private float ComputeLeastSquares(Vec4 alphax_sum, Vec4 betax_sum, Vec4 alphabeta_sum, out Vec4 a, out Vec4 b)
{
Vec4 alpha2_sum = alphax_sum.SplatW();
Vec4 beta2_sum = betax_sum.SplatW();
// compute the least-squares optimal points
Vec4 factor = alphabeta_sum.NegativeMultiplySubtract(alphabeta_sum, alpha2_sum * beta2_sum).Reciprocal();
a = betax_sum.NegativeMultiplySubtract(alphabeta_sum, alphax_sum * beta2_sum) * factor;
b = alphax_sum.NegativeMultiplySubtract(alphabeta_sum, betax_sum * alpha2_sum) * factor;
// clamp to the grid
a = a.Clamp(Vec4.Zero, Vec4.One);
b = b.Clamp(Vec4.Zero, Vec4.One);
a = GRID.MultiplyAdd(a, HALF).Truncate() * GRIDRCP;
b = GRID.MultiplyAdd(b, HALF).Truncate() * GRIDRCP;
// compute the error (we skip the constant xxsum)
Vec4 e1 = (a * a * alpha2_sum) + (b * b * beta2_sum);
Vec4 e2 = a.NegativeMultiplySubtract(alphax_sum, a * b * alphabeta_sum);
Vec4 e3 = b.NegativeMultiplySubtract(betax_sum, e2);
Vec4 e4 = e3 * 2 + e1;
// apply the metric to the error term
Vec4 e5 = e4 * m_metric;
return(e5.X + e5.Y + e5.Z);
}
private void Update(EvaluationContext context)
{
var worldToClipSpace = Matrix.Multiply(context.WorldToCamera, context.CameraToClipSpace);
//Matrix worldToView = context.WorldToCamera * context.CameraProjection;
//var worldToClipSpace = context.WorldToCamera
//var viewToWorld = Matrix.Invert(worldToClipSpace);
var brightness = Brightness.GetValue(context);
var color = Color.GetValue(context);
var randomizeColor = RandomizeColor.GetValue(context);
var size = Size.GetValue(context);
var randomizeSize = RandomizeSize.GetValue(context);
var stretch = Stretch.GetValue(context);
var distanceFromLight = DistanceFromLight.GetValue(context);
var spread = Spread.GetValue(context);
var randomizeSpread = RandomizeSpread.GetValue(context);
var positionFactor = PositionFactor.GetValue(context);
var randomizePosition = RandomizePosition.GetValue(context);
var mixPointLightColor = MixPointLightColor.GetValue(context);
var referencedLightIndex = LightIndex.GetValue(context);
var innerFxZone = InnerFxZone.GetValue(context);
var edgeFxZone = EdgeFxZone.GetValue(context);
var zoneFxScale = FxZoneScale.GetValue(context);
var zoneFxBrightness = FxZoneBrightness.GetValue(context);
var matteBoxZone = MattBoxZone.GetValue(context);
var rand = new Random(RandomSeed.GetValue(context));
var fxZoneMode = (ZoneFxModes)FxZoneMode.GetValue(context);
var rotation = Rotation.GetValue(context);
var rotationSpread = RotationSpread.GetValue(context);
var rotateTowards = (Categories)RotateTowards.GetValue(context);
int startLightIndex = 0;
int endLightIndex = context.PointLights.Count;
_tempList.Clear();
if (brightness > 0.00001f)
{
if (referencedLightIndex >= 0)
{
startLightIndex = referencedLightIndex;
endLightIndex = referencedLightIndex + 1;
}
var aspectRatio = (float)context.RequestedResolution.Width / (float)context.RequestedResolution.Height;
for (int lightIndex = startLightIndex; lightIndex < endLightIndex; lightIndex++)
{
var pointLight = context.PointLights.GetPointLight(lightIndex);
var lightPosDx = pointLight.Position.ToSharpDxVector4(1);
var posInViewDx = SharpDX.Vector4.Transform(lightPosDx, worldToClipSpace);
posInViewDx /= posInViewDx.W;
// Ignore light sources behind
var hideFactor = posInViewDx.Z < 0 ? 0 : 1;
posInViewDx /= posInViewDx.W;
var lightPosInView2D = new Vector2(posInViewDx.X, posInViewDx.Y);
var count = SpriteCount.GetValue(context).Clamp(0, 1000);
if (count != _sprites.NumElements)
{
_sprites = new StructuredList <Sprite>(count);
}
// Render Planes
for (var i = 0; i < count; ++i)
{
var f = count <= 1 ? 0 : ((float)i / (count - 1) - 0.5f);
var positionOnLine = (float)((-distanceFromLight
+ f * spread * 2
+ randomizeSpread * (rand.NextDouble() - 0.5) + 1));
