From ec7d9d417987d69aadb7926eb07be9a6d3b6da8b Mon Sep 17 00:00:00 2001
From: Funwayguy <FunwayguyEmail@gmail.com>
Date: Mon, 2 Mar 2020 08:45:03 +0100
Subject: [PATCH] Re-added patch to enable stencil buffer in
 net.minecraft.client.shader.Framebuffer Add test for the stencil buffer
 feature. Only tests that it doesn't crash when enabling, for now. - giga

---
 .../client/shader/Framebuffer.java.patch      | 46 +++++++++++++++++++
 .../client/rendering/StencilEnableTest.java   | 18 ++++++++
 src/test/resources/META-INF/mods.toml         |  2 +
 3 files changed, 66 insertions(+)
 create mode 100644 patches/minecraft/net/minecraft/client/shader/Framebuffer.java.patch
 create mode 100644 src/test/java/net/minecraftforge/debug/client/rendering/StencilEnableTest.java

diff --git a/patches/minecraft/net/minecraft/client/shader/Framebuffer.java.patch b/patches/minecraft/net/minecraft/client/shader/Framebuffer.java.patch
new file mode 100644
index 000000000..6369428f5
--- /dev/null
+++ b/patches/minecraft/net/minecraft/client/shader/Framebuffer.java.patch
@@ -0,0 +1,46 @@
+--- a/net/minecraft/client/shader/Framebuffer.java
++++ b/net/minecraft/client/shader/Framebuffer.java
+@@ -100,8 +100,14 @@
+       GlStateManager.func_227645_a_(FramebufferConstants.field_227592_a_, FramebufferConstants.field_227594_c_, 3553, this.field_147617_g, 0);
+       if (this.field_147619_e) {
+          GlStateManager.func_227730_i_(FramebufferConstants.field_227593_b_, this.field_147624_h);
++         if (!stencilEnabled) {
+          GlStateManager.func_227678_b_(FramebufferConstants.field_227593_b_, 33190, this.field_147622_a, this.field_147620_b);
+          GlStateManager.func_227693_c_(FramebufferConstants.field_227592_a_, FramebufferConstants.field_227595_d_, FramebufferConstants.field_227593_b_, this.field_147624_h);
++         } else {
++         GlStateManager.func_227678_b_(FramebufferConstants.field_227593_b_, org.lwjgl.opengl.EXTPackedDepthStencil.GL_DEPTH24_STENCIL8_EXT, this.field_147622_a, this.field_147620_b);
++         GlStateManager.func_227693_c_(FramebufferConstants.field_227592_a_, org.lwjgl.opengl.EXTFramebufferObject.GL_DEPTH_ATTACHMENT_EXT, FramebufferConstants.field_227593_b_, this.field_147624_h);
++         GlStateManager.func_227693_c_(FramebufferConstants.field_227592_a_, org.lwjgl.opengl.EXTFramebufferObject.GL_STENCIL_ATTACHMENT_EXT, FramebufferConstants.field_227593_b_, this.field_147624_h);
++         }
+       }
+ 
+       this.func_147611_b();
+@@ -254,4 +260,28 @@
+       GlStateManager.func_227658_a_(i, p_216493_1_);
+       this.func_147609_e();
+    }
++
++    /*================================ FORGE START ================================================*/
++    private boolean stencilEnabled = false;
++    /**
++     * Attempts to enabled 8 bits of stencil buffer on this FrameBuffer.
++     * Modders must call this directly to set things up.
++     * This is to prevent the default cause where graphics cards do not support stencil bits.
++     */
++    public void enableStencil()
++    {
++        if(stencilEnabled) return;
++        stencilEnabled = true;
++        this.func_216491_a(field_147621_c, field_147618_d, net.minecraft.client.Minecraft.field_142025_a);
++    }
++
++    /**
++     * Returns wither or not this FBO has been successfully initialized with stencil bits.
++     * If not, and a modder wishes it to be, they must call enableStencil.
++     */
++    public boolean isStencilEnabled()
++    {
++        return this.stencilEnabled;
++    }
++    /*================================ FORGE END   ================================================*/
+ }
diff --git a/src/test/java/net/minecraftforge/debug/client/rendering/StencilEnableTest.java b/src/test/java/net/minecraftforge/debug/client/rendering/StencilEnableTest.java
new file mode 100644
index 000000000..0ca0993b4
--- /dev/null
+++ b/src/test/java/net/minecraftforge/debug/client/rendering/StencilEnableTest.java
@@ -0,0 +1,18 @@
+package net.minecraftforge.debug.client.rendering;
+
+import net.minecraft.client.Minecraft;
+import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.event.lifecycle.FMLClientSetupEvent;
+import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
+
+@Mod("stencil_enable_test")
+public class StencilEnableTest {
+    public StencilEnableTest() {
+        FMLJavaModLoadingContext.get().getModEventBus().addListener(this::clientSetup);
+    }
+
+    private void clientSetup(FMLClientSetupEvent event) {
+        Minecraft.getInstance().getFramebuffer().enableStencil();
+    }
+}
diff --git a/src/test/resources/META-INF/mods.toml b/src/test/resources/META-INF/mods.toml
index 6a7aa666d..0115bbec8 100644
--- a/src/test/resources/META-INF/mods.toml
+++ b/src/test/resources/META-INF/mods.toml
@@ -69,6 +69,8 @@ loaderVersion="[28,)"
     modId="composite_model_test"
 [[mods]]
     modId="music_disc_test"
+[[mods]]
+    modId="stencil_enable_test"
 [[dependencies.global_loot_test]]
     modId="forge"
     mandatory=true