Other way to fix elytra rendering in first person and add some comments

src/main/java/ganymedes01/etfuturum/EtFuturumMixinPlugin.java

@@ -116,7 +116,6 @@ public List<String> getMixins() {
 				mixins.add("backlytra.client.MixinRenderPlayer");
 				mixins.add("backlytra.client.MixinModelBiped");
 				mixins.add("backlytra.client.MixinEntityRenderer");
-				mixins.add("backlytra.client.MixinGuiInventory");
 			}
 		}
 

src/main/java/ganymedes01/etfuturum/client/renderer/entity/elytra/LayerBetterElytra.java

@@ -26,8 +26,10 @@ public class LayerBetterElytra {
 	private static final ResourceLocation TEXTURE_ELYTRA = new ResourceLocation("textures/entity/elytra.png");
 	private static final ModelElytra modelElytra = new ModelElytra();
 	protected static final ResourceLocation ENCHANTED_ITEM_GLINT_RES = new ResourceLocation("textures/misc/enchanted_item_glint.png");
+	public static float netHeadYaw = 0.0F;
+	public static float headPitch = 0.0F;
 
-	public static void doRenderLayer(EntityLivingBase entityIn, float limbSwing, float limbSwingAmount, float partialTicks, float ageInTicks, float netHeadYaw, float headPitch, float scale) {
+	public static void doRenderLayer(EntityLivingBase entityIn, float limbSwing, float limbSwingAmount, float partialTicks, float ageInTicks, float scale) {
 		ItemStack itemstack = ItemArmorElytra.getElytra(entityIn);
 		if (entityIn instanceof AbstractClientPlayer && itemstack != null) {
 			AbstractClientPlayer player = (AbstractClientPlayer) entityIn;

src/main/java/ganymedes01/etfuturum/client/renderer/entity/elytra/ModelElytra.java

@@ -2,10 +2,8 @@
 
 import cpw.mods.fml.relauncher.Side;
 import cpw.mods.fml.relauncher.SideOnly;
-import ganymedes01.etfuturum.core.proxy.ClientProxy;
 import ganymedes01.etfuturum.elytra.IClientElytraPlayer;
 import ganymedes01.etfuturum.elytra.IElytraPlayer;
-import net.minecraft.client.Minecraft;
 import net.minecraft.client.model.ModelBase;
 import net.minecraft.client.model.ModelRenderer;
 import net.minecraft.entity.Entity;
@@ -34,15 +32,8 @@ public void render(Entity entityIn, float p_78088_2_, float limbSwing, float age
 		GL11.glDisable(GL12.GL_RESCALE_NORMAL);
 		GL11.glDisable(GL11.GL_CULL_FACE);
 
-		if (Minecraft.getMinecraft().gameSettings.thirdPersonView == 0 && entityIn == Minecraft.getMinecraft().thePlayer) {
-			if (ClientProxy.isRenderingInventoryPlayer) {
-				this.leftWing.render(scale);
-				this.rightWing.render(scale);
-			}
-		} else {
-			this.leftWing.render(scale);
-			this.rightWing.render(scale);
-		}
+		this.leftWing.render(scale);
+		this.rightWing.render(scale);
 	}
 
 	/**
@@ -54,7 +45,8 @@ public void render(Entity entityIn, float p_78088_2_, float limbSwing, float age
 	@Override
 	public void setRotationAngles(float limbSwing, float limbSwingAmount, float ageInTicks, float netHeadYaw, float headPitch, float scaleFactor, Entity entityIn) {
 		super.setRotationAngles(limbSwing, limbSwingAmount, ageInTicks, netHeadYaw, headPitch, scaleFactor, entityIn);
-		float f = 0.2617994F;
+
+		float f = 0.2617994F; // 15 degrees in radians
 		float f1 = -0.2617994F;
 		float f2 = 0.0F;
 		float f3 = 0.0F;
@@ -67,7 +59,7 @@ public void setRotationAngles(float limbSwing, float limbSwingAmount, float ageI
 				f4 = 1.0F - (float) Math.pow(-vec3d.yCoord, 1.5D);
 			}
 
