feat: dragging objects

editor/editorcommon.h

@@ -0,0 +1,10 @@
+#pragma once
+
+enum SelectedTool {
+    SELECT,
+    MOVE,
+    SCALE,
+    ROTATE,
+};
+
+extern SelectedTool selectedTool;

editor/mainglwidget.cpp

@@ -6,6 +6,8 @@
 #include <glm/ext/vector_float3.hpp>
 #include <glm/geometric.hpp>
 #include <glm/matrix.hpp>
+#include <memory>
+#include <optional>
 #include <reactphysics3d/collision/RaycastInfo.h>
 #include <vector>
 
@@ -25,6 +27,7 @@
 
 MainGLWidget::MainGLWidget(QWidget* parent): QOpenGLWidget(parent) {
     setFocusPolicy(Qt::FocusPolicy::ClickFocus);
+    setMouseTracking(true);
 }
 
 void MainGLWidget::initializeGL() {
@@ -47,50 +50,72 @@ void MainGLWidget::paintGL() {
     ::render(NULL);
 }
 
-bool isMouseDragging = false;
+bool isMouseRightDragging = false;
 QPoint lastMousePos;
-void MainGLWidget::mouseMoveEvent(QMouseEvent* evt) {
-    // if (!(evt->buttons() & Qt::RightButton)) return;
-    if (!isMouseDragging) return;
+void MainGLWidget::handleCameraRotate(QMouseEvent* evt) {
+    if (!isMouseRightDragging) return;
     
     camera.processRotation(evt->pos().x() - lastMousePos.x(), evt->pos().y() - lastMousePos.y());
     lastMousePos = evt->pos();
+
     // QCursor::setPos(lastMousePos);
 }
 
-class FirstRayHit : public rp::RaycastCallback {
-    rp::Body** target;
+bool isMouseDragging = false;
+std::optional<std::weak_ptr<Part>> draggingObject;
+void MainGLWidget::handleObjectDrag(QMouseEvent* evt) {
+    if (!isMouseDragging) return;
 
-    virtual rp::decimal notifyRaycastHit(const rp::RaycastInfo& raycastInfo) override {
-        if (reinterpret_cast<Part*>(raycastInfo.body->getUserData())->name == "Baseplate") return 1;
+    QPoint position = evt->pos();
 
-        *target = raycastInfo.body;
-        return 0;
-    }
+    glm::vec3 pointDir = camera.getScreenDirection(glm::vec2(position.x(), position.y()), glm::vec2(width(), height()));
+    std::optional<const RaycastResult> rayHit = castRayNearest(camera.cameraPos, pointDir, 50000, [](std::shared_ptr<Part> part) {
+        return (part == draggingObject->lock()) ? FilterResult::PASS : FilterResult::TARGET;
+    });
     
-public:
-    FirstRayHit(rp::Body** target) : target(target) {}
-};
+    if (!rayHit) return;
+    draggingObject->lock()->position = rpToGlm(rayHit->worldPoint);
+    draggingObject->lock()->position += rpToGlm(rayHit->worldNormal) * draggingObject->lock()->scale / 2.f;
+    syncPartPhysics(draggingObject->lock());
+}
+
+void MainGLWidget::handleCursorChange(QMouseEvent* evt) {
+    QPoint position = evt->pos();
+
+    glm::vec3 pointDir = camera.getScreenDirection(glm::vec2(position.x(), position.y()), glm::vec2(width(), height()));
+    std::optional<const RaycastResult> rayHit = castRayNearest(camera.cameraPos, pointDir, 50000);
+    setCursor((rayHit && partFromBody(rayHit->body)->name != "Baseplate") ? Qt::OpenHandCursor : Qt::ArrowCursor);
+}
+
+void MainGLWidget::mouseMoveEvent(QMouseEvent* evt) {
+    handleCameraRotate(evt);
+    handleObjectDrag(evt);
+    handleCursorChange(evt);
+}
 
 void MainGLWidget::mousePressEvent(QMouseEvent* evt) {
     switch(evt->button()) {
     // Camera drag
     case Qt::RightButton: {
         lastMousePos = evt->pos();
-        isMouseDragging = true;
+        isMouseRightDragging = true;
         return;
     // Clicking on objects
     } case Qt::LeftButton: {
         QPoint position = evt->pos();
-        rp::Body* rayHitTarget = NULL;
 
         glm::vec3 pointDir = camera.getScreenDirection(glm::vec2(position.x(), position.y()), glm::vec2(width(), height()));
-        castRay(camera.cameraPos, pointDir, 50000, new FirstRayHit(&rayHitTarget));
-        if (!rayHitTarget) return;
-        std::shared_ptr<Part> part = partFromBody(rayHitTarget);
+        std::optional<const RaycastResult> rayHit = castRayNearest(camera.cameraPos, pointDir, 50000);
+        if (!rayHit || !partFromBody(rayHit->body)) return;
+        std::shared_ptr<Part> part = partFromBody(rayHit->body);
+        if (part->name == "Baseplate") return;
         
