colors

commit ba0d3294c08b43fea5a4571aebc089ff6eef48bd
parent 6b73dd60c1bf9ce6dc80a3a423d24a74de4c922e
Author: sin <sin@2f30.org>
Date:   Fri,  5 Jun 2015 13:44:48 +0100

Simplify png parser

Diffstat:
M
png.c
 | 
61
++++++++++++++++++++-----------------------------------------

1 file changed, 20 insertions(+), 41 deletions(-)
diff --git a/png.c b/png.c
@@ -1,7 +1,6 @@
 /* See LICENSE file for copyright and license details. */
 #include <err.h>
 #include <stdio.h>
-#include <stdlib.h>
 
 #include <png.h>
 #include "colors.h"
@@ -9,61 +8,41 @@
 void
 parseimg(char *f, void (*fn)(int, int, int))
 {
+	png_structp png_struct_p;
+	png_infop png_info_p;
+	png_bytepp png_row_p;
+	png_uint_32 width, height;
+	int depth, color, interlace;
+	int y, x;
 	FILE *fp;
-	png_structp png_ptr;
-	png_infop info_ptr;
-	png_byte hdr[8];
-	png_bytep *rows;
-	int width, height;
-	int x, y;
 
 	if (!(fp = fopen(f, "r")))
 		err(1, "fopen %s", f);
-	fread(hdr, 1, 8, fp);
-	if (png_sig_cmp(hdr, 0, 8))
-		errx(1, "not a png file");
 
-	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-	info_ptr = png_create_info_struct(png_ptr);
-	if (!png_ptr || !info_ptr || setjmp(png_jmpbuf(png_ptr)))
+	png_struct_p = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	png_info_p = png_create_info_struct(png_struct_p);
+	if (!png_struct_p || !png_info_p || setjmp(png_jmpbuf(png_struct_p)))
 		errx(1, "failed to initialize libpng");
 
-	png_init_io(png_ptr, fp);
-	png_set_add_alpha(png_ptr, 255, PNG_FILLER_AFTER);
-	png_set_gray_to_rgb(png_ptr);
-	png_set_sig_bytes(png_ptr, 8);
-	png_read_info(png_ptr, info_ptr);
+	png_init_io(png_struct_p, fp);
+	png_set_add_alpha(png_struct_p, 255, PNG_FILLER_AFTER);
+	png_set_gray_to_rgb(png_struct_p);
+	png_read_png(png_struct_p, png_info_p, PNG_TRANSFORM_STRIP_16 |
+		     PNG_TRANSFORM_PACKING | PNG_TRANSFORM_EXPAND , NULL);
+	png_get_IHDR(png_struct_p, png_info_p, &width, &height, &depth,
+		     &color, &interlace, NULL, NULL);
+	png_row_p = png_get_rows(png_struct_p, png_info_p);
 
-	width = png_get_image_width(png_ptr, info_ptr);
-	height = png_get_image_height(png_ptr, info_ptr);
-	png_read_update_info(png_ptr, info_ptr);
-
-	if (setjmp(png_jmpbuf(png_ptr)))
-		errx(1, "failed to read image");
-
-	rows = malloc(sizeof(*rows) * height);
-	if (!rows)
-		err(1, "malloc");
 	for (y = 0; y < height; y++) {
-		rows[y] = malloc(png_get_rowbytes(png_ptr, info_ptr));
-		if (!rows[y])
-			err(1, "malloc");
-	}
-
-	png_read_image(png_ptr, rows);
-
-	for (y = 0; y < height; y++) {
-		png_byte *row = rows[y];
+		png_byte *row = png_row_p[y];
 		for (x = 0; x < width; x++) {
 			png_byte *p = &row[x * 4];
 			fn(p[0], p[1], p[2]);
 		}
 	}
 
-	for (y = 0; y < height; y++)
-		free(rows[y]);
-	free(rows);
+	png_free_data(png_struct_p, png_info_p, PNG_FREE_ALL, -1);
+	png_destroy_read_struct(&png_struct_p, &png_info_p, NULL);
 
 	fclose(fp);
-
 }