Changes were made in Stroke::Resample(int) in C++ to prevent a potential infinite loop
caused by an inconsistency between Stroke::_Length and the stroke length computed
based on stroke vertices. Such a stroke length inconsistency is usually caused by missing
calls of Stroke::UpdateLength() (i.e., API implementation bugs), but also may occur due
to scripting errors in user-defined style modules. This commit is meant to help script
writters to identify the latter error cases. Now Stroke.resample(int) may raise a runtime
error to signal an error condition.
This commit is intended to fully fix the problem described in
https://developer.blender.org/T36425#19 (see also the previous commit rB08528f577dcb).
Addition of a small offset (to avoid singularity in stroke rendering due to overlapping vertices)
was not performed for all overlapping vertices.
Removed the StrokeCleaner and related helper functions which were added as a
temporary workaround in rB2a5b6d9c8f16.
A description of the problem is found in https://developer.blender.org/T36425#19 .
The cause of the issue was identified as roudning errors in Operators::createStroke() due
to insufficient numerical precision. Precision promotion from float to double was done in
the return values of getPoint3D/2D methods in Interface0D and its subclasses in C++
(data members stored in the 0D classes have already been in double precision).
The scene file provided by the problem report has many degenerate faces coming from
a particle system. These zero-area faces were not expected in the ray-casting line visibility
algorithms of Freestyle. Now degenerate faces are properly excluded from the imported
mesh data and not fed to the line visibility algorithms.
Previously mesh objects were created for individual visible stroke segments (recalling that
a stroke may consist of alternate visible and invisible segments). This could result in an
excessive memory consumption in stroke rendering when strokes are composed of many
short visible segments (for instance by means of dashed lines and/or blueprint geometry
modifiers).
Now mesh objects represent individual strokes instead of stroke segments, which tends to
reduce the number of generated mesh objects by an order of magnitude.
Now that Freestyle employs a separate Main, this workaround is no longer necessary.
Reviewers: sergey
Reviewed By: sergey
Differential Revision: https://developer.blender.org/D513
Legacy texture shaders from the original stand-alone Freestyle program are also
declared as deprecated, in favor of Blender's new line style textures.
Patch contribution by Paolo Acampora. Thanks!
(See commit e1771e72fbbf828dbf5bed871b814288389f3611 for more detail of
the problem).
Fix for a C++ scope issue caused by 'using namespace Freestyle' that was assumed
even within the Freestyle namespace definition.
(See commit e1771e72fbbf828dbf5bed871b814288389f3611 for more detail of
the problem).
Made changes to intern/view_map/Interface0D.h and intern/python/Director.h to
avoid #include <Python.h> and keep non-Python header files independent of it.
(See commit e1771e72fbbf828dbf5bed871b814288389f3611 for more detail of
the problem).
Fixed for #include <Python.h> not properly put in the extern "C" { ... } construct.
Also removed redundant inclusion of the header file in the Freestyle Python API code.
The issue was caused by including both Python.h and BLI_math.h. Since the macro
definition in Python.h was unconditional, it was necessary to include it first and then
BLI_math.h.
Addressing the issue turned out to affect many Freestyle source files. There were several
other coding flaws that complicated the situation:
1. intern/system/FreestyleConfig.h was abused just to include BLI_math.h which was in
fact unnecessary in FreestyleConfig.h. While addressing this, inclusion of both math.h
and BLI_math.h had to be duly dealt with to avoid a compiler error about round().
2. #include <Python.h> was not properly put in the extern "C" { ... } construct.
3. intern/view_map/Interface0D.h and intern/python/Director.h, both of which included
Python.h, were included from within Freestyle header files that were almost or completely
independent of Python. These non-Python header files were used everywhere in the
Freestyle code base, causing many cases of the reported macro redefinitions.
4. The Director.h file was also declaring 'using namespace Freestyle', which was causing
another scope issue in several Freestyle header files.
This commit is intended to address the first problem above. Subsequent commits will deal
with the other three.
Addition of the path to the Freestyle Python API modules to 'sys.path' was delayed until
the first Freestyle rendering, so that any import attempt of the modules in the Python
Console always failed. Now the update of 'sys.path' is done at Blender start-up.
This allows the Freestyle-specific modules to be imported without running Freestyle,
facilitating quick interactive testing in the Console.