Added parallax effect for menu backgrounds.

Signed-off-by: Jeffrey Han <itdelatrisu@gmail.com>

src/itdelatrisu/opsu/GameImage.java

@@ -407,6 +407,9 @@ protected Image process_sub(Image img, int w, int h) {
 	/** The unscaled container height that uiscale is based on. */
 	private static final int UNSCALED_HEIGHT = 768;
 
+	/** Value to scale backgrounds for the parallax effect. */
+	public static final float PARALLAX_SCALE = 1.008f;
+
 	/** Filename suffix for HD images. */
 	public static final String HD_SUFFIX = "@2x";
 

src/itdelatrisu/opsu/OptionGroup.java

@@ -36,7 +36,8 @@ public class OptionGroup {
 			GameOption.SCREENSHOT_FORMAT,
 			GameOption.DYNAMIC_BACKGROUND,
 			GameOption.LOAD_HD_IMAGES,
-			GameOption.LOAD_VERBOSE
+			GameOption.LOAD_VERBOSE,
+			GameOption.PARALLAX
 		}),
 		new OptionGroup("Music", new GameOption[] {
 			GameOption.MASTER_VOLUME,

src/itdelatrisu/opsu/Options.java

@@ -617,6 +617,7 @@ public String getValueString() {
 						val - TimeUnit.MINUTES.toSeconds(TimeUnit.SECONDS.toMinutes(val)));
 			}
 		},
+		PARALLAX ("Parallax", "MenuParallax", "Add a parallax effect based on the current cursor position.", true),
 		ENABLE_THEME_SONG ("Enable Theme Song", "MenuMusic", "Whether to play the theme song upon starting opsu!", true),
 		REPLAY_SEEKING ("Replay Seeking", "ReplaySeeking", "Enable a seeking bar on the left side of the screen during replays.", false),
 		DISABLE_UPDATER ("Disable Automatic Updates", "DisableUpdater", "Disable automatic checking for updates upon starting opsu!.", false),
@@ -1144,6 +1145,12 @@ public static void setDisplayMode(Container app) {
 	 */
 	public static boolean useUnicodeMetadata() { return GameOption.SHOW_UNICODE.getBooleanValue(); }
 
+	/**
+	 * Returns whether parallax is enabled.
+	 * @return true if enabled
+	 */
+	public static boolean isParallaxEnabled() { return GameOption.PARALLAX.getBooleanValue(); }
+
 	/**
 	 * Returns whether or not to play the theme song.
 	 * @return true if enabled

src/itdelatrisu/opsu/beatmap/Beatmap.java

@@ -18,6 +18,7 @@
 
 package itdelatrisu.opsu.beatmap;
 
+import itdelatrisu.opsu.GameImage;
 import itdelatrisu.opsu.Options;
 
 import java.io.File;
@@ -323,11 +324,13 @@ public boolean isBackgroundLoading() {
 	 * Draws the beatmap background image.
 	 * @param width the container width
 	 * @param height the container height
+	 * @param offsetX the x offset (from the screen center)
+	 * @param offsetY the y offset (from the screen center)
 	 * @param alpha the alpha value
 	 * @param stretch if true, stretch to screen dimensions; otherwise, maintain aspect ratio
 	 * @return true if successful, false if any errors were produced
 	 */
-	public boolean drawBackground(int width, int height, float alpha, boolean stretch) {
+	public boolean drawBackground(int width, int height, float offsetX, float offsetY, float alpha, boolean stretch) {
 		if (bg == null)
 			return false;
 
@@ -354,9 +357,16 @@ public boolean drawBackground(int width, int height, float alpha, boolean stretc
 			else
 				sheight = (int) (width * bgImage.getHeight() / (float) bgImage.getWidth());
 		}
+		if (Options.isParallaxEnabled()) {
+			swidth = (int) (swidth * GameImage.PARALLAX_SCALE);
+			sheight = (int) (sheight * GameImage.PARALLAX_SCALE);
+		}
 		bgImage = bgImage.getScaledCopy(swidth, sheight);
 		bgImage.setAlpha(alpha);
-		bgImage.drawCentered(width / 2, height / 2);
+		if (!Options.isParallaxEnabled() && offsetX == 0f && offsetY == 0f)
+			bgImage.drawCentered(width / 2, height / 2);
+		else
+			bgImage.drawCentered(width / 2 + offsetX, height / 2 + offsetY);
 		return true;
 	}
 

src/itdelatrisu/opsu/states/DownloadsMenu.java

@@ -417,7 +417,15 @@ public void render(GameContainer container, StateBasedGame game, Graphics g)
 		boolean inDropdownMenu = serverMenu.contains(mouseX, mouseY);
 
