/// <summary>
/// Renders the scene
/// </summary>
public void Render()
{
// Set the render states for using point sprites
device.RenderState.ZBufferWriteEnable = false;
device.RenderState.AlphaBlendEnable = true;
device.RenderState.SourceBlend = Blend.One;
device.RenderState.DestinationBlend = Blend.One;
bool lightEnabled = device.RenderState.Lighting;
device.RenderState.Lighting = false;
device.SetTexture(0, particleTexture);
device.Transform.World = Matrix.Identity;
device.RenderState.PointSpriteEnable = true;
device.RenderState.PointScaleEnable = true;
device.RenderState.PointSize = 1.0f;
device.RenderState.PointScaleA = 0f;
device.RenderState.PointScaleB = 1.0f;
device.RenderState.PointScaleC = 1.0f;
// Set up the vertex buffer to be rendered
device.SetStreamSource(0, vertexBuffer, 0);
device.VertexFormat = PointVertex.Format;
PointVertex[] vertices = null;
int numParticlesToRender = 0;
// Lock the vertex buffer. We fill the vertex buffer in small
// chunks, using LockFlags.NoOverWrite. When we are done filling
// each chunk, we call DrawPrim, and lock the next chunk. When
// we run out of space in the vertex buffer, we start over at
// the beginning, using LockFlags.Discard.
baseParticle += flush;
if (baseParticle >= discard)
{
baseParticle = 0;
}
int count = 0;
vertices = (PointVertex[])vertexBuffer.Lock(baseParticle * DXHelp.GetTypeSize(typeof(PointVertex)), typeof(PointVertex), (baseParticle != 0) ? LockFlags.NoOverwrite : LockFlags.Discard, flush);
foreach (Particle p in particlesList)
{
Vector3 vPos = p.positionVector;
Vector3 vVel = p.velocityVector;
float fLengthSq = vVel.LengthSq();
uint steps;
if (fLengthSq < 1.0f)
{
steps = 2;
}
else if (fLengthSq < 4.00f)
{
steps = 3;
}
else if (fLengthSq < 9.00f)
{
steps = 4;
}
else if (fLengthSq < 12.25f)
{
steps = 5;
}
else if (fLengthSq < 16.00f)
{
steps = 6;
}
else if (fLengthSq < 20.25f)
{
steps = 7;
}
else
{
steps = 8;
}
vVel *= -0.01f / (float)steps;
System.Drawing.Color diffuse = ColorOperator.Lerp(p.fadeColor, p.diffuseColor, p.fadeProgression);
// Render each particle a bunch of times to get a blurring effect
for (int i = 0; i < steps; i++)
{
vertices[count].v = vPos;
vertices[count].color = diffuse.ToArgb();
count++;
if (++numParticlesToRender == flush)
{
// Done filling this chunk of the vertex buffer. Lets unlock and
// draw this portion so we can begin filling the next chunk.
vertexBuffer.Unlock();
device.DrawPrimitives(PrimitiveType.PointList, baseParticle, numParticlesToRender);
// Lock the next chunk of the vertex buffer. If we are at the
// end of the vertex buffer, LockFlags.Discard the vertex buffer and start
// at the beginning. Otherwise, specify LockFlags.NoOverWrite, so we can
// continue filling the VB while the previous chunk is drawing.
