[cairo] Re: 1.4.2 release planned for today, 1.4.4 in a few weeks

[Hugo Vincent]

Thanks Vlad, that fixed the problem. Sorry for the noise on the list  
- it seemed like a genuine Cairo bug.

Hugo

On 28/03/2007, at 5:12 AM, Vladimir Vukicevic wrote:

>
> Ah, that crash.  So what's happening here is that cairo doesn't  
> gracefully deal with a backend's acquire_*_image returning  
> CAIRO_INT_STATUS_UNSUPPORTED -- it ends up propagating that error  
> all the way up to the user level, at which point the generic "make  
> sure it's a public error" assert in cairo_error triggers.
>
> The reason why you're seeing CAIRO_INT_STATUS_UNSUPPORTED is  
> because Cairo (that is, the Quartz surface) didn't create the CG  
> context itself; when it does, it creates it as an image context and  
> can then do fallback rendering as necessary.  Assuming we don't  
> manage to implement everything natively using Quartz (I think there  
> are a few operators that simply have no equivalents in Quartz, as  
> well as some operations), an easy way to get around this is to wrap  
> your rendering in between cairo_push_group() and  
> cairo_pop_group_to_source()/cairo_paint(); this will give you a  
> temporary Quartz surface that was created by the Quartz backend, so  
> fallback rendering would be possible.
>
>     - Vlad
>
> Hugo Vincent wrote:
>> Hi Baz,
>> The code below seems to replicate the crash; that is to say, even  
>> the simplest use of a radial gradient on Quartz crashes.
>> verbatim error: cairo.c:91: failed assertion `status >  
>> CAIRO_STATUS_SUCCESS && status <= CAIRO_STATUS_LAST_STATUS'
>> System Info:
>> Mac OS X 10.4.9 (on Intel Core 2 Duo), Xcode 2.4.1, Cairo 1.4.2  
>> [release]
>> Note, this code isn't exactly what I've been testing with, but I  
>> am 100% confident the other stuff I have in my code, but not in  
>> the included code here, is not what is causing this crash. Like I  
>> said before, Rsvg renders correctly, assuming the SVG file has no  
>> radial gradients. Also, because both Rsvg (which uses the Cairo C  
>> api) and this code, which is using Cairomm, both crash in the same  
>> way, we can assume the problem isn't with Cairomm. Finally, if you  
>> render this code into a PNG file it works fine.
>> Cheers,
>> Hugo
>> -----------------------------------------------------------
>> testview.h:
>> -----------------------------------------------------------
>> #import <Cocoa/Cocoa.h>
>> @interface TestView : NSView
>> {
>>     // nothing needed here
>> }
>> @end
>> -----------------------------------------------------------
>> testview.m
>> -----------------------------------------------------------
>> #include <cairomm/cairomm.h>
>> #include <cairomm/quartz_surface.h>
>> #ifndef CAIRO_HAS_QUARTZ_SURFACE
>> #error Need to build Cairo and Cairomm with Quartz support  
>> (version 1.4.0 or higher)
>> #endif
>> @implementation TestView
>> - (id)initWithFrame:(NSRect)frameRect
>> {
>>     if ((self = [super initWithFrame:frameRect]) != nil)
>>     {
>>         // nothing needed here
>>     }
>>     return self;
>> }
>> - (void)drawRect:(NSRect)rect
>> {
>>     // Get the size of this NSView
>>     NSRect bounds = [self bounds];
>>     int width = bounds.size.width;
>>     int height = bounds.size.height;
>>         // Get CoreGraphcis context reference
>>     CGContextRef ctx = (CGContextRef)[[NSGraphicsContext  
>> currentContext] graphicsPort];
>>         // Make the CGContext coordinate system sane, as expected  
>> by Cairo
>>     CGContextTranslateCTM (ctx, 0.0, height);
>>     CGContextScaleCTM (ctx, 1.0, -1.0);
>>     // Create the Cairo surface and context
>>     Cairo::RefPtr<Cairo::QuartzSurface> surface =  
>> Cairo::QuartzSurface::create(ctx, width, height);
>>     Cairo::RefPtr<Cairo::Context> cr = Cairo::Context::create 
>> (surface);
>>     // Draw a radial gradient (copied and pasted, more or less,  
>> from http://cairographics.org/samples/gradient.html)
>>     cr->scale(width,height);
>>     Cairo::RefPtr<Cairo::RadialGradient> grad2 =  
>> Cairo::RadialGradient::create(0.45, 0.4, 0.1, 0.4, 0.4, 0.5);
>>     grad2->add_color_stop_rgba(0, 1,0,0, 1);
>>     grad2->add_color_stop_rgba(1, 0,1,0, 1);
>>     cr->set_source(grad2);
>>     cairo_arc (cr, 0.5, 0.5, 0.3, 0, 2 * M_PI);
>>     cr->fill(); //  CRASHES!
>> }
>> @end
>> On 27/03/2007, at 10:22 AM, Baz wrote:
>>> On 17/03/07, Hugo Vincent <hugo.vincent at gmail.com> wrote:
>>>> Can the patch for bug 10036 (Cairo-Quartz Line-width-scaling  
>>>> problem)
>>>> be accepted for into 1.4.2 (or even 1.4.4)? Please!?
>>>> https://bugs.freedesktop.org/show_bug.cgi?id=10036
>>>>
>>>> Also, I have been playing round with Rsvg on Mac OS X, rendering  
>>>> into
>>>> a Cairo-Quartz context. It mostly works (except for the above
>>>> mentioned bug), however in certain cases it crashes rather
>>>> ungracefully when trying to do fallback operations for things that
>>>> aren't supported natively by Cairo-Quartz (certain radial gradients
>>>> seem to be the culprit). I'll prepare a proper test case and  
>>>> submit a
>>>> bug soon after I've tried it with 1.4.2.
>>>>
>>>> Cheers,
>>>> Hugo Vincent
>>>
>>> Hugo, did you ever track down that crasher?
>>>
>>> Cheers,
>>> Baz
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