 		// background
-		GameImage.SEARCH_BG.getImage().draw();
+		Image bg = GameImage.SEARCH_BG.getImage();
+		if (Options.isParallaxEnabled()) {
+			int offset = (int) (height * (GameImage.PARALLAX_SCALE - 1f));
+			float parallaxX = -offset / 2f * (mouseX - width / 2) / (width / 2);
+			float parallaxY = -offset / 2f * (mouseY - height / 2) / (height / 2);
+			bg = bg.getScaledCopy(GameImage.PARALLAX_SCALE);
+			bg.drawCentered(width / 2 + parallaxX, height / 2 + parallaxY);
+		} else
+			bg.drawCentered(width / 2, height / 2);
 
 		// title
 		Fonts.LARGE.drawString(width * 0.024f, height * 0.03f, "Download Beatmaps!", Color.white);

src/itdelatrisu/opsu/states/Game.java

@@ -367,11 +367,11 @@ else if (deathTime > -1)  // "Easy" mod: health bar increasing
 			else
 				dimLevel = 1f;
 		}
-		if (Options.isDefaultPlayfieldForced() || !beatmap.drawBackground(width, height, dimLevel, false)) {
-			Image playfield = GameImage.MENU_BG.getImage();
-			playfield.setAlpha(dimLevel);
-			playfield.draw();
-			playfield.setAlpha(1f);
+		if (Options.isDefaultPlayfieldForced() || !beatmap.drawBackground(width, height, 0, 0, dimLevel, false)) {
+			Image bg = GameImage.MENU_BG.getImage();
+			bg.setAlpha(dimLevel);
+			bg.drawCentered(width / 2, height / 2);
+			bg.setAlpha(1f);
 		}
 
 		if (GameMod.FLASHLIGHT.isActive())

src/itdelatrisu/opsu/states/GamePauseMenu.java

@@ -83,7 +83,7 @@ public void render(GameContainer container, StateBasedGame game, Graphics g)
 			GameImage.PAUSE_RETRY.hasBeatmapSkinImage() ||
 			GameImage.PAUSE_BACK.hasBeatmapSkinImage();
 		if (!buttonsSkinned || bg.hasBeatmapSkinImage())
-			bg.getImage().draw();
+			bg.getImage().drawCentered(container.getWidth() / 2, container.getHeight() / 2);
 		else
 			g.setBackground(Color.black);
 

src/itdelatrisu/opsu/states/GameRanking.java

@@ -105,15 +105,28 @@ public void render(GameContainer container, StateBasedGame game, Graphics g)
 			throws SlickException {
 		int width = container.getWidth();
 		int height = container.getHeight();
+		int mouseX = input.getMouseX(), mouseY = input.getMouseY();
 
 		Beatmap beatmap = MusicController.getBeatmap();
 
 		// background
-		if (!beatmap.drawBackground(width, height, 0.5f, true)) {
-			Image playfield = GameImage.MENU_BG.getImage();
-			playfield.setAlpha(0.5f);
-			playfield.draw();
-			playfield.setAlpha(1f);
+		float parallaxX = 0, parallaxY = 0;
+		if (Options.isParallaxEnabled()) {
+			int offset = (int) (height * (GameImage.PARALLAX_SCALE - 1f));
+			parallaxX = -offset / 2f * (mouseX - width / 2) / (width / 2);
+			parallaxY = -offset / 2f * (mouseY - height / 2) / (height / 2);
+		}
+		if (!beatmap.drawBackground(width, height, parallaxX, parallaxY, 0.5f, true)) {
+			Image bg = GameImage.MENU_BG.getImage();
+			if (Options.isParallaxEnabled()) {
+				bg = bg.getScaledCopy(GameImage.PARALLAX_SCALE);
+				bg.setAlpha(0.5f);
+				bg.drawCentered(width / 2 + parallaxX, height / 2 + parallaxY);
+			} else {
+				bg.setAlpha(0.5f);
+				bg.drawCentered(width / 2, height / 2);
+				bg.setAlpha(1f);
+			}
 		}
 
