/// <inheritdoc/>
public void DrawRibbon(ref RibbonArgs p0, ref RibbonArgs p1, PackedTexture texture)
{
int index, dummy;
_renderBatch.Submit(PrimitiveType.TriangleList, 4, 6, out index, out dummy);
OnDrawRibbon(ref p0, ref p1, texture, _renderBatch.Vertices, index);
}
protected override void OnDrawRibbon(ref RibbonArgs p0, ref RibbonArgs p1, PackedTexture texture, BillboardVertex[] vertices, int index)
{
// p0 and p1 specify a segment of a particle ribbon.
// --+--------------+--
// p0 p1
// --+--------------+--
// Bottom left vertex
var v = new BillboardVertex();
v.Position = p0.Position;
v.Axis = p0.Axis;
v.Color3F = p0.Color;
v.Alpha = p0.Alpha;
v.TextureCoordinate = new Vector2F(p0.TextureCoordinateU, 1);
v.Size = new Vector2F(p0.Size);
v.Softness = p0.Softness;
v.ReferenceAlpha = p0.ReferenceAlpha;
v.AnimationTime = p0.AnimationTime;
v.BlendMode = p0.BlendMode;
v.Texture = texture;
vertices[index] = v;
index++;
// Top left vertex
v.TextureCoordinate.Y = 0;
vertices[index] = v;
index++;
// Top right vertex
v.Position = p1.Position;
v.Axis = p1.Axis;
v.Color3F = p1.Color;
v.Alpha = p1.Alpha;
v.TextureCoordinate = new Vector2F(p1.TextureCoordinateU, 0);
v.Size = new Vector2F(p1.Size);
v.Softness = p1.Softness;
v.ReferenceAlpha = p1.ReferenceAlpha;
v.AnimationTime = p1.AnimationTime;
v.BlendMode = p1.BlendMode;
vertices[index] = v;
index++;
// Bottom right vertex
v.TextureCoordinate.Y = 1;
vertices[index] = v;
}
protected override void OnDrawRibbon(ref RibbonArgs p0, ref RibbonArgs p1, PackedTexture texture, VertexPositionColorTexture[] vertices, int index)
{
// p0 and p1 specify a segment of a particle ribbon.
// --+--------------+--
// p0 p1
// --+--------------+--
#region ----- Handle texture information and size -----
float animationTime = p0.AnimationTime;
Vector2F texCoordTopLeft = texture.GetTextureCoordinates(new Vector2F(p0.TextureCoordinateU, 0), animationTime);
Vector2F texCoordBottomRight = texture.GetTextureCoordinates(new Vector2F(p1.TextureCoordinateU, 1), animationTime);
// Negative sizes (mirroring) is not supported because this conflicts with the
// texture tiling on ribbons.
float size0 = Math.Abs(p0.Size) / 2;
float size1 = Math.Abs(p1.Size) / 2;
// Offset from particle center to upper edge.
Vector3F up0;
up0.X = p0.Axis.X * size0;
up0.Y = p0.Axis.Y * size0;
up0.Z = p0.Axis.Z * size0;
Vector3F up1;
up1.X = p1.Axis.X * size1;
up1.Y = p1.Axis.Y * size1;
up1.Z = p1.Axis.Z * size1;
#endregion
#region ----- Get Color -----
// Premultiply alpha.
Vector4 color4 = new Vector4
{
X = p0.Color.X * p0.Alpha,
Y = p0.Color.Y * p0.Alpha,
Z = p0.Color.Z * p0.Alpha,
// Apply blend mode (0 = additive, 1 = alpha blend).