-			f = f4 * 0.34906584F + (1.0F - f4) * f;
+			f = f4 * 0.34906584F + (1.0F - f4) * f; // 20 degrees in radians
 			f1 = f4 * -((float) Math.PI / 2F) + (1.0F - f4) * f1;
 		} else if (entityIn.isSneaking()) {
 			f = ((float) Math.PI * 2F / 9F);

src/main/java/ganymedes01/etfuturum/core/handlers/ClientEventHandler.java

@@ -18,6 +18,7 @@
 import ganymedes01.etfuturum.client.gui.GuiConfigWarning;
 import ganymedes01.etfuturum.client.gui.GuiGamemodeSwitcher;
 import ganymedes01.etfuturum.client.particle.CustomParticles;
+import ganymedes01.etfuturum.client.renderer.entity.elytra.LayerBetterElytra;
 import ganymedes01.etfuturum.client.sound.AmbienceLoop;
 import ganymedes01.etfuturum.client.sound.BeeFlySound;
 import ganymedes01.etfuturum.client.sound.ElytraSound;
@@ -51,6 +52,7 @@
 import net.minecraft.client.gui.inventory.GuiInventory;
 import net.minecraft.client.particle.EntityDiggingFX;
 import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.entity.passive.EntityHorse;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.event.ClickEvent;
@@ -346,6 +348,10 @@ public void renderPlayerEventPre(RenderPlayerEvent.Pre event) {
 
 	@SubscribeEvent
 	public void renderPlayerSetArmour(SetArmorModel event) {
+		if (event.entityPlayer instanceof IElytraPlayer) {
+			LayerBetterElytra.doRenderLayer(event.entityLiving, event.entityPlayer.limbSwing, event.entityPlayer.limbSwingAmount, Minecraft.getMinecraft().timer.renderPartialTicks, event.entityPlayer.getAge(), 0.0625F);
+		}
+
 		if (isSpectator(event.entityPlayer)) {
 			event.result = 0;
 		} else if (ConfigFunctions.enableTransparentAmour) {

src/main/java/ganymedes01/etfuturum/mixins/backlytra/client/MixinModelBiped.java

@@ -2,11 +2,9 @@
 
 import ganymedes01.etfuturum.client.renderer.entity.elytra.LayerBetterElytra;
 import ganymedes01.etfuturum.elytra.IElytraPlayer;
-import net.minecraft.client.Minecraft;
 import net.minecraft.client.model.ModelBiped;
 import net.minecraft.client.model.ModelRenderer;
 import net.minecraft.entity.Entity;
-import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.util.MathHelper;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
@@ -70,9 +68,8 @@ private void setElytraAngles(float limbSwing, float limbSwingAmount, float ageIn
 	}
 
 	@Inject(method = "setRotationAngles", at = @At("RETURN"))
-	private void renderElytra(float limbSwing, float limbSwingAmount, float ageInTicks, float netHeadYaw, float headPitch, float scaleFactor, Entity entityIn, CallbackInfo ci) {
-		if (entityIn instanceof IElytraPlayer/* && (Minecraft.getMinecraft().gameSettings.thirdPersonView != 0 || Minecraft.getMinecraft().currentScreen instanceof GuiInventory || entityIn != Minecraft.getMinecraft().thePlayer)*/) {
-			LayerBetterElytra.doRenderLayer((EntityLivingBase) entityIn, limbSwing, limbSwingAmount, Minecraft.getMinecraft().timer.renderPartialTicks, ageInTicks, netHeadYaw, headPitch, 0.0625F);
-		}
+	private void hookVars(float limbSwing, float limbSwingAmount, float ageInTicks, float netHeadYaw, float headPitch, float scaleFactor, Entity entityIn, CallbackInfo ci) {
+		LayerBetterElytra.netHeadYaw = netHeadYaw;
+		LayerBetterElytra.headPitch = headPitch;
 	}
 }