#!/usr/bin/env python3

# dual-row, TSSOP-, SOIC-, SO-style packages with ground plane
# version 0.0.5-ti_oval

# using diagram on page 28 of http://www.ti.com/lit/ds/symlink/tps61200.pdf

# added solder mask parameter
# added optional indicator circle
# added ground pad
# made ground pad optional
# fix silkscreen pin 1 marker
# added rounded pads option
# added reference designator to fab layer
# make fab layer pin drawing optional
# added TI's weird ground pad extensions
# v0.0.5
# added indicator marker to fab layer

PARTNAME = "Analog-DFN8-EP"

total_pins = 8
num_per_edge = total_pins // 2

M1 = 0.2 # silkscreen margin
M2 = 0.05 # fab outline margin
M3 = 0.2 # courtyard margin

Z = 3.55 # distance across outer edges of pads
G = 2.10 # distance across inner edges of pads

X = (Z+G)/2. # distance between pad centers
C = 0.5 # footprint pad spacing
w = 0.30 # footprint pad width
h = (Z-G)/2. # footprint pad length

show_fab_pads = False
H = 3.00 # distance from physical pad end to opposite pad end
e = C    # physical pad spacing, same as above
b = 0.25 # physical pad width
L1 = -0.38 # physical pad length

D1 = 3.0 # package width
E1 = 3.0 # package height

has_ground_pad = True
G1 = 1.70  # ground pad width
H1 = 2.43  # ground pad height
ground_pad_num = 0

# NOTE: need to test with SMD footprints
# need to make sure pad size adjustment works
# nsmd = positive
solder_mask_margin = 0.05
indicator_circle_dia = 0.3

pad_radius = None

add_ti_ground_extensions = False
ti_gnd_ext_spacing = 0.5
ti_gnd_ext_len = (3.4 - 2.4)/2
ti_gnd_ext_width = 0.25

if solder_mask_margin < 0.0:
  w -= 2.0*solder_mask_margin
  h -= 2.0*solder_mask_margin
  G1 -= 2.0*solder_mask_margin
  H1 -= 2.0*solder_mask_margin

import math

import time
gen_time = hex(int(time.time()))[2:].upper()


prologue = """(module {} (layer F.Cu) (tedit {})
  (fp_text reference REF** (at 0.0 0.0) (layer F.SilkS)
    (effects (font (size 1 1) (thickness 0.15)))
  )
  (fp_text user %R (at 0.0 0.0) (layer F.Fab)
    (effects (font (size 1 1) (thickness 0.15)))
  )
  (fp_text value %V (at 0 -0.5) (layer F.Fab) hide
    (effects (font (size 1 1) (thickness 0.15)))
  )
"""

prologue = prologue.format(PARTNAME, gen_time, PARTNAME)
epilogue = """)"""

print(prologue)

# print silkscreen outline
inner_edge = C*(num_per_edge/2 - 0.5) + w/2 + M1
x = D1/2 + M1
y = E1/2 + M1
for x, y, nx, ny in [
    (-x, -inner_edge, -x+(y-inner_edge), -y),
    (-x+(y-inner_edge), -y, x, -y), (x, -y, x, -inner_edge),

    (x, inner_edge, x, y), (x, y, -x, y),
    (-x, y, -x, inner_edge)]:
  print("""  (fp_line (start {} {}) (end {} {}) (layer F.SilkS) (width 0.15))""".
      format(x, y, nx, ny))

if indicator_circle_dia is not None:
  x = X/2
  y = E1/2 + M1 + 0.75*indicator_circle_dia
  # add indicator circle
  print("""  (fp_circle (center {} {}) (end {} {}) (layer F.SilkS) (width 0.15))""".
      format(-x, -y - indicator_circle_dia/2., -x, -y))


# draw package outline in fab layer
FC = 0.3
fab_points = [(-D1/2 - M2 + FC, -E1/2 - M2),
              (D1/2 + M2, -E1/2 - M2),
              (D1/2 + M2, E1/2 + M2),
              (-D1/2 + -M2, E1/2 + M2),
              (-D1/2 + -M2, -E1/2 - M2 + FC)]
 
nx, ny = fab_points[-1]
for x, y in fab_points:
  print("""  (fp_line (start {} {}) (end {} {}) (layer F.Fab) (width 0.15))""".
      format(x, y, nx, ny))
  nx, ny = x, y

if show_fab_pads:
  for i in range(num_per_edge):
    x_pos = -D1/2 - M2
    y_pos = C*(i-(num_per_edge/2-0.5))
    print("""  (fp_line (start {} {}) (end {} {}) (layer F.Fab) (width 0.15))""".
        format(x_pos, y_pos - b/2 - M2, x_pos - L1, y_pos - b/2 - M2))
    print("""  (fp_line (start {} {}) (end {} {}) (layer F.Fab) (width 0.15))""".
        format(x_pos - L1, y_pos - b/2 - M2, x_pos - L1, y_pos + b/2 + M2))
    print("""  (fp_line (start {} {}) (end {} {}) (layer F.Fab) (width 0.15))""".
        format(x_pos - L1, y_pos + b/2 + M2, x_pos, y_pos + b/2 + M2))

