1 files changed, 98 insertions, 0 deletions
diff --git a/src/tools/dilate.c b/src/tools/dilate.c
new file mode 100644
index 00000000..f53e7656
--- /dev/null
+++ b/src/tools/dilate.c
@@ -0,0 +1,98 @@
+
+#include "../engine/client/pnglite/pnglite.c"
+
+typedef struct pixel_t
+{
+	unsigned char r, g, b, a;
+} pixel;
+
+static int clamp(int v, int min, int max)
+{
+	if(v > max)
+		return max;
+	if(v < min)
+		return min;
+	return v;
+}
+
+static void dilate(int w, int h, pixel *src, pixel *dst)
+{
+	int x, y, k, m, c;
+	int ix, iy;
+
+	m = 0;
+	for(y = 0; y < h; y++)
+	{
+		for(x = 0; x < w; x++, m++)
+		{
+			dst[m] = src[m];
+			if(src[m].a)
+				continue;
+			
+			const int xo[] = {0, -1, 1, 0};
+			const int yo[] = {-1, 0, 0, 1};
+			for(c = 0; c < 4; c++)
+			{
+				ix = clamp(x + xo[c], 0, w-1);
+				iy = clamp(y + yo[c], 0, h-1);
+				k = iy*w+ix;
+				if(src[k].a)
+				{
+					dst[m] = src[k];
+					dst[m].a = 255;
+					break;
+				}
+			}
+		}
+	}
+}
+
+static void copy_alpha(int w, int h, pixel *src, pixel *dst)
+{
+	int x, y, m;
+
+	for(y = 0; y < h; y++)
+		for(x = 0; x < w; x++, m++)
+			dst[m].a = src[m].a;
+}
+
+int main(int argc, char **argv)
+{
+	png_t png;
+	pixel *buffer[3] = {0,0,0};
+	int i, w, h;
+	
+	png_init(0,0);
+	png_open_file(&png, argv[1]);
+	
+	if(png.color_type != PNG_TRUECOLOR_ALPHA)
+	{
+		printf("not an RGBA image\n");
+		return -1;
+	}
+	
+	buffer[0] = (pixel*)malloc(png.width*png.height*sizeof(pixel));
+	buffer[1] = (pixel*)malloc(png.width*png.height*sizeof(pixel));
+	buffer[2] = (pixel*)malloc(png.width*png.height*sizeof(pixel));
+	png_get_data(&png, (unsigned char *)buffer[0]);
+	png_close_file(&png);
+	
+	w = png.width;
+	h = png.height;
+	
+	dilate(w, h, buffer[0], buffer[1]);
+	for(i = 0; i < 5; i++)
+	{
+		dilate(w, h, buffer[1], buffer[2]);
+		dilate(w, h, buffer[2], buffer[1]);
+	}
+	
+	copy_alpha(w, h, buffer[0], buffer[1]);
+	
+	// save here
+	png_open_file_write(&png, argv[1]);
+	png_set_data(&png, w, h, 8, PNG_TRUECOLOR_ALPHA, (unsigned char *)buffer[1]);
+	png_close_file(&png);
+	
+	return 0;
+}