new feature: use pre-drawn leaf textures if available

some refactoring

src/main/java/mods/betterfoliage/common/util/Utils.java

@@ -0,0 +1,70 @@
+package mods.betterfoliage.common.util;
+
+import java.io.IOException;
+import java.lang.reflect.Field;
+import java.util.Map;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.resources.IResource;
+import net.minecraft.client.resources.IResourceManager;
+import net.minecraft.util.ResourceLocation;
+import cpw.mods.fml.client.registry.ISimpleBlockRenderingHandler;
+import cpw.mods.fml.client.registry.RenderingRegistry;
+
+public class Utils {
+
+	private Utils() {}
+	
+	@SuppressWarnings("unchecked")
+	public static Map<String, IResourceManager> getDomainResourceManagers() {
+		IResourceManager manager = Minecraft.getMinecraft().getResourceManager();
+		Map<String, IResourceManager> result = getField(manager, DeobfNames.SRRM_DRM_MCP, Map.class);
+		if (result == null) result = getField(manager, DeobfNames.SRRM_DRM_SRGNAME, Map.class);
+		return result;
+	}
+	
+	@SuppressWarnings("unchecked")
+	public static <T> T getField(Object target, String fieldName, Class<T> resultClass) {
+		try {
+			Field field = target.getClass().getDeclaredField(fieldName);
+			field.setAccessible(true);
+			return (T) field.get(target);
+		} catch (Exception e) {
+			return null;
+		}
+	}
+	
+	@SuppressWarnings("unchecked")
+	public static <T> T getStaticField(Class<?> clazz, String fieldName, Class<T> resultClass) {
+		try {
+			Field field = clazz.getDeclaredField(fieldName);
+			field.setAccessible(true);
+			return (T) field.get(null);
+		} catch (Exception e) {
+			return null;
+		}
+	}
+	
+	@SuppressWarnings("unchecked")
+	public static ISimpleBlockRenderingHandler getRenderingHandler(int renderType) {
+		try {
+			Field field = RenderingRegistry.class.getDeclaredField("INSTANCE");
+			field.setAccessible(true);
+			RenderingRegistry inst = (RenderingRegistry) field.get(null);
+			field = RenderingRegistry.class.getDeclaredField("blockRenderers");
+			field.setAccessible(true);
+			return ((Map<Integer, ISimpleBlockRenderingHandler>) field.get(inst)).get(renderType);
+		} catch (Exception e) {
+			return null;
+		}
+	}
+	
+	public static boolean resourceExists(ResourceLocation resourceLocation) {
+		try {
+			IResource resource = Minecraft.getMinecraft().getResourceManager().getResource(resourceLocation);
+			if (resource != null) return true;
+		} catch (IOException e) {
+		}
+		return false;
+	}
+}