Basic transform stuff

src/dawn/display/Transform.cpp

@@ -0,0 +1,156 @@
+// Copyright (c) 2022 Dominic Masters
+// 
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+#include "Transform.hpp"
+#include "scene/SceneItem.hpp"
+
+using namespace Dawn;
+
+Transform::Transform(SceneItem &item) :
+  item(item),
+  transformLocal(1.0f),
+  transformWorld(1.0f)
+{
+  this->updateLocalValuesFromLocalTransform();
+}
+
+void Transform::updateLocalValuesFromLocalTransform() {
+  glm::vec3 skew;
+  glm::vec4 perspective;
+  glm::decompose(
+    this->transformLocal,
+    this->localScale,
+    this->localRotation,
+    this->localPosition,
+    skew, perspective
+  );
+}
+
+void Transform::updateLocalTransformFromLocalValues() {
+  glm::mat4 translate = glm::translate(glm::mat4(1.0), this->localPosition);
+  glm::mat4 rotate = glm::mat4_cast(this->localRotation);
+  glm::mat4 scale = glm::scale(glm::mat4(1.0), this->localScale);
+  this->transformLocal = translate * rotate * scale;
+  this->updateWorldTransformFromLocalTransform();
+}
+
+void Transform::updateWorldTransformFromLocalTransform() {
+  glm::mat4 newWorld(1.0f);
+  auto parent = this->getParent();
+  if(parent != nullptr) newWorld = parent->getWorldTransform();
+  this->transformWorld = newWorld * transformLocal;
+}
+
+void Transform::updateLocalTransformFromWorldTransform() {
+  glm::mat4 parentMat(1.0f);
+  auto parent = this->getParent();
+  if(parent != nullptr) parentMat = parent->getWorldTransform();
+  this->transformLocal = parentMat / this->transformWorld;
+  this->updateLocalValuesFromLocalTransform();
+}
+
+void Transform::updateChildrenTransforms() {
+  auto it = this->children.begin();
+  while(it != this->children.end()) {
+    (*it)->updateWorldTransformFromLocalTransform();
+    ++it;
+  }
+}
+
+void Transform::lookAt(glm::vec3 pos, glm::vec3 look) {
+  this->lookAt(pos, look, glm::vec3(0, 1, 0));
+}
+
+void Transform::lookAt(glm::vec3 pos, glm::vec3 look, glm::vec3 up) {
+  this->setWorldTransform(glm::lookAt(pos, look, up));
+}
+
+
+glm::vec3 Transform::getLocalPosition() {
+  return this->localPosition;
+}
+
+void Transform::setLocalPosition(glm::vec3 position) {
+  this->localPosition = position;
+  this->updateLocalTransformFromLocalValues();
+  this->updateChildrenTransforms();
+}
+
+glm::vec3 Transform::getLocalScale() {
+  return this->scale;
+}
+
+void Transform::setLocalScale(glm::vec3 scale) {
+  this->localScale = scale;
+  this->updateLocalTransformFromLocalValues();
+  this->updateChildrenTransforms();
+}
+
+glm::quat Transform::getLocalRotation() {
+  return this->localRotation;
+}
+
+void Transform::setLocalRotation(glm::quat rotation) {
+  this->localRotation = rotation;
+  this->updateLocalTransformFromLocalValues();
+  this->updateChildrenTransforms();
+}
+
+
+glm::mat4 Transform::getLocalTransform() {
+  return this->transformLocal;
+}
+
+void Transform::setLocalTransform(glm::mat4 transform) {
+  this->transformLocal = transform;
+
+  this->updateLocalValuesFromLocalTransform();
+  this->updateChildrenTransforms();
+}
+
+glm::mat4 Transform::getWorldTransform() {
+  return this->transformWorld;
+}
+
+void Transform::setWorldTransform(glm::mat4 transform) {
+  this->transformWorld = transform;
+  this->updateLocalTransformFromWorldTransform();
+  this->updateChildrenTransforms();
+}
+
+
+void Transform::setParent(Transform *parent) {
+  if(parent == this) throw "Cannot self reference";
+  
+  auto currentParent = this->getParent();
+  if(currentParent == parent) return;
+
+  if(currentParent != nullptr) {
+    auto it = currentParent->children.begin();
+    while(it != currentParent->children.end()) {
+      if(*it == this) {
+        currentParent->children.erase(it);
+        break;
+      }
+      ++it;
+    }
+  }
+
+  this->parent = parent;
+  if(parent != nullptr) parent->children.push_back(this);
+}
+
+Transform * Transform::getParent() {
+  return this->parent;
+}
+
+Transform::~Transform() {
+  this->setParent(nullptr);
+  auto it = this->parent->children.begin();
+  while(it != this->parent->children.end()) {
+    (*it)->setParent(nullptr);
+    ++it;
+  }
+}