urho3d/Source/Samples/08_Decals/Decals.h

// Copyright (c) 2008-2023 the Urho3D project
// License: MIT

#pragma once

#include "Sample.h"

namespace Urho3D
{

class Drawable;
class Node;
class Scene;

}

/// Decals example.
/// This sample demonstrates:
///     - Performing a raycast to the octree and adding a decal to the hit location
///     - Defining a Cursor UI element which stays inside the window and can be shown/hidden
///     - Marking suitable (large) objects as occluders for occlusion culling
///     - Displaying renderer debug geometry to see the effect of occlusion
class Decals : public Sample
{
    URHO3D_OBJECT(Decals, Sample);

public:
    /// Construct.
    explicit Decals(Context* context);

    /// Setup after engine initialization and before running the main loop.
    void Start() override;

protected:
    /// Return XML patch instructions for screen joystick layout for a specific sample app, if any.
    String GetScreenJoystickPatchString() const override { return
        "<patch>"
        "    <remove sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]/attribute[@name='Is Visible']\" />"
        "    <replace sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]/element[./attribute[@name='Name' and @value='Label']]/attribute[@name='Text']/@value\">Paint</replace>"
        "    <add sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]\">"
        "        <element type=\"Text\">"
        "            <attribute name=\"Name\" value=\"MouseButtonBinding\" />"
        "            <attribute name=\"Text\" value=\"LEFT\" />"
        "        </element>"
        "    </add>"
        "    <remove sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]/attribute[@name='Is Visible']\" />"
        "    <replace sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]/element[./attribute[@name='Name' and @value='Label']]/attribute[@name='Text']/@value\">Debug</replace>"
        "    <add sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]\">"
        "        <element type=\"Text\">"
        "            <attribute name=\"Name\" value=\"KeyBinding\" />"
        "            <attribute name=\"Text\" value=\"SPACE\" />"
        "        </element>"
        "    </add>"
        "</patch>";
    }

private:
    /// Construct the scene content.
    void CreateScene();
    /// Construct user interface elements.
    void CreateUI();
    /// Set up a viewport for displaying the scene.
    void SetupViewport();
    /// Subscribe to application-wide logic update and post-render update events.
    void SubscribeToEvents();
    /// Reads input and moves the camera.
    void MoveCamera(float timeStep);
    /// Paint a decal using a ray cast from the mouse cursor.
    void PaintDecal();
    /// Utility function to raycast to the cursor position. Return true if hit
    bool Raycast(float maxDistance, Vector3& hitPos, Drawable*& hitDrawable);
    /// Handle the logic update event.
    void HandleUpdate(StringHash eventType, VariantMap& eventData);
    /// Handle the post-render update event.
    void HandlePostRenderUpdate(StringHash eventType, VariantMap& eventData);

    /// Flag for drawing debug geometry.
    bool drawDebug_;
};