split out driver functions into its own file

1 files changed, 237 insertions, 0 deletions

diff --git a/source/blender/python/intern/bpy_driver.c b/source/blender/python/intern/bpy_driver.c
new file mode 100644
index 00000000000..9acd6b1cd44
--- /dev/null
+++ b/source/blender/python/intern/bpy_driver.c
@@ -0,0 +1,237 @@
+/**
+ * $Id:
+ *
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * Contributor(s): Willian P. Germano, Campbell Barton
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+/* ****************************************** */
+/* Drivers - PyExpression Evaluation */
+
+#include "DNA_anim_types.h"
+
+#include "BPY_extern.h"
+#include "BKE_fcurve.h"
+
+#include <Python.h>
+
+/* 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);
+
+	// BPy_errors_to_report(NULL); // TODO - reports
+	PyErr_Print();
+	PyErr_Clear();
+
+	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= NULL;
+	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 dict that will be used as '__locals__' dict */
+	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);
+
+		/* try to add to dictionary */
+		if (PyDict_SetItemString(driver_vars, dtar->name, driver_arg)) {
+			/* this target failed - bad name */
+			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);
+			BPy_errors_to_report(NULL); // TODO - reports
+		}
+	}
+
+#if 0 // slow
+	/* execute expression to get a value */
+	retval = PyRun_String(expr, Py_eval_input, bpy_pydriver_Dict, driver_vars);
+#else
+	if(driver->flag & DRIVER_FLAG_RECOMPILE || driver->expr_comp==NULL) {
+		Py_XDECREF(driver->expr_comp);
+		driver->expr_comp= Py_CompileString(expr, "<bpy driver>", Py_eval_input);
+		driver->flag &= ~DRIVER_FLAG_RECOMPILE;
+	}
+	if(driver->expr_comp)
+		retval= PyEval_EvalCode(driver->expr_comp, bpy_pydriver_Dict, driver_vars);
+#endif
+
+	/* 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;
+}