3 replies to this topic

[thecheeselover]

Hi,

I am a beginner with hlsl and I'd like to know if you actually can do something like this, which is setting a global variable's index with another global scalar variable:

int t = 5;
float g[t];

If you can't do something like this in hlsl, then can you change the array to a greater or lower number through xna?

Thank you
Thecheeselover

[ViperG]

You can do something like this:

#define Global 5;

float g[Global];
int t = Global;
int z = Global;

[MJP]

Arrays in HLSL need to have a length that is static at compile time. So in other words..

// You can do this...
static const uint ArraySize = 5
float Array[ArraySize];

// Or you can do this...
#define ArraySize 5
float Array[ArraySize];

// But you can't do this
uint ArraySize = 5; 
float Array[ArraySize];

Usually what you do, is you define the array to some maximum size and then set another variable to a value representing how many values to actually use from the array. Like this:

static const uint MaxValues = 5;
float Values[MaxValues];
uint NumValuesToUse;

Just be careful...depending on the shader profile you use the compiler's ability to represent loops in shader assembly may be limited.

[thecheeselover]

Thank you both!