/// <summary>
/// Build the vertex buffer from particle data
/// Should come before <see cref="KickVertexBuffer"/>
/// </summary>
/// <param name="device">The graphics device, used to rebuild vertex layouts and shaders if needed</param>
/// <param name="invViewMatrix">The current camera's inverse view matrix</param>
public void BuildVertexBuffer(CommandList commandList, ref Matrix invViewMatrix)
{
// Get camera-space X and Y axes for billboard expansion and sort the particles if needed
var unitX = new Vector3(invViewMatrix.M11, invViewMatrix.M12, invViewMatrix.M13);
var unitY = new Vector3(invViewMatrix.M21, invViewMatrix.M22, invViewMatrix.M23);
depthSortVector = Vector3.Cross(unitX, unitY);
ParticleSorter.Sort();
// If the particles are in world space they don't need to be fixed as their coordinates are already in world space
// If the particles are in local space they need to be drawn in world space using the emitter's current location matrix
var posIdentity = new Vector3(0, 0, 0);
var rotIdentity = new Quaternion(0, 0, 0, 1);
var scaleIdentity = 1f;
if (simulationSpace == EmitterSimulationSpace.Local)
{
posIdentity = drawPosition;
rotIdentity = drawRotation;
scaleIdentity = drawScale;
}
VertexBuilder.MapBuffer(commandList);
ShapeBuilder.BuildVertexBuffer(VertexBuilder, unitX, unitY, ref posIdentity, ref rotIdentity, scaleIdentity, ParticleSorter);
VertexBuilder.RestartBuffer();
ShapeBuilder.SetRequiredQuads(ShapeBuilder.QuadsPerParticle, pool.LivingParticles, pool.ParticleCapacity);
Material.PatchVertexBuffer(VertexBuilder, unitX, unitY, ParticleSorter);
VertexBuilder.UnmapBuffer(commandList);
}