3 files changed, 71 insertions, 0 deletions
diff --git a/util/png2cuddleimg/.gitignore b/util/png2cuddleimg/.gitignore
new file mode 100644
index 0000000..daad221
--- /dev/null
+++ b/util/png2cuddleimg/.gitignore
@@ -0,0 +1 @@
+png2cuddleimg
diff --git a/util/png2cuddleimg/Makefile b/util/png2cuddleimg/Makefile
new file mode 100644
index 0000000..3a18ee6
--- /dev/null
+++ b/util/png2cuddleimg/Makefile
@@ -0,0 +1,2 @@
+png2cuddleimg: main.c
+	gcc $$(pkg-config --cflags --libs libpng) -Wall -Wextra main.c -o png2cuddleimg
diff --git a/util/png2cuddleimg/main.c b/util/png2cuddleimg/main.c
new file mode 100644
index 0000000..8dbfb14
--- /dev/null
+++ b/util/png2cuddleimg/main.c
@@ -0,0 +1,68 @@
+#include <png.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <endian.h>
+
+int main(int argc, char *argv[])
+{
+#define TRY(expr, ...) if (!(expr)) { \
+	fprintf(stderr, "%s: ", argv[0]); \
+	fprintf(stderr, __VA_ARGS__); \
+	if (file != NULL) fclose(file); \
+	png_destroy_read_struct(&png, &info, NULL); \
+	return EXIT_FAILURE; }
+
+	FILE *file = NULL;
+	png_structp png = NULL;
+	png_infop info = NULL;
+
+	TRY(argc == 2, "usage: %s infile.png > outfile.cuddleimg\n", argv[0]);
+	TRY((file = fopen(argv[1], "r")) != NULL, "failed to open %s\n", argv[1]);
+
+	TRY(png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL),
+		"png_create_read_struct failed\n");
+
+	TRY(info = png_create_info_struct(png), "png_create_info_struct failed\n");
+
+	png_init_io(png, file);
+	png_read_info(png, info);
+
+	png_uint_32 width = png_get_image_width(png, info);
+	png_uint_32 height = png_get_image_height(png, info);
+	png_byte color_type = png_get_color_type(png, info);
+	png_byte bit_depth  = png_get_bit_depth(png, info);
+
+	if (bit_depth == 16)
+		png_set_strip_16(png);
+	if (color_type == PNG_COLOR_TYPE_PALETTE)
+		png_set_palette_to_rgb(png);
+	if(png_get_valid(png, info, PNG_INFO_tRNS))
+		png_set_tRNS_to_alpha(png);
+	if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_GRAY_ALPHA || color_type == PNG_COLOR_TYPE_PALETTE)
+		png_set_filler(png, 0xFF, PNG_FILLER_AFTER);
+	if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+		png_set_gray_to_rgb(png);
+
+	png_read_update_info(png, info);
+
+	fwrite(&width, 1, sizeof width, stdout);
+	fwrite(&height, 1, sizeof height, stdout);
+
+	png_uint_32 pitch = png_get_rowbytes(png, info);
+	png_byte row[pitch];
+	for (png_uint_32 y = 0; y < height; y++) {
+		png_read_row(png, row, NULL);
+
+		for (png_uint_32 x = 0; x < width; x++) {
+			png_byte tmp = row[4*x];
+			row[4*x] = row[4*x+2];
+			row[4*x+2] = tmp;
+		}
+
+		fwrite(row, 1, pitch, stdout);
+	}
+
+	fclose(file);
+	png_destroy_read_struct(&png, &info, NULL);
+	return EXIT_SUCCESS;
+}