Vector2 objectScreenPos = lightPosInView2D * positionOnLine * positionFactor + (new Vector2(1, 1) - positionFactor) * lightPosInView2D;
objectScreenPos += new Vector2((float)(randomizePosition.X * (rand.NextDouble() - 0.5)),
(float)(randomizePosition.Y * (rand.NextDouble() - 0.5)));
var sizeWithRandom = size * (float)(1.0 + randomizeSize * (rand.NextDouble() - 0.5)) / 0.2f;
var colorWithLight = new Vector4((color.X + randomizeColor.X * (float)(rand.NextDouble() - 0.5) * 4) * MathUtils.Lerp(1f, pointLight.Color.X, mixPointLightColor),
(color.Y + randomizeColor.Y * (float)(rand.NextDouble() - 0.5) * 4) * MathUtils.Lerp(1f, pointLight.Color.Y, mixPointLightColor),
(color.Z + randomizeColor.Z * (float)(rand.NextDouble() - 0.5) * 4) * MathUtils.Lerp(1f, pointLight.Color.Z, mixPointLightColor),
color.W * (1 - randomizeColor.W * (float)(rand.NextDouble() * 2)));
var spriteColor = Vector4.Clamp(colorWithLight, Vector4.Zero, new Vector4(100, 100, 100, 1));
var triggerPosition = fxZoneMode == ZoneFxModes.Lights
? lightPosInView2D
: objectScreenPos;
var d = GetDistanceToEdge(triggerPosition);
var cInnerZone = MathUtils.SmootherStep(innerFxZone.Y, innerFxZone.X, 1 - d);
var cEdgeZone = MathUtils.SmootherStep(edgeFxZone.X, edgeFxZone.Y, 1 - d);
var cMatteBox = MathUtils.SmootherStep(matteBoxZone.Y, matteBoxZone.X, 1 - d);
var totalTriggerAmount = (cInnerZone + cEdgeZone) * cMatteBox;
sizeWithRandom *= (1 + zoneFxScale * totalTriggerAmount).Clamp(0, 100);
var brightnessEffect = (zoneFxBrightness * totalTriggerAmount).Clamp(0, 100);
spriteColor.X += brightnessEffect;
spriteColor.Y += brightnessEffect;
spriteColor.Z += brightnessEffect;
spriteColor.W = ((spriteColor.W + brightnessEffect)).Clamp(0, 1);
spriteColor.W *= cMatteBox * pointLight.Color.W;
// This might actually be a good idea. Maybe we should do this later..
// Fade with incoming alpha from FlatShaders and Materials
//color.W *= materialAlpha;
float spriteRotation = rotation;
switch (rotateTowards)
{
case Categories.Object:
break;
case Categories.Light:
spriteRotation -=
(float)(Math.Atan2((objectScreenPos.X - lightPosInView2D.X) * aspectRatio, objectScreenPos.Y - lightPosInView2D.Y) +
MathF.PI) * (180 / MathF.PI);
break;
case Categories.ScreenCenter:
spriteRotation -= (float)(Math.Atan2(objectScreenPos.X, objectScreenPos.Y) + MathF.PI) * 180f / MathF.PI;
break;
default:
throw new ArgumentOutOfRangeException();
}
// // Transforom UV to pick correct texture cell
// if (TextureCellsRows == 0)
// TextureCellsRows = 1;
//
// if (TextureCellsColumns == 0)
// TextureCellsColumns = 1;
// int row = (int)(Math.Floor(i / TextureCellsColumns) % TextureCellsRows);
// int column = (int)(i % TextureCellsRows);
//
// var translationUV = new Vector3(1 / TextureCellsColumns * column, 1 / TextureCellsRows * row, 0);
// var rotationUV = new Quaternion();
// var scaleUV = new Vector3(1 / TextureCellsColumns, 1 / TextureCellsRows, 0);
// var pivotUV = new Vector3(0, 0, 0);
//
// var transformUV = Matrix.Transformation(pivotUV, new Quaternion(), scaleUV, pivotUV, rotationUV, translationUV);
// var prevTransformUV = context.TextureMatrix;
// context.TextureMatrix = transformUV * prevTransformUV;
spriteColor.W *= brightness;
_tempList.Add(new Sprite
{
PosInClipSpace = objectScreenPos,
Size = sizeWithRandom * stretch * hideFactor,
Color = spriteColor,
RotationDeg = spriteRotation + f * rotationSpread * 180,
UvMin = Vector2.Zero,
UvMax = Vector2.One,
});
}
}
}
// Copy to structured array
if (_tempList.Count != _sprites.NumElements)
{
_sprites = new StructuredList <Sprite>(_tempList.Count);
}
for (var spriteIndex = 0; spriteIndex < _tempList.Count; spriteIndex++)
{
_sprites.TypedElements[spriteIndex] = _tempList[spriteIndex];
}
OutBuffer.Value = _sprites;
}