baseParticle += flush;
if (baseParticle >= discard)
{
baseParticle = 0;
}
vertices = (PointVertex[])vertexBuffer.Lock(baseParticle * DXHelp.GetTypeSize(typeof(PointVertex)), typeof(PointVertex), (baseParticle != 0) ? LockFlags.NoOverwrite : LockFlags.Discard, flush);
count = 0;
numParticlesToRender = 0;
}
vPos += vVel;
}
}
// Unlock the vertex buffer
vertexBuffer.Unlock();
// Render any remaining particles
if (numParticlesToRender > 0)
{
device.DrawPrimitives(PrimitiveType.PointList, baseParticle, numParticlesToRender);
}
// Reset render states
device.RenderState.PointSpriteEnable = false;
device.RenderState.PointScaleEnable = false;
device.RenderState.Lighting = lightEnabled;
device.RenderState.ZBufferWriteEnable = true;
device.RenderState.AlphaBlendEnable = false;
}
/// <summary>
/// Updates the scene
/// </summary>
public void Update(float fSecsPerFrame, int NumParticlesToEmit,
System.Drawing.Color clrEmitColor, System.Drawing.Color clrFadeColor, float fEmitVel, Vector3 vPosition)
{
time += fSecsPerFrame;
for (int ii = particlesList.Count - 1; ii >= 0; ii--)
{
Particle p = (Particle)particlesList[ii];
// Calculate new position
float fT = time - p.creationTime;
float fGravity;
if (p.isSpark)
{
fGravity = -5.0f;
p.fadeProgression -= (fSecsPerFrame * 2.25f);
}
else
{
fGravity = -9.8f;
p.fadeProgression -= fSecsPerFrame * 0.25f;
}
p.positionVector = p.initialVelocity * fT + p.initialPosition;
p.positionVector.Y += (0.5f * fGravity) * (fT * fT);
p.velocityVector.Y = p.initialVelocity.Y + fGravity * fT;
if (p.fadeProgression < 0.0f)
{
p.fadeProgression = 0.0f;
}
// Kill old particles
if (p.positionVector.Y < radius ||
p.isSpark && p.fadeProgression <= 0.0f)
{
// Emit sparks
if (!p.isSpark)
{
for (int i = 0; i < 4; i++)
{
Particle spark;
if (freeParticles.Count > 0)
{
spark = (Particle)freeParticles[0];
freeParticles.RemoveAt(0);
}
else
{
spark = new Particle();
}
spark.isSpark = true;
spark.initialVelocity = new Vector3();
spark.initialPosition = p.positionVector;
spark.initialPosition.Y = radius;
float fRand1 = ((float)rand.Next(int.MaxValue) / (float)int.MaxValue) * (float)Math.PI * 2.00f;
float fRand2 = ((float)rand.Next(int.MaxValue) / (float)int.MaxValue) * (float)Math.PI * 0.25f;
spark.initialVelocity.X = p.velocityVector.X * 0.25f + (float)Math.Cos(fRand1) * (float)Math.Sin(fRand2);
spark.initialVelocity.Z = p.velocityVector.Z * 0.25f + (float)Math.Sin(fRand1) * (float)Math.Sin(fRand2);
spark.initialVelocity.Y = (float)Math.Cos(fRand2);
spark.initialVelocity.Y *= ((float)rand.Next(int.MaxValue) / (float)int.MaxValue) * 1.5f;
spark.positionVector = spark.initialPosition;
spark.velocityVector = spark.initialVelocity;
spark.diffuseColor = ColorOperator.Lerp(p.fadeColor, p.diffuseColor, p.fadeProgression);
spark.fadeColor = System.Drawing.Color.Black;
spark.fadeProgression = 1.0f;
spark.creationTime = time;
particlesList.Add(spark);
}
}
// Kill particle
freeParticles.Add(p);
particlesList.RemoveAt(ii);
if (!p.isSpark)
{
particles--;
}
}
else
{
particlesList[ii] = p;
}
}
// Emit new particles
int particlesEmit = particles + NumParticlesToEmit;
while (particles < particlesLimit && particles < particlesEmit)
{
Particle particle;
if (freeParticles.Count > 0)
{
particle = (Particle)freeParticles[0];
freeParticles.RemoveAt(0);
}
else
{
particle = new Particle();
}
// Emit new particle
float fRand1 = ((float)rand.Next(int.MaxValue) / (float)int.MaxValue) * (float)Math.PI * 2.0f;
float fRand2 = ((float)rand.Next(int.MaxValue) / (float)int.MaxValue) * (float)Math.PI * 0.25f;
particle.isSpark = false;
particle.initialPosition = vPosition + new Vector3(0.0f, radius, 0.0f);
particle.initialVelocity.X = (float)Math.Cos(fRand1) * (float)Math.Sin(fRand2) * 2.5f;
particle.initialVelocity.Z = (float)Math.Sin(fRand1) * (float)Math.Sin(fRand2) * 2.5f;
particle.initialVelocity.Y = (float)Math.Cos(fRand2);
particle.initialVelocity.Y *= ((float)rand.Next(int.MaxValue) / (float)int.MaxValue) * fEmitVel;
particle.positionVector = particle.initialPosition;
particle.velocityVector = particle.initialVelocity;
particle.diffuseColor = clrEmitColor;
particle.fadeColor = clrFadeColor;
particle.fadeProgression = 1.0f;
particle.creationTime = time;
particlesList.Add(particle);
particles++;
}
}