public unsafe int UpdateBuffer()
{
int quadIndex = 0;
fixed(ParticleVertex *pQuads = _quads)
{
fixed(Particle *pParticles = _particlesBuffer)
{
for (int i = 0, len = _particlesBuffer.Length; i < len; i++)
{
int k = 4 * quadIndex++;
Particle *ptc = pParticles + i;
for (int j = 0; j < 4; j++)
{
ParticleVertex *vertex = pQuads + k + j;
vertex->PositionPtc = ptc->GlobalPosition;
vertex->Alpha = ptc->Alpha;
vertex->Color = ptc->Color;
vertex->Size = ptc->Size;
}
}
}
_vb.Write(_quads);
}
return(quadIndex);
}
/// <summary>
/// Performs rendering of particles.
/// </summary>
/// <param name="iterator">The particle iterator object.</param>
/// <param name="context">The render context containing rendering information.</param>
protected override void Render(ref RenderContext context, ref ParticleIterator iterator)
{
Int32 vertexCount = 0;
Vector3 cameraPos = context.CameraPosition;
Vector3 rotationAxis = context.BillboardRotationalAxis;
bool squareTexture = (context.Texture.Height == context.Texture.Width);
float aspectRatio = context.Texture.Height / (float)context.Texture.Width ;
SetDataOptions setDataOptions = SetDataOptions.NoOverwrite;
//Use the SpriteBatch style of filling buffers
//http://blogs.msdn.com/b/shawnhar/archive/2010/07/07/setdataoptions-nooverwrite-versus-discard.aspx
if (_vertexBufferPosition + context.Count * VerticesPerParticle > NumVertices)
{
//Too much to fit in the remaining space - start at the beginning and discard
_vertexBufferPosition = 0;
setDataOptions = SetDataOptions.Discard;
}
#if UNSAFE
unsafe
{
fixed (ParticleVertex* vertexArray = Vertices)
{
ParticleVertex* verts = vertexArray +_vertexBufferPosition;
#else
int vertexIndex = _vertexBufferPosition;
#endif
var particle = iterator.First;
do
{
#if UNSAFE
Single scale = particle->Scale;
Vector3 position = particle->Position;
Vector3 rotation = particle->Rotation;
Vector4 colour = particle->Colour;
//Work out our world transform - and set a flag to avoid some multiplies if world ends up as zero
bool worldIsNotIdentity = true;
Matrix effectWorld;
if (context.WorldIsIdentity)
{
if (particle->EffectProxyIndex > 0)
{
effectWorld = ParticleEffectProxy.Proxies[particle->EffectProxyIndex].World;
}
else
{
worldIsNotIdentity = false;
effectWorld = Matrix.Identity; //Makes the compiler happy though we will never actually use it.
}
}
else
{
effectWorld = particle->EffectProxyIndex > 0 ? ParticleEffectProxy.Proxies[particle->EffectProxyIndex].FinalWorld : context.World;
}
#else
Single scale = particle.Scale;
Vector3 position = particle.Position;
Vector3 rotation = particle.Rotation;
Vector4 colour = particle.Colour;
//If we have a proxy then multiply in the proxy world matrix
bool worldIsNotIdentity = true;
Matrix effectWorld;
if (context.WorldIsIdentity)
{
if (particle.EffectProxyIndex > 0)
{
effectWorld = ParticleEffectProxy.Proxies[particle.EffectProxyIndex].World;
}
else
{
worldIsNotIdentity = false;
effectWorld = Matrix.Identity;
//Makes the compiler happy though we will never actually use it.
