Pixel layout & console output

[luc4s]

Pixel layout & console output

[igagis]

Hi,

1. The pixel format is somewhat outside of the library's scope. Internaly, rendering is done in RGBA 32 bit format, it is not possible to change it in runtime. So, supporting different pixel formats would mean converting the pixels after rasterization is done, and this looks like a functionality of some raster image manipulation library. Writing such conversion functions yourself is not a difficult task.

2. As far as I see, there should be no console output in normal operation in both debug and release builds. In release build there should be no any console output at all. In debug build there is some console output about some abnormal or suspicious situations. Do you use NuGet version of the library? Could you give examples of what console output you observe?

[luc4s]

1. I already did implement such rearrangement myself, but since there is already some per pixel formatting happening there:

   svgren/src/svgren/canvas.cpp

   Lines 47 to 80 in fa92b8b

   	std::vector<pixel> canvas::release(){
   	#if SVGREN_BACKEND == SVGREN_BACKEND_CAIRO
   	auto& ret = this->pixels;
   	#elif SVGREN_BACKEND == SVGREN_BACKEND_AGG
   	ASSERT(!this->group_stack.empty())
   	auto& ret = this->group_stack.front().pixels;
   	#endif
   	for(auto &c : ret){
   	#if SVGREN_BACKEND == SVGREN_BACKEND_CAIRO
   	// swap red and blue channels, as cairo works in BGRA format, while we need to return RGBA
   	c = (c & 0xff00ff00) | ((c << 16) & 0xff0000) | ((c >> 16) & 0xff);
   	#endif
   	// unpremultiply alpha
   	pixel a = (c >> 24);
   	if(a == 0xff){
   	continue;
   	}
   	if(a != 0){
   	using std::min;
   	pixel r = (c & 0xff) * 0xff / a;
   	r = min(r, pixel(0xff)); // clamp top
   	pixel g = ((c >> 8) & 0xff) * 0xff / a;
   	g = min(g, pixel(0xff)); // clamp top
   	pixel b = ((c >> 16) & 0xff) * 0xff / a;
   	b = min(b, pixel(0xff)); // clamp top
   	c = ((a << 24) | (b << 16) | (g << 8) | r);
   	}else{
   	c = 0;
   	}
   	}
   	return std::move(ret);
   	}

   
   I thought an option could have been added.
2. Here is a sample of debug messages I get when loading an SVG:

selector END
selector chain END
property name: fill
property value: #008DD0
style properties END
selector class: AccentRoot
selector END
selector chain END
property name: fill
property value: #FF5504
style properties END
crawler::reset(): invoked
crawler::reset(): invoked
crawler::reset(): invoked
crawler::reset(): invoked

The SVG contains some CSS, could it be the reason?

[igagis]

1. The BGR->RGB conversion in the code is only done for Cairo backend which is not used anymore, instead AGG is the default backend now which does not require that BGR->RGB.

2. Ok, the output comes when loading SVG, then it comes from svgdom and cssdom libraries. I'll remove those prints.

[igagis]

Ok, I have removed the console output. Just update cssdom and svgdom to latest versions.

[luc4s]

Great, thank you 👍.