/// <summary>
/// we do not store input linearGradient
/// </summary>
/// <param name="linearGradient"></param>
static void Build(Drawing.PolygonGradientBrush linearGradient,
PixelFarm.CpuBlit.VertexProcessing.TessTool tess,
out float[] v2f,
out float[] colors)
{
//reverse user input order
List <Drawing.PolygonGradientBrush.ColorVertex2d> vertices = linearGradient.Vertices;
s_v2fList.Clear();
s_colorList.Clear();
int j = vertices.Count;
for (int m = 0; m < j; ++m)
{
Drawing.PolygonGradientBrush.ColorVertex2d v = vertices[m];
s_v2fList.Add(v.X);
s_v2fList.Add(v.Y);
}
ushort[] indexList = PixelFarm.CpuBlit.VertexProcessing.TessToolExtensions.TessAsTriIndexArray(
tess, s_v2fList.ToArray(), null,
out float[] tessCoords,
out int vertexCount
);
int n1 = 0;
int n2 = 0;
float[] colors2 = new float[indexList.Length * 4];
float[] tessCoord2 = new float[indexList.Length * 2];
for (int i = 0; i < indexList.Length; ++i)
{
ushort index = indexList[i];
Drawing.PolygonGradientBrush.ColorVertex2d v = vertices[index];
Color color = v.C;
//a,b,g,r
colors2[n1] = (color.B / 255f); //r
colors2[n1 + 1] = (color.G / 255f); //g
colors2[n1 + 2] = (color.R / 255f); //b
colors2[n1 + 3] = (color.A / 255f); //a
tessCoord2[n2] = v.X;
tessCoord2[n2 + 1] = v.Y;
n1 += 4;
n2 += 2;
}
v2f = tessCoord2;
colors = colors2;
}
public static PolygonGradientBrush Resolve(Drawing.PolygonGradientBrush polygonGr, PixelFarm.CpuBlit.VertexProcessing.TessTool tess)
{
if (!(polygonGr.InnerBrush is PolygonGradientBrush glGradient))
{
//create a new one
Build(polygonGr, tess, out float[] v2f, out float[] colors);
glGradient = new PolygonGradientBrush(v2f, colors);
polygonGr.InnerBrush = glGradient;
}
return(glGradient);
}
