[hackers] [farbfeld] Refactor png-conversion-utilities || Laslo Hunhold

From: <git_AT_suckless.org>
Date: Wed, 12 Apr 2017 23:45:17 +0200 (CEST)

commit da99b58226c8dbb0cf764bbc7b42b7e3a36ff292
Author: Laslo Hunhold <dev_AT_frign.de>
AuthorDate: Wed Apr 12 23:41:00 2017 +0200
Commit: Laslo Hunhold <dev_AT_frign.de>
CommitDate: Wed Apr 12 23:41:00 2017 +0200

    Refactor png-conversion-utilities
    
    We split out the libpng-setup into a separate function, it is very very
    ugly.
    The code also received a general cleanup and aligns itself much better
    with the general coding style and structure.

diff --git a/ff2png.c b/ff2png.c
index 360ab00..a00e257 100644
--- a/ff2png.c
+++ b/ff2png.c
_AT_@ -11,73 +11,77 @@
 
 #include "util.h"
 
-void
-pngerr(png_structp pngs, const char *msg)
+static void
+png_err(png_struct *pngs, const char *msg)
 {
         (void)pngs;
         fprintf(stderr, "%s: libpng: %s\n", argv0, msg);
         exit(1);
 }
 
+static void
+png_setup_writer(png_struct **s, png_info **i, uint32_t w, uint32_t h)
+{
+ *s = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, png_err, NULL);
+ *i = png_create_info_struct(*s);
+
+ if (!*s || !*i) {
+ fprintf(stderr, "%s: failed to initialize libpng\n", argv0);
+ exit(1);
+ }
+
+ png_init_io(*s, stdout);
+ png_set_IHDR(*s, *i, w, h, 16, PNG_COLOR_TYPE_RGB_ALPHA,
+ PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
+ PNG_FILTER_TYPE_BASE);
+ png_write_info(*s, *i);
+}
+
+static void
+usage(void)
+{
+ fprintf(stderr, "usage: %s\n", argv0);
+ exit(1);
+}
+
 int
 main(int argc, char *argv[])
 {
- png_structp pngs;
- png_infop pngi;
+ png_struct *pngs;
+ png_info *pngi;
         size_t rowlen;
         uint32_t width, height, i;
         uint16_t *row;
 
+ /* arguments */
         argv0 = argv[0], argc--, argv++;
 
         if (argc) {
- fprintf(stderr, "usage: %s\n", argv0);
- return 1;
+ usage();
         }
 
- read_ff_header(&width, &height);
-
- /* load png */
- pngs = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, pngerr,
- NULL);
- pngi = png_create_info_struct(pngs);
-
- if (!pngs || !pngi) {
- fprintf(stderr, "%s: failed to initialize libpng\n", argv0);
- return 1;
- }
- png_init_io(pngs, stdout);
- png_set_IHDR(pngs, pngi, width, height, 16, PNG_COLOR_TYPE_RGB_ALPHA,
- PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
- PNG_FILTER_TYPE_BASE);
- png_write_info(pngs, pngi);
-
- /* write rows */
- if (width > SIZE_MAX / ((sizeof("RGBA") - 1) * sizeof(uint16_t))) {
- fprintf(stderr, "%s: row length integer overflow\n", argv0);
- return 1;
- }
+ /* prepare */
+ ff_read_header(&width, &height);
+ png_setup_writer(&pngs, &pngi, width, height);
+ row = ereallocarray(NULL, width, (sizeof("RGBA") - 1) * sizeof(uint16_t));
         rowlen = width * (sizeof("RGBA") - 1);
- if (!(row = malloc(rowlen * sizeof(uint16_t)))) {
- fprintf(stderr, "%s: malloc: out of memory\n", argv0);
- return 1;
- }
+
+ /* write data */
         for (i = 0; i < height; ++i) {
                 if (fread(row, sizeof(uint16_t), rowlen, stdin) != rowlen) {
- goto readerr;
+ if (ferror(stdin)) {
+ fprintf(stderr, "%s: fread: %s\n", argv0, strerror(errno));
+ } else {
+ fprintf(stderr, "%s: unexpected end of file\n", argv0);
+ }
+ return 1;
                 }
                 png_write_row(pngs, (uint8_t *)row);
         }
+
+ /* clean up */
         png_write_end(pngs, NULL);
         png_destroy_write_struct(&pngs, NULL);
 
         return 0;
-readerr:
- if (ferror(stdin)) {
- fprintf(stderr, "%s: fread: %s\n", argv0, strerror(errno));
- } else {
- fprintf(stderr, "%s: unexpected end of file\n", argv0);
- }
-
- return 1;
 }
diff --git a/png2ff.c b/png2ff.c
index 515979d..dd9073c 100644
--- a/png2ff.c
+++ b/png2ff.c
_AT_@ -5,69 +5,75 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include <png.h>
 
