SDL: GPU: Metal: Rebind storage buffers when changing the pipeline moves them.

From 73c9f25867e60c8a7c18ff9b427c1c5e7ffdc8be Mon Sep 17 00:00:00 2001
From: Jakub Wasilewski <[EMAIL REDACTED]>
Date: Sun, 14 Dec 2025 11:16:02 +0100
Subject: [PATCH] GPU: Metal: Rebind storage buffers when changing the pipeline
 moves them.

---
 src/gpu/metal/SDL_gpu_metal.m | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/gpu/metal/SDL_gpu_metal.m b/src/gpu/metal/SDL_gpu_metal.m
index fd6c399d9a05f..6672db16059e0 100644
--- a/src/gpu/metal/SDL_gpu_metal.m
+++ b/src/gpu/metal/SDL_gpu_metal.m
@@ -2409,6 +2409,7 @@ static void METAL_BindGraphicsPipeline(
 {
     @autoreleasepool {
         MetalCommandBuffer *metalCommandBuffer = (MetalCommandBuffer *)commandBuffer;
+        MetalGraphicsPipeline *previousPipeline = metalCommandBuffer->graphics_pipeline;
         MetalGraphicsPipeline *pipeline = (MetalGraphicsPipeline *)graphicsPipeline;
         SDL_GPURasterizerState *rast = &pipeline->rasterizerState;
         Uint32 i;
@@ -2453,6 +2454,17 @@ static void METAL_BindGraphicsPipeline(
                     metalCommandBuffer);
             }
         }
+
+        if (previousPipeline && previousPipeline != pipeline) {
+            // if the number of uniform buffers has changed, the storage buffers will move as well
+            // and need a rebind at their new locations
+            if (previousPipeline->header.num_vertex_uniform_buffers != pipeline->header.num_vertex_uniform_buffers) {
+                metalCommandBuffer->needVertexStorageBufferBind = true;
+            }
+            if (previousPipeline->header.num_fragment_uniform_buffers != pipeline->header.num_fragment_uniform_buffers) {
+                metalCommandBuffer->needFragmentStorageBufferBind = true;
+            }
+        }
     }
 }