Implementation of lerp without a function requires repeating one of
the arguments, which is not ideal. To avoid that, add a new function
to the driver namespace. In addition, provide a function for clamping
between 0 and 1 to support easy clamped lerp, and a smoothstep function
from GLSL that is somewhat related.
The function implementations are added to a new bl_math module.
As an aside, add the round function and two-argument log to the
pylike expression subset.
Differential Revision: https://developer.blender.org/D8205
Custom driver functions need access to the dependency graph that is
triggering the evaluation of the driver. This patch passes the
dependency graph pointer through all the animation-related calls.
Instead of passing the evaluation time to functions, the code now passes
an `AnimationEvalContext` pointer:
```
typedef struct AnimationEvalContext {
struct Depsgraph *const depsgraph;
const float eval_time;
} AnimationEvalContext;
```
These structs are read-only, meaning that the code cannot change the
evaluation time. Note that the `depsgraph` pointer itself is const, but
it points to a non-const depsgraph.
FCurves and Drivers can be evaluated at a different time than the
current scene time, for example when evaluating NLA strips. This means
that, even though the current time is stored in the dependency graph, we
need an explicit evaluation time.
There are two functions that allow creation of `AnimationEvalContext`
objects:
- `BKE_animsys_eval_context_construct(Depsgraph *depsgraph, float
eval_time)`, which creates a new context object from scratch, and
- `BKE_animsys_eval_context_construct_at(AnimationEvalContext
*anim_eval_context, float eval_time)`, which can be used to create a
`AnimationEvalContext` with the same depsgraph, but at a different
time. This makes it possible to later add fields without changing any
of the code that just want to change the eval time.
This also provides a fix for T75553, although it does require a change
to the custom driver function. The driver should call
`custom_function(depsgraph)`, and the function should use that depsgraph
instead of information from `bpy.context`.
Reviewed By: brecht, sergey
Differential Revision: https://developer.blender.org/D8047
All the driver-specific code in `fcurve.c` has been moved into a new file
`fcurve_driver.c`. The corresponding declarations have been moved from
`BKE_fcurve.h` to `BKE_fcurve_driver.h`.
All the `#include "BKE_fcurve.h"` statements have been investigated and
replaced with `BKE_fcurve_driver.h` where necessary.
No functional changes.
BF-admins agree to remove header information that isn't useful,
to reduce noise.
- BEGIN/END license blocks
Developers should add non license comments as separate comment blocks.
No need for separator text.
- Contributors
This is often invalid, outdated or misleading
especially when splitting files.
It's more useful to git-blame to find out who has developed the code.
See P901 for script to perform these edits.
Limit to a restricted set of built-ins, as well as the math module.
Also restrict of op-codes, disallowing imports and attribute access.
This allows most math expressions to run
without any performance cost once the initial check is done.
See: D1862 for details.
Drivers can use this to refer to the data which the driver is applied to,
useful for objects, bones, to avoid having to create a variable pointing to its self.
Support for driver variables that don't resolve to numbers, eg:
objects, bones, curves... etc.
Without this, Python expressions to access this data needed to use an absolute path from `bpy.data`,
however this is inconvenient, breaks easily (based on naming) and wouldn't set the dependencies correctly.
- script execution is off by default
- if a blend file attempts to execute a script
this shows a message in the header with the action
that was suppressed (script/driver/game-autostart) and 2 buttons to either reload the file trusted, or to ignore the message.
- the file selector will always default to use the trust setting in the user preferences,
but reloading an open file will keep using the current setting (whatever was set before or set on the command-line).
- added SCons setting WITH_BF_PYTHON_SECURITY, this sets the default state for the user prefereces not to trust blend files on load.
... this option was in CMake before, but always off, now its enabled by default for SCons and CMake, and forced on in CMake for now.
