this file allows to make an antialiased black-on-white png, antialiased black-on-transparent

it's used for perl-install/pixmaps/langs/lang-*.png

1 files changed, 167 insertions, 0 deletions

diff --git a/tools/make_lang_png_transparent.c b/tools/make_lang_png_transparent.c
new file mode 100644
index 000000000..30c2557ba
--- /dev/null
+++ b/tools/make_lang_png_transparent.c
@@ -0,0 +1,167 @@
+/*
+ * Guillaume Cottenceau (gc at mandrakesoft.com)
+ *
+ * Copyright 2002 MandrakeSoft
+ *
+ * This software may be freely redistributed under the terms of the GNU
+ * public license.
+ *
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+
+#define PNG_DEBUG 3
+#include <png.h>
+
+void abort_(const char * s, ...)
+{
+	va_list args;
+	va_start(args, s);
+	vfprintf(stderr, s, args);
+	fprintf(stderr, "\n");
+	va_end(args);
+	abort();
+}
+
+int x, y;
+
+int width, height;
+png_byte color_type;
+png_byte bit_depth;
+
+png_structp png_ptr;
+png_infop info_ptr;
+int number_of_passes;
+png_bytep * row_pointers;
+
+void read_png_file(char* file_name)
+{
+	char header[8];	// 8 is the maximum size that can be checked
+
+	/* open file and test for it being a png */
+	FILE *fp = fopen(file_name, "rb");
+	if (!fp)
+		abort_("[read_png_file] File %s could not be opened for reading", file_name);
+	fread(header, 1, 8, fp);
+	if (png_sig_cmp(header, 0, 8))
+		abort_("[read_png_file] File %s is not recognized as a PNG file", file_name);
+
+
+	/* initialize stuff */
+	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	
+	if (!png_ptr)
+		abort_("[read_png_file] png_create_read_struct failed");
+
+	info_ptr = png_create_info_struct(png_ptr);
+	if (!info_ptr)
+		abort_("[read_png_file] png_create_info_struct failed");
+
+	if (setjmp(png_jmpbuf(png_ptr)))
+		abort_("[read_png_file] Error during init_io");
+
+	png_init_io(png_ptr, fp);
+	png_set_sig_bytes(png_ptr, 8);
+
+	png_read_info(png_ptr, info_ptr);
+
+	width = info_ptr->width;
+	height = info_ptr->height;
+	color_type = info_ptr->color_type;
+	bit_depth = info_ptr->bit_depth;
+
+	number_of_passes = png_set_interlace_handling(png_ptr);
+	png_read_update_info(png_ptr, info_ptr);
+
+
+	/* read file */
+	if (setjmp(png_jmpbuf(png_ptr)))
+		abort_("[read_png_file] Error during read_image");
+
+	row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
+	for (y=0; y<height; y++)
+		row_pointers[y] = (png_byte*) malloc(info_ptr->rowbytes);
+
+	png_read_image(png_ptr, row_pointers);
+}
+
+
+void write_png_file(char* file_name)
+{
+	/* create file */
+	FILE *fp = fopen(file_name, "wb");
+	if (!fp)
+		abort_("[write_png_file] File %s could not be opened for writing", file_name);
+
+
+	/* initialize stuff */
+	png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	
+	if (!png_ptr)
+		abort_("[write_png_file] png_create_write_struct failed");
+
+	info_ptr = png_create_info_struct(png_ptr);
+	if (!info_ptr)
+		abort_("[write_png_file] png_create_info_struct failed");
+
+	if (setjmp(png_jmpbuf(png_ptr)))
+		abort_("[write_png_file] Error during init_io");
+
+	png_init_io(png_ptr, fp);
+
+
+	/* write header */
+	if (setjmp(png_jmpbuf(png_ptr)))
+		abort_("[write_png_file] Error during writing header");
+
+	png_set_IHDR(png_ptr, info_ptr, width, height,
+		     bit_depth, color_type, PNG_INTERLACE_NONE,
+		     PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+	png_write_info(png_ptr, info_ptr);
+
+
+	/* write bytes */
+	if (setjmp(png_jmpbuf(png_ptr)))
+		abort_("[write_png_file] Error during writing bytes");
+
+	png_write_image(png_ptr, row_pointers);
+
+
+	/* end write */
+	if (setjmp(png_jmpbuf(png_ptr)))
+		abort_("[write_png_file] Error during end of write");
+
+	png_write_end(png_ptr, NULL);
+
+}
+
+void process_file(void)
+{
+	if (info_ptr->color_type != PNG_COLOR_TYPE_RGBA)
+		abort_("[process_file] color_type of input file must be PNG_COLOR_TYPE_RGBA (is %d)", info_ptr->color_type);
+
+	for (y=0; y<height; y++) {
+		png_byte* row = row_pointers[y];
+		for (x=0; x<width; x++) {
+			png_byte* ptr = &(row[x*4]);
+			ptr[3] = 255-ptr[0];
+			ptr[0] = ptr[1] = ptr[2] = 0;
+		}
+	}
+
+}
+
+
+int main(int argc, char **argv)
+{
+	if (argc != 3)
+		abort_("Usage: program_name <file_in> <file_out>");
+
+	read_png_file(argv[1]);
+	process_file();
+	write_png_file(argv[2]);
+}