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osu-lazer/osu.Game.Rulesets.Osu/UI/Cursor/CursorTrail.cs
2019-09-11 13:28:46 +09:00

304 lines
9.7 KiB
C#

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using osu.Framework.Allocation;
using osu.Framework.Caching;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Batches;
using osu.Framework.Graphics.OpenGL.Vertices;
using osu.Framework.Graphics.Primitives;
using osu.Framework.Graphics.Shaders;
using osu.Framework.Graphics.Textures;
using osu.Framework.Input;
using osu.Framework.Input.Events;
using osu.Framework.Timing;
using osuTK;
using osuTK.Graphics;
using osuTK.Graphics.ES30;
namespace osu.Game.Rulesets.Osu.UI.Cursor
{
public class CursorTrail : Drawable, IRequireHighFrequencyMousePosition
{
private const int max_sprites = 2048;
private readonly TrailPart[] parts = new TrailPart[max_sprites];
private int currentIndex;
private IShader shader;
private double timeOffset;
private float time;
public CursorTrail()
{
// as we are currently very dependent on having a running clock, let's make our own clock for the time being.
Clock = new FramedClock();
RelativeSizeAxes = Axes.Both;
for (int i = 0; i < max_sprites; i++)
{
// InvalidationID 1 forces an update of each part of the cursor trail the first time ApplyState is run on the draw node
// This is to prevent garbage data from being sent to the vertex shader, resulting in visual issues on some platforms
parts[i].InvalidationID = 1;
}
}
[BackgroundDependencyLoader]
private void load(ShaderManager shaders)
{
shader = shaders.Load(@"CursorTrail", FragmentShaderDescriptor.TEXTURE);
}
protected override void LoadComplete()
{
base.LoadComplete();
resetTime();
}
private Texture texture = Texture.WhitePixel;
public Texture Texture
{
get => texture;
set
{
if (texture == value)
return;
texture = value;
Invalidate(Invalidation.DrawNode);
}
}
private readonly Cached<Vector2> partSizeCache = new Cached<Vector2>();
private Vector2 partSize => partSizeCache.IsValid
? partSizeCache.Value
: (partSizeCache.Value = new Vector2(Texture.DisplayWidth, Texture.DisplayHeight) * DrawInfo.Matrix.ExtractScale().Xy);
public override bool Invalidate(Invalidation invalidation = Invalidation.All, Drawable source = null, bool shallPropagate = true)
{
if ((invalidation & (Invalidation.DrawInfo | Invalidation.RequiredParentSizeToFit | Invalidation.Presence)) > 0)
partSizeCache.Invalidate();
return base.Invalidate(invalidation, source, shallPropagate);
}
/// <summary>
/// The amount of time to fade the cursor trail pieces.
/// </summary>
protected virtual double FadeDuration => 300;
public override bool IsPresent => true;
protected override void Update()
{
base.Update();
Invalidate(Invalidation.DrawNode, shallPropagate: false);
const int fade_clock_reset_threshold = 1000000;
time = (float)((Time.Current - timeOffset) / FadeDuration);
if (time > fade_clock_reset_threshold)
resetTime();
}
private void resetTime()
{
for (int i = 0; i < parts.Length; ++i)
{
parts[i].Time -= time;
++parts[i].InvalidationID;
}
time = 0;
timeOffset = Time.Current;
}
/// <summary>
/// Whether to interpolate mouse movements and add trail pieces at intermediate points.
