[cairo] Recording surfaces fail to replay onto SVG surfaces

[Adrian Johnson]

I've pushed a fix for painting unbounded recordings to the SVG surface.

On 04/10/17 22:49, Adrian Johnson wrote:
> Seems to be a bug with unbounded recording surfaces and SVG. As a
> workaround if you specify an extents for the recording surface it works.
> 
> 
> On 04/10/17 08:39, Antony Lee wrote:
>> Hi all,
>>
>> I am having an issue with replaying a recording surface onto an SVG
>> surface.  A minimal example is included at the end of the email.
>>
>> Briefly, the example sets up a recording surface and two 100x100
>> surfaces -- one IMAGE and one SVG.  It then draws a 10x10 rectangle on
>> each of them at position (10, 10) and saves the results (the IMAGE to a
>> PNG).  Both resulting files display the box at the correct position.
>>
>> The example then tries to replay the recording surface onto a separate
>> 100x100 SVG surface, and also save that surface.  Unfortunately, this
>> results in a blank SVG.  Note that if, instead, the recording surface is
>> played onto a separate 100x100 IMAGE surface (code not included for
>> simplicity), this works perfectly well (the resulting PNG also displays
>> the box); so the basic setup of the recording surface seems correct.
>>
>> I am using cairo 1.15.8 from Arch Linux.
>>
>> Any help would be very welcome.  Thanks!
>>
>> Antony Lee
>>
>>
>>
>> === Example program; compile and run with:
>>     gcc main.c $(pkg-config --cflags --libs cairo) -o main && ./main
>>
>> #include <stddef.h>
>> #include <cairo/cairo.h>
>> #include <cairo/cairo-svg.h>
>>
>> int main() {
>>   cairo_surface_t* rec_surf =
>> cairo_recording_surface_create(CAIRO_CONTENT_COLOR_ALPHA, NULL);
>>   cairo_t* rec_ctx = cairo_create(rec_surf);
>>
>>   cairo_surface_t* img_surf =
>> cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 100, 100);
>>   cairo_t* img_ctx = cairo_create(img_surf);
>>
>>   cairo_surface_t* svg_surf = cairo_svg_surface_create("/tmp/test.svg",
>> 100, 100);
>>   cairo_t* svg_ctx = cairo_create(svg_surf);
>>
>>   cairo_t* ctxs[3] = {rec_ctx, img_ctx, svg_ctx};
>>
>>   for (unsigned i = 0; i < 3; ++i) {
>>     cairo_rectangle(ctxs[i], 10, 10, 10, 10);
>>     cairo_fill(ctxs[i]);
>>   }
>>
>>   // Dump image to png.
>>   cairo_surface_write_to_png(img_surf, "/tmp/test.png");
>>
>>   // Transfer recording surface to SVG.
>>   cairo_surface_t* svg1_surf =
>> cairo_svg_surface_create("/tmp/test1.svg", 100, 100);
>>   cairo_t* svg1_ctx = cairo_create(svg1_surf);
>>   cairo_set_source_surface(svg1_ctx, rec_surf, 0, 0);
>>   cairo_paint(svg1_ctx);
>>
>>   // Done.
>>   for (unsigned i = 0; i < 3; ++i) {
>>     if (cairo_status(ctxs[i])) {
>>       return 1;
>>     }
>>   }
>>   cairo_surface_finish(svg_surf);
>>   cairo_surface_finish(svg1_surf);
>>   for (unsigned i = 0; i < 3; ++i) {
>>     cairo_surface_destroy(cairo_get_target(ctxs[i]));
>>     cairo_destroy(ctxs[i]);
>>   }
>>   cairo_surface_destroy(svg1_surf);
>>   cairo_destroy(svg1_ctx);
>> }
>>
>>
>