}
}
else
{
effectWorld = particle.EffectProxyIndex > 0
? ParticleEffectProxy.Proxies[particle.EffectProxyIndex].FinalWorld
: context.World;
}
#endif
//Individual particle transformations - scale and rotation
//The Rotation setup will fill in the top 3x3 so we just need to initialise 44
var transform = new Matrix {M44 = 1};
float scaleX = scale;
float scaleY = squareTexture ? scale : scale * aspectRatio;
//ScaleZ is always 1 so no need multiple into M_3
//Inline the rotation and scale calculations and do each element in one go
//Fast rotation matrix - see http://en.wikipedia.org/wiki/Rotation_matrix#General_rotations
//This set matches
//Matrix temp2 = Matrix.CreateRotationX(rotation.X) * Matrix.CreateRotationY(rotation.Y) * Matrix.CreateRotationZ(rotation.Z); //Matches math od Rotx*RotY*RotZ
//var cosX = (float) Math.Cos(rotation.X);
//var cosY = (float) Math.Cos(rotation.Y);
//var cosZ = (float) Math.Cos(rotation.Z);
//var sinX = (float) Math.Sin(rotation.X);
//var sinY = (float) Math.Sin(rotation.Y);
//var sinZ = (float) Math.Sin(rotation.Z);
//transform.M11 = cosY*cosZ;
//transform.M12 = cosY * sinZ;
//transform.M13 = -sinY;
//transform.M21 = sinX*sinY*cosZ - cosX * sinZ;
//transform.M22 = sinX*sinY*sinZ + cosX*cosZ;
//transform.M23 = sinX*cosY;
//transform.M31 = cosX*sinY*cosZ + sinX * sinZ;
//transform.M32 = cosX*sinY*sinZ - sinX * cosZ;
//transform.M33 = cosX * cosY;
//This set matches
//Matrix temp2 = Matrix.CreateScale(new VEctor3(scaleX, scaleY,1) * Matrix.CreateRotationZ(rotation.Z) * Matrix.CreateRotationX(rotation.Y) * Matrix.CreateRotationY(rotation.X) ; //Matches YawPitchRoll order
//Matrix temp = Matrix.CreateScale(new VEctor3(scaleX, scaleY,1) * Matrix.CreateFromYawPitchRoll(rotation.X, rotation.Y, rotation.Z);
//TODO - can we optimise out a rotation e.g.fast path if rotation.Y=0 etc
//TODO - can we optimise out rotation(s) if we know its a billboard? That overwrites much of the transform
var cosX = (float)Math.Cos(rotation.Y);
var cosY = (float)Math.Cos(rotation.X);
var cosZ = (float)Math.Cos(rotation.Z);
var sinX = (float)Math.Sin(rotation.Y);
var sinY = (float)Math.Sin(rotation.X);
var sinZ = (float)Math.Sin(rotation.Z);
var cosYcosZ = cosY*cosZ;
var cosYsinZ = cosY*sinZ;
var sinXsinY = sinX*sinY;
transform.M11 = (cosYcosZ + sinXsinY * sinZ) * scaleX;
transform.M12 = (cosX * sinZ) * scaleX;
transform.M13 = (sinX * cosYsinZ - sinY * cosZ) * scaleX;
transform.M21 = (sinXsinY * cosZ - cosYsinZ) * scaleY;
transform.M22 = (cosX * cosZ) *scaleY;
transform.M23 = (sinY * sinZ + sinX * cosYcosZ) * scaleY;
transform.M31 = cosX * sinY;
transform.M32 = -sinX;
transform.M33 = cosX * cosY;
switch (context.BillboardStyle)
{
case BillboardStyle.None:
//Position the particle without a multiplication!
transform.M41 = position.X;
transform.M42 = position.Y;
transform.M43 = position.Z;
//Just apply the world
//TODO - we can just do this in Basic effect instead of per vertex - only if there is no proxy, sort of a fast path!
