[Bf-blender-cvs] [fc1f5bded46] blender-v2.82-release: Depsgraph: fix false positive time dependencies for simple drivers.
Alexander Gavrilov
noreply at git.blender.org
Fri Jan 24 18:48:22 CET 2020
Commit: fc1f5bded46afbb9b16fffe9e4c7f7c212566255
Author: Alexander Gavrilov
Date: Sun Jan 19 12:44:34 2020 +0300
Branches: blender-v2.82-release
https://developer.blender.org/rBfc1f5bded46afbb9b16fffe9e4c7f7c212566255
Depsgraph: fix false positive time dependencies for simple drivers.
The dependency graph has to know whether a driver must be re-evaluated
every frame due to a dependency on the current frame number. For python
drivers it was using a heuristic based on searching for certain sub-
strings in the expression, notably including '('.
When the expression is actually evaluated using Python, this can't be
easily improved; however if the Simple Expression evaluator is used,
this check can be done precisely by accessing the parsed data.
Differential Revision: https://developer.blender.org/D6624
===================================================================
M source/blender/blenkernel/BKE_fcurve.h
M source/blender/blenkernel/intern/fcurve.c
M source/blender/blenlib/BLI_expr_pylike_eval.h
M source/blender/blenlib/intern/expr_pylike_eval.c
M source/blender/depsgraph/intern/builder/deg_builder_relations.cc
M tests/gtests/blenlib/BLI_expr_pylike_eval_test.cc
===================================================================
diff --git a/source/blender/blenkernel/BKE_fcurve.h b/source/blender/blenkernel/BKE_fcurve.h
index 426e0ed4b0e..405b052f477 100644
--- a/source/blender/blenkernel/BKE_fcurve.h
+++ b/source/blender/blenkernel/BKE_fcurve.h
@@ -107,6 +107,7 @@ bool driver_get_variable_property(struct ChannelDriver *driver,
int *r_index);
bool BKE_driver_has_simple_expression(struct ChannelDriver *driver);
+bool BKE_driver_expression_depends_on_time(struct ChannelDriver *driver);
void BKE_driver_invalidate_expression(struct ChannelDriver *driver,
bool expr_changed,
bool varname_changed);
diff --git a/source/blender/blenkernel/intern/fcurve.c b/source/blender/blenkernel/intern/fcurve.c
index 08687ef8cee..833b8409f7d 100644
--- a/source/blender/blenkernel/intern/fcurve.c
+++ b/source/blender/blenkernel/intern/fcurve.c
@@ -2142,20 +2142,34 @@ ChannelDriver *fcurve_copy_driver(const ChannelDriver *driver)
/* Driver Expression Evaluation --------------- */
+/* Index constants for the expression parameter array. */
+enum {
+ /* Index of the 'frame' variable. */
+ VAR_INDEX_FRAME = 0,
+ /* Index of the first user-defined driver variable. */
+ VAR_INDEX_CUSTOM
+};
+
static ExprPyLike_Parsed *driver_compile_simple_expr_impl(ChannelDriver *driver)
{
/* Prepare parameter names. */
int names_len = BLI_listbase_count(&driver->variables);
- const char **names = BLI_array_alloca(names, names_len + 1);
- int i = 0;
+ const char **names = BLI_array_alloca(names, names_len + VAR_INDEX_CUSTOM);
+ int i = VAR_INDEX_CUSTOM;
- names[i++] = "frame";
+ names[VAR_INDEX_FRAME] = "frame";
for (DriverVar *dvar = driver->variables.first; dvar; dvar = dvar->next) {
names[i++] = dvar->name;
}
- return BLI_expr_pylike_parse(driver->expression, names, names_len + 1);
+ return BLI_expr_pylike_parse(driver->expression, names, names_len + VAR_INDEX_CUSTOM);
+}
+
