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/* See LICENSE file for copyright and license details. */
#include "common.h"
USAGE("[-i] alpha-stream")
#define PROCESS(TYPE, INV)\
do {\
size_t i;\
TYPE *luma = (TYPE *)(alpha->buf) + alpha->luma_chan;\
TYPE *alph = (TYPE *)(alpha->buf) + alpha->alpha_chan;\
TYPE *out = (TYPE *)(colour->buf) + colour->alpha_chan;\
n /= colour->chan_size;\
for (i = 0; i < n; i += colour->n_chan)\
out[i] *= (INV luma[i]) * alph[i];\
} while (0)
static void process_lf (struct stream *colour, struct stream *alpha, size_t n) {PROCESS(double,);}
static void process_lf_i(struct stream *colour, struct stream *alpha, size_t n) {PROCESS(double, 1 -);}
static void process_f (struct stream *colour, struct stream *alpha, size_t n) {PROCESS(float,);}
static void process_f_i (struct stream *colour, struct stream *alpha, size_t n) {PROCESS(float, 1 -);}
int
main(int argc, char *argv[])
{
int invert = 0;
struct stream colour, alpha;
void (*process)(struct stream *colour, struct stream *alpha, size_t n);
ARGBEGIN {
case 'i':
invert = 1;
break;
default:
usage();
} ARGEND;
if (argc != 1)
usage();
eopen_stream(&colour, NULL);
eopen_stream(&alpha, argv[0]);
CHECK_CHANS(&colour, != -1, != -1);
CHECK_ALPHA(&colour);
if (colour.encoding == DOUBLE)
process = invert ? process_lf_i : process_lf;
else if (colour.encoding == FLOAT)
process = invert ? process_f_i : process_f;
else
eprintf("pixel format %s is not supported, try xyza\n", colour.pixfmt);
fprint_stream_head(stdout, &colour);
efflush(stdout, "<stdout>");
process_two_streams(&colour, &alpha, STDOUT_FILENO, "<stdout>", process);
return 0;
}
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