cppfw/agg

anti-grain geometry

agg's Issues

Include symbolic link doesn't work on Windows

Hi

This is not really an issue ot, at least, it's a partial issue. In this project you have a symbolic link inside the in "include" folder on root project. Other your projects that needs this library (like svgren) refer to the include file here as:

#	include <agg/agg_rendering_buffer.h>
#	include <agg/agg_pixfmt_rgba.h>
#	include <agg/agg_renderer_base.h>

than work on linux able to manage symbolic link but compilation fails on Windows cause the path is missing (pull git project doesn't produce the correct path). Do you think it would be possible to change folders structure by avoid the use of symbolic links?
Thank you

How to get correct results with Porter-Duff composition

Hi

I apologise in advance if this question does not fit here. I don't know of others using AGG and as you know the main development stopped a long time ago so I'm taking a shot with this repo :-)

I'm maintaining and developing a set of graphic backends to R based on AGG (https://github.com/r-lib/ragg). I'm attempting to add support for various blend modes, and for most parts it works correctly using agg::comp_op_adaptor_rgba_pre and agg::pixfmt_custom_blend_rgba.

However, for the rendering operations that should modify the area outside of the polygon getting rasterised I do not get the correct result as that area is not touched during the scanline rendering. The composition operators this relates to are agg::comp_op_src, agg::comp_op_src_in, agg::comp_op_src_out, agg::comp_op_dst, agg::comp_op_dst_over, agg::comp_op_dst_in, and agg::comp_op_dst_atop. All of these requires the rendering buffer to be cleared outside of the areas touched by the scanline renderer.

Am I missing a scanline mode that scans the full buffer or is this a deficiency in AGG?

I hope you are able to help - thanks in advance