deepin-pdfium: API brekage compared to original pdfium

[mara004]

pypdfium2 developer here. I'm interested in deepin-pdfium's portable CMake build system, but noticed there is some (unnecessary) API breakage compared to the original pdfium:

On the FPDF_RenderPageBitmap() API, two new parameters src_size_w and src_size_h have been added.
I presume the objective here was to facilitate cropping, but note that you can already achieve this with the original API by shifting start_x, start_y into negative coords and setting size_x, size_y to the target size. So adding these extra parameters is actually unnecessary, and you could instead handle this on the caller side in dpdfpage.cpp.

I would prefer if deeping-pdfium could remain API compatible to the original. This way, it'll also be easier for you to update pdfium.¹

BTW: The resulting binary is much larger than when built with pdfium's original build system (17.5 vs 5.5 MiB for the shared library). Further, some APIs are missing in the build: FPDFBookmark_GetCount(), FPDFImageObj_GetImagePixelSize(), FPDFPageObj_GetRotatedBounds(), FPDF_ImportPagesByIndex(), FPDFPageObj_SetMatrix(), FPDF_NewXObjectFromPage(). Perhaps this is simply because the pdfium version bundled here is outdated.

Footnotes

1. Unless your intent is to fork off pdfium completely, but then you'll likely end up stuck with an outdated codebase that lacks upstream fixes and improvements. ↩

[mara004]

Also, it raises questions how the file lists should be updated when switching to a newer pdfium.
Maybe an automatic form of source discovery would be more suitable here? Or at least a way to automatically update the lists.

[lzwind]

Thank you for your attention. We are sorting out this code and will optimize it later. API compatibility has always been an issue we are concerned about, and we will deal with it later.

[Johnson-zs]

Here's my understanding of why we bundled an old PDFium version:

The main reason was probably that Deepin's repo didn't have a proper PDFium package back then. Bundling it made building easier, but now we're stuck with this outdated version.

We've got a couple options to fix this:

Make an official PDFium package for Deepin's repo
Quick fix: Just update the bundled PDFium to a newer stable version

[BLumia]

Is this PR somewhat related?