1 files changed, 55 insertions, 0 deletions
diff --git a/crawl-ref/source/rltiles/tool/tile_colour.cc b/crawl-ref/source/rltiles/tool/tile_colour.cc
index 88cb69c75f..69df5e97f7 100644
--- a/crawl-ref/source/rltiles/tool/tile_colour.cc
+++ b/crawl-ref/source/rltiles/tool/tile_colour.cc
@@ -1,4 +1,7 @@
 #include "tile_colour.h"
+#include <vector>
+#include <stdio.h>
+#include <png.h>
 
 tile_colour tile_colour::background(71, 108, 108, 255);
 tile_colour tile_colour::transparent(0, 0, 0, 0);
@@ -23,3 +26,55 @@ const tile_colour &tile_colour::operator=(const tile_colour &rhs)
 
     return *this;
 }
+
+bool write_png(const char *filename, tile_colour *pixels, 
+    int width, int height)
+{
+    FILE *fp = fopen(filename, "wb");
+    if (!fp)
+    {
+        fprintf(stderr, "Error: Can't open file '%s' for write.\n", filename);
+        return false;
+    }
+
+    png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, 
+        NULL, NULL, NULL);
+    if (!png_ptr)
+       return false;
+
+    png_infop info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+       png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
+       return false;
+    }
+
+    png_init_io(png_ptr, fp);
+
+    int bit_depth = 8;
+    int colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
+    int interlace_type = PNG_INTERLACE_NONE;
+    int compression_type = PNG_COMPRESSION_TYPE_DEFAULT;
+    int filter_method = PNG_FILTER_TYPE_DEFAULT;
+    png_set_IHDR(png_ptr, info_ptr, width, height,
+       bit_depth, colour_type, interlace_type,
+       compression_type, filter_method);
+
+    png_bytep* row_pointers = (png_bytep*)malloc(sizeof(png_bytep) * height);
+    for (unsigned int y = 0; y < height; y++)
+        row_pointers[y] = (png_byte*)&pixels[y * width];
+
+    png_set_rows(png_ptr, info_ptr, row_pointers);
+
+    int png_transforms = PNG_TRANSFORM_IDENTITY;
+    png_write_png(png_ptr, info_ptr, png_transforms, NULL);
+    png_write_end(png_ptr, info_ptr);
+    png_destroy_write_struct(&png_ptr, &info_ptr);
+
+    free(row_pointers);
+    fclose(fp);
+
+    return true;
+}
+
+