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 $usage = "Usage: combine.pl { 8 | 16 } < pixman-combine.c.template";

 $#ARGV == 0 or die $usage;

 # Get the component size.

 $size = int($ARGV[0]);

 $size == 8 or $size == 16 or die $usage;

 $pixel_size = $size * 4;

 $half_pixel_size = $size * 2;

 sub mask {

     my $str = shift;

     my $suffix;

     $suffix = "ULL" if $size > 8;

     return "0x" . $str . $suffix;

 }

 # Generate mask strings.

 $nibbles = $size / 4;

 $mask = "f" x $nibbles;

 $zero_mask = "0" x $nibbles;

 $one_half = "8" . "0" x ($nibbles - 1);

 print "/* WARNING: This file is generated by combine.pl from combine.inc.\n";

 print "   Please edit one of those files rather than this one. */\n";

 print "\n";

 print "#line 1 \"pixman-combine.c.template\"\n";

 $mask_ = mask($mask);

 $one_half_ = mask($one_half);

 $g_mask = mask($mask . $zero_mask);

 $b_mask = mask($mask . $zero_mask x 2);

 $a_mask = mask($mask . $zero_mask x 3);

 $rb_mask = mask($mask . $zero_mask . $mask);

 $ag_mask = mask($mask . $zero_mask . $mask . $zero_mask);

 $rb_one_half = mask($one_half . $zero_mask . $one_half);

 $rb_mask_plus_one = mask("1" . $zero_mask x 2 . "1" .  $zero_mask);

 while (<STDIN>) {

     # Mask and 1/2 value for a single component.

     s/#define COMPONENT_SIZE\b/$& $size/;

     s/#define MASK\b/$& $mask_/;

     s/#define ONE_HALF\b/$& $one_half_/;

     # Shifts and masks for green, blue, and alpha.

     s/#define G_SHIFT\b/$& $size/;

     s/#define R_SHIFT\b/$& $size * 2/;

     s/#define A_SHIFT\b/$& $size * 3/;

     s/#define G_MASK\b/$& $g_mask/;

     s/#define R_MASK\b/$& $b_mask/;

     s/#define A_MASK\b/$& $a_mask/;

     # Special values for dealing with red + blue at the same time.

     s/#define RB_MASK\b/$& $rb_mask/;

     s/#define AG_MASK\b/$& $ag_mask/;

     s/#define RB_ONE_HALF\b/$& $rb_one_half/;

     s/#define RB_MASK_PLUS_ONE\b/$& $rb_mask_plus_one/;

     # Add 32/64 suffix to combining function types.

     s/\bCombineFunc\b/CombineFunc$pixel_size/;

     s/\bFbComposeFunctions\b/FbComposeFunctions$pixel_size/;

     s/combine_width/combine_$pixel_size/;

     s/_pixman_setup_combiner_functions_width/_pixman_setup_combiner_functions_$pixel_size/;

     s/UNc/UN$size/g;

     s/ALPHA_c/ALPHA_$size/g;

     s/RED_c/RED_$size/g;

     s/GREEN_c/GREEN_$size/g;

     s/BLUE_c/BLUE_$size/g;

     # Convert comp*_t values into the appropriate real types.

     s/comp1_t/uint${size}_t/g;

     s/comp2_t/uint${half_pixel_size}_t/g;

     s/comp4_t/uint${pixel_size}_t/g;

     # Change the function table name for the 64-bit version.

     s/pixman_composeFunctions/pixman_composeFunctions64/ if $size == 16;

     # Change the header for the 64-bit version

     s/pixman-combine.h/pixman-combine64.h/ if $size == 16;

     s/pixman-combine.h/pixman-combine32.h/ if $size == 8;

     print;

 }