feat: add smooth zoom option (#1890)

src/main/java/com/gtnewhorizons/angelica/zoom/Zoom.java

@@ -4,6 +4,8 @@ import cpw.mods.fml.client.registry.ClientRegistry;
 import cpw.mods.fml.common.FMLCommonHandler;
 import cpw.mods.fml.common.eventhandler.SubscribeEvent;
 import cpw.mods.fml.common.gameevent.InputEvent;
+import cpw.mods.fml.common.gameevent.TickEvent;
+import jss.notfine.core.Settings;
 import lombok.Getter;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.settings.KeyBinding;
@@ -19,6 +21,13 @@ public class Zoom {
 
     @Getter
     private static float zoom = ZOOM_DEFAULT;
+
+    public static final float ZOOM_SMOOTH_SNAP_EPSILON = 0.001F;
+
+    @Getter
+    private static float currentZoom = 1.0F;
+    private static long zoomLerpLastNano = 0L;
+
     @Getter
     private static final KeyBinding zoomKey = new KeyBinding("Zoom", 0, "key.categories.misc");
 
@@ -38,6 +47,29 @@ public class Zoom {
         zoom = MathHelper.clamp_float((float) (zoom * Math.pow(ZOOM_STEP, Integer.signum(eventDWheel))), ZOOM_MIN, ZOOM_MAX);
     }
 
+    public static void updateZoomLerp() {
+        final long now = System.nanoTime();
+        float dt = zoomLerpLastNano == 0L ? 0.0F : (now - zoomLerpLastNano) / 1.0e9F;
+        zoomLerpLastNano = now;
+
+        final float target = zoomEnabled ? zoom : 1.0F;
+
+        if (dt <= 0.0F || !(boolean) Settings.ZOOM_SMOOTH.option.getStore()) {
+            currentZoom = target;
+            return;
+        }
+
+        // Clamp dt so a long frame (alt-tab, GC pause) does not snap the zoom.
+        dt = Math.min(dt, 0.1F);
+
+        final int rate = (int) Settings.ZOOM_SMOOTH_SPEED.option.getStore();
+        currentZoom += (target - currentZoom) * (1.0F - (float) Math.exp(-dt * rate));
+
+        if (Math.abs(target - currentZoom) < ZOOM_SMOOTH_SNAP_EPSILON) {
+            currentZoom = target;
+        }
+    }
+
     private static void resetMouseFilters(Minecraft mc) {
         if (mc.entityRenderer != null) {
             ((IMouseFilterExt) mc.entityRenderer.mouseFilterXAxis).angelica$reset();
@@ -79,4 +111,10 @@ public class Zoom {
             handleKeyEvent();
         }
     }
+
+    @SubscribeEvent
+    public void onRenderTick(TickEvent.RenderTickEvent e) {
+        if (e.phase != TickEvent.Phase.START) return;
+        updateZoomLerp();
+    }
 }

src/main/java/jss/notfine/core/Settings.java

@@ -174,7 +174,9 @@ public enum Settings {
             RenderStars.reloadStarRenderList(Minecraft.getMinecraft().renderGlobal);
         }
     },
-    VOID_FOG(new NotFineOptionTickBox(false, OptionImpact.LOW));
+    VOID_FOG(new NotFineOptionTickBox(false, OptionImpact.LOW)),
+    ZOOM_SMOOTH(new NotFineOptionTickBox(true, OptionImpact.LOW)),
+    ZOOM_SMOOTH_SPEED(new NotFineOptionSlider(14, 1, 30, 1, OptionImpact.LOW));
 
     public final NotFineOption<?> option;
 

src/main/java/jss/notfine/gui/NotFineGameOptionPages.java

@@ -1,6 +1,7 @@
 package jss.notfine.gui;
 
 import com.google.common.collect.ImmutableList;
+import com.gtnewhorizons.angelica.config.AngelicaConfig;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import jss.notfine.config.NotFineConfig;
 import jss.notfine.core.Settings;
@@ -169,6 +170,12 @@ public class NotFineGameOptionPages {
                 .build());
         }
 
+        if (AngelicaConfig.enableZoom) {
+            groups.add(OptionGroup.createBuilder()
+                .add(Settings.ZOOM_SMOOTH.option)
+                .add(Settings.ZOOM_SMOOTH_SPEED.option)
+                .build());
+        }
 
         return new OptionPage(I18n.format("options.video"), ImmutableList.copyOf(groups));
     }

src/main/java/me/jellysquid/mods/sodium/client/gui/SodiumGameOptionPages.java

@@ -532,6 +532,13 @@ public class SodiumGameOptionPages {
                         .build())
                 .build());
 
+        if (AngelicaConfig.enableZoom) {
+            groups.add(OptionGroup.createBuilder()
+                .add(Settings.ZOOM_SMOOTH.option)
+                .add(Settings.ZOOM_SMOOTH_SPEED.option)
+                .build());
+        }
+
         return new OptionPage(I18n.format("sodium.options.pages.appearance"), ImmutableList.copyOf(groups));
     }
 

src/main/resources/assets/notfine/lang/en_US.lang

@@ -78,3 +78,7 @@ options.void_fog=Void Fog
 options.void_fog.tooltip=Void Fog
 options.hurt_shake=Hurt Screen Shake
 options.background.random=Random
+options.zoom_smooth=Smooth Zoom
+options.zoom_smooth.tooltip=Smoothly interpolates the camera toward the zoom level instead of snapping instantly.
+options.zoom_smooth_speed=Smooth Zoom Speed
+options.zoom_smooth_speed.tooltip=How fast smooth zoom converges to the target zoom. Higher is snappier, lower is floatier. No effect when Smooth Zoom is off.

src/mixin/java/com/gtnewhorizons/angelica/mixins/early/angelica/zoom/MixinEntityRenderer_Zoom.java

@@ -16,10 +16,8 @@ public class MixinEntityRenderer_Zoom {
 
     @ModifyReturnValue(method = "getFOVModifier", at = @At("RETURN"))
     private float angelica$modifyFOV(float original) {
-        if (Zoom.getZoomKey().getIsKeyPressed()) {
-            return original / Zoom.getZoom();
-        }
-        return original;
+        final float current = Zoom.getCurrentZoom();
+        return current > 1.0001F ? original / current : original;
     }
 
     @ModifyConstant(method = "updateCameraAndRender", constant = @Constant(floatValue = 8.0F))