XCEngine/editor/src/Viewport/SceneViewportEditorOverlayData.h

#pragma once

#include "IViewportHostService.h"

#include <XCEngine/Core/Math/Color.h>
#include <XCEngine/Core/Math/Vector2.h>
#include <XCEngine/Core/Math/Vector3.h>

#include <array>
#include <limits>
#include <vector>

namespace XCEngine {
namespace Editor {

enum class SceneViewportOverlayDepthMode : uint8_t {
    DepthTested = 0,
    AlwaysOnTop
};

enum class SceneViewportOverlaySpriteTextureKind : uint8_t {
    Camera = 0,
    Light = 1
};

enum class SceneViewportOverlayHandleKind : uint8_t {
    None = 0,
    SceneIcon,
    MoveAxis,
    MovePlane,
    RotateAxis,
    ScaleAxis,
    ScaleUniform
};

enum class SceneViewportOverlayHandleShape : uint8_t {
    None = 0,
    WorldRect,
    ScreenSegment,
    ScreenRect,
    ScreenQuad
};

struct SceneViewportOverlayLinePrimitive {
    Math::Vector3 startWorld = Math::Vector3::Zero();
    Math::Vector3 endWorld = Math::Vector3::Zero();
    Math::Color color = Math::Color::White();
    float thicknessPixels = 1.0f;
    SceneViewportOverlayDepthMode depthMode = SceneViewportOverlayDepthMode::AlwaysOnTop;
};

struct SceneViewportOverlaySpritePrimitive {
    Math::Vector3 worldPosition = Math::Vector3::Zero();
    Math::Vector2 sizePixels = Math::Vector2::Zero();
    Math::Color tintColor = Math::Color::White();
    float sortDepth = 0.0f;
    uint64_t entityId = 0;
    SceneViewportOverlaySpriteTextureKind textureKind = SceneViewportOverlaySpriteTextureKind::Camera;
    SceneViewportOverlayDepthMode depthMode = SceneViewportOverlayDepthMode::AlwaysOnTop;
};

struct SceneViewportOverlayScreenTriangleVertex {
    Math::Vector2 screenPosition = Math::Vector2::Zero();
    Math::Color color = Math::Color::White();
};

struct SceneViewportOverlayScreenTrianglePrimitive {
    std::array<SceneViewportOverlayScreenTriangleVertex, 3> vertices = {};
    SceneViewportOverlayDepthMode depthMode = SceneViewportOverlayDepthMode::AlwaysOnTop;
};

struct SceneViewportOverlayHandleRecord {
    SceneViewportOverlayHandleKind kind = SceneViewportOverlayHandleKind::None;
    uint64_t handleId = 0;
    uint64_t entityId = 0;
    SceneViewportOverlayHandleShape shape = SceneViewportOverlayHandleShape::None;
    int priority = 0;
    Math::Vector3 worldPosition = Math::Vector3::Zero();
    Math::Vector2 sizePixels = Math::Vector2::Zero();
    float sortDepth = 0.0f;
    Math::Vector2 screenStart = Math::Vector2::Zero();
    Math::Vector2 screenEnd = Math::Vector2::Zero();
    Math::Vector2 screenCenter = Math::Vector2::Zero();
    Math::Vector2 screenHalfSize = Math::Vector2::Zero();
    std::array<Math::Vector2, 4> screenQuad = {};
    float hitThicknessPixels = 0.0f;
};

struct SceneViewportOverlayHandleHitResult {
    SceneViewportOverlayHandleKind kind = SceneViewportOverlayHandleKind::None;
    uint64_t handleId = 0;
    uint64_t entityId = 0;
    int priority = (std::numeric_limits<int>::min)();
    float distanceSq = (std::numeric_limits<float>::max)();
    float depth = (std::numeric_limits<float>::max)();

    bool HasHit() const {
        return kind != SceneViewportOverlayHandleKind::None;
    }
};

struct SceneViewportOverlayFrameData {
    SceneViewportOverlayData overlay = {};
    std::vector<SceneViewportOverlayLinePrimitive> worldLines = {};
    std::vector<SceneViewportOverlaySpritePrimitive> worldSprites = {};
    std::vector<SceneViewportOverlayScreenTrianglePrimitive> screenTriangles = {};
    std::vector<SceneViewportOverlayHandleRecord> handleRecords = {};

    bool HasOverlayPrimitives() const {
        return overlay.valid && (!worldLines.empty() || !worldSprites.empty() || !screenTriangles.empty());
    }

    bool HasWorldOverlay() const {
        return HasOverlayPrimitives();
    }
};

inline void AppendSceneViewportOverlayFrameData(
    SceneViewportOverlayFrameData& target,
    const SceneViewportOverlayFrameData& source) {
    if (!target.overlay.valid && source.overlay.valid) {
        target.overlay = source.overlay;
    }

    target.worldLines.insert(
        target.worldLines.end(),
        source.worldLines.begin(),
        source.worldLines.end());
    target.worldSprites.insert(
        target.worldSprites.end(),
        source.worldSprites.begin(),
        source.worldSprites.end());
    target.screenTriangles.insert(
        target.screenTriangles.end(),
        source.screenTriangles.begin(),
        source.screenTriangles.end());
    target.handleRecords.insert(
        target.handleRecords.end(),
        source.handleRecords.begin(),
        source.handleRecords.end());
}

} // namespace Editor
} // namespace XCEngine