urho3d/Source/Samples/15_Navigation/Navigation.cpp

//
// Copyright (c) 2008-2013 the Urho3D project.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// THE SOFTWARE.
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#include "Camera.h"
#include "CoreEvents.h"
#include "Cursor.h"
#include "DebugRenderer.h"
#include "Engine.h"
#include "Font.h"
#include "Graphics.h"
#include "Input.h"
#include "Light.h"
#include "Material.h"
#include "Model.h"
#include "Navigable.h"
#include "NavigationMesh.h"
#include "Octree.h"
#include "Renderer.h"
#include "ResourceCache.h"
#include "StaticModel.h"
#include "Text.h"
#include "UI.h"
#include "XMLFile.h"
#include "Zone.h"

#include "Navigation.h"

#include "DebugNew.h"

// Expands to this example's entry-point
DEFINE_APPLICATION_MAIN(Navigation)

Navigation::Navigation(Context* context) :
    Sample(context),
    yaw_(0.0f),
    pitch_(0.0f),
    drawDebug_(false)
{
}

void Navigation::Start()
{
    // Execute base class startup
    Sample::Start();

    // Create the scene content
    CreateScene();
    
    // Create the UI content
    CreateUI();
    
    // Setup the viewport for displaying the scene
    SetupViewport();

    // Hook up to the frame update and render post-update events
    SubscribeToEvents();
}

void Navigation::CreateScene()
{
    ResourceCache* cache = GetSubsystem<ResourceCache>();
    
    scene_ = new Scene(context_);
    
    // Create octree, use default volume (-1000, -1000, -1000) to (1000, 1000, 1000)
    // Also create a DebugRenderer component so that we can draw debug geometry
    scene_->CreateComponent<Octree>();
    scene_->CreateComponent<DebugRenderer>();
    
    // Create scene node & StaticModel component for showing a static plane
    Node* planeNode = scene_->CreateChild("Plane");
    planeNode->SetScale(Vector3(100.0f, 1.0f, 100.0f));
    StaticModel* planeObject = planeNode->CreateComponent<StaticModel>();
    planeObject->SetModel(cache->GetResource<Model>("Models/Plane.mdl"));
    planeObject->SetMaterial(cache->GetResource<Material>("Materials/StoneTiled.xml"));
    
    // Create a Zone component for ambient lighting & fog control
    Node* zoneNode = scene_->CreateChild("Zone");
    Zone* zone = zoneNode->CreateComponent<Zone>();
    zone->SetBoundingBox(BoundingBox(-1000.0f, 1000.0f));
    zone->SetAmbientColor(Color(0.15f, 0.15f, 0.15f));
    zone->SetFogColor(Color(0.5f, 0.5f, 0.7f));
    zone->SetFogStart(100.0f);
    zone->SetFogEnd(300.0f);
    
    // Create a directional light to the world. Enable cascaded shadows on it
    Node* lightNode = scene_->CreateChild("DirectionalLight");
    lightNode->SetDirection(Vector3(0.6f, -1.0f, 0.8f));
    Light* light = lightNode->CreateComponent<Light>();
    light->SetLightType(LIGHT_DIRECTIONAL);
    light->SetCastShadows(true);
    light->SetShadowBias(BiasParameters(0.0001f, 0.5f));
    // Set cascade splits at 10, 50 and 200 world units, fade shadows out at 80% of maximum shadow distance
    light->SetShadowCascade(CascadeParameters(10.0f, 50.0f, 200.0f, 0.0f, 0.8f));
    
    // Create some mushrooms
    const unsigned NUM_MUSHROOMS = 100;
    for (unsigned i = 0; i < NUM_MUSHROOMS; ++i)
        CreateMushroom(Vector3(Random(90.0f) - 45.0f, 0.0f, Random(90.0f) - 45.0f));
    
