public static TextureShapeType GetTextureShapeType(Vector2[] texCoords, bool isForTriangle)
{
bool isClockwise = !(MathC.CalculateArea(texCoords) > 0.0f);
if (isForTriangle)
{
Vector2 midPoint = (texCoords[0] + texCoords[1] + texCoords[2]) * (1.0f / 3.0f);
// Determine closest edge to the mid
float distance0 = (texCoords[0] - midPoint).LengthSquared();
float distance1 = (texCoords[1] - midPoint).LengthSquared();
float distance2 = (texCoords[2] - midPoint).LengthSquared();
byte closeEdgeIndex = 0;
if (distance1 < Math.Min(distance0, distance2))
{
closeEdgeIndex = 1;
}
if (distance2 < Math.Min(distance0, distance1))
{
closeEdgeIndex = 2;
}
// Determine case
Vector2 toClosestEdge = texCoords[closeEdgeIndex] - midPoint;
if (toClosestEdge.X < 0)
{
if (toClosestEdge.Y < 0)
{ // Negative X, Negative Y
// +---+
// | /
// | /
// |/
// +
if (isClockwise)
{
return((TextureShapeType)0); //static constexpr Diverse::Vec<2, float> Triangle0[3] = { { 0.5f, 0.5f }, { -0.5f, 0.5f }, { 0.5f, -0.5f } };
}
else
{
return((TextureShapeType)5); //static constexpr Diverse::Vec<2, float> Triangle5[3] = { { 0.5f, 0.5f }, { 0.5f, -0.5f }, { -0.5f, 0.5f } };
}
}
else
{ // Negative X, Postive Y
// +
// |\
// | \
// | \
// +---+
if (isClockwise)
{
return((TextureShapeType)3); //static constexpr Diverse::Vec<2, float> Triangle3[3] = { { 0.5f, -0.5f }, { 0.5f, 0.5f }, { -0.5f, -0.5f } };
}
else
{
return((TextureShapeType)6); //static constexpr Diverse::Vec<2, float> Triangle6[3] = { { 0.5f, -0.5f }, { -0.5f, -0.5f }, { 0.5f, 0.5f } };
}
}
}
else
if (toClosestEdge.Y < 0)
{ // Postive X, Negative Y
// +---+
// \ |
// \ |
// \|
// +
if (isClockwise)
{
return((TextureShapeType)1); //static constexpr Diverse::Vec<2, float> Triangle1[3] = { { -0.5f, 0.5f }, { -0.5f, -0.5f }, { 0.5f, 0.5f } };
}
else
{
return((TextureShapeType)4); //static constexpr Diverse::Vec<2, float> Triangle4[3] = { { -0.5f, 0.5f }, { 0.5f, 0.5f }, { -0.5f, -0.5f } };
}
}
else
{ // Postive X, Postive Y
// +
// /|
// / |
// / |
// +---+
if (isClockwise)
{
return((TextureShapeType)2); //static constexpr Diverse::Vec<2, float> Triangle2[3] = { { -0.5f, -0.5f }, { 0.5f, -0.5f }, { -0.5f, 0.5f } };
}
else
{
return((TextureShapeType)7); //static constexpr Diverse::Vec<2, float> Triangle7[3] = { { -0.5f, -0.5f }, { -0.5f, 0.5f }, { 0.5f, -0.5f } };
}
}
}
else if (!isClockwise)
{
return((TextureShapeType)1);
}
else
{
return((TextureShapeType)0);
}
}