artemp/mapnik — Issue #873: faster line rendering
Author: artemp
Created: 2011-10-11 16:39:51+00:00
State: open
Labels: Core_Library

needs testing but possibility we should be using u8 for thin lines:

"You might be able to speed the
rendering up a little if you use the scanline_p8 type (the packed version)
for thicker strokes and the unpacked version (scanline_u8) for thin strokes"

http://comments.gmane.org/gmane.comp.graphics.agg/3610

{{{
#!diff
Index: src/agg/process_line_symbolizer.cpp
===================================================================
--- src/agg/process_line_symbolizer.cpp	(revision 3296)
+++ src/agg/process_line_symbolizer.cpp	(working copy)
@@ -69,7 +69,7 @@
ras_ptr->reset();
ras_ptr->gamma(agg::gamma_linear(0.0, stroke_.get_gamma()));

- agg::scanline_p8 sl;
+ agg::scanline_u8 sl;
metawriter_with_properties writer = sym.get_metawriter();
for (unsigned i=0;i