Foxit PDF SDK doesn’t directly support X-Windows output, however, you can use the Foxit Device Independent Bitmap (FXDIB) features provided in the SDK to render any PDF page into a bitmap device. You can then transfer the bitmap onto X-Windows surface, or image file, or other type of devices.
Before you can use a bitmap device, you need to create one and you can use the FPDFBitmap_Create function to do that. Foxit PDF SDK supports two types of bitmaps: RGB bitmap and ARGB bitmap, you can choose which format you want to use when you create the bitmap.
When the bitmap is created, you need to fill the buffer with the background that you like. Normally it can be a white background or a non-colored background (if alpha channel is used).
Now you can use it in the FPDF_RenderPageBitmap function. This function is pretty much the same as the FPDF_RenderPage function, but instead of sending output to a Windows device, it outputs to the bitmap device.
Here is a sample for basic rendering on Linux:
FPDF_DOCUMENT pdf_doc; // you must load document before page can be loaded
FPDF_PAGE pdf_page; // you must load page before it can be rendered
// Create bitmap first. We don't use alpha channel here.
bitmap = FPDFBitmap_Create(400, 500, FALSE);
// Fill the bitmap with white background
FPDFBitmap_FillRect(bitmap, 0, 0, 400, 500, 255, 255, 255, 255);
// Call FPDF_RenderPageBitmap function to render the whole page
FPDF_RenderPageBitmap(bitmap, pdf_page, 10, 10, 400, 500, 0, 0);
The following tutorials introduce more features of rendering in Foxit PDF SDK. All the samples use the FPDF_RenderPage function however the same techniques apply to FPDF_RenderPageBitmap, in the same way.