CODEWITHSUNDEEP
cfile-ioaccess-violation
meriley
meriley

Reputation: 1881

Access violation writing location during File Parsing

Ive narrowed the issue down to a few lines of code but im having trouble identifying what is illegal about the function call causing a "Access violation writing location" I was hoping someone better with C could help me out?

The input the code is breaking on is 

vn 0.185492 -0.005249 0.982604

I want to assign the 3 float values to an Array of Struct vn

struct Normals{
    float vn1;
    float vn2;
    float vn3;
};
struct Normals vn[50000];

and the code that is crashing is

if (line[0] == 'v' && line[1] == 'n' && line[1] != 't'){
    sscanf(line, "%*c%*c%f%f%f", 
            &vn[normCount].vn1, 
            &vn[normCount].vn2, 
            vn[normCount].vn3);
    normCount++;
    }

Any tips would be great! Thanks

Upvotes: 0

Views: 330

Answers (3)

Brian Roach
Brian Roach

Reputation: 76888

sscanf(line, "%*c%*c%f%f%f", &vn[normCount].vn1, &vn[normCount].vn2, vn[normCount].vn3);
                                                                    ^^^^

You forgot an &. This is causing the value contained in vn[normCount].vn3 to be evaluated as a memory address (which you obviously don't have access to write to).

Upvotes: 0

thumbmunkeys
thumbmunkeys

Reputation: 20764

the type of arguments supplied to scanf i wrong:

    sscanf(line, "%*c%*c%f%f%f",            
        &vn[normCount].vn1, 
        &vn[normCount].vn2, 
        &vn[normCount].vn3); // address

Upvotes: 0

asaelr
asaelr

Reputation: 5456

You forgot the & before vn[normCount].vn3.

By the way, what is the point of line[1] == 'n' && line[1] != 't'?

Upvotes: 4

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