 #include "util.h"
 
 void
-pngerr(png_structp pngs, const char *msg)
+png_err(png_struct *pngs, const char *msg)
 {
+ (void)pngs;
         fprintf(stderr, "%s: libpng: %s\n", argv0, msg);
         exit(1);
 }
 
+void
+png_setup_reader(png_struct **s, png_info **i, uint32_t *w, uint32_t *h)
+{
+ *s = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, png_err, NULL);
+ *i = png_create_info_struct(*s);
+
+ if (!*s || !*i) {
+ fprintf(stderr, "%s: failed to initialize libpng\n", argv0);
+ exit(1);
+ }
+
+ png_init_io(*s, stdin);
+ if (png_get_valid(*s, *i, PNG_INFO_tRNS)) {
+ png_set_tRNS_to_alpha(*s);
+ }
+ png_set_add_alpha(*s, 255*257, PNG_FILLER_AFTER);
+ png_set_expand_gray_1_2_4_to_8(*s);
+ png_set_gray_to_rgb(*s);
+ png_set_packing(*s);
+ png_read_png(*s, *i, PNG_TRANSFORM_PACKING | PNG_TRANSFORM_EXPAND, NULL);
+ *w = png_get_image_width(*s, *i);
+ *h = png_get_image_height(*s, *i);
+}
+
+static void
+usage(void)
+{
+ fprintf(stderr, "usage: %s\n", argv0);
+ exit(1);
+}
+
 int
 main(int argc, char *argv[])
 {
- png_structp pngs;
- png_infop pngi;
+ png_struct *pngs;
+ png_info *pngi;
         uint32_t width, height, rowlen, r, i;
         uint16_t *row;
         uint8_t **pngrows;
 
+ /* arguments */
         argv0 = argv[0], argc--, argv++;
 
         if (argc) {
- fprintf(stderr, "usage: %s\n", argv0);
- return 1;
+ usage();
         }
 
- /* load png */
- pngs = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, pngerr,
- NULL);
- pngi = png_create_info_struct(pngs);
-
- if (!pngs || !pngi) {
- fprintf(stderr, "%s: failed to initialize libpng\n", argv0);
- return 1;
- }
- png_init_io(pngs, stdin);
- if (png_get_valid(pngs, pngi, PNG_INFO_tRNS))
- png_set_tRNS_to_alpha(pngs);
- png_set_add_alpha(pngs, 255*257, PNG_FILLER_AFTER);
- png_set_expand_gray_1_2_4_to_8(pngs);
- png_set_gray_to_rgb(pngs);
- png_set_packing(pngs);
- png_read_png(pngs, pngi, PNG_TRANSFORM_PACKING |
- PNG_TRANSFORM_EXPAND, NULL);
- width = png_get_image_width(pngs, pngi);
- height = png_get_image_height(pngs, pngi);
- pngrows = png_get_rows(pngs, pngi);
-
- /* allocate output row buffer */
- if (width > SIZE_MAX / ((sizeof("RGBA") - 1) * sizeof(uint16_t))) {
- fprintf(stderr, "%s: row length integer overflow\n", argv0);
- return 1;
- }
+ /* prepare */
+ png_setup_reader(&pngs, &pngi, &width, &height);
+ row = ereallocarray(NULL, width, (sizeof("RGBA") - 1) * sizeof(uint16_t));
         rowlen = width * (sizeof("RGBA") - 1);
- if (!(row = malloc(rowlen * sizeof(uint16_t)))) {
- fprintf(stderr, "%s: malloc: out of memory\n", argv0);
- return 1;
- }
+ pngrows = png_get_rows(pngs, pngi);
 
         /* write data */
- write_ff_header(width, height);
+ ff_write_header(width, height);
 
         switch(png_get_bit_depth(pngs, pngi)) {
         case 8:
_AT_@ -77,7 +83,9 @@ main(int argc, char *argv[])
                         }
                         if (fwrite(row, sizeof(uint16_t), rowlen,
                                    stdout) != rowlen) {
- goto writerr;
+ fprintf(stderr, "%s: fwrite: %s\n", argv0,
+ strerror(errno));
+ return 1;
                         }
                 }
                 break;
_AT_@ -85,7 +93,9 @@ main(int argc, char *argv[])
                 for (r = 0; r < height; ++r) {
                         if (fwrite(pngrows[r], sizeof(uint16_t), rowlen,
                                    stdout) != rowlen) {
- goto writerr;
+ fprintf(stderr, "%s: fwrite: %s\n", argv0,
+ strerror(errno));
+ return 1;
                         }
                 }
                 break;
_AT_@ -94,12 +104,8 @@ main(int argc, char *argv[])
                 return 1;
         }
 
+ /* clean up */
         png_destroy_read_struct(&pngs, &pngi, NULL);
 
         return 0;
-writerr:
- fprintf(stderr, "%s: fwrite: ", argv0);
- perror(NULL);
-
- return 1;
 }
Received on Wed Apr 12 2017 - 23:45:17 CEST

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