mirror of
https://codeberg.org/dnkl/foot.git
synced 2026-02-04 04:06:06 -05:00
70 lines
2.2 KiB
Python
Executable file
70 lines
2.2 KiB
Python
Executable file
#!/usr/bin/env python3
|
|
|
|
import argparse
|
|
import math
|
|
|
|
|
|
# Note: we use a pure gamma 2.2 function, rather than the piece-wise
|
|
# sRGB transfer function, since that is what all compositors do.
|
|
|
|
def srgb_to_linear(f: float) -> float:
|
|
assert(f >= 0 and f <= 1.0)
|
|
return math.pow(f, 2.2)
|
|
|
|
|
|
def linear_to_srgb(f: float) -> float:
|
|
return math.pow(f, 1 / 2.2)
|
|
|
|
|
|
def main() -> None:
|
|
parser = argparse.ArgumentParser()
|
|
parser.add_argument('c_output', type=argparse.FileType('w'))
|
|
parser.add_argument('h_output', type=argparse.FileType('w'))
|
|
opts = parser.parse_args()
|
|
|
|
linear_table: list[int] = []
|
|
|
|
for i in range(256):
|
|
linear_table.append(int(srgb_to_linear(float(i) / 255) * 65535 + 0.5))
|
|
|
|
|
|
opts.h_output.write("#pragma once\n")
|
|
opts.h_output.write("#include <stdint.h>\n")
|
|
opts.h_output.write("\n")
|
|
opts.h_output.write('/* 8-bit input, 16-bit output */\n')
|
|
opts.h_output.write("extern const uint16_t srgb_decode_8_to_16_table[256];")
|
|
|
|
opts.h_output.write('\n')
|
|
opts.h_output.write('static inline uint16_t\n')
|
|
opts.h_output.write('srgb_decode_8_to_16(uint8_t v)\n')
|
|
opts.h_output.write('{\n')
|
|
opts.h_output.write(' return srgb_decode_8_to_16_table[v];\n')
|
|
opts.h_output.write('}\n')
|
|
|
|
opts.h_output.write('\n')
|
|
opts.h_output.write('/* 8-bit input, 8-bit output */\n')
|
|
opts.h_output.write("extern const uint8_t srgb_decode_8_to_8_table[256];\n")
|
|
|
|
opts.h_output.write('\n')
|
|
opts.h_output.write('static inline uint8_t\n')
|
|
opts.h_output.write('srgb_decode_8_to_8(uint8_t v)\n')
|
|
opts.h_output.write('{\n')
|
|
opts.h_output.write(' return srgb_decode_8_to_8_table[v];\n')
|
|
opts.h_output.write('}\n')
|
|
|
|
opts.c_output.write('#include "srgb.h"\n')
|
|
opts.c_output.write('\n')
|
|
|
|
opts.c_output.write("const uint16_t srgb_decode_8_to_16_table[256] = {\n")
|
|
for i in range(256):
|
|
opts.c_output.write(f' {linear_table[i]},\n')
|
|
opts.c_output.write('};\n')
|
|
|
|
opts.c_output.write("const uint8_t srgb_decode_8_to_8_table[256] = {\n")
|
|
for i in range(256):
|
|
opts.c_output.write(f' {linear_table[i] >> 8},\n')
|
|
opts.c_output.write('};\n')
|
|
|
|
|
|
if __name__ == '__main__':
|
|
main()
|