[hackers] [farbfeld] Optimize ff2ppm(1) || FRIGN

From: <git_AT_suckless.org>
Date: Mon, 21 Mar 2016 22:26:53 +0100 (CET)

commit f0a4ce113d0e9dc50110a0ad9e98433d05aa2307
Author: FRIGN <dev_AT_frign.de>
AuthorDate: Mon Mar 21 22:26:37 2016 +0100
Commit: FRIGN <dev_AT_frign.de>
CommitDate: Mon Mar 21 22:26:37 2016 +0100

    Optimize ff2ppm(1)
    
    use the proper multiplication factors :)

diff --git a/ff2ppm.c b/ff2ppm.c
index 7f6aa61..09eb346 100644
--- a/ff2ppm.c
+++ b/ff2ppm.c
_AT_@ -23,45 +23,33 @@ int
 main(int argc, char *argv[])
 {
         size_t rowlen;
- uint32_t hdr[4], width, height, i, j, k;
- uint16_t *row, mr = 0xffff, mg = 0xffff, mb = 0xffff;
+ uint64_t a;
+ uint32_t hdr[4], width, height, i, j, k, l;
+ uint16_t *row, mask[3] = { 0xffff, 0xffff, 0xffff };
         uint8_t *rowout;
- char *color;
- unsigned int r = 0xff, g = 0xff, b = 0xff;
- float a;
+ char *color, colfmt[] = "%#x%#x%#x";
+ unsigned int collen, col[3], colfac;
 
         argv0 = argv[0];
         ARGBEGIN {
         case 'b':
- for (color = EARGF(usage()); *color && *color == '#'; color++)
- ;
-
- switch (strlen(color)) {
- case 3:
- if (sscanf(color, "%1x%1x%1x", &r, &g, &b) != 3)
- usage();
- mr = (r | r << 4) * 257;
- mg = (g | g << 4) * 257;
- mb = (b | b << 4) * 257;
- break;
- case 6:
- if (sscanf(color, "%2x%2x%2x", &r, &g, &b) != 3)
- usage();
- mr = r * 257;
- mg = g * 257;
- mb = b * 257;
- break;
- case 12:
- if (sscanf(color, "%4x%4x%4x", &r, &g, &b) != 3)
- usage();
- mr = r;
- mg = g;
- mb = b;
- break;
- default:
+ color = EARGF(usage());
+ if (color[0] == '#') {
+ color++;
+ }
+ collen = strlen(color);
+ if (collen != 3 && collen != 6 && collen != 12) {
+ usage();
+ }
+ colfmt[1] = colfmt[4] = colfmt[7] = ((collen / 3) - '0');
+ if (sscanf(color, colfmt, col, col + 1, col + 2) != 3) {
                         usage();
                 }
- break;
+ /* UINT16_MAX / 255 = 257; UINT16_MAX / 15 = 4369 */
+ colfac = (collen == 3) ? 4369 : (collen == 6) ? 257 : 1;
+ for (i = 0; i < 3; i++) {
+ mask[i] = col[i] * colfac;
+ }
         default:
                 usage();
         } ARGEND
_AT_@ -111,15 +99,18 @@ main(int argc, char *argv[])
                         return 1;
                 }
                 for (j = 0, k = 0; j < rowlen; j += 4, k += 3) {
- a = ntohs(row[j + 3]) / 65535.0f;
- rowout[k] = ((ntohs(row[j]) * a) + (mr * (1 - a))) / 257;
- rowout[k + 1] = ((ntohs(row[j + 1]) * a) + (mg * (1 - a))) / 257;
- rowout[k + 2] = ((ntohs(row[j + 2]) * a) + (mb * (1 - a))) / 257;
+ a = ntohs(row[j + 3]);
+ for (l = 0; l < 3; l++) {
+ rowout[k + l] = (a * ntohs(row[j + l]) +
+ (65535 - a) * mask[l]) /
+ (257 * 65535);
+ }
                 }
                 if (fwrite(rowout, 3, width, stdout) != width) {
                         fprintf(stderr, "%s: fwrite: %s\n", argv0, strerror(errno));
                         return 1;
                 }
         }
+
         return 0;
 }
Received on Mon Mar 21 2016 - 22:26:53 CET