From 332e00198914bb6cd34199fffb3832e170066959 Mon Sep 17 00:00:00 2001 From: Joshua Leung Date: Mon, 20 Apr 2009 09:17:43 +0000 Subject: Drivers: "Scripted Expression" drivers (i.e. PyDrivers) work again Now it is possible to write a Python Expression using the variable names for driver targets (see mockup from initial commit) to substitute the appropriate values into the expression. In the __global__ namespace for PyDriver evaluation, the following modules are available: * __builtins__ - i.e. the builtin Python functions * bpy - new Python API * math or m - math module For example: Consider a driver with three targets, named: A, B, C Now, you could write an expression like: C if A < 5 else B or even: 2*C if A < 5 or A > 20 else m.PI*B Of course, you don't have to have three targets, the above was just an example. TODO: * Bring back way to load pydrivers.py * Blender.Noise equivalent would be nice to have P.S. I hope I haven't made any terrible Python API coding errors here (i.e. mem leaks, etc.) --- source/blender/python/intern/bpy_interface.c | 199 +++++++++++++++++++++++++++ 1 file changed, 199 insertions(+) (limited to 'source/blender/python/intern/bpy_interface.c') diff --git a/source/blender/python/intern/bpy_interface.c b/source/blender/python/intern/bpy_interface.c index ecf1cc828f3..86406134253 100644 --- a/source/blender/python/intern/bpy_interface.c +++ b/source/blender/python/intern/bpy_interface.c @@ -20,6 +20,7 @@ #include "bpy_operator.h" #include "bpy_ui.h" +#include "DNA_anim_types.h" #include "DNA_space_types.h" #include "DNA_text_types.h" @@ -29,6 +30,7 @@ #include "BLI_string.h" #include "BKE_context.h" +#include "BKE_fcurve.h" #include "BKE_text.h" #include "BPY_extern.h" @@ -415,3 +417,200 @@ void BPY_run_ui_scripts(bContext *C) #endif } +/* ****************************************** */ +/* Drivers - PyExpression Evaluation */ +// XXX Hopefully I haven't committed any PyAPI coding sins here ;) - Aligorith, 2009Apr20 + +/* for pydrivers (drivers using one-line Python expressions to express relationships between targets) */ +PyObject *bpy_pydriver_Dict = NULL; + +/* For faster execution we keep a special dictionary for pydrivers, with + * the needed modules and aliases. + */ +static int bpy_pydriver_create_dict(void) +{ + PyObject *d, *mod; + + /* validate namespace for driver evaluation */ + if (bpy_pydriver_Dict) return -1; + + d = PyDict_New(); + if (d == NULL) + return -1; + else + bpy_pydriver_Dict = d; + + /* import some modules: builtins, bpy, math, (Blender.noise )*/ + PyDict_SetItemString(d, "__builtins__", PyEval_GetBuiltins()); + + mod = PyImport_ImportModule("math"); + if (mod) { + PyDict_Merge(d, PyModule_GetDict(mod), 0); /* 0 - dont overwrite existing values */ + + /* Only keep for backwards compat! - just import all math into root, they are standard */ + PyDict_SetItemString(d, "math", mod); + PyDict_SetItemString(d, "m", mod); + Py_DECREF(mod); + } + + /* add bpy to global namespace */ + mod= PyImport_ImportModuleLevel("bpy", NULL, NULL, NULL, 0); + if (mod) { + PyDict_SetItemString(bpy_pydriver_Dict, "bpy", mod); + Py_DECREF(mod); + } + + +#if 0 // non existant yet + mod = PyImport_ImportModule("Blender.Noise"); + if (mod) { + PyDict_SetItemString(d, "noise", mod); + PyDict_SetItemString(d, "n", mod); + Py_DECREF(mod); + } else { + PyErr_Clear(); + } + + /* If there's a Blender text called pydrivers.py, import it. + * Users can add their own functions to this module. + */ + if (G.f & G_DOSCRIPTLINKS) { + mod = importText("pydrivers"); /* can also use PyImport_Import() */ + if (mod) { + PyDict_SetItemString(d, "pydrivers", mod); + PyDict_SetItemString(d, "p", mod); + Py_DECREF(mod); + } else { + PyErr_Clear(); + } + } +#endif // non existant yet + + return 0; +} + +/* Update function, it gets rid of pydrivers global dictionary, forcing + * BPY_pydriver_eval to recreate it. This function is used to force + * reloading the Blender text module "pydrivers.py", if available, so + * updates in it reach pydriver evaluation. + */ +void BPY_pydriver_update(void) +{ + PyGILState_STATE gilstate = PyGILState_Ensure(); + + if (bpy_pydriver_Dict) { /* free the global dict used by pydrivers */ + PyDict_Clear(bpy_pydriver_Dict); + Py_DECREF(bpy_pydriver_Dict); + bpy_pydriver_Dict = NULL; + } + + PyGILState_Release(gilstate); + + return; +} + +/* error return function for BPY_eval_pydriver */ +static float pydriver_error(ChannelDriver *driver) +{ + if (bpy_pydriver_Dict) { /* free the global dict used by pydrivers */ + PyDict_Clear(bpy_pydriver_Dict); + Py_DECREF(bpy_pydriver_Dict); + bpy_pydriver_Dict = NULL; + } + + driver->flag |= DRIVER_FLAG_INVALID; /* py expression failed */ + fprintf(stderr, "\nError in Driver: The following Python expression failed:\n\t'%s'\n\n", driver->expression); + + PyErr_Print(); + + return 0.0f; +} + +/* This evals py driver expressions, 'expr' is a Python expression that + * should evaluate to a float number, which is returned. + */ +float BPY_pydriver_eval (ChannelDriver *driver) +{ + PyObject *driver_vars=NULL; + PyObject *retval; + PyGILState_STATE gilstate; + + DriverTarget *dtar; + float result = 0.0f; /* default return */ + char *expr = NULL; + short targets_ok= 1; + + /* sanity checks - should driver be executed? */ + if ((driver == NULL) /*|| (G.f & G_DOSCRIPTLINKS)==0*/) + return result; + + /* get the py expression to be evaluated */ + expr = driver->expression; + if ((expr == NULL) || (expr[0]=='\0')) + return result; + + gilstate = PyGILState_Ensure(); + + /* init global dictionary for py-driver evaluation settings */ + if (!bpy_pydriver_Dict) { + if (bpy_pydriver_create_dict() != 0) { + fprintf(stderr, "Pydriver error: couldn't create Python dictionary"); + PyGILState_Release(gilstate); + return result; + } + } + + /* add target values to a py dictionary that we add to the drivers dict as 'd' */ + driver_vars = PyDict_New(); // XXX do we need to decref this? + for (dtar= driver->targets.first; dtar; dtar= dtar->next) { + PyObject *driver_arg = NULL; + float tval = 0.0f; + + /* try to get variable value */ + tval= driver_get_target_value(driver, dtar); + driver_arg= PyFloat_FromDouble((double)tval); + if (driver_arg == NULL) continue; + + /* try to add to dictionary */ + if (PyDict_SetItemString(driver_vars, dtar->name, driver_arg)) { + /* this target failed */ + if (targets_ok) { + /* first one - print some extra info for easier identification */ + fprintf(stderr, "\nBPY_pydriver_eval() - Error while evaluating PyDriver:\n"); + targets_ok= 0; + } + + fprintf(stderr, "\tBPY_pydriver_eval() - couldn't add variable '%s' to namespace \n", dtar->name); + PyErr_Print(); + } + } + + /* execute expression to get a value */ + retval = PyRun_String(expr, Py_eval_input, bpy_pydriver_Dict, driver_vars); + + /* decref the driver vars first... */ + Py_DECREF(driver_vars); + + /* process the result */ + if (retval == NULL) { + result = pydriver_error(driver); + PyGILState_Release(gilstate); + return result; + } + + result = (float)PyFloat_AsDouble(retval); + Py_DECREF(retval); + + if ((result == -1) && PyErr_Occurred()) { + result = pydriver_error(driver); + PyGILState_Release(gilstate); + return result; + } + + /* all fine, make sure the "invalid expression" flag is cleared */ + driver->flag &= ~DRIVER_FLAG_INVALID; + + PyGILState_Release(gilstate); + + return result; +} -- cgit v1.2.3