    // Create randomly sized boxes. If boxes are big enough, make them occluders
    const unsigned NUM_BOXES = 20;
    for (unsigned i = 0; i < NUM_BOXES; ++i)
    {
        Node* boxNode = scene_->CreateChild("Box");
        float size = 1.0f + Random(10.0f);
        boxNode->SetPosition(Vector3(Random(80.0f) - 40.0f, size * 0.5f, Random(80.0f) - 40.0f));
        boxNode->SetScale(size);
        StaticModel* boxObject = boxNode->CreateComponent<StaticModel>();
        boxObject->SetModel(cache->GetResource<Model>("Models/Box.mdl"));
        boxObject->SetMaterial(cache->GetResource<Material>("Materials/Stone.xml"));
        boxObject->SetCastShadows(true);
        if (size >= 3.0f)
            boxObject->SetOccluder(true);
    }
    
    // Create a NavigationMesh component to the scene root
    NavigationMesh* navMesh = scene_->CreateComponent<NavigationMesh>();
    // Create a Navigable component to the scene root. This tags all of the geometry in the scene as being part of the
    // navigation mesh. By default this is recursive, but the recursion could be turned off from Navigable
    scene_->CreateComponent<Navigable>();
    // Add padding to the navigation mesh in Y-direction so that we can add objects on top of the tallest boxes
    // in the scene and still update the mesh correctly
    navMesh->SetPadding(Vector3(0.0f, 10.0f, 0.0f));
    // Now build the navigation geometry. This will take some time. Note that the navigation mesh will prefer to use
    // physics geometry from the scene nodes, as it often is simpler, but if it can not find any (like in this example)
    // it will use renderable geometry instead
    navMesh->Build();
    
    // Create the camera. Limit far clip distance to match the fog
    cameraNode_ = scene_->CreateChild("Camera");
    Camera* camera = cameraNode_->CreateComponent<Camera>();
    camera->SetFarClip(300.0f);
    
    // Set an initial position for the camera scene node above the plane
    cameraNode_->SetPosition(Vector3(0.0f, 5.0f, 0.0f));
}

void Navigation::CreateUI()
{
    ResourceCache* cache = GetSubsystem<ResourceCache>();
    UI* ui = GetSubsystem<UI>();
    
    // Create a Cursor UI element because we want to be able to hide and show it at will. When hidden, the mouse cursor will
    // control the camera, and when visible, it will point the raycast target
    XMLFile* style = cache->GetResource<XMLFile>("UI/DefaultStyle.xml");
    SharedPtr<Cursor> cursor(new Cursor(context_));
    cursor->SetStyleAuto(style);
    ui->SetCursor(cursor);

    // Set starting position of the cursor at the rendering window center
    Graphics* graphics = GetSubsystem<Graphics>();
    cursor->SetPosition(graphics->GetWidth() / 2, graphics->GetHeight() / 2);
    
    // Construct new Text object, set string to display and font to use
    Text* instructionText = ui->GetRoot()->CreateChild<Text>();
    instructionText->SetText(
        "Use WASD keys to move, RMB to rotate view\n"
        "Shift+LMB to set path start, LMB to set path end\n"
        "MMB to add or remove obstacles\n"
        "Space to toggle debug geometry"
    );
    instructionText->SetFont(cache->GetResource<Font>("Fonts/Anonymous Pro.ttf"), 15);
    // The text has multiple rows. Center them in relation to each other
    instructionText->SetTextAlignment(HA_CENTER);
    
    // Position the text relative to the screen center
    instructionText->SetHorizontalAlignment(HA_CENTER);
    instructionText->SetVerticalAlignment(VA_CENTER);
    instructionText->SetPosition(0, ui->GetRoot()->GetHeight() / 4);
}

void Navigation::SetupViewport()
{
    Renderer* renderer = GetSubsystem<Renderer>();
    
    // Set up a viewport to the Renderer subsystem so that the 3D scene can be seen
    SharedPtr<Viewport> viewport(new Viewport(context_, scene_, cameraNode_->GetComponent<Camera>()));
    renderer->SetViewport(0, viewport);
}

void Navigation::SubscribeToEvents()
{
    // Subscribe HandleUpdate() function for processing update events
    SubscribeToEvent(E_UPDATE, HANDLER(Navigation, HandleUpdate));
    