+static bool driver_check_simple_expr_depends_on_time(ExprPyLike_Parsed *expr)
+{
+ /* Check if the 'frame' parameter is actually used. */
+ return BLI_expr_pylike_is_using_param(expr, VAR_INDEX_FRAME);
}
static bool driver_evaluate_simple_expr(ChannelDriver *driver,
@@ -2165,10 +2179,10 @@ static bool driver_evaluate_simple_expr(ChannelDriver *driver,
{
/* Prepare parameter values. */
int vars_len = BLI_listbase_count(&driver->variables);
- double *vars = BLI_array_alloca(vars, vars_len + 1);
- int i = 0;
+ double *vars = BLI_array_alloca(vars, vars_len + VAR_INDEX_CUSTOM);
+ int i = VAR_INDEX_CUSTOM;
- vars[i++] = time;
+ vars[VAR_INDEX_FRAME] = time;
for (DriverVar *dvar = driver->variables.first; dvar; dvar = dvar->next) {
vars[i++] = driver_get_variable_value(driver, dvar);
@@ -2176,7 +2190,8 @@ static bool driver_evaluate_simple_expr(ChannelDriver *driver,
/* Evaluate expression. */
double result_val;
- eExprPyLike_EvalStatus status = BLI_expr_pylike_eval(expr, vars, vars_len + 1, &result_val);
+ eExprPyLike_EvalStatus status = BLI_expr_pylike_eval(
+ expr, vars, vars_len + VAR_INDEX_CUSTOM, &result_val);
const char *message;
switch (status) {
@@ -2245,6 +2260,44 @@ bool BKE_driver_has_simple_expression(ChannelDriver *driver)
return driver_compile_simple_expr(driver) && BLI_expr_pylike_is_valid(driver->expr_simple);
}
+/* TODO(sergey): This is somewhat weak, but we don't want neither false-positive
+ * time dependencies nor special exceptions in the depsgraph evaluation. */
+static bool python_driver_exression_depends_on_time(const char *expression)
+{
+ if (expression[0] == '\0') {
+ /* Empty expression depends on nothing. */
+ return false;
+ }
+ if (strchr(expression, '(') != NULL) {
+ /* Function calls are considered dependent on a time. */
+ return true;
+ }
+ if (strstr(expression, "frame") != NULL) {
+ /* Variable `frame` depends on time. */
+ /* TODO(sergey): This is a bit weak, but not sure about better way of handling this. */
+ return true;
+ }
+ /* Possible indirect time relation s should be handled via variable targets. */
+ return false;
+}
+
+/* Check if the expression in the driver may depend on the current frame. */
+bool BKE_driver_expression_depends_on_time(ChannelDriver *driver)
+{
+ if (driver->type != DRIVER_TYPE_PYTHON) {
+ return false;
+ }
+
+ if (BKE_driver_has_simple_expression(driver)) {
+ /* Simple expressions can be checked exactly. */
+ return driver_check_simple_expr_depends_on_time(driver->expr_simple);
+ }
+ else {
+ /* Otherwise, heuristically scan the expression string for certain patterns. */
+ return python_driver_exression_depends_on_time(driver->expression);
+ }
+}
+
/* Reset cached compiled expression data */
void BKE_driver_invalidate_expression(ChannelDriver *driver,
bool expr_changed,
diff --git a/source/blender/blenlib/BLI_expr_pylike_eval.h b/source/blender/blenlib/BLI_expr_pylike_eval.h
index b8bf88dd85b..1db91ea4205 100644
--- a/source/blender/blenlib/BLI_expr_pylike_eval.h
+++ b/source/blender/blenlib/BLI_expr_pylike_eval.h
@@ -45,6 +45,7 @@ typedef enum eExprPyLike_EvalStatus {
void BLI_expr_pylike_free(struct ExprPyLike_Parsed *expr);
bool BLI_expr_pylike_is_valid(struct ExprPyLike_Parsed *expr);
bool BLI_expr_pylike_is_constant(struct ExprPyLike_Parsed *expr);
+bool BLI_expr_pylike_is_using_param(struct ExprPyLike_Parsed *expr, int index);
