@ -2,11 +2,13 @@
// Licensed under the Apache License, Version 2.0.
using System ;
using System.Buffers ;
using System.Collections.Generic ;
using System.Linq ;
using System.Numerics ;
using SixLabors.ImageSharp.PixelFormats ;
using SixLabors.Memory ;
using SixLabors.Primitives ;
using SixLabors.Shapes ;
@ -47,7 +49,7 @@ namespace SixLabors.ImageSharp.Processing
throw new ArgumentNullException ( nameof ( colors ) ) ;
}
if ( ! colors . Any ( ) )
if ( colors . Length = = 0 )
{
throw new ArgumentOutOfRangeException (
nameof ( colors ) ,
@ -99,7 +101,7 @@ namespace SixLabors.ImageSharp.Processing
throw new ArgumentNullException ( nameof ( colors ) ) ;
}
if ( ! colors . Any ( ) )
if ( colors . Length = = 0 )
{
throw new ArgumentOutOfRangeException (
nameof ( colors ) ,
@ -133,22 +135,19 @@ namespace SixLabors.ImageSharp.Processing
private readonly float length ;
private readonly PointF [ ] buffer ;
public Edge ( Path path , Color startColor , Color endColor )
{
this . path = path ;
Vector2 [ ] points = path . LineSegments . SelectMany ( s = > s . Flatten ( ) ) . Select ( p = > ( Vector2 ) p ) . ToArray ( ) ;
this . Start = points . First ( ) ;
this . Start = points [ 0 ] ;
this . StartColor = ( Vector4 ) startColor ;
this . End = points . Last ( ) ;
this . EndColor = ( Vector4 ) endColor ;
this . length = DistanceBetween ( this . End , this . Start ) ;
this . buffer = new PointF [ this . path . MaxIntersections ] ;
}
public PointF Start { get ; }
@ -159,18 +158,38 @@ namespace SixLabors.ImageSharp.Processing
public Vector4 EndColor { get ; }
public Intersection ? FindIntersection ( PointF start , PointF end )
public Intersection ? FindIntersection ( PointF start , PointF end , MemoryAllocator allocator )
{
int intersections = this . path . FindIntersections ( start , end , this . buffer ) ;
if ( intersections = = 0 )
// TODO: The number of max intersections is upper bound to the number of nodes of the path.
// Normally these numbers would be small and could potentially be stackalloc rather than pooled.
// Investigate performance beifit of checking length and choosing approach.
using ( IMemoryOwner < PointF > memory = allocator . Allocate < PointF > ( this . path . MaxIntersections ) )
{
return null ;
}
Span < PointF > buffer = memory . Memory . Span ;
int intersections = this . path . FindIntersections ( start , end , buffer ) ;
if ( intersections = = 0 )
{
return null ;
}
buffer = buffer . Slice ( 0 , intersections ) ;
PointF minPoint = buffer [ 0 ] ;
var min = new Intersection ( minPoint , ( ( Vector2 ) ( minPoint - start ) ) . LengthSquared ( ) ) ;
for ( int i = 1 ; i < buffer . Length ; i + + )
{
PointF point = buffer [ i ] ;
var current = new Intersection ( point , ( ( Vector2 ) ( point - start ) ) . LengthSquared ( ) ) ;
return this . buffer . Take ( intersections )
. Select ( p = > new Intersection ( point : p , distance : ( ( Vector2 ) ( p - start ) ) . LengthSquared ( ) ) )
. Aggregate ( ( min , current ) = > min . Distance > current . Distance ? current : min ) ;
if ( min . Distance > current . Distance )
{
min = current ;
}
}
return min ;
}
}
public Vector4 ColorAt ( float distance )
@ -197,6 +216,10 @@ namespace SixLabors.ImageSharp.Processing
private readonly IList < Edge > edges ;
private readonly TPixel centerPixel ;
private readonly TPixel transparentPixel ;
/// <summary>
/// Initializes a new instance of the <see cref="PathGradientBrushApplicator{TPixel}"/> class.
/// </summary>
@ -214,13 +237,15 @@ namespace SixLabors.ImageSharp.Processing
: base ( configuration , options , source )
{
this . edges = edges ;
PointF [ ] points = edges . Select ( s = > s . Start ) . ToArray ( ) ;
this . center = points . Aggregate ( ( p1 , p2 ) = > p1 + p2 ) / edges . Count ;
this . centerColor = ( Vector4 ) centerColor ;
this . centerPixel = centerColor . ToPixel < TPixel > ( ) ;
this . maxDistance = points . Select ( p = > ( Vector2 ) ( p - this . center ) ) . Max ( d = > d . Length ( ) ) ;
this . maxDistance = points . Select ( p = > ( Vector2 ) ( p - this . center ) ) . Select ( d = > d . Length ( ) ) . Max ( ) ;
this . transparentPixel = Color . Transparent . ToPixel < TPixel > ( ) ;
}
/// <inheritdoc />
@ -232,22 +257,20 @@ namespace SixLabors.ImageSharp.Processing
if ( point = = this . center )
{
return new Color ( this . centerColor ) . To Pixel < TPixel > ( ) ;
return this . centerPixel ;
}
var direction = Vector2 . Normalize ( point - this . center ) ;
PointF end = point + ( PointF ) ( direction * this . maxDistance ) ;
( Edge edge , Intersection ? info ) = this . FindIntersection ( point , end ) ;
if ( ! info . HasValue )
{
return Color . Transparent . ToPixel < TPixel > ( ) ;
return this . transparentPixel ;
}
PointF intersection = info . Value . Point ;
Vector4 edgeColor = edge . ColorAt ( intersection ) ;
float length = DistanceBetween ( intersection , this . center ) ;
@ -263,9 +286,10 @@ namespace SixLabors.ImageSharp.Processing
{
( Edge edge , Intersection ? info ) closest = default ;
MemoryAllocator allocator = this . Target . MemoryAllocator ;
foreach ( Edge edge in this . edges )
{
Intersection ? intersection = edge . FindIntersection ( start , end ) ;
Intersection ? intersection = edge . FindIntersection ( start , end , allocator ) ;
if ( ! intersection . HasValue )
{
James Jackson-South
6 years ago
