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util: Use bitshift arithmetic to unpack pixels.

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All test cases pass now.
This commit is contained in:
José Fonseca 2010-03-06 14:22:56 +00:00
parent b999e9c03d
commit 45ae4434b5
1 changed files with 92 additions and 23 deletions
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115
src/gallium/auxiliary/util/u_format_pack.py
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@ -304,6 +304,8 @@ def conversion_expr(src_channel, dst_channel, dst_native_type, value, clamp=True
def generate_format_unpack(format, dst_channel, dst_native_type, dst_suffix):
'''Generate the function to unpack pixels from a particular format'''
assert format.layout == PLAIN
name = format.short_name()
src_native_type = native_type(format)
@ -311,32 +313,99 @@ def generate_format_unpack(format, dst_channel, dst_native_type, dst_suffix):
print 'static INLINE void'
print 'util_format_%s_unpack_%s(%s *dst, const void *src)' % (name, dst_suffix, dst_native_type)
print '{'
print ' union util_format_%s pixel;' % format.short_name()
print ' memcpy(&pixel, src, sizeof pixel);'
bswap_format(format)
if format.is_bitmask():
depth = format.block_size()
print ' uint%u_t value = *(uint%u_t *)src;' % (depth, depth)
assert format.layout == PLAIN
# Declare the intermediate variables
for i in range(format.nr_channels()):
src_channel = format.channels[i]
if src_channel.type == UNSIGNED:
print ' uint%u_t %s;' % (depth, src_channel.name)
elif src_channel.type == SIGNED:
print ' int%u_t %s;' % (depth, src_channel.name)
for i in range(4):
swizzle = format.swizzles[i]
if swizzle < 4:
src_channel = format.channels[swizzle]
value = 'pixel.chan.%s' % src_channel.name
value = conversion_expr(src_channel, dst_channel, dst_native_type, value)
elif swizzle == SWIZZLE_0:
value = '0'
elif swizzle == SWIZZLE_1:
value = get_one(dst_channel)
elif swizzle == SWIZZLE_NONE:
value = '0'
else:
assert False
if format.colorspace == ZS:
if i == 3:
print '#ifdef PIPE_ARCH_BIG_ENDIAN'
print ' value = util_bswap%u(value);' % depth
print '#endif'
# Compute the intermediate unshifted values
shift = 0
for i in range(format.nr_channels()):
src_channel = format.channels[i]
value = 'value'
if src_channel.type == UNSIGNED:
if shift:
value = '%s >> %u' % (value, shift)
if shift + src_channel.size < depth:
value = '(%s) & 0x%x' % (value, (1 << src_channel.size) - 1)
elif src_channel.type == SIGNED:
if shift + src_channel.size < depth:
# Align the sign bit
lshift = depth - (shift + src_channel.size)
value = '%s << %u' % (value, lshift)
# Cast to signed
value = '(int%u_t)(%s) ' % (depth, value)
if src_channel.size < depth:
# Align the LSB bit
rshift = depth - src_channel.size
value = '(%s) >> %u' % (value, rshift)
else:
value = None
if value is not None:
print ' %s = %s;' % (src_channel.name, value)
shift += src_channel.size
# Convert, swizzle, and store final values
for i in range(4):
swizzle = format.swizzles[i]
if swizzle < 4:
src_channel = format.channels[swizzle]
value = src_channel.name
value = conversion_expr(src_channel, dst_channel, dst_native_type, value)
elif swizzle == SWIZZLE_0:
value = '0'
elif swizzle == SWIZZLE_1:
value = get_one(dst_channel)
elif i >= 1:
value = 'dst[0]'
print ' dst[%u] = %s; /* %s */' % (i, value, 'rgba'[i])
elif swizzle == SWIZZLE_NONE:
value = '0'
else:
assert False
if format.colorspace == ZS:
if i == 3:
value = get_one(dst_channel)
elif i >= 1:
value = 'dst[0]'
print ' dst[%u] = %s; /* %s */' % (i, value, 'rgba'[i])
else:
print ' union util_format_%s pixel;' % format.short_name()
print ' memcpy(&pixel, src, sizeof pixel);'
bswap_format(format)
for i in range(4):
swizzle = format.swizzles[i]
if swizzle < 4:
src_channel = format.channels[swizzle]
value = 'pixel.chan.%s' % src_channel.name
value = conversion_expr(src_channel, dst_channel, dst_native_type, value)
elif swizzle == SWIZZLE_0:
value = '0'
elif swizzle == SWIZZLE_1:
value = get_one(dst_channel)
elif swizzle == SWIZZLE_NONE:
value = '0'
else:
assert False
if format.colorspace == ZS:
if i == 3:
value = get_one(dst_channel)
elif i >= 1:
value = 'dst[0]'
print ' dst[%u] = %s; /* %s */' % (i, value, 'rgba'[i])
print '}'
print