Partial rewrite of the Collada Module for Blender 2.8

Most important changes are in the Animation exporter and Animation Importer.
There is still some cleaning up to be done. But the Exporter/Importer basically
work within Blender 2.8

Some details:

User Interface:
The interface has been reorganized to look more like the FBX interface.

New options in user interface:

* keep_keyframes:
  When sampling the distance between 2 keyframes is defined by
  the sampling rate. Furthermore the keyframes defined in the
  FCurves are not exported. However when this option is enabled
  then also the defined keyframes will be added to the exported fcurves

* keep_smooth_curves:
  When sampling we do not use FCurves. So we also have no Curve handles
  for smooth exporting. However when this option is enabled, Blender
  does its best to recreate the handles for export. This is a very
  experimental feature and it is know to break when:

  - the exported animated objects have parent inverse matrices
    different from the unit matrix
  - The exported objects have negative scaling

  There may be many other situations when this feature breaks.
  This needs to be further tested. It may be removed later or replaced
  by something less wonky.

BlenderContext:
is a new class that contains the bridge to Blender. It contains
pointers to the current export/import context plus derived values
of Depsgraph, Scene, Main

Reporting:
I reorganized the output on the Blender Console to become more
informative and more readable

Preservation of Item names:
name attributes are now encoded with XML entities. This makes
sure that i can export/import names exactly defined in the tool.
This affects material names, bone names and object names.

Hierarchy export:
* Object and Bone Hierarchies are now exported correctly
  by taking the Blender parent/child hierarchy into account
* Export also not selected intermediate objects

  Problem:
  When we export an Object Hierarchy, then we must export
  all elements of the hierarchy to maintain the transforms. This
  is especially important when exporting animated objects, because the
  animation curves are exported as relative curves based on the
  parent-child hierarchy. If an intermediate animated object is missing
  then the exported animation breaks.

  Solution:
  If the "Selected" Optioon is enabled, then take care
  to also export all objects which are not selected and hidden,
  but which are parents of selected objects.

Node Based Material Importer (wip):
Added basic support for Materials with diffuse color and
diffuse textures. More properties (opacity, emission) need
changes in the used shader.
Note: Materials are all constructed by using the principled BSDF shader.

Animation Exporter:
* Massive optimization of the Animation Bake tool (Animation Sampler).
  Instead of sampling each fcurve separately, i now sample all
  exported fcurves simultaneously. So i avoid many (many!)
  scene updates during animation export.
* Add support for Continuous Acceleration (Fcurve handles)
  This allows us to create smoother FCurves during importing Collada
  Animation curves. Possibly this should become an option ionstead of
  a fixed import feature.
* Add support for sampling curves (to bake animations)
* The animation sampler now can be used for any animation curve.
  Before the sampler only looked at curves which are supported by
  Standard Collada 1.4. However the Collada exporter currently
  ignores all animation curves which are not covered by the 1.4.1
  Collada Standards. There is still some room for improvements
  here (work in progres)

  Known issues:

    * Some exports do currently not work reliably, among those
      are the camera animations, material animations and light animations
      those animations will be added back next (work in progres)

    * Exporting animation curves with keyframes (and tangents)
      sometimes results in odd curves (when parent inverse matrix is involved)
      This needs to be checked in more depth (probably it can not be solved).

    * Export of "all animations in scene" is disabled because the
      Collada Importer can not handle this reliably at the
      moment (work in progres).

* Support for Animation Clip export
  Added one extra level to the exported animations
  such that now all scene animations are enclosed:

  <Animation name="id_name(ob)_Action">
    <Animation>...</Animation>
    ...
  </Animation>

Animation Importer:
* Import of animations for objects with multiple materials
  When importing multiple materials for one object,
  the imported material animation curves have all been
  assigned to the first material in the object.

Error handling (wip):
The Importer was a bit confused as it sometimes ignored fatal
parsing errors and continued to import. I did my best to
unconfuse it, but i believe that this needs to be tested more.

