Switch from 32-bit floats to 16-bit half-floats.

Massive bandwidth savings, or so I'm told. Yay?

1 files changed, 29 insertions, 2 deletions

diff --git a/src/bicubic_table.py b/src/bicubic_table.py
index 3657cbc9..232ccb70 100755
--- a/src/bicubic_table.py
+++ b/src/bicubic_table.py
@@ -2,6 +2,32 @@
 
 import struct
 
+def half(i):
+ fs, fe, fm = ((i >> 31) & 0x1, (i >> 23) & 0xff, i & 0x7fffff)
+ s, e, m = (fs, 0, 0)
+
+ if (fe == 0x0):
+  pass
+ if ((fe == 0xff) and (fm == 0x0)):
+  e = 31
+ elif (fe == 0xff):
+  m = 1
+  e = 31
+ else:
+  exp = fe - 127;
+  if (exp < -24):
+   pass
+  elif (exp < -14):
+   temp = 10 - (-14 - exp)
+   m = 2**temp + (m >> (23 - temp))
+  elif (exp > 15):
+   e = 31
+  else:
+   e = exp + 15
+   m = fm >> 13
+
+ return ((s << 15) | (e << 10) | m)
+
 def texgen(pix):
 
  tex = []
@@ -26,14 +52,15 @@ def texgen(pix):
 
 def printrow(l, offset):
 
- seq = [ hex(struct.unpack('<I',struct.pack('f',i))[0]) for i in l[offset:offset+4] ]
+ seq = [ struct.unpack('<I',struct.pack('f',i))[0] for i in l[offset:offset+4] ]
+ seq = [ hex(half(i)) for i in seq ]
  return "\t" + ", ".join(seq) + ","
 
 def maketable(pix):
 
  l = texgen(pix)
 
- print "static const uint32_t bicubic_tex_" + str(pix) + "[] = {"
+ print "static const uint16_t bicubic_tex_" + str(pix) + "[] = {"
 
  for i in range(0, pix, 4):