A question about D3DXCreateTexture()
Author
Hi all,
I use D3DXCreateTexture() to create a 512*512 texture, the code is as follows:
---------------------------------------------
int width = 512, height = 512;
float imageData[512][512][3];
int index = 0;
int x,y;
for(x=0; x<width; x++)
{
for(y=0; y<height; y++)
{
if(x==0 || x==width-1 || y==0 || y==height-1)
imageData[x][y][0] = imageData[x][y][1] = imageData[x][y][2] = 1.0f;
else
imageData[x][y][0] = imageData[x][y][1] = imageData[x][y][2] = (2 + rand() % 5)/10.0f;
}
}
HRESULT hr = 0;
hr = D3DXCreateTexture(Device, width, height, 0, 0, D3DFMT_R8G8B8, D3DPOOL_MANAGED, &pRandomTexture);
if(FAILED(hr)) MessageBox(0,"D3DXCreateTexture() error!",0,0);
hr = pRandomTexture->GetSurfaceLevel(0, &pRandomRenderSurface);
if(FAILED(hr)) MessageBox(0,"GetSurfaceLevel() error!",0,0);
D3DSURFACE_DESC surfaceDesc;
hr = pRandomRenderSurface->GetDesc(&surfaceDesc);
if(FAILED(hr)) MessageBox(0,"GetDesc() error!",0,0);
D3DLOCKED_RECT lockedRect;
hr = pRandomRenderSurface->LockRect(&lockedRect, 0, 0); // entire surface
if(FAILED(hr)) MessageBox(0,"LockRect() error!",0,0);
DWORD* imageDataTemp = (DWORD*)lockedRect.pBits;
for(int i = 0; i < surfaceDesc.Height; i++)
{
for(int j = 0; j < surfaceDesc.Width; j++)
{
int index = i * (lockedRect.Pitch / 4) + j; // because pitch is in bytes, and 4 bytes per DWORD
imageDataTemp[index] = D3DCOLOR_XRGB(int(imageData[j][0]*255.0f), int(imageData[j][1]*255.0f), int(imageData[j][2]*255.0f));
}
}
pRandomRenderSurface->UnlockRect();
D3DXSaveTextureToFile("height-alpha.bmp", D3DXIFF_BMP, pRandomTexture, NULL);
d3d::Release<LPDIRECT3DTEXTURE9>(pRandomTexture);
d3d::Release<LPDIRECT3DSURFACE9>(pRandomRenderSurface);
--------------------------------------------------------------------------
But when I run it, it prompts an error:
Unhandled exception at 0x00413885 in TexQuad.exe: 0xC00000FD: Stack overflow.
However, when I set width=height=256, it runs ok!
Can anyone tell me why?
Thanks in advance!
You can't allocate 512x512x3 floats on the stack. That's just too big. Use new and delete to allocate it on the heap:
float *imageData = new float[512][512][3];// Use data...delete [] imageData;
The stack thing above looks like a probable fix, but there is another bug. You card likely doesn't support R8G8B8, and D3DX is silently upgrading to X8R8G8B8, so your code works. If you run this code on a card that supports R8G8B8, your code won't work. It's all designed around moving DWORDs, assuming the pitch is a DWORD multiple, etc. The easiest fix would be to actually request a 32-bit texture.
This topic is closed to new replies.
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