CreateDIBSection and Access violation

Hello,

I hope, some of the experts can help me.
I want to draw to a DIB created with CreateDIBSection, but I get an access violation.

Code:

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        BITMAPINFO bmi;
        memset(&bmi,0,sizeof(BITMAPINFO));
        tBYTE*            lpBits;
        bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
    glTexSize=4096;
        bmi.bmiHeader.biWidth = glTexSize;
        bmi.bmiHeader.biHeight = glTexSize;
        bmi.bmiHeader.biPlanes = 1;                    /* must be 1 */
        bmi.bmiHeader.biBitCount = 24;
        bmi.bmiHeader.biCompression = BI_RGB;

        // Create DIB for rendering context
        tHANDLE dib =CreateDIBSection(dcMem.m_hDC,&bmi,DIB_RGB_COLORS,(void**)&lpBits, NULL, 0);
        tHANDLE old=::SelectObject(dcMem.m_hDC,dib);

    // Draw to dcMem with GDI
        .......

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Draw to dcMem leads to an access violation.
What is wrong?
Do I need to allocate memory?

thx.

What is 'dcMem'? How is it being created?

Viggy

Quote:

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Originally Posted by MrViggy

What is 'dcMem'? How is it being created?

Viggy

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CDC dcMem;
dcMem.CreateCompatibleDC(NULL);

Quote:

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Originally Posted by Ralf Schneider

Code:

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        // ... snip ...
        tBYTE*            lpBits;

        // ... snip ...
        tHANDLE dib =CreateDIBSection(dcMem.m_hDC,&bmi,DIB_RGB_COLORS,(void**)&lpBits, NULL, 0);

---

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What's a "tBYTE"? The fact that you had to forcefully cast it, in order to get the CreateDIBSection call to compile, should have been a hint that you are using the wrong type.

Try this:

Code:

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        // ... snip ...
        void*            lpBits;

        // ... snip ...
        tHANDLE dib =CreateDIBSection(dcMem.m_hDC,&bmi,DIB_RGB_COLORS, /* no cast needed (void**) */ &lpBits, NULL, 0);

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