Refactoring:

update : move generation of effect id names into own function
update : adjust importer/exporter for no longer supported HEMI lights
cleanup: Removed no lopnger existing attribute from the exporter presets
cleanup: Removed not needed Context attribute from DocumentExporter
fix    : Avoid duplicate deletion of temporary items
cleanup: fixed indentation and white space issues
update : Make BCAnimation class more self contained
cleanup: Renamed classes, updated comments for better reading
cleanup: Moved static class functions to collada_utils
cleanup: Moved typedefs to more intuitive locations
cleanup: indentation and class method declarations
cleanup: Removed no longer needed methods
update : Moved Classes into separate files
cleanup: Added comments
cleanup: take care of name conventions
...    : many more small changes, not helpful to list them all

1 files changed, 679 insertions, 0 deletions

diff --git a/source/blender/collada/BCAnimationCurve.cpp b/source/blender/collada/BCAnimationCurve.cpp
new file mode 100644
index 00000000000..3925cde8516
--- /dev/null
+++ b/source/blender/collada/BCAnimationCurve.cpp
@@ -0,0 +1,679 @@
+/*
+* ***** 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+*
+* The Original Code is Copyright (C) 2008 Blender Foundation.
+* All rights reserved.
+*
+* Contributor(s): Blender Foundation
+*
+* ***** END GPL LICENSE BLOCK *****
+*/
+
+#include "BCAnimationCurve.h"
+
+BCAnimationCurve::BCAnimationCurve()
+{
+	this->curve_key.set_object_type(BC_ANIMATION_TYPE_OBJECT);
+	this->fcurve = NULL;
+	this->curve_is_local_copy = false;
+}
+
+BCAnimationCurve::BCAnimationCurve(const BCAnimationCurve &other)
+{
+	this->min = other.min;
+	this->max = other.max;
+	this->fcurve = other.fcurve;
+	this->curve_key = other.curve_key;
+	this->curve_is_local_copy = false;
+	this->id_ptr = other.id_ptr;
+
+	/* The fcurve of the new instance is a copy and can be modified */
+
+	get_edit_fcurve();
+}
+
+BCAnimationCurve::BCAnimationCurve(BCCurveKey key, Object *ob, FCurve *fcu)
+{
+	this->min = 0;
+	this->max = 0;
+	this->curve_key = key;
+	this->fcurve = fcu;
+	this->curve_is_local_copy = false;
+	init_pointer_rna(ob);
+}
+
+BCAnimationCurve::BCAnimationCurve(const BCCurveKey &key, Object *ob)
+{
+	this->curve_key = key;
+	this->fcurve = NULL;
+	this->curve_is_local_copy = false;
+	init_pointer_rna(ob);
+}
+
+void BCAnimationCurve::init_pointer_rna(Object *ob)
+{
+	switch (this->curve_key.get_animation_type()) {
+	case BC_ANIMATION_TYPE_BONE:
+	{
+		bArmature * arm = (bArmature *)ob->data;
+		RNA_id_pointer_create(&arm->id, &id_ptr);
+	}
+	break;
+	case BC_ANIMATION_TYPE_OBJECT:
+	{
+		RNA_id_pointer_create(&ob->id, &id_ptr);
+	}
+	break;
+	case BC_ANIMATION_TYPE_MATERIAL:
+	{
+		Material *ma = give_current_material(ob, curve_key.get_subindex() + 1);
+		RNA_id_pointer_create(&ma->id, &id_ptr);
+	}
+	break;
+	case BC_ANIMATION_TYPE_CAMERA:
+	{
+		Camera * camera = (Camera *)ob->data;
+		RNA_id_pointer_create(&camera->id, &id_ptr);
+	}
+	break;
+	case BC_ANIMATION_TYPE_LIGHT:
+	{
+		Lamp * lamp = (Lamp *)ob->data;
+		RNA_id_pointer_create(&lamp->id, &id_ptr);
+	}
+	break;
+	default:
+		fprintf(stderr, "BC_animation_curve_type %d not supported", this->curve_key.get_array_index());
+		break;
+	}
+}
+
+void BCAnimationCurve::delete_fcurve(FCurve *fcu)
+{
+	free_fcurve(fcu);
+}
+
+FCurve *BCAnimationCurve::create_fcurve(int array_index, const char *rna_path)
+{
+	FCurve *fcu = (FCurve *)MEM_callocN(sizeof(FCurve), "FCurve");
