blind-quaternion-product.c - blind - suckless command-line video editing utility
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       ---
       blind-quaternion-product.c (1418B)
       ---
            1 /* See LICENSE file for copyright and license details. */
            2 #ifndef TYPE
            3 #include "common.h"
            4 
            5 USAGE("right-hand-stream")
            6 
            7 #define FILE "blind-quaternion-product.c"
            8 #include "define-functions.h"
            9 
           10 int
           11 main(int argc, char *argv[])
           12 {
           13         struct stream left, right;
           14         void (*process)(struct stream *left, struct stream *right, size_t n);
           15 
           16         UNOFLAGS(argc != 1);
           17 
           18         eopen_stream(&left, NULL);
           19         eopen_stream(&right, argv[0]);
           20 
           21         SELECT_PROCESS_FUNCTION(&left);
           22         CHECK_ALPHA_CHAN(&left);
           23         CHECK_N_CHAN(&left, 4, 4);
           24 
           25         fprint_stream_head(stdout, &left);
           26         efflush(stdout, "<stdout>");
           27         process_two_streams(&left, &right, STDOUT_FILENO, "<stdout>", process);
           28         return 0;
           29 }
           30 
           31 #else
           32 
           33 static void
           34 PROCESS(struct stream *left, struct stream *right, size_t n)
           35 {
           36         size_t i;
           37         TYPE *lx, *ly, *lz, *la, *rx, *ry, *rz, *ra, x, y, z, a;
           38         for (i = 0; i < n; i += 4 * sizeof(TYPE)) {
           39                 lx = ((TYPE *)(left->buf + i)) + 0, rx = ((TYPE *)(right->buf + i)) + 0;
           40                 ly = ((TYPE *)(left->buf + i)) + 1, ry = ((TYPE *)(right->buf + i)) + 1;
           41                 lz = ((TYPE *)(left->buf + i)) + 2, rz = ((TYPE *)(right->buf + i)) + 2;
           42                 la = ((TYPE *)(left->buf + i)) + 3, ra = ((TYPE *)(right->buf + i)) + 3;
           43                 x = *lx * *rx - *ly * *ry - *lz * *rz - *la * *ra;
           44                 y = *lz * *ra - *la * *rz + *lx * *ry + *ly * *rx;
           45                 z = *la * *ry - *ly * *rz + *lx * *rz + *lz * *rx;
           46                 a = *ly * *rz - *lz * *rz + *lx * *ra + *la * *rx;
           47                 *lx = x;
           48                 *ly = y;
           49                 *lz = z;
           50                 *la = a;
           51         }
           52 }
           53 
           54 #endif