         //part.selected = true;
+        isMouseDragging = true;
+        draggingObject = part;
         setSelection(std::vector<InstanceRefWeak> { part });
+        // Disable bit so that we can ignore the part while raycasting
+        // part->rigidBody->getCollider(0)->setCollisionCategoryBits(0b10);
 
         return;
     } default:
@@ -99,7 +124,10 @@ void MainGLWidget::mousePressEvent(QMouseEvent* evt) {
 }
 
 void MainGLWidget::mouseReleaseEvent(QMouseEvent* evt) {
+    // if (isMouseDragging) draggingObject->lock()->rigidBody->getCollider(0)->setCollisionCategoryBits(0b11);
+    isMouseRightDragging = false;
     isMouseDragging = false;
+    draggingObject = std::nullopt;
 }
 
 static int moveZ = 0;

editor/mainglwidget.h

@@ -18,6 +18,10 @@ protected:
     void resizeGL(int w, int h) override;
     void paintGL() override;
 
+    void handleCameraRotate(QMouseEvent* evt);
+    void handleObjectDrag(QMouseEvent* evt);
+    void handleCursorChange(QMouseEvent* evt);
+
     void mouseMoveEvent(QMouseEvent* evt) override;
     void mousePressEvent(QMouseEvent* evt) override;
     void mouseReleaseEvent(QMouseEvent* evt) override;

editor/mainwindow.cpp

@@ -13,11 +13,14 @@
 #include <optional>
 
 #include "common.h"
+#include "editorcommon.h"
 #include "physics/simulation.h"
 #include "objects/part.h"
 #include "qitemselectionmodel.h"
 #include "qobject.h"
 
+SelectedTool selectedTool;
+
 MainWindow::MainWindow(QWidget *parent)
     : QMainWindow(parent)
     , ui(new Ui::MainWindow)
@@ -35,6 +38,12 @@ MainWindow::MainWindow(QWidget *parent)
         ui->propertiesView->setSelected(inst);
     });
 
+    connect(ui->actionToolSelect, &QAction::triggered, this, [&]() { selectedTool = SelectedTool::SELECT; updateSelectedTool(); });
+    connect(ui->actionToolMove, &QAction::triggered, this, [&](bool state) { selectedTool = state ? SelectedTool::MOVE : SelectedTool::SELECT; updateSelectedTool(); });
+    connect(ui->actionToolScale, &QAction::triggered, this, [&](bool state) { selectedTool = state ? SelectedTool::SCALE : SelectedTool::SELECT; updateSelectedTool(); });
+    connect(ui->actionToolRotate, &QAction::triggered, this, [&](bool state) { selectedTool = state ? SelectedTool::ROTATE : SelectedTool::SELECT; updateSelectedTool(); });
+    ui->actionToolSelect->setChecked(true);
+    
     // ui->explorerView->Init(ui);
 
     simulationInit();
@@ -82,6 +91,13 @@ void MainWindow::timerEvent(QTimerEvent* evt) {
     ui->mainWidget->updateCycle();
 }
 
+void MainWindow::updateSelectedTool() {
+    ui->actionToolSelect->setChecked(selectedTool == SelectedTool::SELECT);
+    ui->actionToolMove->setChecked(selectedTool == SelectedTool::MOVE);
+    ui->actionToolScale->setChecked(selectedTool == SelectedTool::SCALE);
+    ui->actionToolRotate->setChecked(selectedTool == SelectedTool::ROTATE);
+}
+
 MainWindow::~MainWindow()
 {
     delete ui;

editor/mainwindow.h

@@ -26,6 +26,7 @@ public:
 private:
     QBasicTimer timer;
 
+    void updateSelectedTool();
     void timerEvent(QTimerEvent*) override;
 };
 #endif // MAINWINDOW_H

src/physics/simulation.cpp

@@ -61,6 +61,7 @@ void syncPartPhysics(std::shared_ptr<Part> part) {
     if (part->rigidBody->getNbColliders() == 0)
         part->rigidBody->addCollider(shape, rp::Transform());
     part->rigidBody->setType(part->anchored ? rp::BodyType::STATIC : rp::BodyType::DYNAMIC);
+    part->rigidBody->getCollider(0)->setCollisionCategoryBits(0b11);
 
     part->rigidBody->setUserData(&*part);
 }
@@ -81,7 +82,56 @@ void physicsStep(float deltaTime) {
     }
 }
 