+	fcu->flag = (FCURVE_VISIBLE | FCURVE_AUTO_HANDLES | FCURVE_SELECTED);
+	fcu->rna_path = BLI_strdupn(rna_path, strlen(rna_path));
+	fcu->array_index = array_index;
+	return fcu;
+}
+
+void BCAnimationCurve::create_bezt(float frame, float output)
+{
+	FCurve *fcu = get_edit_fcurve();
+	BezTriple bez;
+	memset(&bez, 0, sizeof(BezTriple));
+	bez.vec[1][0] = frame;
+	bez.vec[1][1] = output;
+	bez.ipo = U.ipo_new; /* use default interpolation mode here... */
+	bez.f1 = bez.f2 = bez.f3 = SELECT;
+	bez.h1 = bez.h2 = HD_AUTO;
+	insert_bezt_fcurve(fcu, &bez, INSERTKEY_NOFLAGS);
+	calchandles_fcurve(fcu);
+}
+
+BCAnimationCurve::~BCAnimationCurve()
+{
+	if (curve_is_local_copy && fcurve) {
+		//fprintf(stderr, "removed fcurve %s\n", fcurve->rna_path);
+		delete_fcurve(fcurve);
+		this->fcurve = NULL;
+	}
+}
+
+const bool BCAnimationCurve::is_of_animation_type(BC_animation_type type) const
+{
+	return curve_key.get_animation_type() == type;
+}
+
+const std::string BCAnimationCurve::get_channel_target() const
+{
+	const std::string path = curve_key.get_path();
+	return bc_string_after(path, '.');
+}
+
+const std::string BCAnimationCurve::get_animation_name(Object *ob) const
+{
+	std::string name;
+
+	switch (curve_key.get_animation_type()) {
+		case BC_ANIMATION_TYPE_OBJECT:
+		{
+			name = id_name(ob);
+		}
+		break;
+
+		case BC_ANIMATION_TYPE_BONE:
+		{
+			if (fcurve == NULL || fcurve->rna_path == NULL)
+				name = "";
+			else {
+				const char *boneName = BLI_str_quoted_substrN(fcurve->rna_path, "pose.bones[");
+				name = (boneName) ? std::string(boneName) : "";
+			}
+		}
+		break;
+
+		case BC_ANIMATION_TYPE_CAMERA:
+		{
+			Camera *camera = (Camera *)ob->data;
+			name = id_name(ob) + "-" + id_name(camera) + "-camera";
+		}
+		break;
+
+		case BC_ANIMATION_TYPE_LIGHT:
+		{
+			Lamp *lamp = (Lamp *)ob->data;
+			name = id_name(ob) + "-" + id_name(lamp) + "-light";
+		}
+		break;
+
+		case BC_ANIMATION_TYPE_MATERIAL:
+		{
+			Material * ma = give_current_material(ob, this->curve_key.get_subindex() + 1);
+			name = id_name(ob) + "-" + id_name(ma) + "-material";
+		}
+		break;
+
+		default:
+		{
+			name = "";
+		}
+	}
+
+	return name;
+}
+
+const int BCAnimationCurve::get_channel_index() const
+{
+	return curve_key.get_array_index();
+}
+
+const int BCAnimationCurve::get_subindex() const
+{
+	return curve_key.get_subindex();
+}
+
+const std::string BCAnimationCurve::get_rna_path() const
+{
+	return curve_key.get_path();
+}
+
+const int BCAnimationCurve::sample_count() const
+{
+	if (fcurve == NULL)
+		return 0;
+	return fcurve->totvert;
+}
+
+const int BCAnimationCurve::closest_index_above(const float sample_frame, const int start_at) const
+{
+	if (fcurve == NULL)
+		return -1;
+
+	const int cframe = fcurve->bezt[start_at].vec[1][0]; // inacurate!
+
+	if (fabs(cframe - sample_frame) < 0.00001)
+		return start_at;
+	return (fcurve->totvert > start_at + 1) ? start_at + 1 : start_at;
+}
+
+const int BCAnimationCurve::closest_index_below(const float sample_frame) const
+{
+	if (fcurve == NULL)
+		return -1;
+
+	float lower_frame = sample_frame;
+	float upper_frame = sample_frame;
+	int lower_index = 0;
+	int upper_index = 0;
+
+	for (int fcu_index = 0; fcu_index < fcurve->totvert; ++fcu_index) {
+		upper_index = fcu_index;
+
+		const int cframe = fcurve->bezt[fcu_index].vec[1][0]; // inacurate!
+		if (cframe <= sample_frame) {
+			lower_frame = cframe;
+			lower_index = fcu_index;
+		}
+		if (cframe >= sample_frame) {
+			upper_frame = cframe;
+			break;
+		}
+	}
+