W = p0.Alpha * p0.BlendMode
};
var color0 = new Color(color4);
color4 = new Vector4
{
X = p1.Color.X * p1.Alpha,
Y = p1.Color.Y * p1.Alpha,
Z = p1.Color.Z * p1.Alpha,
W = p1.Alpha * p1.BlendMode
};
var color1 = new Color(color4);
#endregion
#region ----- Initializes vertices in vertex array -----
// Bottom left vertex
vertices[index].Position.X = p0.Position.X - up0.X;
vertices[index].Position.Y = p0.Position.Y - up0.Y;
vertices[index].Position.Z = p0.Position.Z - up0.Z;
vertices[index].Color = color0;
vertices[index].TextureCoordinate.X = texCoordTopLeft.X;
vertices[index].TextureCoordinate.Y = texCoordBottomRight.Y;
index++;
// Top left vertex
vertices[index].Position.X = p0.Position.X + up0.X;
vertices[index].Position.Y = p0.Position.Y + up0.Y;
vertices[index].Position.Z = p0.Position.Z + up0.Z;
vertices[index].Color = color0;
vertices[index].TextureCoordinate.X = texCoordTopLeft.X;
vertices[index].TextureCoordinate.Y = texCoordTopLeft.Y;
index++;
// Top right vertex
vertices[index].Position.X = p1.Position.X + up1.X;
vertices[index].Position.Y = p1.Position.Y + up1.Y;
vertices[index].Position.Z = p1.Position.Z + up1.Z;
vertices[index].Color = color1;
vertices[index].TextureCoordinate.X = texCoordBottomRight.X;
vertices[index].TextureCoordinate.Y = texCoordTopLeft.Y;
index++;
// Bottom right vertex
vertices[index].Position.X = p1.Position.X - up1.X;
vertices[index].Position.Y = p1.Position.Y - up1.Y;
vertices[index].Position.Z = p1.Position.Z - up1.Z;
vertices[index].Color = color1;
vertices[index].TextureCoordinate.X = texCoordBottomRight.X;
vertices[index].TextureCoordinate.Y = texCoordBottomRight.Y;
#endregion
}
private void DrawParticleRibbonsAuto(ParticleSystemData particleSystemData, bool requiresTransformation, ref Vector3F scale, ref Pose pose, ref Vector3F color, float alpha)
{
// At least two particles are required to create a ribbon.
int numberOfParticles = particleSystemData.Particles.Count;
if (numberOfParticles < 2)
{
return;
}
// The up axis is not defined and needs to be derived automatically:
// - Compute tangents along the ribbon curve.
// - Build cross-products of normal and tangent vectors.
// Is normal uniform across all particles?
Vector3F?uniformNormal;
switch (particleSystemData.BillboardOrientation.Normal)
{
case BillboardNormal.ViewPlaneAligned:
uniformNormal = _defaultNormal;
break;
case BillboardNormal.ViewpointOriented:
uniformNormal = _cameraPose.Position - pose.Position;
if (!uniformNormal.Value.TryNormalize())
{
uniformNormal = _defaultNormal;
}
break;
default:
var normalParameter = particleSystemData.NormalParameter;
if (normalParameter == null)
{
uniformNormal = _defaultNormal;
}
else if (normalParameter.IsUniform)
{
uniformNormal = normalParameter.DefaultValue;
if (requiresTransformation)
{
uniformNormal = pose.ToWorldDirection(uniformNormal.Value);
}
}
else
{
// Normal is set in particle data.
uniformNormal = null;
}
break;
}
var texture = particleSystemData.Texture ?? _debugTexture;
var particles = particleSystemData.Particles.Array;
int index = 0;
do
{
// ----- Skip dead particles.
while (index < numberOfParticles && !particles[index].IsAlive)
{
index++;
}
// ----- Start of new ribbon.
int endIndex = index + 1;
while (endIndex < numberOfParticles && particles[endIndex].IsAlive)
{
endIndex++;
}
int numberOfSegments = endIndex - index - 1;
var p0 = new RibbonArgs
{
// Uniform parameters
Softness = particleSystemData.Softness,
ReferenceAlpha = particleSystemData.AlphaTest
};
var p1 = new RibbonArgs
{
// Uniform parameters
Softness = particleSystemData.Softness,
ReferenceAlpha = particleSystemData.AlphaTest
};
// Compute axes and render ribbon.