 		// ranking screen elements

src/itdelatrisu/opsu/states/MainMenu.java

@@ -238,16 +238,30 @@ public void render(GameContainer container, StateBasedGame game, Graphics g)
 			throws SlickException {
 		int width = container.getWidth();
 		int height = container.getHeight();
+		int mouseX = input.getMouseX(), mouseY = input.getMouseY();
 
-		// draw background
 		Beatmap beatmap = MusicController.getBeatmap();
-		if (Options.isDynamicBackgroundEnabled() &&
-			beatmap != null && beatmap.drawBackground(width, height, bgAlpha.getValue(), true))
-				;
+
+		// draw background
+		float parallaxX = 0, parallaxY = 0;
+		if (Options.isParallaxEnabled()) {
+			int offset = (int) (height * (GameImage.PARALLAX_SCALE - 1f));
+			parallaxX = -offset / 2f * (mouseX - width / 2) / (width / 2);
+			parallaxY = -offset / 2f * (mouseY - height / 2) / (height / 2);
+		}
+		if (Options.isDynamicBackgroundEnabled() && beatmap != null &&
+			beatmap.drawBackground(width, height, parallaxX, parallaxY, bgAlpha.getValue(), true))
+			;
 		else {
 			Image bg = GameImage.MENU_BG.getImage();
-			bg.setAlpha(bgAlpha.getValue());
-			bg.draw();
+			if (Options.isParallaxEnabled()) {
+				bg = bg.getScaledCopy(GameImage.PARALLAX_SCALE);
+				bg.setAlpha(bgAlpha.getValue());
+				bg.drawCentered(width / 2 + parallaxX, height / 2 + parallaxY);
+			} else {
+				bg.setAlpha(bgAlpha.getValue());
+				bg.drawCentered(width / 2, height / 2);
+			}
 		}
 
 		// top/bottom horizontal bars
@@ -289,7 +303,6 @@ public void render(GameContainer container, StateBasedGame game, Graphics g)
 		musicPrevious.draw();
 
 		// draw music position bar
-		int mouseX = input.getMouseX(), mouseY = input.getMouseY();
 		g.setColor((musicPositionBarContains(mouseX, mouseY)) ? Colors.BLACK_BG_HOVER : Colors.BLACK_BG_NORMAL);
 		g.fillRoundRect(musicBarX, musicBarY, musicBarWidth, musicBarHeight, 4);
 		g.setColor(Color.white);

src/itdelatrisu/opsu/states/SongMenu.java

@@ -496,11 +496,23 @@ public void render(GameContainer container, StateBasedGame game, Graphics g)
 		// background
 		if (focusNode != null) {
 			Beatmap focusNodeBeatmap = focusNode.getSelectedBeatmap();
-			if (!focusNodeBeatmap.drawBackground(width, height, bgAlpha.getValue(), true)) {
-				Image playfield = GameImage.MENU_BG.getImage();
-				playfield.setAlpha(bgAlpha.getValue());
-				playfield.draw();
-				playfield.setAlpha(1f);
+			float parallaxX = 0, parallaxY = 0;
+			if (Options.isParallaxEnabled()) {
+				int offset = (int) (height * (GameImage.PARALLAX_SCALE - 1f));
+				parallaxX = -offset / 2f * (mouseX - width / 2) / (width / 2);
+				parallaxY = -offset / 2f * (mouseY - height / 2) / (height / 2);
+			}
+			if (!focusNodeBeatmap.drawBackground(width, height, parallaxX, parallaxY, bgAlpha.getValue(), true)) {
+				Image bg = GameImage.MENU_BG.getImage();
+				if (Options.isParallaxEnabled()) {
+					bg = bg.getScaledCopy(GameImage.PARALLAX_SCALE);
+					bg.setAlpha(bgAlpha.getValue());
+					bg.drawCentered(width / 2 + parallaxX, height / 2 + parallaxY);
+				} else {
+					bg.setAlpha(bgAlpha.getValue());
+					bg.drawCentered(width / 2, height / 2);
+					bg.setAlpha(1f);
+				}
 			}
 		}