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else // Otherwise... We Are Loading From A File
{
GetCurrentDirectory(MAX_PATH, szPath); // Get Our Working Directory
strcat(szPath, "\\"); // Append "\" After The Working Directory
strcat(szPath, szPathName); // Append The PathName
}
MultiByteToWideChar(CP_ACP, 0, szPath, -1, wszPath, MAX_PATH); // Convert From ASCII To Unicode
HRESULT hr = OleLoadPicturePath(wszPath, 0, 0, 0, IID_IPicture, (void**)&pPicture);
if(FAILED(hr)) // If Loading Failed
return FALSE; // Return False
hdcTemp = CreateCompatibleDC(GetDC(0)); // Create The Windows Compatible Device Context
if(!hdcTemp) // Did Creation Fail?
{
pPicture->Release(); // Decrements IPicture Reference Count
return FALSE; // Return False (Failure)
}
glGetIntegerv(GL_MAX_TEXTURE_SIZE, &glMaxTexDim); // Get Maximum Texture Size Supported
pPicture->get_Width(&lWidth); // Get IPicture Width (Convert To Pixels)
lWidthPixels = MulDiv(lWidth, GetDeviceCaps(hdcTemp, LOGPIXELSX), 2540);
pPicture->get_Height(&lHeight); // Get IPicture Height (Convert To Pixels)
lHeightPixels = MulDiv(lHeight, GetDeviceCaps(hdcTemp, LOGPIXELSY), 2540);
// Resize Image To Closest Power Of Two
if (lWidthPixels <= glMaxTexDim) // Is Image Width Less Than Or Equal To Cards Limit
lWidthPixels = 1 << (int)floor((log((double)lWidthPixels)/log(2.0f)) + 0.5f);
else // Otherwise Set Width To "Max Power Of Two" That The Card Can Handle
lWidthPixels = glMaxTexDim;
if (lHeightPixels <= glMaxTexDim) // Is Image Height Greater Than Cards Limit
lHeightPixels = 1 << (int)floor((log((double)lHeightPixels)/log(2.0f)) + 0.5f);
else // Otherwise Set Height To "Max Power Of Two" That The Card Can Handle
lHeightPixels = glMaxTexDim;
// Create A Temporary Bitmap
BITMAPINFO bi = {0}; // The Type Of Bitmap We Request
DWORD *pBits = 0; // Pointer To The Bitmap Bits
bi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); // Set Structure Size
bi.bmiHeader.biBitCount = 32; // 32 Bit
bi.bmiHeader.biWidth = lWidthPixels; // Power Of Two Width
bi.bmiHeader.biHeight = lHeightPixels; // Make Image Top Up (Positive Y-Axis)
bi.bmiHeader.biCompression = BI_RGB; // RGB Encoding
bi.bmiHeader.biPlanes = 1; // 1 Bitplane
// Creating A Bitmap This Way Allows Us To Specify Color Depth And Gives Us Imediate Access To The Bits
hbmpTemp = CreateDIBSection(hdcTemp, &bi, DIB_RGB_COLORS, (void**)&pBits, 0, 0);
if(!hbmpTemp) // Did Creation Fail?
{
DeleteDC(hdcTemp); // Delete The Device Context
pPicture->Release(); // Decrements IPicture Reference Count
return FALSE; // Return False (Failure)
}
SelectObject(hdcTemp, hbmpTemp); // Select Handle To Our Temp DC And Our Temp Bitmap Object
// Render The IPicture On To The Bitmap
pPicture->Render(hdcTemp, 0, 0, lWidthPixels, lHeightPixels, 0, lHeight, lWidth, -lHeight, 0);
// Convert From BGR To RGB Format And Add An Alpha Value Of 255
for(long i = 0; i < lWidthPixels * lHeightPixels; i++) // Loop Through All Of The Pixels
{
BYTE* pPixel = (BYTE*)(&pBits); // Grab The Current Pixel
BYTE temp = pPixel[0]; // Store 1st Color In Temp Variable (Blue)
pPixel[0] = pPixel[2]; // Move Red Value To Correct Position (1st)
pPixel[2] = temp; // Move Temp Value To Correct Blue Position (3rd)
// This Will Make Any Black Pixels, Completely Transparent (You Can Hardcode The Value If You Wish)
if ((pPixel[0]==0) && (pPixel[1]==0) && (pPixel[2]==0)) // Is Pixel Completely Black
pPixel[3] = 0; // Set The Alpha Value To 0
else // Otherwise
pPixel[3] = 255; // Set The Alpha Value To 255
}
glGenTextures(1, &texid); // Create The Texture
// Typical Texture Generation Using Data From The Bitmap
glBindTexture(GL_TEXTURE_2D, texid); // Bind To The Texture ID
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR); // (Modify This For The Type Of Filtering You Want)
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR); // (Modify This For The Type Of Filtering You Want)
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_LINEAR ); // (Modify This For The Type Of Filtering You Want)
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR_MIPMAP_LINEAR ); // (Modify This For The Type Of Filtering You Want)
gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGBA, lWidthPixels, lHeightPixels, GL_RGBA, GL_UNSIGNED_BYTE, pBits);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, lWidthPixels, lHeightPixels, 0, GL_RGBA, GL_UNSIGNED_BYTE, pBits); // (Modify This If You Want Mipmaps)
DeleteObject(hbmpTemp); // Delete The Object
DeleteDC(hdcTemp); // Delete The Device Context
pPicture->Release(); // Decrements IPicture Reference Count
return TRUE; // Return True (All Good)
}
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发表于 2007-5-22 14:24:00
