[cairo] cairo with loading PDF and related questions

[Gerdus van Zyl]

Generating PDF in cairo is no problem so you can solve no 5 and 6. To
read a PDF(no.4) and render using cairo take a look at Poppler
[http://poppler.freedesktop.org/]. For no. 7 you can use cairo for
rendering but for the rest you would have to build your own, maybe
modify an open source vector editor? Since most of your use is around
PDF creation and modification you might be better served by a PDF
focused library.

~Gerdus

On Fri, Jan 23, 2009 at 11:18 AM, Pavel Dudrenov <dudrenov at gmail.com> wrote:
> Heh, I'm wrong it does have a PDF backend.
>
> On Fri, Jan 23, 2009 at 1:16 AM, Pavel Dudrenov <dudrenov at gmail.com> wrote:
>> Not sure that I understood everything from your post, but here goes nothing.
>>
>> I don't know any pdf backend for cairo, but I'm new to cairo and don't
>> know much. That said I think that you are probably better of finding
>> some pdf parser/generator (such as gostscript, pdflib, or some such).
>> Use that to convert pdf to some intermediate structure, then use that
>> structure to communicate with cairo and vise versa.
>>
>> Also gostscript guys have something called `mupdf' and`fitz'. Fitz
>> claims to be "a modern graphics library" and mupdf, apparently,
>> generates fitz trees.
>>
>> As I mentioned earlier I'm a novice at this, so unless you can prove
>> the above to be true you should consider everything I say as nothing
>> but lies!
>>
>> Pavel
>>
>>
>> On Fri, Jan 23, 2009 at 12:07 AM, Fan Zhang <fz at chinasoft.dk> wrote:
>>> Hello all,
>>>
>>> I'm new to cairo, and was introduced to cairo because we thought it
>>> might be the solution for vector graphic library in our php project.
>>> So here's a little detail of the setup:
>>>
>>> 1. using cairo 1.6.4 fc9. (we are running fedora core 9)
>>> 2. lampp installed with pear, that's how to get to install cairo_wrapper.
>>> 3. running php 5 and the project is developed in php 5.
>>>
>>> And here's the scope and objective of the project
>>> 1. Able to generate text images (single or multiple lines), giving the
>>> text string, font size, font color, etc. (completed)
>>> 2. Able to display text images in PNG format in the browser. (completed
>>> with cairo_surface_show_png in cairo_wrapper)
>>> 3. Able to generate PDF file contain the vector graphics of the text
>>> image. (completed with cairo_text_path)
>>> 4. Able to load PDF file generated by Adobe Illustrator (assuming one
>>> vector graphic only), change the fill color of the content to solid or
>>> gradient color. (no solution yet)
>>> 5. Generate both PNG and PDF file after the modification of the PDF file
>>> in 4, display the PNG file similar to "show png". (no solution yet)
>>> 6. Able to generate a layered PDF file from different source (png, pdf,
>>> eps etc). (no solution yet)
>>> 7. Future support for loading AI file and construct a canvas editor
>>> similar to AI, with path editor and abstract drawings.
>>>
>>> Our project is developed half way to the point where we don't know if
>>> the functions could be supported by cairo, or we have to find another
>>> solution.
>>>
>>>
>>> For goal no.4, the original idea is to have vector shapes saved as pdf
>>> file and loaded into cairo, right now cairo wrapper does not support
>>> reading form pdf (cairo_pdf_surface_create_from_pdf, or something like
>>> that). We are going to develop in the way to allow user drawing the
>>> shape instead of loading it. But the question is: can cairo support
>>> loading from pdf? Since it could generate a vector format (with path)
>>> pdf, is loading it back in and change the color too difficult?
>>>
>>> For goal no.5, how to generate PNG from PDF surface? Maybe "how to load
>>> PDF as PNG"? Because I think to convert between PNG and PDF is not the
>>> case of cairo.
>>>
>>> For goal no.6, The final PDF generated will be from texts and shapes
>>> previously output from cairo, I understand cairo is not a PDF generator,
>>> but is it possible to have layered context in cairo?
>>>
>>> All this comes to text->path->png->pdf->more text->transform text->load
>>> shape->change color->transform shape->generate PNG for proof->generate
>>> PDF for printing and editing.
>>>
>>> We've tried GD, Imagicks, and now cairo. We don't know whether any one
>>> of these libraries can help or several of them, even to write our own
>>> libraries?
>>>
>>> Please help, we don't want to end up switch it to a .net project as this
>>> will cost too much. We can only stay with php.
>>>
>>> Fan
>>>
>>> _______________________________________________
>>> cairo mailing list
>>> cairo at cairographics.org
>>> http://lists.cairographics.org/mailman/listinfo/cairo
>>>
>>
> _______________________________________________
> cairo mailing list
> cairo at cairographics.org
> http://lists.cairographics.org/mailman/listinfo/cairo
>