From 84a32581b76cd80b74ef82543f5c9e7455d4d0a6 Mon Sep 17 00:00:00 2001
From: mcrcortex <18544518+MCRcortex@users.noreply.github.com>
Date: Fri, 2 May 2025 16:12:47 +1000
Subject: [PATCH] Attempted improvements for outline performance

---
 .../client/core/rendering/ChunkBoundRenderer.java  | 14 ++++++++++++--
 .../assets/voxy/shaders/chunkoutline/outline.vsh   |  4 +++-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/main/java/me/cortex/voxy/client/core/rendering/ChunkBoundRenderer.java b/src/main/java/me/cortex/voxy/client/core/rendering/ChunkBoundRenderer.java
index 31ce07d6..506113d5 100644
--- a/src/main/java/me/cortex/voxy/client/core/rendering/ChunkBoundRenderer.java
+++ b/src/main/java/me/cortex/voxy/client/core/rendering/ChunkBoundRenderer.java
@@ -26,6 +26,7 @@ import static org.lwjgl.opengl.GL30.glBindVertexArray;
 import static org.lwjgl.opengl.GL30C.*;
 import static org.lwjgl.opengl.GL31.GL_UNIFORM_BUFFER;
 import static org.lwjgl.opengl.GL31.glDrawElementsInstanced;
+import static org.lwjgl.opengl.GL42.glDrawElementsInstancedBaseInstance;
 import static org.lwjgl.opengl.GL45.glClearNamedFramebufferfv;
 
 //This is a render subsystem, its very simple in what it does
@@ -134,10 +135,19 @@ public class ChunkBoundRenderer {
         glBindFramebuffer(GL_FRAMEBUFFER, this.frameBuffer.id);
         this.rasterShader.bind();
         glBindBufferBase(GL_UNIFORM_BUFFER, 0, this.uniformBuffer.id);
-        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, SharedIndexBuffer.INSTANCE.id());
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, SharedIndexBuffer.INSTANCE_BYTE.id());
         //TODO: BATCH with multiple cubes per instance, this helps fill the pipe and should greatly improve performance of this
 
-        glDrawElementsInstanced(GL_TRIANGLES, 6*2*3, GL_UNSIGNED_BYTE, SharedIndexBuffer.CUBE_INDEX_OFFSET, this.chunk2idx.size());
+        int count = this.chunk2idx.size();
+        int i = 0;
+        if (count/32 > 0) {
+            glDrawElementsInstanced(GL_TRIANGLES, 6 * 2 * 3 * 32, GL_UNSIGNED_BYTE, SharedIndexBuffer.CUBE_INDEX_OFFSET, count/32);
+            i = (count/32)*32;
+            count -= i;
+        }
+        if (count > 0) {
+            glDrawElementsInstancedBaseInstance(GL_TRIANGLES, 6 * 2 * 3 * count, GL_UNSIGNED_BYTE, SharedIndexBuffer.CUBE_INDEX_OFFSET, 1, i);
+        }
 
         {
             glFrontFace(GL_CCW);//Restore winding order
diff --git a/src/main/resources/assets/voxy/shaders/chunkoutline/outline.vsh b/src/main/resources/assets/voxy/shaders/chunkoutline/outline.vsh
index 81dbd780..e8d61f9a 100644
--- a/src/main/resources/assets/voxy/shaders/chunkoutline/outline.vsh
+++ b/src/main/resources/assets/voxy/shaders/chunkoutline/outline.vsh
@@ -11,7 +11,9 @@ layout(binding = 1, std430) restrict readonly buffer ChunkPosBuffer {
 };
 
 void main() {
-    ivec3 origin = ivec3(chunkPos[gl_InstanceID], 0).xzy;
+    uint id = gl_InstanceID+gl_BaseInstance+(gl_VertexID>>3);
+
+    ivec3 origin = ivec3(chunkPos[id], 0).xzy;
     origin -= section.xyz;
 
     ivec3 cubeCornerI = ivec3(gl_VertexID&1, (gl_VertexID>>2)&1, (gl_VertexID>>1)&1);