overte-lubosz/libraries/animation/src/AnimPose.cpp
2019-03-07 14:11:01 -08:00

97 lines
3.3 KiB
C++

//
// AnimPose.cpp
//
// Created by Anthony J. Thibault on 10/14/15.
// Copyright (c) 2015 High Fidelity, Inc. All rights reserved.
//
// Distributed under the Apache License, Version 2.0.
// See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//
#include "AnimPose.h"
#include <GLMHelpers.h>
#include <algorithm>
#include "AnimUtil.h"
const AnimPose AnimPose::identity = AnimPose(glm::vec3(1.0f),
glm::quat(),
glm::vec3(0.0f));
AnimPose::AnimPose(const glm::mat4& mat) {
glm::mat3 m(mat);
_scale = glm::vec3(glm::length(m[0]), glm::length(m[1]), glm::length(m[2]));
float det = glm::determinant(m);
glm::mat3 tmp;
if (det < 0.0f) {
_scale *= -1.0f;
}
// quat_cast doesn't work so well with scaled matrices, so cancel out scale.
// also, as a side effect, multiply mirrored matrices by -1 to get the right rotation out.
tmp[0] = m[0] * (1.0f / _scale[0]);
tmp[1] = m[1] * (1.0f / _scale[1]);
tmp[2] = m[2] * (1.0f / _scale[2]);
_rot = glm::quat_cast(tmp);
// normalize quat if necessary
float lengthSquared = glm::length2(_rot);
if (glm::abs(lengthSquared - 1.0f) > EPSILON) {
float oneOverLength = 1.0f / sqrtf(lengthSquared);
_rot = glm::quat(_rot.w * oneOverLength, _rot.x * oneOverLength, _rot.y * oneOverLength, _rot.z * oneOverLength);
}
_trans = extractTranslation(mat);
}
glm::vec3 AnimPose::operator*(const glm::vec3& rhs) const {
return _trans + (_rot * (_scale * rhs));
}
glm::vec3 AnimPose::xformPoint(const glm::vec3& rhs) const {
return *this * rhs;
}
// really slow, but accurate for transforms with non-uniform scale
glm::vec3 AnimPose::xformVector(const glm::vec3& rhs) const {
glm::vec3 xAxis = _rot * glm::vec3(_scale.x, 0.0f, 0.0f);
glm::vec3 yAxis = _rot * glm::vec3(0.0f, _scale.y, 0.0f);
glm::vec3 zAxis = _rot * glm::vec3(0.0f, 0.0f, _scale.z);
glm::mat3 mat(xAxis, yAxis, zAxis);
glm::mat3 transInvMat = glm::inverse(glm::transpose(mat));
return transInvMat * rhs;
}
// faster, but does not handle non-uniform scale correctly.
glm::vec3 AnimPose::xformVectorFast(const glm::vec3& rhs) const {
return _rot * (_scale * rhs);
}
AnimPose AnimPose::operator*(const AnimPose& rhs) const {
glm::mat4 result;
glm_mat4u_mul(*this, rhs, result);
return AnimPose(result);
}
AnimPose AnimPose::inverse() const {
return AnimPose(glm::inverse(static_cast<glm::mat4>(*this)));
}
// mirror about x-axis without applying negative scale.
AnimPose AnimPose::mirror() const {
return AnimPose(_scale, glm::quat(_rot.w, _rot.x, -_rot.y, -_rot.z), glm::vec3(-_trans.x, _trans.y, _trans.z));
}
AnimPose::operator glm::mat4() const {
glm::vec3 xAxis = _rot * glm::vec3(_scale.x, 0.0f, 0.0f);
glm::vec3 yAxis = _rot * glm::vec3(0.0f, _scale.y, 0.0f);
glm::vec3 zAxis = _rot * glm::vec3(0.0f, 0.0f, _scale.z);
return glm::mat4(glm::vec4(xAxis, 0.0f), glm::vec4(yAxis, 0.0f),
glm::vec4(zAxis, 0.0f), glm::vec4(_trans, 1.0f));
}
void AnimPose::blend(const AnimPose& srcPose, float alpha) {
_scale = lerp(srcPose._scale, _scale, alpha);
_rot = safeLerp(srcPose._rot, _rot, alpha);
_trans = lerp(srcPose._trans, _trans, alpha);
}