    // Subscribe HandlePostRenderUpdate() function for processing the post-render update event, during which we request
    // debug geometry
    SubscribeToEvent(E_POSTRENDERUPDATE, HANDLER(Navigation, HandlePostRenderUpdate));
}

void Navigation::MoveCamera(float timeStep)
{
    // Right mouse button controls mouse cursor visibility: hide when pressed
    UI* ui = GetSubsystem<UI>();
    Input* input = GetSubsystem<Input>();
    ui->GetCursor()->SetVisible(!input->GetMouseButtonDown(MOUSEB_RIGHT));
    
    // Do not move if the UI has a focused element (the console)
    if (ui->GetFocusElement())
        return;
    
    // Movement speed as world units per second
    const float MOVE_SPEED = 20.0f;
    // Mouse sensitivity as degrees per pixel
    const float MOUSE_SENSITIVITY = 0.1f;
    
    // Use this frame's mouse motion to adjust camera node yaw and pitch. Clamp the pitch between -90 and 90 degrees
    // Only move the camera when the cursor is hidden
    if (!ui->GetCursor()->IsVisible())
    {
        IntVector2 mouseMove = input->GetMouseMove();
        yaw_ += MOUSE_SENSITIVITY * mouseMove.x_;
        pitch_ += MOUSE_SENSITIVITY * mouseMove.y_;
        pitch_ = Clamp(pitch_, -90.0f, 90.0f);
        
        // Construct new orientation for the camera scene node from yaw and pitch. Roll is fixed to zero
        cameraNode_->SetRotation(Quaternion(pitch_, yaw_, 0.0f));
    }
    
    // Read WASD keys and move the camera scene node to the corresponding direction if they are pressed
    if (input->GetKeyDown('W'))
        cameraNode_->TranslateRelative(Vector3::FORWARD * MOVE_SPEED * timeStep);
    if (input->GetKeyDown('S'))
        cameraNode_->TranslateRelative(Vector3::BACK * MOVE_SPEED * timeStep);
    if (input->GetKeyDown('A'))
        cameraNode_->TranslateRelative(Vector3::LEFT * MOVE_SPEED * timeStep);
    if (input->GetKeyDown('D'))
        cameraNode_->TranslateRelative(Vector3::RIGHT * MOVE_SPEED * timeStep);
    
    // Set route start/endpoint with left mouse button, recalculate route if applicable
    if (input->GetMouseButtonPress(MOUSEB_LEFT))
        SetPathPoint();
    // Add or remove objects with middle mouse button, then rebuild navigation mesh partially
    if (input->GetMouseButtonPress(MOUSEB_MIDDLE))
        AddOrRemoveObject();
        
    // Toggle debug geometry with space
    if (input->GetKeyPress(KEY_SPACE))
        drawDebug_ = !drawDebug_;
}

void Navigation::SetPathPoint()
{
    Vector3 hitPos;
    Drawable* hitDrawable;
    
    if (Raycast(250.0f, hitPos, hitDrawable))
    {
        bool setStart = GetSubsystem<Input>()->GetQualifierDown(QUAL_SHIFT);
        if (setStart)
        {
            startPos_ = hitPos;
            startPosDefined_ = true;
        }
        else
        {
            endPos_ = hitPos;
            endPosDefined_ = true;
        }
        
        if (startPosDefined_ && endPosDefined_)
            RecalculatePath();
    }
}

void Navigation::AddOrRemoveObject()
{
    // Raycast and check if we hit a mushroom node. If yes, remove it, if no, create a new one
    Vector3 hitPos;
    Drawable* hitDrawable;
    
    if (Raycast(250.0f, hitPos, hitDrawable))
    {
        // The part of the navigation mesh we must update, which is the world bounding box of the associated
        // drawable component
        BoundingBox updateBox;
        
        Node* hitNode = hitDrawable->GetNode();
        if (hitNode->GetName() == "Mushroom")
        {
            updateBox = hitDrawable->GetWorldBoundingBox();
            hitNode->Remove();
        }
        else
        {
            Node* newNode = CreateMushroom(hitPos);
            updateBox = newNode->GetComponent<StaticModel>()->GetWorldBoundingBox();
        }
        
