FlaxEngine/Source/Engine/UI/TextRender.h

// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.

#pragma once

#include "Engine/Level/Actor.h"
#include "Engine/Core/Math/Matrix.h"
#include "Engine/Render2D/TextLayoutOptions.h"
#include "Engine/Render2D/FontAsset.h"
#include "Engine/Renderer/DrawCall.h"
#include "Engine/Content/Assets/MaterialBase.h"
#include "Engine/Content/Assets/MaterialInstance.h"
#include "Engine/Graphics/DynamicBuffer.h"
#include "Engine/Graphics/Models/Config.h"
#if USE_PRECISE_MESH_INTERSECTS
#include "Engine/Graphics/Models/CollisionProxy.h"
#endif

/// <summary>
/// Text rendering object.
/// </summary>
API_CLASS() class FLAXENGINE_API TextRender : public Actor
{
DECLARE_SCENE_OBJECT(TextRender);
private:

    struct DrawChunk
    {
        TextRender* Actor;
        int32 FontAtlasIndex;
        int32 StartIndex;
        int32 IndicesCount;
        AssetReference<MaterialInstance> Material;
    };

    bool _isDirty = false;
    bool _buffersDirty = false;
    String _text;
    Color _color;
    TextLayoutOptions _layoutOptions;
    int32 _size;

    BoundingBox _localBox;
    Matrix _world;
    GeometryDrawStateData _drawState;
    DynamicIndexBuffer _ib;
    DynamicVertexBuffer _vb0;
    DynamicVertexBuffer _vb1;
    DynamicVertexBuffer _vb2;
#if USE_PRECISE_MESH_INTERSECTS
    CollisionProxy _collisionProxy;
#endif
    Array<DrawChunk, InlinedAllocation<8>> _drawChunks;

public:

    /// <summary>
    /// Gets the text.
    /// </summary>
    API_PROPERTY(Attributes="EditorOrder(0), DefaultValue(\"\"), MultilineText, EditorDisplay(\"Text\")")
    FORCE_INLINE const String& GetText() const
    {
        return _text;
    }

    /// <summary>
    /// Sets the text.
    /// </summary>
    API_PROPERTY() void SetText(const StringView& value);

    /// <summary>
    /// Gets the color of the text.
    /// </summary>
    API_PROPERTY(Attributes="EditorOrder(10), DefaultValue(typeof(Color), \"1,1,1,1\"), EditorDisplay(\"Text\")")
    FORCE_INLINE Color GetColor() const
    {
        return _color;
    }

    /// <summary>
    /// Sets the color of the text.
    /// </summary>
    API_PROPERTY() void SetColor(const Color& value);

    /// <summary>
    /// The material used for the text rendering. It must contain texture parameter named Font used to sample font texture.
    /// </summary>
    API_FIELD(Attributes="EditorOrder(20), DefaultValue(null), AssetReference(true), EditorDisplay(\"Text\")")
    AssetReference<MaterialBase> Material;

    /// <summary>
    /// The font asset used as a text characters source.
    /// </summary>
    API_FIELD(Attributes="EditorOrder(30), DefaultValue(null), AssetReference(true), EditorDisplay(\"Text\")")
    AssetReference<FontAsset> Font;

    /// <summary>
    /// Gets the font characters size.
    /// </summary>
    API_PROPERTY(Attributes="EditorOrder(40), DefaultValue(32), Limit(1, 1000), EditorDisplay(\"Text\")")
    FORCE_INLINE int32 GetFontSize() const
    {
        return _size;
    }

    /// <summary>
    /// Sets the font characters size.
    /// </summary>
    API_PROPERTY() void SetFontSize(int32 value);

    /// <summary>
    /// The draw passes to use for rendering this object.
    /// </summary>
    API_FIELD(Attributes="EditorOrder(75), DefaultValue(DrawPass.Default), EditorDisplay(\"Text\")")
    DrawPass DrawModes = DrawPass::Default;

    /// <summary>
    /// The shadows casting mode by this visual element.
    /// </summary>
    API_FIELD(Attributes="EditorOrder(80), DefaultValue(ShadowsCastingMode.All), EditorDisplay(\"Text\")")
    ShadowsCastingMode ShadowsMode = ShadowsCastingMode::All;

    /// <summary>
    /// Gets the layout options. Layout is defined in local space of the object (on XY plane).
    /// </summary>
    API_PROPERTY(Attributes="EditorOrder(100), EditorDisplay(\"Text\")")
    FORCE_INLINE TextLayoutOptions GetLayoutOptions() const
    {
        return _layoutOptions;
    }

    /// <summary>
    /// Sets the layout options. Layout is defined in local space of the object (on XY plane).
    /// </summary>
    API_PROPERTY() void SetLayoutOptions(TextLayoutOptions& value);

    /// <summary>
    /// Gets the axis=aligned bounding box of the text vertices in the local-space of the actor.
    /// </summary>
    API_PROPERTY() FORCE_INLINE BoundingBox GetLocalBox() const
    {
        return _localBox;
    }

    /// <summary>
    /// Updates the text vertex buffer layout and cached data if its dirty.
    /// </summary>
    API_FUNCTION() void UpdateLayout();

#if USE_PRECISE_MESH_INTERSECTS

    /// <summary>
    /// Gets the collision proxy used by the text geometry.
    /// </summary>
    /// <returns>The collisions proxy container object reference.</returns>
    FORCE_INLINE const CollisionProxy& GetCollisionProxy() const
    {
        return _collisionProxy;
    }

#endif

private:

    void Invalidate()
    {
        // Invalidate data
        _isDirty = true;
    }

public:

    // [Actor]
    bool HasContentLoaded() const override;
    void Draw(RenderContext& renderContext) override;
    void DrawGeneric(RenderContext& renderContext) override;
#if USE_EDITOR
    void OnDebugDrawSelected() override;
#endif
    bool IntersectsItself(const Ray& ray, float& distance, Vector3& normal) override;
    void Serialize(SerializeStream& stream, const void* otherObj) override;
    void Deserialize(DeserializeStream& stream, ISerializeModifier* modifier) override;

protected:

    // [Actor]
    void OnEnable() override;
    void OnDisable() override;
    void OnTransformChanged() override;
};