Fix paths of files that are supposed to be in the mc data dir (fixes #40)

src/main/java/com/replaymod/render/ReplayModRender.java

@@ -1,11 +1,17 @@
 package com.replaymod.render;
 
 import com.replaymod.core.ReplayMod;
+import net.minecraft.crash.CrashReport;
+import net.minecraft.util.ReportedException;
 import net.minecraftforge.common.config.Configuration;
 import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
+import org.apache.commons.io.FileUtils;
 import org.apache.logging.log4j.Logger;
 
+import java.io.File;
+import java.io.IOException;
+
 @Mod(modid = ReplayModRender.MOD_ID, useMetadata = true)
 public class ReplayModRender {
     public static final String MOD_ID = "replaymod-render";
@@ -32,6 +38,17 @@ public class ReplayModRender {
         core.getSettingsRegistry().register(Setting.class);
     }
 
+    public File getVideoFolder() {
+        String path = core.getSettingsRegistry().get(Setting.RENDER_PATH);
+        File folder = new File(path.startsWith("./") ? core.getMinecraft().mcDataDir : null, path);
+        try {
+            FileUtils.forceMkdir(folder);
+        } catch (IOException e) {
+            throw new ReportedException(CrashReport.makeCrashReport(e, "Cannot create video folder."));
+        }
+        return folder;
+    }
+
     public Configuration getConfiguration() {
         return configuration;
     }