static public VFXExpression SafeNormalize(VFXExpression v)
{
var sqrDist = Dot(v, v);
var condition = new VFXExpressionCondition(VFXValueType.Float, VFXCondition.Less, sqrDist, VFXOperatorUtility.EpsilonSqrExpression[VFXValueType.Float]);
return(new VFXExpressionBranch(condition, VFXOperatorUtility.ZeroExpression[v.valueType], Normalize(v)));
}
static public VFXExpression ApplyAddressingMode(VFXExpression index, VFXExpression count, SequentialAddressingMode mode)
{
VFXExpression r = null;
if (mode == SequentialAddressingMode.Wrap)
{
r = Modulo(index, count);
}
else if (mode == SequentialAddressingMode.Clamp)
{
var countMinusOne = count - OneExpression[VFXValueType.Uint32];
r = new VFXExpressionMin(index, countMinusOne);
}
else if (mode == SequentialAddressingMode.Mirror)
{
var two = TwoExpression[VFXValueType.Uint32];
var cycle = count * two - two;
cycle = new VFXExpressionMax(cycle, OneExpression[VFXValueType.Uint32]);
var modulo = Modulo(index, cycle);
//var compare = new VFXExpressionCondition(VFXCondition.Less, new VFXExpressionCastUintToFloat(modulo), new VFXExpressionCastUintToFloat(count)); <= Use this line for 7.x.x/8.x.x/9.x.x backport
var compare = new VFXExpressionCondition(VFXValueType.Uint32, VFXCondition.Less, modulo, count);
r = new VFXExpressionBranch(compare, modulo, cycle - modulo);
}
return(r);
}
static public VFXExpression IsTRSMatrixZeroScaled(VFXExpression matrix)
{
var i = new VFXExpressionMatrixToVector3s(matrix, VFXValue.Constant(0));
var j = new VFXExpressionMatrixToVector3s(matrix, VFXValue.Constant(1));
var k = new VFXExpressionMatrixToVector3s(matrix, VFXValue.Constant(2));
var sqrLengthI = Dot(i, i);
var sqrLengthJ = Dot(j, j);
var sqrLengthK = Dot(k, k);
var epsilon = EpsilonSqrExpression[VFXValueType.Float];
var compareI = new VFXExpressionCondition(VFXValueType.Float, VFXCondition.Less, sqrLengthI, epsilon);
var compareJ = new VFXExpressionCondition(VFXValueType.Float, VFXCondition.Less, sqrLengthJ, epsilon);
var compareK = new VFXExpressionCondition(VFXValueType.Float, VFXCondition.Less, sqrLengthK, epsilon);
var condition = new VFXExpressionLogicalOr(compareI, new VFXExpressionLogicalOr(compareJ, compareK));
return(condition);
}