Add png writing function, skip [.] in directories

utils.cpp

@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <dirent.h>
+#include <png.h>
 #include <sys/stat.h>
 #include <SDL_ttf.h>
 
@@ -47,7 +48,7 @@ static int cmpstringp(const void *p1, const void *p2)
 	const char *p1_s = *(const char**)p1;
 	const char *p2_s = *(const char**)p2;
 
-	/* Put directories first */
+	/* Put directories first and handle some special cases */
 	if (*p1_s == '[' && *p2_s != '[')
 		return -1;
 	if (*p1_s != '[' && *p2_s == '[')
@@ -107,6 +108,9 @@ const char **get_file_list(const char *base_dir, const char *exts[])
 			char *p;
 			size_t len = strlen(de->d_name) + 4;
 
+			/* We don't need the current dir */
+			if (strcmp(de->d_name, ".") == 0)
+				continue;
 			p = (char*)malloc( len );
 			snprintf(p, len, "[%s]", de->d_name);
 			file_list[cur++] = p;
@@ -134,3 +138,103 @@ const char **get_file_list(const char *base_dir, const char *exts[])
 
         return file_list;
 }
+
+
+/* PNG writing */
+struct  png_write_user_struct
+{
+	size_t sz;
+	void *data;
+};
+
+static void user_write_fn(png_structp png_ptr, png_bytep bytes, png_size_t sz)
+{
+	struct png_write_user_struct *out = (struct png_write_user_struct *)png_ptr->io_ptr;
+
+	out->data = xrealloc(out->data, out->sz + sz);
+	memcpy((uint8_t*)out->data + out->sz, bytes, sz);
+	out->sz += sz;
+}
+
+
+static int png_colortype_from_surface(SDL_Surface *surface)
+{
+	int colortype = PNG_COLOR_MASK_COLOR; /* grayscale not supported */
+
+	if (surface->format->palette)
+		colortype |= PNG_COLOR_MASK_PALETTE;
+	else if (surface->format->Amask)
+		colortype |= PNG_COLOR_MASK_ALPHA;
+
+	return colortype;
+}
+
+
+static void png_user_warn(png_structp ctx, png_const_charp str)
+{
+	fprintf(stderr, "libpng: warning: %s\n", str);
+}
+
+
+static void png_user_error(png_structp ctx, png_const_charp str)
+{
+	fprintf(stderr, "libpng: error: %s\n", str);
+}
+
+
+/* This is taken from http://encelo.netsons.org/programming/sdl (GPLed) */
+void *sdl_surface_to_png(SDL_Surface *surf, size_t *out_sz)
+{
+	png_structp png_ptr;
+	png_infop info_ptr;
+	int i, colortype;
+	png_bytep *row_pointers;
+	struct png_write_user_struct out;
+
+	out.sz = 0;
+	out.data = NULL;
+
+	/* Initializing png structures and callbacks */
+	png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+		NULL, png_user_error, png_user_warn);
+	if (png_ptr == NULL) {
+		printf("png_create_write_struct error!\n");
+		return NULL;
+	}
+
+	info_ptr = png_create_info_struct(png_ptr);
+	if (info_ptr == NULL) {
+		png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
+		printf("png_create_info_struct error!\n");
+		exit(-1);
+	}
+
+	if (setjmp(png_jmpbuf(png_ptr))) {
+		png_destroy_write_struct(&png_ptr, &info_ptr);
+		exit(-1);
+	}
+
+	png_set_write_fn(png_ptr, (void *)&out, user_write_fn, NULL);
+
+	colortype = png_colortype_from_surface(surf);
+	png_set_IHDR(png_ptr, info_ptr, surf->w, surf->h, 8, colortype,	PNG_INTERLACE_NONE,
+		PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+	/* Writing the image */
+	png_write_info(png_ptr, info_ptr);
+	png_set_packing(png_ptr);
+
+	row_pointers = (png_bytep*) malloc(sizeof(png_bytep)*surf->h);
+	for (i = 0; i < surf->h; i++)
+		row_pointers[i] = (png_bytep)(Uint8 *)surf->pixels + i*surf->pitch;
+	png_write_image(png_ptr, row_pointers);
+	png_write_end(png_ptr, info_ptr);
+
+	/* Cleaning out... */
+	free(row_pointers);
+	png_destroy_write_struct(&png_ptr, &info_ptr);
+
+	*out_sz = out.sz;
+
+	return out.data;
+}

utils.hh

@@ -5,6 +5,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include <SDL.h>
 #include <SDL_ttf.h>
 
 #define BUG_ON(cond)
@@ -57,4 +58,6 @@ TTF_Font *read_and_alloc_font(const char *path, int pt_size);
 
 const char **get_file_list(const char *base_dir, const char *exts[]);
 
+void *sdl_surface_to_png(SDL_Surface *src, size_t *out_sz);
+
 #endif /* __UTILS_H__ */