/// </summary>
protected virtual bool InterpolateMovements => true;
private Vector2? lastPosition;
private readonly InputResampler resampler = new InputResampler();
public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => true;
protected override bool OnMouseMove(MouseMoveEvent e)
{
Vector2 pos = e.ScreenSpaceMousePosition;
if (lastPosition == null)
{
lastPosition = pos;
resampler.AddPosition(lastPosition.Value);
return base.OnMouseMove(e);
}
foreach (Vector2 pos2 in resampler.AddPosition(pos))
{
Trace.Assert(lastPosition.HasValue);
if (InterpolateMovements)
{
// ReSharper disable once PossibleInvalidOperationException
Vector2 pos1 = lastPosition.Value;
Vector2 diff = pos2 - pos1;
float distance = diff.Length;
Vector2 direction = diff / distance;
float interval = partSize.X / 2.5f;
for (float d = interval; d < distance; d += interval)
{
lastPosition = pos1 + direction * d;
addPart(lastPosition.Value);
}
}
else
{
lastPosition = pos2;
addPart(lastPosition.Value);
}
}
return base.OnMouseMove(e);
}
private void addPart(Vector2 screenSpacePosition)
{
parts[currentIndex].Position = screenSpacePosition;
parts[currentIndex].Time = time;
++parts[currentIndex].InvalidationID;
currentIndex = (currentIndex + 1) % max_sprites;
}
protected override DrawNode CreateDrawNode() => new TrailDrawNode(this);
private struct TrailPart
{
public Vector2 Position;
public float Time;
public long InvalidationID;
}
private class TrailDrawNode : DrawNode
{
protected new CursorTrail Source => (CursorTrail)base.Source;
private IShader shader;
private Texture texture;
private float time;
private readonly TrailPart[] parts = new TrailPart[max_sprites];
private Vector2 size;
private readonly TrailBatch vertexBatch = new TrailBatch(max_sprites, 1);
public TrailDrawNode(CursorTrail source)
: base(source)
{
for (int i = 0; i < max_sprites; i++)
parts[i].InvalidationID = 0;
}
public override void ApplyState()
{
base.ApplyState();
shader = Source.shader;
texture = Source.texture;
size = Source.partSize;
time = Source.time;
for (int i = 0; i < Source.parts.Length; ++i)
{
if (Source.parts[i].InvalidationID > parts[i].InvalidationID)
parts[i] = Source.parts[i];
}
}
public override void Draw(Action<TexturedVertex2D> vertexAction)
{
base.Draw(vertexAction);
shader.Bind();
shader.GetUniform<float>("g_FadeClock").UpdateValue(ref time);
for (int i = 0; i < parts.Length; ++i)
{
vertexBatch.DrawTime = parts[i].Time;
Vector2 pos = parts[i].Position;
DrawQuad(
texture,
new Quad(pos.X - size.X / 2, pos.Y - size.Y / 2, size.X, size.Y),
DrawColourInfo.Colour,
null,
vertexBatch.AddAction);
}
shader.Unbind();
}
protected override void Dispose(bool isDisposing)
{
base.Dispose(isDisposing);
vertexBatch.Dispose();
}
// Todo: This shouldn't exist, but is currently used to reduce allocations by caching variable-capturing closures.
private class TrailBatch : QuadBatch<TexturedTrailVertex>
{
public new readonly Action<TexturedVertex2D> AddAction;
public float DrawTime;
public TrailBatch(int size, int maxBuffers)
: base(size, maxBuffers)
{
AddAction = v => Add(new TexturedTrailVertex
{
Position = v.Position,
TexturePosition = v.TexturePosition,
Time = DrawTime + 1,
Colour = v.Colour,
});
}
}
}
[StructLayout(LayoutKind.Sequential)]
public struct TexturedTrailVertex : IEquatable<TexturedTrailVertex>, IVertex
{
[VertexMember(2, VertexAttribPointerType.Float)]
public Vector2 Position;
[VertexMember(4, VertexAttribPointerType.Float)]
public Color4 Colour;
[VertexMember(2, VertexAttribPointerType.Float)]
public Vector2 TexturePosition;
[VertexMember(1, VertexAttribPointerType.Float)]
public float Time;
public bool Equals(TexturedTrailVertex other)
{
return Position.Equals(other.Position)
&& TexturePosition.Equals(other.TexturePosition)
&& Colour.Equals(other.Colour)
&& Time.Equals(other.Time);
}
}
}
}