// First particle.
if (requiresTransformation)
{
p0.Position = pose.ToWorldPosition(particles[index].Position * scale);
p0.Size = particles[index].Size.Y * scale.Y;
}
else
{
p0.Position = particles[index].Position;
p0.Size = particles[index].Size.Y;
}
p0.Color = particles[index].Color * color;
p0.Alpha = particles[index].Alpha * alpha;
p0.AnimationTime = particles[index].AnimationTime;
p0.BlendMode = particles[index].BlendMode;
p0.TextureCoordinateU = 0;
index++;
Vector3F nextPosition;
if (requiresTransformation)
{
nextPosition = pose.ToWorldPosition(particles[index].Position * scale);
}
else
{
nextPosition = particles[index].Position;
}
Vector3F normal;
if (uniformNormal.HasValue)
{
// Uniform normal.
normal = uniformNormal.Value;
}
else
{
// Varying normal.
normal = particles[index].Normal;
if (requiresTransformation)
{
normal = pose.ToWorldDirection(normal);
}
}
Vector3F previousDelta = nextPosition - p0.Position;
p0.Axis = Vector3F.Cross(normal, previousDelta);
p0.Axis.TryNormalize();
// Intermediate particles.
while (index < endIndex - 1)
{
p1.Position = nextPosition;
if (requiresTransformation)
{
nextPosition = pose.ToWorldPosition(particles[index + 1].Position * scale);
p1.Size = particles[index].Size.Y * scale.Y;
}
else
{
nextPosition = particles[index + 1].Position;
p1.Size = particles[index].Size.Y;
}
if (uniformNormal.HasValue)
{
// Uniform normal.
normal = uniformNormal.Value;
}
else
{
// Varying normal.
normal = particles[index].Normal;
if (requiresTransformation)
{
normal = pose.ToWorldDirection(normal);
}
}
Vector3F delta = nextPosition - p1.Position;
Vector3F tangent = delta + previousDelta; // Note: Should we normalize vectors for better average?
p1.Axis = Vector3F.Cross(normal, tangent);
p1.Axis.TryNormalize();
p1.Color = particles[index].Color * color;
p1.Alpha = particles[index].Alpha * alpha;
p1.AnimationTime = particles[index].AnimationTime;
p1.BlendMode = particles[index].BlendMode;
p1.TextureCoordinateU = GetTextureCoordinateU1(index - 1, numberOfSegments, particleSystemData.TextureTiling);
// Draw ribbon segment.
_billboardBatch.DrawRibbon(ref p0, ref p1, texture);
p0 = p1;
p0.TextureCoordinateU = GetTextureCoordinateU0(index, numberOfSegments, particleSystemData.TextureTiling);
previousDelta = delta;
index++;
}
// Last particle.
p1.Position = nextPosition;
if (uniformNormal.HasValue)
{
// Uniform normal.
normal = uniformNormal.Value;
}
else
{
// Varying normal.
normal = particles[index].Normal;
if (requiresTransformation)
{
normal = pose.ToWorldDirection(normal);
}
}
p1.Axis = Vector3F.Cross(normal, previousDelta);
p1.Axis.TryNormalize();
if (requiresTransformation)
{
p1.Size = particles[index].Size.Y * scale.Y;
}
else
{
p1.Size = particles[index].Size.Y;
}
p1.Color = particles[index].Color * color;
p1.Alpha = particles[index].Alpha * alpha;
p1.AnimationTime = particles[index].AnimationTime;
p1.BlendMode = particles[index].BlendMode;
p1.TextureCoordinateU = GetTextureCoordinateU1(index - 1, numberOfSegments, particleSystemData.TextureTiling);
// Draw last ribbon segment.
_billboardBatch.DrawRibbon(ref p0, ref p1, texture);
index++;
} while (index < numberOfParticles);
}
// Particle ribbons:
// Particles can be rendered as ribbons (a.k.a. trails, lines). Subsequent living
// particles are connected using rectangles.
