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Filling Array with different types

Started by dabx11 Jul 31, 2002 at 6:35 AM 3 replies 300+ views

Original Post

Jul 31, 2002 at 6:35 AM

I''m trying to fill an array/memory with different types of data, kinda like this. example.... byte B[1024]; void* pB = B; *(float*)pB++ = (float)10; *(byte *)pB++ = (byte)5; *(int *)pB++ = (int)15; causes this error..doesn''t know how to increase the pointer error C2036: ''void *'' : unknown size but something like this works ok..but the pointer doesn''t change to the address after the float. *(float*)pB = (float)10; so how can I get pB to point after the float...or maybe i''m missing an easier way of doing this..

mentat

Jul 31, 2002 at 6:44 AM

instead of using void*, use your byte array..


int ind = 0;
b[ind] = somebytedata;
ind += sizeof(byte);
*((float*)&b[ind]) = (float)somefloatdata;

however, even if it works, it is ugly.. why do you want to do this in the first place? Can't you use a struct or sth?

EDIT: he he, cannot post i as index (i in brackets means italics), changed to ind

[edited by - mentat on July 31, 2002 7:49:25 AM]

LessBread

558

LessBread

Jul 31, 2002 at 6:45 AM

quote:
Original post by dabx11
I'm trying to fill an array/memory with different types of data, kinda like this.

example....
byte B[1024];
void* pB = B;

*(float*)pB++ = (float)10;
*(byte *)pB++ = (byte)5;
*(int *)pB++ = (int)15;

causes this error..doesn't know how to increase the pointer
error C2036: 'void *' : unknown size

but something like this works ok..but the pointer doesn't change to the address after the float.
*(float*)pB = (float)10;

so how can I get pB to point after the float...or maybe i'm missing an easier way of doing this..

Um, yeah, a better way, but um, here's another hack

byte B[1024];
byte* pB = B;

*(pB += sizeof(float)) = (float)10.0;
*pB++ = (byte)5;
*(pB += sizeof(int)) = (int)15;

I haven't tested this. Those += aren't gonna cut it.
How do you propose retrieving the values?

int i = 0;
*( pB + i ) = (float)10.0; i += sizeof(float);
*( pB + i ) = (byte)5; i += sizeof(byte);
*( pB + i ) = (int)15; i += sizeof(int);

[edited by - lessbread on July 31, 2002 7:49:50 AM]

dabx11

Author

dabx11

Jul 31, 2002 at 7:16 AM

Thanks guys..i''ve got it working now...

what I was doing is storing information about a mesh, and I needed to convert it to a vertex buffer depending on the vertex format...so it''s kinda like a dynamic structure.

  

class CVertexBuffer {
public:
	CVertexBuffer(){};

	void RefreshVertexBuffer();

	vector<D3DXVECTOR3> Position;
	vector<D3DXVECTOR3> Normal;
	vector<D3DXCOLOR> Diffuse;
	vector<D3DXCOLOR> Specular;
	vector<D3DXVECTOR2> Tex1;
	vector<D3DXVECTOR2> Tex2;
	vector<D3DXVECTOR2> Tex3;
	vector<D3DXVECTOR2> Tex4;
	vector<D3DXVECTOR2> Tex5;
	vector<D3DXVECTOR2> Tex6;
	vector<D3DXVECTOR2> Tex7;
	vector<D3DXVECTOR2> Tex8;
	DWORD VertexFormat;	
};

[\source]

as you can see, the D3DVECTOR3 uses floats..and the D3DXCOLOR uses DWORD....

mentat

Jul 31, 2002 at 7:38 AM

well, I don''t exactly get the meaning of your last post, but I can say that, using stl vector to store the vertices is a SUICIDE!!!

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