+	if (lower_index == upper_index)
+		return lower_index;
+
+	const float fraction = float(sample_frame - lower_frame) / (upper_frame - lower_frame);
+	return (fraction < 0.5) ? lower_index : upper_index;
+}
+
+const int BCAnimationCurve::get_interpolation_type(float sample_frame) const
+{
+	const int index = closest_index_below(sample_frame);
+	if (index < 0)
+		return BEZT_IPO_BEZ;
+	return fcurve->bezt[index].ipo;
+}
+
+const FCurve *BCAnimationCurve::get_fcurve() const
+{
+	return fcurve;
+}
+
+FCurve *BCAnimationCurve::get_edit_fcurve()
+{
+	if (!curve_is_local_copy) {
+		const int index = curve_key.get_array_index();
+		const std::string &path = curve_key.get_path();
+		fcurve = create_fcurve(index, path.c_str());
+
+		/* Caution here:
+		Replacing the pointer here is OK only because the original value
+		of FCurve was a const pointer into Blender territory. We do not
+		touch that! We use the local copy to prepare data for export.
+		*/
+
+		curve_is_local_copy = true;
+	}
+	return fcurve;
+}
+
+void BCAnimationCurve::clean_handles()
+{
+	if (fcurve == NULL)
+		fcurve = get_edit_fcurve();
+
+	/* Keep old bezt data for copy)*/
+	BezTriple *old_bezts = fcurve->bezt;
+	int totvert = fcurve->totvert;
+	fcurve->bezt = NULL;
+	fcurve->totvert = 0;
+
+	for (int i = 0; i < totvert; i++) {
+		BezTriple *bezt = &old_bezts[i];
+		float x = bezt->vec[1][0];
+		float y = bezt->vec[1][1];
+		insert_vert_fcurve(fcurve, x, y, (eBezTriple_KeyframeType)BEZKEYTYPE(bezt), INSERTKEY_NOFLAGS);
+		BezTriple *lastb = fcurve->bezt + (fcurve->totvert - 1);
+		lastb->f1 = lastb->f2 = lastb->f3 = 0;
+	}
+
+	/* now free the memory used by the old BezTriples */
+	if (old_bezts)
+		MEM_freeN(old_bezts);
+}
+
+const bool BCAnimationCurve::is_transform_curve() const
+{
+	std::string channel_target = this->get_channel_target();
+	return (
+		is_rotation_curve() ||
+		channel_target == "scale" ||
+		channel_target == "location"
+		);
+}
+
+const bool BCAnimationCurve::is_rotation_curve() const
+{
+	std::string channel_target = this->get_channel_target();
+	return (
+		channel_target == "rotation" ||
+		channel_target == "rotation_euler" ||
+		channel_target == "rotation_quaternion"
+		);
+}
+
+const float BCAnimationCurve::get_value(const float frame)
+{
+	if (fcurve) {
+		return evaluate_fcurve(fcurve, frame);
+	}
+	return 0; // TODO: handle case where neither sample nor fcu exist
+}
+
+void BCAnimationCurve::update_range(float val)
+{
+	if (val < min) {
+			min = val;
+	}
+	if (val > max) {
+		max = val;
+	}
+}
+
+void BCAnimationCurve::init_range(float val)
+{
+	min = max = val;
+}
+
+void BCAnimationCurve::adjust_range(const int frame_index)
+{
+	if (fcurve && fcurve->totvert > 1) {
+		const float eval = evaluate_fcurve(fcurve, frame_index);
+
+		int first_frame = fcurve->bezt[0].vec[1][0];
+		if (first_frame == frame_index) {
+			init_range(eval);
+		}
+		else {
+			update_range(eval);
+		}
+	}
+}
+
+void BCAnimationCurve::add_value(const float val, const int frame_index)
+{
+	FCurve *fcu = get_edit_fcurve();
+	fcu->auto_smoothing = FCURVE_SMOOTH_CONT_ACCEL;
+	insert_vert_fcurve(
+		fcu, 
+		frame_index, val, 
+		BEZT_KEYTYPE_KEYFRAME,
+		INSERTKEY_NOFLAGS);
+
+	if (fcu->totvert == 1) {
+		init_range(val);
+	}
+	else {
+		update_range(val);
+	}
+}
+
+bool BCAnimationCurve::add_value_from_matrix(const BCSample &sample, const int frame_index)
+{
+	int array_index = curve_key.get_array_index();
+
+	/* transformation curves are feeded directly from the transformation matrix
