Some platforms have a 'memstream' type of stdio file - i.e. it provides all
the stdio operations that you would expect from a FILE* (apart from
fileno()), and writes to an block of memory.
If your platform doesn't have that, there are some examples around on how to
write a FILE* that does that. It should be possible to implement a FILE*
that outputs using JNA based callbacks - it would be a bit slow, however.
On 27/11/2007, Cameron Taggart <came...@gmail.com> wrote:
That gvRenderData doesn't do what I thought it would, so back to my
original question...
How can I map the file pointer in this method?
int gvRender (GVC_t * gvc, graph_t * g, char * format, FILE * out);
I was thinking something like this:
public int gvRender(Pointer gvc, Pointer g, String format, ??? out);
I was hoping to be able to render the output to memory (on the heap[1]);
[1] http://weblogs.java.net/blog/mlam/archive/2007/08/cvm_why_use_the.html
cheers,
Cameron
On Nov 26, 2007 12:04 AM, Cameron Taggart <came...@gmail.com>
wrote:
The library I'm trying to map to is Graphviz. To render an graph,
there are three methods[1]: gvRender, gvRenderData, and
gvRenderFilename. I was able to get gvRenderFilename to work using
JNA, but I'm looking for a way to not write the file to disk. May be
gvRenderData would work, but my C programming abilities are failing me
and I'm not sure what to pass in for the "char ** result" argument in
C or Java via JNA.
[1]
http://www.graphviz.org/pub/graphviz/CURRENT/doxygen/html/gvc_8c.html#c81890a1c646b7534fc23350b8d3f85f
On Nov 25, 2007 2:55 PM, Cameron Taggart <came...@gmail.com>
wrote:
I want to render an image to an java.io.OutputStream. I want to use a
C library to render that image and the function looks like:
render(File *out);
Any ideas how this might be accomplished? Must the image be rendered
to a file system in C and then read in Java once complete? Is there
any way to not write it to disk first?
cheers,
Cameron
5 messages in net.java.dev.jna.usersRe: [jna-users] Re: Rendering a Graph...
