++) {
> > 12.           c = ((((i&0x8)==0)^((j&0x8))==0))*255;
> > 13.           checkImage[i][j][0] = (GLubyte) c;
> > 14.           checkImage[i][j][1] = (GLubyte) c;
> > 15.           checkImage[i][j][2] = (GLubyte) c;
> > 16.           checkImage[i][j][3] = (GLubyte) 255;
> > 17.        }
> > 18.     }
> > 19. }
> >
> > 1st, How can I do that same thing or equivalent from line #4 in Vala or
> > is it not possible?
> GL.ubyte[] checkImage =
>    new GL.ubyte[checkImageHeight,checkImageWidth,4];
>
> See https://wiki.gnome.org/Vala/Tutorial#Arrays for more information.
>
> > 2nd. When I try to run line #12 in Vala I get an error "Operation not
> > supported for types bool and bool. So is there a way to get Vala to
> > evaluate this expression correctly?
> Simon already mentioned one possible solution.  However, if you want to
> do it without branching, you can just cast to an integer type.
> Something like this should do the trick:
>
> c = (((GL.ubyte)((i&0x8)==0))^((GL.ubyte)((j&0x8)==0)))*255;
>
>
> -Evan