// +--------------+--------------+
// | | |
// p0 p1 p2
// | | |
// +--------------+--------------+
// At least two living particles are required to create a ribbon. Dead particles
// ("NormalizedAge" ≥ 1) can be used as delimiters to terminate one ribbon and
// start the next ribbon.
//
// p0 and p1 can have different colors and alpha values to create color gradients
// or a ribbon that fades in/out.
private void DrawParticleRibbonsFixed(ParticleSystemData particleSystemData, bool requiresTransformation, ref Vector3F scale, ref Pose pose, ref Vector3F color, float alpha)
{
// At least two particles are required to create a ribbon.
int numberOfParticles = particleSystemData.Particles.Count;
if (numberOfParticles < 2)
{
return;
}
var particles = particleSystemData.Particles.Array;
bool isAxisInViewSpace = particleSystemData.BillboardOrientation.IsAxisInViewSpace;
int index = 0;
do
{
// ----- Skip dead particles.
while (index < numberOfParticles && !particles[index].IsAlive)
{
index++;
}
// ----- Start of new ribbon.
int endIndex = index + 1;
while (endIndex < numberOfParticles && particles[endIndex].IsAlive)
{
endIndex++;
}
int numberOfSegments = endIndex - index - 1;
var p0 = new RibbonArgs
{
// Uniform parameters
Softness = particleSystemData.Softness,
ReferenceAlpha = particleSystemData.AlphaTest
};
var p1 = new RibbonArgs
{
// Uniform parameters
Softness = particleSystemData.Softness,
ReferenceAlpha = particleSystemData.AlphaTest
};
p0.Axis = particles[index].Axis;
if (requiresTransformation)
{
p0.Position = pose.ToWorldPosition(particles[index].Position * scale);
if (!isAxisInViewSpace)
{
p0.Axis = pose.ToWorldDirection(p0.Axis);
}
p0.Size = particles[index].Size.Y * scale.Y;
}
else
{
p0.Position = particles[index].Position;
p0.Size = particles[index].Size.Y;
}
p0.Color = particles[index].Color * color;
p0.Alpha = particles[index].Alpha * alpha;
p0.AnimationTime = particles[index].AnimationTime;
p0.BlendMode = particles[index].BlendMode;
p0.TextureCoordinateU = 0;
index++;
while (index < endIndex)
{
p1.Axis = particles[index].Axis;
if (requiresTransformation)
{
p1.Position = pose.ToWorldPosition(particles[index].Position * scale);
if (!isAxisInViewSpace)
{
p1.Axis = pose.ToWorldDirection(p1.Axis);
}
p1.Size = particles[index].Size.Y * scale.Y;
}
else
{
p1.Position = particles[index].Position;
p1.Size = particles[index].Size.Y;
}
p1.Color = particles[index].Color * color;
p1.Alpha = particles[index].Alpha * alpha;
p1.AnimationTime = particles[index].AnimationTime;
p1.BlendMode = particles[index].BlendMode;
p1.TextureCoordinateU = GetTextureCoordinateU1(index - 1, numberOfSegments, particleSystemData.TextureTiling);
// Draw ribbon segment.
var texture = particleSystemData.Texture ?? _debugTexture;
_billboardBatch.DrawRibbon(ref p0, ref p1, texture);
p0 = p1;
p0.TextureCoordinateU = GetTextureCoordinateU0(index, numberOfSegments, particleSystemData.TextureTiling);
index++;
}
} while (index < numberOfParticles);
}
/// <summary> /// Adds a segment of a particle ribbon (4 vertices) to the vertex buffer. /// </summary> /// <param name="p0">The segment start.</param> /// <param name="p1">The segment end.</param> /// <param name="texture">The packed texture.</param> /// <param name="vertices">The vertex buffer.</param> /// <param name="index">The index of the next free slot in the vertex buffer.</param> protected abstract void OnDrawRibbon(ref RibbonArgs p0, ref RibbonArgs p1, PackedTexture texture, T[] vertices, int index);