public bool SetElementValue(int index, Vector4 value)
{
if (index > elements.Count - 1 || index < 0)
{
return(false);
}
GradientElement el = elements[index];
el.value = value;
elements[index] = el;
return(true);
}
public Vector4 Sample(float position)
{
if (elements.Count == 0)
{
return(Vector4.Zero);
}
if (elements[0].position > position)
{
return(elements[0].value);
}
if (elements[elements.Count - 1].position < position)
{
return(elements[elements.Count - 1].value);
}
GradientElement firstElement = elements[0];
for (int i = 1; i < elements.Count; i++)
{
GradientElement secondElement = elements[i];
if (position == secondElement.position) // small check
{
return(secondElement.value);
}
if (firstElement.position < position && secondElement.position > position)
{
float sample = (position - firstElement.position) / (secondElement.position - firstElement.position);
return(Vector4.Lerp(firstElement.value, secondElement.value, sample));
}
firstElement = secondElement;
}
throw new Exception("unexpected end of sampling method!");
}
private void LoadGradientNode(string key, XmlNode node)
{
LinearGradientMode mode;
XmlAttribute attrMode = node.Attributes ["mode"];
switch (attrMode.Value)
{
case "vertical": mode = LinearGradientMode.Vertical; break;
case "horizontal": mode = LinearGradientMode.Horizontal; break;
case "forward-diagonal": mode = LinearGradientMode.ForwardDiagonal; break;
case "backward-diagonal": mode = LinearGradientMode.BackwardDiagonal; break;
default:
throw new Exception("Invalid or unspecified <gradient> mode");
}
XmlNode gradStartNode = node.SelectSingleNode("startcolor");
if (gradStartNode == null)
{
throw new Exception("Gradient <startcolor> not specified");
}
Color startColor = LoadColorFromNode(gradStartNode);
XmlNode gradEndNode = node.SelectSingleNode("endcolor");
if (gradEndNode == null)
{
throw new Exception("Gradient <endcolor> not specified");
}
Color endColor = LoadColorFromNode(gradEndNode);
float[] blendPositions = null;
float[] blendFactors = null;
XmlNodeList blendNodes = node.SelectNodes("blend");
if (blendNodes.Count > 0)
{
blendPositions = new float [blendNodes.Count + 2];
blendFactors = new float [blendNodes.Count + 2];
blendPositions [0] = 0.0f;
blendFactors [0] = 0.0f;
blendPositions [blendNodes.Count + 1] = 1.0f;
blendFactors [blendNodes.Count + 1] = 1.0f;
for (int i = 0; i < blendNodes.Count; i++)
{
XmlNode blendNode = blendNodes [i];
XmlAttribute attrPosition = blendNode.Attributes ["position"];
if (attrPosition == null)
{
throw new Exception("<blend> position not specified");
}
XmlAttribute attrFactor = blendNode.Attributes ["factor"];
if (attrFactor == null)
{
throw new Exception("<blend> factor not specified");
}
blendPositions [i + 1] = (float)Double.Parse(attrPosition.Value, CultureInfo.InvariantCulture);
blendFactors [i + 1] = (float)Double.Parse(attrFactor.Value, CultureInfo.InvariantCulture);
}
}
_schemeElements [key] = new GradientElement(startColor, endColor, mode,
blendPositions, blendFactors);
}