  for i in range(num_per_edge):
    x_pos = D1/2 + M2
    y_pos = -C*(i-(num_per_edge/2-0.5))
    print("""  (fp_line (start {} {}) (end {} {}) (layer F.Fab) (width 0.15))""".
        format(x_pos, y_pos + b/2 + M2, x_pos + L1, y_pos + b/2 + M2))
    print("""  (fp_line (start {} {}) (end {} {}) (layer F.Fab) (width 0.15))""".
        format(x_pos + L1, y_pos + b/2 + M2, x_pos + L1, y_pos - b/2 - M2))
    print("""  (fp_line (start {} {}) (end {} {}) (layer F.Fab) (width 0.15))""".
        format(x_pos + L1, y_pos - b/2 - M2, x_pos, y_pos - b/2 - M2))


# print courtyard outline
inner_x = D1/2 + M3
outer_x = X/2 + h/2 + M3/2
inner_y = C*(num_per_edge/2-0.5) + b/2 + M3/2
outer_y = E1/2 + M3
if L1 > 0:
  pts = [
      (-inner_x, -outer_y),
      (inner_x, -outer_y),
      (inner_x, -inner_y),
      (outer_x, -inner_y),
      (outer_x, inner_y),
      (inner_x, inner_y),
      (inner_x, outer_y),
      (-inner_x, outer_y),
      (-inner_x, inner_y),
      (-outer_x, inner_y),
      (-outer_x, -inner_y),
      (-inner_x, -inner_y)
      ]
else:
  pts = [
      (-outer_x, -outer_y),
      (-outer_x, outer_y),
      (outer_x, outer_y),
      (outer_x, -outer_y)
      ]
nx, ny = pts[-1]
for px, py in pts:
  x, y, nx, ny = nx, ny, px, py
  print("""  (fp_line (start {} {}) (end {} {}) (layer F.CrtYd) (width 0.15))""".
      format(x, y, nx, ny))


for i in range(0, num_per_edge):
  if pad_radius is None:
    print("""  (pad {} smd rect (at {} {}) (size {} {}) (layers F.Cu F.Paste F.Mask)
      (solder_mask_margin {}))""".
          format(
              i+1,
              -X/2,
              C*(i-(num_per_edge/2-0.5)),
              h,
              w,
              solder_mask_margin))
  else:
    print("""  (pad {} smd roundrect (at {} {}) (size {} {}) (layers F.Cu F.Paste F.Mask)
      (roundrect_rratio {}) (solder_mask_margin {}))""".
          format(
              i+1,
              -X/2,
              C*(i-(num_per_edge/2-0.5)),
              h,
              w,
              pad_radius/min(h, w),
              solder_mask_margin))

for i in range(0, num_per_edge):
  if pad_radius is None:
    print("""  (pad {} smd rect (at {} {}) (size {} {}) (layers F.Cu F.Paste F.Mask)
      (solder_mask_margin {}))""".
          format(
              i+1+1*num_per_edge,
              X/2,
              -C*(i-(num_per_edge/2-0.5)),
              h,
              w,
              solder_mask_margin))
  else:
    print("""  (pad {} smd roundrect (at {} {}) (size {} {}) (layers F.Cu F.Paste F.Mask)
      (roundrect_rratio {}) (solder_mask_margin {}))""".
          format(
              i+1+1*num_per_edge,
              X/2,
              -C*(i-(num_per_edge/2-0.5)),
              h,
              w,
              pad_radius/min(h, w),
              solder_mask_margin))

if has_ground_pad: 
  if pad_radius is None:
    # add ground pad
    print("""  (pad {} smd {} (at {} {}) (size {} {}) (layers F.Cu F.Paste F.Mask)
      (solder_mask_margin {}))""".
          format(
              ground_pad_num,
              "rect",
              0,
              0,
              G1,
              H1,
              solder_mask_margin))
  else:
    print("""  (pad {} smd {} (at {} {}) (size {} {}) (layers F.Cu F.Paste F.Mask)
      (roundrect_rratio {}) (solder_mask_margin {}))""".
          format(
              ground_pad_num,
              "roundrect",
              0,
              0,
              G1,
              H1,
              pad_radius/min(G1, H1),
              solder_mask_margin))

if add_ti_ground_extensions:
  for i in [-1, 1]:
    for j in [-1, 1]:
      print("""  (pad {} smd {} (at {} {}) (size {} {}) (layers F.Cu F.Paste F.Mask)
        (solder_mask_margin {}))""".
            format(
                ground_pad_num,
                "rect",
                i*ti_gnd_ext_spacing/2,
                j*(H1 + ti_gnd_ext_len)/2.,
                ti_gnd_ext_width,
                ti_gnd_ext_len,
                solder_mask_margin))

print(epilogue)