surf:fillTriangle

surf:drawTriangle(x1, y1, x2, y2, x3, y3[, b, t, c])

• x1, y1 (float)
  First point
• x2, y2 (float)
  Second point
• x3, y3 (float)
  Third point
• b, t, c (colour)
  Drawing colour

Draws a filled triangle.
Note that this has support for non-integer coordinates, and uses the midpoint of a pixel (+0.5, +0.5) to determine whether or not it is in the triangle.