if (worldIsNotIdentity)
{
Matrix.Multiply(ref transform, ref effectWorld, out transform);
}
break;
default: //Its billboarded
Vector3 worldPos;
if (worldIsNotIdentity)
{
Vector3.Transform(ref position, ref effectWorld, out worldPos);
}
else
{
worldPos = position;
}
//Apply the billboard (which includes the world translation)
Matrix billboardMatrix;
if (context.BillboardStyle == BillboardStyle.Spherical)
{
//Spherical billboards (always face the camera)
Matrix.CreateBillboard(ref worldPos, ref cameraPos, ref Up, Forward,
out billboardMatrix);
}
else
{
//HACK: For progenitor DBP use the velocity as the axis for a per particle axis
if (context.UseVelocityAsBillboardAxis)
{
#if UNSAFE
Matrix.CreateConstrainedBillboard(ref worldPos, ref cameraPos, ref particle->Velocity,
Forward, null, out billboardMatrix);
#else
Matrix.CreateConstrainedBillboard(ref worldPos, ref cameraPos, ref particle.Velocity,
Forward, null, out billboardMatrix);
#endif
}
else
{
//Cylindrical billboards have a vector they are allowed to rotate around
Matrix.CreateConstrainedBillboard(ref worldPos, ref cameraPos, ref rotationAxis,
Forward, null, out billboardMatrix);
}
}
Matrix.Multiply(ref transform, ref billboardMatrix, out transform);
break;
}
Vector3 v1;
Vector3 v2;
Vector3 v3;
Vector3 v4;
Vector3.Transform(ref inv1, ref transform, out v1);
Vector3.Transform(ref inv2, ref transform, out v2);
Vector3.Transform(ref inv3, ref transform, out v3);
Vector3.Transform(ref inv4, ref transform, out v4);
#if UNSAFE
//inline particle value assignments - removes 4 calls with their parameters and its a struct anyway
verts->Position.X = v1.X;
verts->Position.Y = v1.Y;
verts->Position.Z = v1.Z;
verts->Colour.X = colour.X;
verts->Colour.Y = colour.Y;
verts->Colour.Z = colour.Z;
verts->Colour.W = colour.W;
verts++;
verts->Position.X = v2.X;
verts->Position.Y = v2.Y;
verts->Position.Z = v2.Z;
verts->Colour.X = colour.X;
verts->Colour.Y = colour.Y;
verts->Colour.Z = colour.Z;
verts->Colour.W = colour.W;
verts++;
verts->Position.X = v3.X;
verts->Position.Y = v3.Y;
verts->Position.Z = v3.Z;
verts->Colour.X = colour.X;
verts->Colour.Y = colour.Y;
verts->Colour.Z = colour.Z;
verts->Colour.W = colour.W;
verts++;
verts->Position.X = v4.X;
verts->Position.Y = v4.Y;
verts->Position.Z = v4.Z;
verts->Colour.X = colour.X;
verts->Colour.Y = colour.Y;
verts->Colour.Z = colour.Z;
verts->Colour.W = colour.W;
verts++;
#else
//inline particle value assignments - removes 4 calls with their parameters and its a struct anyway
this.Vertices[vertexIndex].Position = v1;
this.Vertices[vertexIndex].Colour = colour;
this.Vertices[vertexIndex++].TextureCoordinate = uv1;
this.Vertices[vertexIndex].Position = v2;
this.Vertices[vertexIndex].Colour = colour;
this.Vertices[vertexIndex++].TextureCoordinate = uv2;
this.Vertices[vertexIndex].Position = v3;
this.Vertices[vertexIndex].Colour = colour;
this.Vertices[vertexIndex++].TextureCoordinate = uv3;
this.Vertices[vertexIndex].Position = v4;
this.Vertices[vertexIndex].Colour = colour;
this.Vertices[vertexIndex++].TextureCoordinate = uv4;
#endif
vertexCount += 4;
}
#if UNSAFE
while (iterator.MoveNext(&particle));
#else
while (iterator.MoveNext(ref particle));
#endif
base.GraphicsDeviceService.GraphicsDevice.BlendState = context.BlendState;
this.BasicEffect.Texture = context.Texture;
//Xbox need the vertex buffer to be set to null before SetData is called
//Windows does not
//TODO: Is this a bug? see http://forums.create.msdn.com/forums/p/61885/399495.aspx#399495
#if XBOX
if (setDataOptions == SetDataOptions.Discard)
{
base.GraphicsDeviceService.GraphicsDevice.SetVertexBuffer(null);
}
#endif
_vertexBuffer.SetData(_vertexBufferPosition * ParticleVertex.Size, Vertices, _vertexBufferPosition, vertexCount, ParticleVertex.Size, setDataOptions);
Debug.WriteLine(String.Format("position: {0} Count: {1} Hint: {2}", _vertexBufferPosition, vertexCount, setDataOptions));
base.GraphicsDeviceService.GraphicsDevice.SetVertexBuffer(_vertexBuffer);
foreach (EffectPass pass in this.BasicEffect.CurrentTechnique.Passes)
{
pass.Apply();
base.GraphicsDeviceService.GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, _vertexBufferPosition, vertexCount,
_vertexBufferPosition/4*6, vertexCount/2);
}
//Move to the next free part of the array
_vertexBufferPosition += vertexCount;
#if UNSAFE
}
}
#endif
}
