public void setShader()
{
if (!parameters.Directional)
{
shader.SetTechnique("Billboard");
}
else
{
shader.SetTechnique("DirectionalBillboard");
shader.Effect.GetVariableByName("startPosition").AsVector().Set(parameters.position);
}
shader.Effect.GetVariableByName("world").AsMatrix().SetMatrix(Matrix.Identity);
shader.Effect.GetVariableByName("viewProjection").AsMatrix().SetMatrix(Matrix.Identity);
shader.Effect.GetVariableByName("viewInverse").AsMatrix().SetMatrix(Matrix.Identity);
shader.Effect.GetVariableByName("txDiffuse").AsResource().SetResource(texturePool.LoadTexture(parameters.texture));
shader.Effect.GetVariableByName("size").AsScalar().Set(parameters.size);
//effect parameter
shader.Effect.GetVariableByName("timeTexture").AsResource().SetResource(timeTextureRSV);
shader.Effect.GetVariableByName("width").AsScalar().Set(parameters.particleWidth);
shader.Effect.GetVariableByName("height").AsScalar().Set(parameters.particleHeight);
shader.Effect.GetVariableByName("widthEnd").AsScalar().Set(parameters.particleWidthEnd);
shader.Effect.GetVariableByName("heightEnd").AsScalar().Set(parameters.particleHeightEnd);
shader.Effect.GetVariableByName("startColor").AsVector().Set(new Color4(StartColor.ToVector3() * parameters.darkScale));
shader.Effect.GetVariableByName("endColor").AsVector().Set(new Color4(EndColor.ToVector3() * parameters.darkScale));
shader.Effect.GetVariableByName("oneOverTotalLifeTime").AsScalar().Set(1 / (parameters.MaxLifeTime));
shader.Effect.GetVariableByName("uvStart").AsVector().Set(parameters.UvStart);
shader.Effect.GetVariableByName("uvSize").AsVector().Set(parameters.UvSize);
shader.Apply();
}