+	* to resolve parent inverse matrix issues with object hierarchies.
+	* Maybe this can be unified with the
+	*/
+	const std::string channel_target = get_channel_target();
+	float val = 0;
+	/* Pick the value from the sample according to the definition of the FCurve */
+	bool good = sample.get_value(channel_target, array_index, &val);
+	if (good) {
+		add_value(val, frame_index);
+	}
+	return good;
+}
+
+bool BCAnimationCurve::add_value_from_rna(const int frame_index)
+{
+	PointerRNA ptr;
+	PropertyRNA *prop;
+	float value = 0.0f;
+	int array_index = curve_key.get_array_index();
+	const std::string full_path = curve_key.get_full_path();
+
+	/* get property to read from, and get value as appropriate */
+	bool path_resolved = RNA_path_resolve_full(&id_ptr, full_path.c_str(), &ptr, &prop, &array_index);
+	if (!path_resolved && array_index == 0) {
+		const std::string rna_path = curve_key.get_path();
+		path_resolved = RNA_path_resolve_full(&id_ptr, rna_path.c_str(), &ptr, &prop, &array_index);
+	}
+
+	if (path_resolved) {
+		bool is_array = RNA_property_array_check(prop);
+		if (is_array) {
+			/* array */
+			if ((array_index >= 0) && (array_index < RNA_property_array_length(&ptr, prop))) {
+				switch (RNA_property_type(prop)) {
+				case PROP_BOOLEAN:
+					value = (float)RNA_property_boolean_get_index(&ptr, prop, array_index);
+					break;
+				case PROP_INT:
+					value = (float)RNA_property_int_get_index(&ptr, prop, array_index);
+					break;
+				case PROP_FLOAT:
+					value = RNA_property_float_get_index(&ptr, prop, array_index);
+					break;
+				default:
+					break;
+				}
+			}
+			else {
+				fprintf(stderr, "Out of Bounds while reading data for Curve %s\n", curve_key.get_full_path().c_str());
+				return false;
+			}
+		}
+		else {
+			/* not an array */
+			switch (RNA_property_type(prop)) {
+			case PROP_BOOLEAN:
+				value = (float)RNA_property_boolean_get(&ptr, prop);
+				break;
+			case PROP_INT:
+				value = (float)RNA_property_int_get(&ptr, prop);
+				break;
+			case PROP_FLOAT:
+				value = RNA_property_float_get(&ptr, prop);
+				break;
+			case PROP_ENUM:
+				value = (float)RNA_property_enum_get(&ptr, prop);
+				break;
+			default:
+				fprintf(stderr, "property type %d not supported for Curve %s\n", RNA_property_type(prop), curve_key.get_full_path().c_str());
+				return false;
+				break;
+			}
+		}
+	}
+	else {
+		/* path couldn't be resolved */
+		fprintf(stderr, "Path not recognized for Curve %s\n", curve_key.get_full_path().c_str());
+		return false;
+	}
+
+	add_value(value, frame_index);
+	return true;
+}
+
+void BCAnimationCurve::get_value_map(BCValueMap &value_map)
+{
+	value_map.clear();
+	if (fcurve == NULL) {
+		return;
+	}
+
+	for (int i = 0; i < fcurve->totvert; i++) {
+		const float frame = fcurve->bezt[i].vec[1][0];
+		const float val = fcurve->bezt[i].vec[1][1];
+		value_map[frame] = val;
+	}
+}
+
+void BCAnimationCurve::get_frames(BCFrames &frames) const
+{
+	frames.clear();
+	if (fcurve) {
+		for (int i = 0; i < fcurve->totvert; i++) {
+			const float val = fcurve->bezt[i].vec[1][0];
+			frames.push_back(val);
+		}
+	}
+}
+
+void BCAnimationCurve::get_values(BCValues &values) const
+{
+	values.clear();
+	if (fcurve) {
+		for (int i = 0; i < fcurve->totvert; i++) {
+			const float val = fcurve->bezt[i].vec[1][1];
+			values.push_back(val);
+		}
+	}
+}
+
+bool BCAnimationCurve::is_animated()
+{
+	static float MIN_DISTANCE = 0.00001;
+	return fabs(max - min) > MIN_DISTANCE;
+}
+
+
+bool BCAnimationCurve::is_keyframe(int frame) {
