use Derelict/FreeImage instead of libpng to fix library version issues

dlanguilib.visualdproj

@@ -190,13 +190,10 @@
  </Config>
  <Folder name="dlangui">
   <Folder name="3rdparty">
-   <Folder name="DerelictUtil">
+   <Folder name="DerelictFT">
-    <File path="..\DerelictUtil\source\derelict\util\exception.d" />
+    <File path="..\DerelictFT\source\derelict\freetype\ft.d" />
-    <File path="..\DerelictUtil\source\derelict\util\loader.d" />
+    <File path="..\DerelictFT\source\derelict\freetype\functions.d" />
-    <File path="..\DerelictUtil\source\derelict\util\sharedlib.d" />
+    <File path="..\DerelictFT\source\derelict\freetype\types.d" />
-    <File path="..\DerelictUtil\source\derelict\util\system.d" />
-    <File path="..\DerelictUtil\source\derelict\util\wintypes.d" />
-    <File path="..\DerelictUtil\source\derelict\util\xtypes.d" />
    </Folder>
    <Folder name="DerelictGL3">
     <File path="..\DerelictGL3\source\derelict\opengl3\arb.d" />
@@ -215,10 +212,18 @@
     <File path="..\DerelictGL3\source\derelict\opengl3\wgl.d" />
     <File path="..\DerelictGL3\source\derelict\opengl3\wglext.d" />
    </Folder>
-   <Folder name="DerelictFT">
+   <Folder name="DerelictUtil">
-    <File path="..\DerelictFT\source\derelict\freetype\ft.d" />
+    <File path="..\DerelictUtil\source\derelict\util\exception.d" />
-    <File path="..\DerelictFT\source\derelict\freetype\functions.d" />
+    <File path="..\DerelictUtil\source\derelict\util\loader.d" />
-    <File path="..\DerelictFT\source\derelict\freetype\types.d" />
+    <File path="..\DerelictUtil\source\derelict\util\sharedlib.d" />
+    <File path="..\DerelictUtil\source\derelict\util\system.d" />
+    <File path="..\DerelictUtil\source\derelict\util\wintypes.d" />
+    <File path="..\DerelictUtil\source\derelict\util\xtypes.d" />
+   </Folder>
+   <Folder name="DerelictFI">
+    <File path="..\DerelictFI\source\derelict\freeimage\freeimage.d" />
+    <File path="..\DerelictFI\source\derelict\freeimage\functions.d" />
+    <File path="..\DerelictFI\source\derelict\freeimage\types.d" />
    </Folder>
    <Folder name="gl3n">
     <File path="..\gl3n\gl3n\aabb.d" />

src/dlangui/graphics/images.d

@@ -216,9 +216,12 @@ ColorDrawBuf loadImage(string filename) {
 ColorDrawBuf loadImage(InputStream stream) {
     if (stream is null || !stream.isOpen)
         return null;
-    // TODO: support more image types
+	static if (USE_FREEIMAGE) {
+		return loadFreeImage(stream);
+	} else static if (USE_LIBPNG) {
 	    return loadPngImage(stream);
 	}
+}
 
 class ImageDecodingException : Exception {
     this(string msg) {
@@ -226,6 +229,100 @@ class ImageDecodingException : Exception {
     }
 }
 
+immutable bool USE_LIBPNG = false;
+immutable bool USE_FREEIMAGE = true;
+
+shared static this() {
+	//import derelict.freeimage.freeimage;
+	//DerelictFI.load();
+}
+
+static if (USE_FREEIMAGE) {
+	ColorDrawBuf loadFreeImage(InputStream stream) {
+		import derelict.freeimage.freeimage;
+
+		static bool FREE_IMAGE_LOADED;
+		if (!FREE_IMAGE_LOADED) {
+			DerelictFI.load();
+			FREE_IMAGE_LOADED = true;
+		}
+
+		ubyte imagebuf[];
+		ubyte readbuf[4096];
+		for (;;) {
+			size_t bytesRead = stream.read(readbuf);
+			if (!bytesRead)
+				break;
+			imagebuf ~= readbuf[0..bytesRead];
+		}
+		//pointer to the image, once loaded
+		FIBITMAP *dib = null;		//image format
+		FREE_IMAGE_FORMAT fif = FIF_UNKNOWN;
+		// attach the binary data to a memory stream
+		FIMEMORY *hmem = FreeImage_OpenMemory(imagebuf.ptr, imagebuf.length);
+		fif = FreeImage_GetFileTypeFromMemory(hmem);
+		//check that the plugin has reading capabilities and load the file
+		if(!FreeImage_FIFSupportsReading(fif)) {
+			FreeImage_CloseMemory(hmem);
+			return null;
+		}
+
+		// load an image from the memory stream
+		dib = FreeImage_LoadFromMemory(fif, hmem, 0);
+		
+		//if the image failed to load, return failure
+		if (!dib) {
+			Log.e("Failed to decode image");
+			FreeImage_CloseMemory(hmem);
+			return null;
+		}
+		//retrieve the image data
+		ubyte * data = cast(ubyte*)FreeImage_GetBits(dib);
+		//get the image width and height, and size per pixel
+		int width = FreeImage_GetWidth(dib);
+		int height = FreeImage_GetHeight(dib);
+		int pixelSize = FreeImage_GetBPP(dib)/8;
+		int size = width*height*pixelSize;
+
+		ColorDrawBuf res = new ColorDrawBuf(width, height);
+
+		//swap R and B and invert image while copying
+		ubyte* src;
+		uint* dst;
+		uint r, g, b, a;
+		for( int i = 0, ii = height-1; i < height ; ++i, --ii ) {
+			dst = res.scanLine(i);
+			src = data + (ii * width) * pixelSize;
+			for( int j = 0; j < width; ++j, ++dst, src += pixelSize ) {
+				a = 0;
+				switch (pixelSize) {
+				case 4:
+					a = src[3] ^ 255;
+				case 3:
+					r = src[2];
+					g = src[1];
+					b = src[0];
+					break;
+				case 2:
+					// todo: do something better
+					r = g = src[1];
+					b = src[0];
+					break;
+				default:
+				case 1:
+					r = g = b = src[0];
+					break;
+				}
+				dst[0] = (a << 24) | (r << 16) | (g << 8) | b;
+			}
+		}
+		FreeImage_CloseMemory(hmem);
+		return res;
+	}
+}
+
+static if (USE_LIBPNG) {
+
 	extern (C) void lvpng_error_func (png_structp png, png_const_charp msg)
 	{
 		string s = fromStringz(msg);
@@ -333,3 +430,4 @@ ColorDrawBuf loadPngImage(InputStream stream)
 		//return( !png_sig_cmp((unsigned char *)buf, (png_size_t)0, 4) );
 	//}
 
+}