meshoptimizer: Update to 1.1.1

(cherry picked from commit f2b42696965815c7d1de1c4303b25e7b5d0ea7b8)

thirdparty/README.md

@@ -720,7 +720,7 @@ Update instructions:
 ## meshoptimizer
 
 - Upstream: https://github.com/zeux/meshoptimizer
-- Version: 1.1 (dc9d09ed83e1004aef47a1c3c597e0ec64848a37, 2026)
+- Version: 1.1.1 (b22872835dbabc56a6e4a366ea9917f62b7daf1a, 2026)
 - License: MIT
 
 Files extracted from upstream repository:

thirdparty/meshoptimizer/allocator.cpp

@@ -1,6 +1,8 @@
 // This file is part of meshoptimizer library; see meshoptimizer.h for version/license details
 #include "meshoptimizer.h"
 
+#include <assert.h>
+
 #ifdef MESHOPTIMIZER_ALLOC_EXPORT
 meshopt_Allocator::Storage& meshopt_Allocator::storage()
 {
@@ -11,6 +13,8 @@ meshopt_Allocator::Storage& meshopt_Allocator::storage()
 
 void meshopt_setAllocator(void* (MESHOPTIMIZER_ALLOC_CALLCONV* allocate)(size_t), void (MESHOPTIMIZER_ALLOC_CALLCONV* deallocate)(void*))
 {
+	assert(allocate && deallocate);
+
 	meshopt_Allocator::Storage& s = meshopt_Allocator::storage();
 	s.allocate = allocate;
 	s.deallocate = deallocate;

thirdparty/meshoptimizer/meshletutils.cpp

@@ -491,7 +491,7 @@ void meshopt_optimizeMeshletLevel(unsigned int* meshlet_vertices, size_t vertex_
 				// if subsequent triangles don't share edges ca or bc, we can rotate the triangle to fix this
 				bool needab = false, needbc = false, needca = false;
 
-				for (size_t j = i + 1; j < triangle_count && j <= i + 3; ++j)
+				for (size_t j = i + 1; j < triangle_count && j <= i + cache_cutoff; ++j)
 				{
 					unsigned char oa = indices[j * 3 + 0], ob = indices[j * 3 + 1], oc = indices[j * 3 + 2];
 
@@ -513,6 +513,12 @@ void meshopt_optimizeMeshletLevel(unsigned int* meshlet_vertices, size_t vertex_
 					unsigned char t = c;
 					c = b, b = a, a = t;
 				}
+				else if (!needab && needbc && !needca)
+				{
+					// abc -> cab: put bc at most recent FIFO position
+					unsigned char t = c;
+					c = b, b = a, a = t;
+				}
 			}
 
 			indices[i * 3 + 0] = a, indices[i * 3 + 1] = b, indices[i * 3 + 2] = c;

thirdparty/meshoptimizer/meshoptimizer.h

@@ -1215,7 +1215,7 @@ template <typename T>
 inline void meshopt_remapIndexBuffer(T* destination, const T* indices, size_t index_count, const unsigned int* remap)
 {
 	meshopt_IndexAdapter<T> in(NULL, indices, indices ? index_count : 0);
-	meshopt_IndexAdapter<T> out(destination, 0, index_count);
+	meshopt_IndexAdapter<T> out(destination, NULL, index_count);
 
 	meshopt_remapIndexBuffer(out.data, indices ? in.data : NULL, index_count, remap);
 }
@@ -1263,7 +1263,7 @@ inline size_t meshopt_generateProvokingIndexBuffer(T* destination, unsigned int*
 	meshopt_IndexAdapter<T> out(destination, NULL, index_count);
 
 	size_t bound = vertex_count + (index_count / 3);
-	assert(size_t(T(bound - 1)) == bound - 1); // bound - 1 must fit in T
+	assert(bound == 0 || size_t(T(bound - 1)) == bound - 1); // bound - 1 must fit in T
 	(void)bound;
 
 	return meshopt_generateProvokingIndexBuffer(out.data, reorder, in.data, index_count, vertex_count);
@@ -1435,7 +1435,7 @@ template <typename T>
 inline size_t meshopt_unstripify(T* destination, const T* indices, size_t index_count, T restart_index)
 {
 	meshopt_IndexAdapter<T> in(NULL, indices, index_count);
-	meshopt_IndexAdapter<T> out(destination, NULL, (index_count - 2) * 3);
+	meshopt_IndexAdapter<T> out(destination, NULL, index_count == 0 ? 0 : (index_count - 2) * 3);
 
 	return meshopt_unstripify(out.data, in.data, index_count, unsigned(restart_index));
 }

thirdparty/meshoptimizer/rasterizer.cpp

@@ -172,7 +172,7 @@ static float transformTriangles(float* triangles, const unsigned int* indices, s
 	extent = (maxv[1] - minv[1]) < extent ? extent : (maxv[1] - minv[1]);
 	extent = (maxv[2] - minv[2]) < extent ? extent : (maxv[2] - minv[2]);
 
-	float scale = kViewport / extent;
+	float scale = extent == 0.f ? 0.f : kViewport / extent;
 
 	for (size_t i = 0; i < index_count; ++i)
 	{

thirdparty/meshoptimizer/vertexcodec.cpp

@@ -1416,7 +1416,7 @@ inline v128_t unzigzag16(v128_t v)
 SIMD_TARGET
 inline v128_t rotate32(v128_t v, int r)
 {
-	return wasm_v128_or(wasm_i32x4_shl(v, r), wasm_i32x4_shr(v, 32 - r));
+	return wasm_v128_or(wasm_i32x4_shl(v, r), wasm_u32x4_shr(v, 32 - r));
 }
 #endif