        // Rebuild part of the navigation mesh, then recalculate path if applicable
        scene_->GetComponent<NavigationMesh>()->Build(updateBox);
        RecalculatePath();
    }
}

Node* Navigation::CreateMushroom(const Vector3& pos)
{
    ResourceCache* cache = GetSubsystem<ResourceCache>();
    
    Node* mushroomNode = scene_->CreateChild("Mushroom");
    mushroomNode->SetPosition(pos);
    mushroomNode->SetRotation(Quaternion(0.0f, Random(360.0f), 0.0f));
    mushroomNode->SetScale(2.0f + Random(0.5f));
    StaticModel* mushroomObject = mushroomNode->CreateComponent<StaticModel>();
    mushroomObject->SetModel(cache->GetResource<Model>("Models/Mushroom.mdl"));
    mushroomObject->SetMaterial(cache->GetResource<Material>("Materials/Mushroom.xml"));
    mushroomObject->SetCastShadows(true);
    
    return mushroomNode;
}

void Navigation::RecalculatePath()
{
    NavigationMesh* navMesh = scene_->GetComponent<NavigationMesh>();
    navMesh->FindPath(currentPath_, startPos_, endPos_);
}

bool Navigation::Raycast(float maxDistance, Vector3& hitPos, Drawable*& hitDrawable)
{
    hitDrawable = 0;
    
    UI* ui = GetSubsystem<UI>();
    IntVector2 pos = ui->GetCursorPosition();
    // Check the cursor is visible and there is no UI element in front of the cursor
    if (!ui->GetCursor()->IsVisible() || ui->GetElementAt(pos, true))
        return false;
    
    Graphics* graphics = GetSubsystem<Graphics>();
    Camera* camera = cameraNode_->GetComponent<Camera>();
    Ray cameraRay = camera->GetScreenRay((float)pos.x_ / graphics->GetWidth(), (float)pos.y_ / graphics->GetHeight());
    // Pick only geometry objects, not eg. zones or lights, only get the first (closest) hit
    PODVector<RayQueryResult> results;
    RayOctreeQuery query(results, cameraRay, RAY_TRIANGLE, maxDistance, DRAWABLE_GEOMETRY);
    scene_->GetComponent<Octree>()->RaycastSingle(query);
    if (results.Size())
    {
        RayQueryResult& result = results[0];
        
        // Calculate hit position in world space
        hitPos = cameraRay.origin_ + cameraRay.direction_ * result.distance_;
        hitDrawable = result.drawable_;
        return true;
    }
    
    return false;
}

void Navigation::HandleUpdate(StringHash eventType, VariantMap& eventData)
{
    using namespace Update;

    // Take the frame time step, which is stored as a float
    float timeStep = eventData[P_TIMESTEP].GetFloat();
    
    // Move the camera, scale movement with time step
    MoveCamera(timeStep);
}

void Navigation::HandlePostRenderUpdate(StringHash eventType, VariantMap& eventData)
{
    // If draw debug mode is enabled, draw navigation mesh debug geometry
    if (drawDebug_)
        scene_->GetComponent<NavigationMesh>()->DrawDebugGeometry(true);
    
    // Visualize the start and end points and the last calculated path
    DebugRenderer* debug = scene_->GetComponent<DebugRenderer>();
    if (startPosDefined_)
        debug->AddBoundingBox(BoundingBox(startPos_ - 0.1f * Vector3::ONE, startPos_ + 0.1f * Vector3::ONE), Color::WHITE);
    if (endPosDefined_)
        debug->AddBoundingBox(BoundingBox(endPos_ - 0.1f * Vector3::ONE, endPos_ + 0.1f * Vector3::ONE), Color::WHITE);
    if (currentPath_.Size() > 1)
    {
        // Draw the path with a small upward bias so that it does not clip into the surfaces
        Vector3 bias = 0.05f * Vector3::UP;
        for (unsigned i = 0; i < currentPath_.Size() - 1; ++i)
            debug->AddLine(currentPath_[i] + bias, currentPath_[i + 1] + bias, Color::WHITE);
    }
}