From 8462dde3749cd66ff9286fe82e17ceb88fa8af93 Mon Sep 17 00:00:00 2001
From: mcrcortex <18544518+MCRcortex@users.noreply.github.com>
Date: Tue, 3 Jun 2025 00:08:01 +1000
Subject: [PATCH] use provoking vertex

---
 .../core/rendering/section/MDICSectionRenderer.java |  2 ++
 .../assets/voxy/shaders/lod/gl46/quads2.vert        | 13 ++++++++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/main/java/me/cortex/voxy/client/core/rendering/section/MDICSectionRenderer.java b/src/main/java/me/cortex/voxy/client/core/rendering/section/MDICSectionRenderer.java
index c878c7a1..1c1a6f7d 100644
--- a/src/main/java/me/cortex/voxy/client/core/rendering/section/MDICSectionRenderer.java
+++ b/src/main/java/me/cortex/voxy/client/core/rendering/section/MDICSectionRenderer.java
@@ -136,6 +136,7 @@ public class MDICSectionRenderer extends AbstractSectionRenderer<MDICViewport, B
         this.bindRenderingBuffers(viewport, depthBoundTexture);
 
         glMemoryBarrier(GL_COMMAND_BARRIER_BIT|GL_SHADER_STORAGE_BARRIER_BIT);//Barrier everything is needed
+        glProvokingVertex(GL_FIRST_VERTEX_CONVENTION);
         glMultiDrawElementsIndirectCountARB(GL_TRIANGLES, GL_UNSIGNED_SHORT, indirectOffset, drawCountOffset, maxDrawCount, 0);
 
         glEnable(GL_CULL_FACE);
@@ -169,6 +170,7 @@ public class MDICSectionRenderer extends AbstractSectionRenderer<MDICViewport, B
         glBindVertexArray(RenderService.STATIC_VAO);//Needs to be before binding
         this.bindRenderingBuffers(viewport, depthBoundTexture);
 
+        glProvokingVertex(GL_FIRST_VERTEX_CONVENTION);
         glMultiDrawElementsIndirectCountARB(GL_TRIANGLES, GL_UNSIGNED_SHORT, TRANSLUCENT_OFFSET*5*4, 4*4, Math.min(this.geometryManager.getSectionCount(), 100_000), 0);
 
         glEnable(GL_CULL_FACE);
diff --git a/src/main/resources/assets/voxy/shaders/lod/gl46/quads2.vert b/src/main/resources/assets/voxy/shaders/lod/gl46/quads2.vert
index ab2c9b5b..713d57bb 100644
--- a/src/main/resources/assets/voxy/shaders/lod/gl46/quads2.vert
+++ b/src/main/resources/assets/voxy/shaders/lod/gl46/quads2.vert
@@ -104,13 +104,16 @@ void main() {
     uvec2 encPos = positionBuffer[gl_BaseInstance];
     uint lodLevel = extractDetail(encPos);
 
-
-    vec2 modelUV = vec2(modelId&0xFFu, (modelId>>8)&0xFFu)*(1.0/(256.0));
-    baseUV = modelUV + (vec2(face>>1, face&1u) * (1.0/(vec2(3.0, 2.0)*256.0)));
-
     ivec2 quadSize = extractSize(quad);
 
-    { //Generate tinting and flag data
+
+
+    if (cornerIdx == 1) //Only if we are the provoking vertex
+    {
+        vec2 modelUV = vec2(modelId&0xFFu, (modelId>>8)&0xFFu)*(1.0/(256.0));
+        baseUV = modelUV + (vec2(face>>1, face&1u) * (1.0/(vec2(3.0, 2.0)*256.0)));
+
+        //Generate tinting and flag data
         flags = faceHasAlphaCuttout(faceData);
 
         //We need to have a conditional override based on if the model size is < a full face + quadSize > 1