ExprPyLike_Parsed *BLI_expr_pylike_parse(const char *expression,
const char **param_names,
int param_names_len);
diff --git a/source/blender/blenlib/intern/expr_pylike_eval.c b/source/blender/blenlib/intern/expr_pylike_eval.c
index 43923ce8c98..6020dc41a62 100644
--- a/source/blender/blenlib/intern/expr_pylike_eval.c
+++ b/source/blender/blenlib/intern/expr_pylike_eval.c
@@ -140,6 +140,24 @@ bool BLI_expr_pylike_is_constant(ExprPyLike_Parsed *expr)
return expr != NULL && expr->ops_count == 1 && expr->ops[0].opcode == OPCODE_CONST;
}
+/** Check if the parsed expression uses the parameter with the given index. */
+bool BLI_expr_pylike_is_using_param(ExprPyLike_Parsed *expr, int index)
+{
+ int i;
+
+ if (expr == NULL) {
+ return false;
+ }
+
+ for (i = 0; i < expr->ops_count; i++) {
+ if (expr->ops[i].opcode == OPCODE_PARAMETER && expr->ops[i].arg.ival == index) {
+ return true;
+ }
+ }
+
+ return false;
+}
+
/** \} */
/* -------------------------------------------------------------------- */
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index 7d7a183ee75..fa7a63227f5 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -123,28 +123,6 @@ namespace DEG {
namespace {
-/* TODO(sergey): This is somewhat weak, but we don't want neither false-positive
- * time dependencies nor special exceptions in the depsgraph evaluation. */
-
-bool python_driver_exression_depends_on_time(const char *expression)
-{
- if (expression[0] == '\0') {
- /* Empty expression depends on nothing. */
- return false;
- }
- if (strchr(expression, '(') != NULL) {
- /* Function calls are considered dependent on a time. */
- return true;
- }
- if (strstr(expression, "frame") != NULL) {
- /* Variable `frame` depends on time. */
- /* TODO(sergey): This is a bit weak, but not sure about better way of handling this. */
- return true;
- }
- /* Possible indirect time relation s should be handled via variable targets. */
- return false;
-}
-
bool driver_target_depends_on_time(const DriverTarget *target)
{
if (target->idtype == ID_SCE &&
@@ -176,10 +154,8 @@ bool driver_variables_depends_on_time(const ListBase *variables)
bool driver_depends_on_time(ChannelDriver *driver)
{
- if (driver->type == DRIVER_TYPE_PYTHON) {
- if (python_driver_exression_depends_on_time(driver->expression)) {
- return true;
- }
+ if (BKE_driver_expression_depends_on_time(driver)) {
+ return true;
}
if (driver_variables_depends_on_time(&driver->variables)) {
return true;
diff --git a/tests/gtests/blenlib/BLI_expr_pylike_eval_test.cc b/tests/gtests/blenlib/BLI_expr_pylike_eval_test.cc
index 32e33e2e118..449577401d7 100644
--- a/tests/gtests/blenlib/BLI_expr_pylike_eval_test.cc
+++ b/tests/gtests/blenlib/BLI_expr_pylike_eval_test.cc
@@ -282,6 +282,19 @@ TEST(expr_pylike, MultipleArgs)
BLI_expr_pylike_free(expr);
}
+TEST(expr_pylike, UsingParam)
+{
+ const char *names[3] = {"x", "y", "z"};
+
+ ExprPyLike_Parsed *expr = BLI_expr_pylike_parse("x + z", names, ARRAY_SIZE(names));
+
+ EXPECT_TRUE(BLI_expr_pylike_is_using_param(expr, 0));
+ EXPECT_FALSE(BLI_expr_pylike_is_using_param(expr, 1));
+ EXPECT_TRUE(BLI_expr_pylike_is_using_param(expr, 2));
+
+ BLI_expr_pylike_free(expr);
+}
+
#define TEST_ERROR(name, str, x, code) \
TEST(expr_pylike, Error_##name) \
{ \
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