Help with PlayStation programming

[DEBRO]

Hi there,

 

I'm looking at some source code and don't quite understand the values they plug into OT_LENGTH.

 

For instance, in spaceguy.c (which I think is included in the Yaroze samples) they have

/*  Ordering table related variables */
GsOT		WorldOT[2];
GsOT_TAG	OTTags[2][1<<OT_LENGTH];

 

and later they have

	// Init the ordering table
for (i = 0; i < 2; i++) 
	{
	WorldOT[i].length = OT_LENGTH;
	WorldOT[i].org = OTTags[i];
	}

 

Where do they come up with the OT_LENGTH number? What does it represent? Every example I see has some magical number for this and they don't show how they came up with the number so I can understand it's origin or purpose.

[Tursi]

IIRC, it's just defining the maximum size of the object list. The value is pretty much arbitrary, based on how many objects you need to sort versus how much RAM you want to reserve.

 

But it's been a long time for me.

[DEBRO]

Hi there,

IIRC, it's just defining the maximum size of the object list. The value is pretty much arbitrary, based on how many objects you need to sort versus how much RAM you want to reserve.

 

But it's been a long time for me.

Thanks for the response. So am I right in assuming this is used for Z-ordering?

[Tursi]

Sorry for the long delay. Technically z-ordering, I guess, it's a sorted list of objects for the GPU to draw. IE: if you have 5 depths but 10 objects the list is still 10 entries long.