drawQuadFast
fun drawQuadFast(x0: Float, y0: Float, x1: Float, y1: Float, x2: Float, y2: Float, x3: Float, y3: Float, tex: BmpCoords, colorMul: RGBA, texIndex: Int = currentTexIndex)
Draws/buffers a textured (tex) and colored colorMul quad with this shape:
0..1 | | 3..2
Vertices: 0: x0, y0 (top left) 1: x1, y1 (top right) 2: x2, y2 (bottom right) 3: x3, y3 (bottom left)