+	if (this->fcurve == NULL)
+		return false;
+
+	for (int i = 0; i < fcurve->totvert; ++i) {
+		const int cframe = nearbyint(fcurve->bezt[i].vec[1][0]);
+		if (cframe == frame)
+			return true;
+		if (cframe > frame)
+			break;
+	}
+	return false;
+}
+
+/* Needed for adding a BCAnimationCurve into a BCAnimationCurveSet */
+inline bool operator< (const BCAnimationCurve& lhs, const BCAnimationCurve& rhs) {
+	std::string lhtgt = lhs.get_channel_target();
+	std::string rhtgt = rhs.get_channel_target();
+	if (lhtgt == rhtgt)
+	{
+		const int lha = lhs.get_channel_index();
+		const int rha = rhs.get_channel_index();
+		return lha < rha;
+	}
+	else
+		return lhtgt < rhtgt;
+}
+
+BCCurveKey::BCCurveKey()
+{
+	this->key_type = BC_ANIMATION_TYPE_OBJECT;
+	this->rna_path = "";
+	this->curve_array_index = 0;
+	this->curve_subindex = -1;
+}
+
+BCCurveKey::BCCurveKey(const BC_animation_type type, const std::string path, const int array_index, const int subindex)
+{
+	this->key_type = type;
+	this->rna_path = path;
+	this->curve_array_index = array_index;
+	this->curve_subindex = subindex;
+}
+
+void BCCurveKey::operator=(const BCCurveKey &other)
+{
+	this->key_type = other.key_type;
+	this->rna_path = other.rna_path;
+	this->curve_array_index = other.curve_array_index;
+	this->curve_subindex = other.curve_subindex;
+}
+
+const std::string BCCurveKey::get_full_path() const
+{
+	return this->rna_path + '[' + std::to_string(this->curve_array_index) + ']';
+}
+
+const std::string BCCurveKey::get_path() const
+{
+	return this->rna_path;
+}
+
+const int BCCurveKey::get_array_index() const
+{
+	return this->curve_array_index;
+}
+
+const int BCCurveKey::get_subindex() const
+{
+	return this->curve_subindex;
+}
+
+void BCCurveKey::set_object_type(BC_animation_type object_type)
+{
+	this->key_type = object_type;
+}
+
+const BC_animation_type BCCurveKey::get_animation_type() const
+{
+	return this->key_type;
+}
+
+const bool BCCurveKey::operator<(const BCCurveKey &other) const
+{
+	/* needed for using this class as key in maps and sets */
+	if (this->key_type != other.key_type)
+		return this->key_type < other.key_type;
+
+	if (this->curve_subindex != other.curve_subindex)
+		return this->curve_subindex < other.curve_subindex;
+
+	if (this->rna_path != other.rna_path)
+		return this->rna_path < other.rna_path;
+
+	return this->curve_array_index < other.curve_array_index;
+}
+
+BCBezTriple::BCBezTriple(BezTriple bezt) :
+	bezt(bezt) {}
+
+const float BCBezTriple::get_frame() const
+{
+	return bezt.vec[1][0];
+}
+
+const float BCBezTriple::get_time(Scene *scene) const
+{
+	return FRA2TIME(bezt.vec[1][0]);
+}
+
+const float BCBezTriple::get_value() const
+{
+	return bezt.vec[1][1];
+}
+
+const float BCBezTriple::get_angle() const
+{
+	return RAD2DEGF(get_value());
+}
+
+void BCBezTriple::get_in_tangent(Scene *scene, float point[2], bool as_angle) const
+{
+	get_tangent(scene, point, as_angle, 0);
+}
+
+void BCBezTriple::get_out_tangent(Scene *scene, float point[2], bool as_angle) const
+{
+	get_tangent(scene, point, as_angle, 2);
+}
+
+void BCBezTriple::get_tangent(Scene *scene, float point[2], bool as_angle, int index) const
+{
+	point[0] = FRA2TIME(bezt.vec[index][0]);
+	if (bezt.ipo != BEZT_IPO_BEZ) {
+		/* We're in a mixed interpolation scenario, set zero as it's irrelevant but value might contain unused data */
+		point[0] = 0;
+		point[1] = 0;
+	}
+	else if (as_angle) {
+		point[1] = RAD2DEGF(bezt.vec[index][1]);
+	}
+	else {
+		point[1] = bezt.vec[index][1];
+	}
+}
+