Writing vertices to my own file format

Graphics and GPU Programming Programming

Started by Anddos May 28, 2014 04:20 PM

8 comments, last by unbird 9 years, 11 months ago

Anddos

588

Author

May 28, 2014 04:20 PM

I am abit stuck on how to read vertices from a binary file,here is my code,the result is in the picture i have added

struct CUSTOMVERTEX

{

FLOAT X, Y, Z;

D3DVECTOR NORMAL;

FLOAT U, V;

};

// create the vertices using the CUSTOMVERTEX struct

CUSTOMVERTEX vertices[] =

{

{ -3.0f, -3.0f, 3.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, }, // side 1

{ 3.0f, -3.0f, 3.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, },

{ -3.0f, 3.0f, 3.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, },

{ 3.0f, 3.0f, 3.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, },

{ -3.0f, -3.0f, -3.0f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, }, // side 2

{ -3.0f, 3.0f, -3.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, },

{ 3.0f, -3.0f, -3.0f, 0.0f, 0.0f, -1.0f, 1.0f, 0.0f, },

{ 3.0f, 3.0f, -3.0f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f, },

{ -3.0f, 3.0f, -3.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, }, // side 3

{ -3.0f, 3.0f, 3.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, },

{ 3.0f, 3.0f, -3.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, },

{ 3.0f, 3.0f, 3.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, },

{ -3.0f, -3.0f, -3.0f, 0.0f, -1.0f, 0.0f, 0.0f, 0.0f, }, // side 4

{ 3.0f, -3.0f, -3.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, },

{ -3.0f, -3.0f, 3.0f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, },

{ 3.0f, -3.0f, 3.0f, 0.0f, -1.0f, 0.0f, 1.0f, 1.0f, },

{ 3.0f, -3.0f, -3.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, }, // side 5

{ 3.0f, 3.0f, -3.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, },

{ 3.0f, -3.0f, 3.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, },

{ 3.0f, 3.0f, 3.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, },

{ -3.0f, -3.0f, -3.0f, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f, }, // side 6

{ -3.0f, -3.0f, 3.0f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, },

{ -3.0f, 3.0f, -3.0f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, },

{ -3.0f, 3.0f, 3.0f, -1.0f, 0.0f, 0.0f, 1.0f, 1.0f, },

};

//Write to out outstream file as a new binary format

outfile.write((char*)vertices,sizeof(CUSTOMVERTEX)*24);

outfile.close();

//Now read from the newly created file

CUSTOMVERTEX vertsArray[23];

infile.read((char*)VertsArray,sizeof(CUSTOMVERTEX)*24);

//Now load the data that was fetched from the binary in to the directx vertexbuffer

// create a vertex buffer interface called v_buffer

d3ddev->CreateVertexBuffer(24*sizeof(CUSTOMVERTEX),

CUSTOMFVF,

D3DPOOL_MANAGED,

&v_buffer,

NULL);

VOID* pVoid; // a void pointer

// lock v_buffer and load the vertices into it

v_buffer->Lock(0, 0, (void**)&pVoid, 0);

// memcpy(pVoid, vertices, sizeof(vertices)); //loading from a hardcoded struct array which works fine

memcpy(pVoid, VertsArray, sizeof(CUSTOMVERTEX)*24); //loading from an array loaded with ifstream

v_buffer->Unlock();

phil_t

8,087

May 28, 2014 04:42 PM

Why is your vertsArray only 23 elements instead of 24?

Cascade Quest - IceFall Games - Dev blog - twitter - youtube

Anddos

588

Author

May 28, 2014 05:09 PM

oh your right,i was thinking 0 to 23 is 24 allocations

phil_t

8,087

May 28, 2014 05:12 PM

That's incorrect. The code you have right now is reading file data in one beyond the end of the array. The number in the array declaration specifies the size of the array, not the last index. It needs to be:

CUSTOMVERTEX vertsArray[24];

Cascade Quest - IceFall Games - Dev blog - twitter - youtube

Anddos

588

Author

May 28, 2014 05:32 PM

would it be possible to write the "texture.jpg" as data to the binary file and load it that way ?

Burnt_Fyr

1,668

May 28, 2014 06:05 PM

do you mean write the texture itself, or write a locator like a path or a filename? it's a yes in both cases, but the former may be a lot of work. Take a look at the OBJ format to see how materials can be bundled with geometry.

unbird

8,359

May 28, 2014 06:22 PM

...but the former may be a lot of work...

Hmmm, I sort of disagree. In the simplest form you write the size of the sub-blob (and also a format tag for proper dispatch at loading) and then the blob itself. Think of concatenating files to one file (or rather non-compressing archivers like tar). At loading the size and tag help you split it up again.

Or am I missing something ?

21st Century Moose

13,459

May 28, 2014 06:39 PM

oh your right,i was thinking 0 to 23 is 24 allocations

0 to 23 is 24 allocations, but you need to declare the array with size 24, not size 23 which is what you've done:

CUSTOMVERTEX vertsArray[23];

This isn't 0 to 23, this is 0 to 22. The "[23]" isn't the last element in the array, it's the size of the array, so this array only has space for 23 CUSTOMVERTEX structs.

Direct3D has need of instancing, but we do not. We have plenty of glVertexAttrib calls.

Burnt_Fyr

1,668

May 28, 2014 10:00 PM

...but the former may be a lot of work...

Hmmm, I sort of disagree. In the simplest form you write the size of the sub-blob (and also a format tag for proper dispatch at loading) and then the blob itself. Think of concatenating files to one file (or rather non-compressing archivers like tar). At loading the size and tag help you split it up again.

Or am I missing something ?

I was thinking parsing a single field that can be passed directly to a ::load() function would be less work, but after reading your thoughts it does seem quite comparable in difficulty.

unbird

8,359

May 28, 2014 11:17 PM

Yeah, depends on what functions/library you have at your disposal. Assuming D3DX9 is used, this is really simple, since the texture functions come with overloads for both files and memory. One can even (ab)use them to convert texture formats in-memory.

Writing vertices to my own file format

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