-void castRay(glm::vec3 point, glm::vec3 rotation, float maxLength, rp::RaycastCallback* callback) {
+RaycastResult::RaycastResult(const rp::RaycastInfo& raycastInfo)
+    : worldPoint(raycastInfo.worldPoint)
+    , worldNormal(raycastInfo.worldNormal)
+    , hitFraction(raycastInfo.hitFraction)
+    , triangleIndex(raycastInfo.triangleIndex)
+    , body(raycastInfo.body)
+    , collider(raycastInfo.collider) {}
+
+class NearestRayHit : public rp::RaycastCallback {
+    rp::Vector3 startPos;
+    std::optional<RaycastFilter> filter;
+
+    std::optional<RaycastResult> nearestHit;
+    float nearestHitDistance = -1;
+
+    // Order is not guaranteed, so we have to figure out the nearest object using a more sophisticated algorith,
+    rp::decimal notifyRaycastHit(const rp::RaycastInfo& raycastInfo) override {
+        // If the detected object is further away than the nearest object, continue.
+        int distance = (raycastInfo.worldPoint - startPos).length();
+        if (nearestHitDistance != -1 && distance >= nearestHitDistance)
+            return 1;
+
+        if (!filter) {
+            nearestHit = raycastInfo;
+            nearestHitDistance = distance;
+            return 1;
+        }
+
+        std::shared_ptr<Part> part = partFromBody(raycastInfo.body);
+        FilterResult result = filter.value()(part);
+        if (result == FilterResult::BLOCK) {
+            nearestHit = std::nullopt;
+            nearestHitDistance = distance;
+            return 1;
+        } else if (result == FilterResult::TARGET) {
+            nearestHit = raycastInfo;
+            nearestHitDistance = distance;
+            return 1;
+        }
+        return 1;
+    };
+
+public:
+    NearestRayHit(rp::Vector3 startPos, std::optional<RaycastFilter> filter = std::nullopt) : startPos(startPos), filter(filter) {}
+    std::optional<const RaycastResult> getNearestHit() { return nearestHit; };
+};
+
+std::optional<const RaycastResult> castRayNearest(glm::vec3 point, glm::vec3 rotation, float maxLength, std::optional<RaycastFilter> filter, unsigned short categoryMaskBits) {
     rp::Ray ray(glmToRp(point), glmToRp(glm::normalize(rotation)) * maxLength);
-    world->raycast(ray, callback);
+    NearestRayHit rayHit(glmToRp(point), filter);
+    world->raycast(ray, &rayHit, categoryMaskBits);
+    return rayHit.getNearestHit();
 }

src/physics/simulation.h

@@ -5,7 +5,26 @@
 #include <memory>
 #include <reactphysics3d/collision/RaycastInfo.h>
 
+struct RaycastResult {
+    rp::Vector3 worldPoint;
+    rp::Vector3 worldNormal;
+    rp::decimal hitFraction;
+    int triangleIndex;
+    rp::Body* body;
+    rp::Collider* collider;
+
+    RaycastResult(const rp::RaycastInfo& raycastInfo);
+};
+
+enum FilterResult {
+    TARGET, // The object is captured
+    BLOCK, // The object blocks any objects behind it, but is not captured
+    PASS, // The object is transparent, ignore it
+};
+
+typedef std::function<FilterResult(std::shared_ptr<Part>)> RaycastFilter;
+
 void simulationInit();
 void syncPartPhysics(std::shared_ptr<Part> part);
 void physicsStep(float deltaTime);
-void castRay(glm::vec3 point, glm::vec3 rotation, float maxLength, rp::RaycastCallback* callback);
+std::optional<const RaycastResult> castRayNearest(glm::vec3 point, glm::vec3 rotation, float maxLength, std::optional<RaycastFilter> filter = std::nullopt, unsigned short categoryMaskBits = 0xFFFF);

src/physics/util.h

@@ -26,6 +26,7 @@ inline glm::quat rpToGlm(rp::Quaternion quat) {
     return glm::quat(quat.w, quat.x, quat.y, quat.z);
 }
 
+// Make this std::optional
 inline std::shared_ptr<Part> partFromBody(rp::Body* body) {
     Part* raw = reinterpret_cast<Part*>(body->getUserData());
     std::shared_ptr<Part> shared = std::dynamic_pointer_cast<Part>(raw->shared_from_this());