Question

(iPhone) Pulling my hair out just trying to declare and set a stupid variable. Here’s the code:

const GLfloat zNear = 0.01, zFar = 1000.0, fieldOfView = 60.0; 
GLfloat size;
size = zNear * tanf(DEGREES_TO_RADIANS*fieldOfView / 2.0));

Gives me the error “Conflicting types for ‘size'”.

If I write it like this instead:

const GLfloat zNear = 0.01, zFar = 1000.0, fieldOfView = 60.0; 
GLfloat size = zNear * tanf(DEGREES_TO_RADIANS*fieldOfView / 2.0));

I get the error, “Initializer element is not constant”.

What’s really weird is that this code worked fine when it was inside a method. I moved it out of the method, and now it fails. What’s going on here?

Answer 1

When dealing at global-scope, statements can be assigned to only constant literals.

// At global scope
int a = 10 ; // fine
int b = a ;  // Not allowed
b = a ;      // Not allowed
b = 100 ;    // fine

const int aa = 10 ;  // fine
const int bb ;
bb = aa ;   // Not allowed

---

The solution is #define. Try this –

#define zNear 0.01
#define zFar 1000.0
#define fieldOfView 60.0

GLfloat size;
size = zNear * tanf(DEGREES_TO_RADIANS*fieldOfView / 2.0));