gpu: Initialize Metal stencil state more aggressively

libsdl-org · Jan 12, 2025 · 4f5f99d · 4f5f99d
1 parent 307dac9
commit 4f5f99d
Showing 1 changed file with 20 additions and 4 deletions.
diff --git a/src/gpu/metal/SDL_gpu_metal.m b/src/gpu/metal/SDL_gpu_metal.m
@@ -1121,25 +1121,41 @@ static void METAL_ReleaseGraphicsPipeline(
 
         if (createinfo->target_info.has_depth_stencil_target) {
             pipelineDescriptor.depthAttachmentPixelFormat = SDLToMetal_TextureFormat(createinfo->target_info.depth_stencil_format);
+            pipelineDescriptor.stencilAttachmentPixelFormat = SDLToMetal_TextureFormat(createinfo->target_info.depth_stencil_format);
 
-            if (createinfo->depth_stencil_state.enable_stencil_test) {
-                pipelineDescriptor.stencilAttachmentPixelFormat = SDLToMetal_TextureFormat(createinfo->target_info.depth_stencil_format);
+            frontStencilDescriptor = [MTLStencilDescriptor new];
+            backStencilDescriptor = [MTLStencilDescriptor new];
 
-                frontStencilDescriptor = [MTLStencilDescriptor new];
+            if (createinfo->depth_stencil_state.enable_stencil_test) {
                 frontStencilDescriptor.stencilCompareFunction = SDLToMetal_CompareOp[createinfo->depth_stencil_state.front_stencil_state.compare_op];
                 frontStencilDescriptor.stencilFailureOperation = SDLToMetal_StencilOp[createinfo->depth_stencil_state.front_stencil_state.fail_op];
                 frontStencilDescriptor.depthStencilPassOperation = SDLToMetal_StencilOp[createinfo->depth_stencil_state.front_stencil_state.pass_op];
                 frontStencilDescriptor.depthFailureOperation = SDLToMetal_StencilOp[createinfo->depth_stencil_state.front_stencil_state.depth_fail_op];
                 frontStencilDescriptor.readMask = createinfo->depth_stencil_state.compare_mask;
                 frontStencilDescriptor.writeMask = createinfo->depth_stencil_state.write_mask;
 
-                backStencilDescriptor = [MTLStencilDescriptor new];
                 backStencilDescriptor.stencilCompareFunction = SDLToMetal_CompareOp[createinfo->depth_stencil_state.back_stencil_state.compare_op];
                 backStencilDescriptor.stencilFailureOperation = SDLToMetal_StencilOp[createinfo->depth_stencil_state.back_stencil_state.fail_op];
                 backStencilDescriptor.depthStencilPassOperation = SDLToMetal_StencilOp[createinfo->depth_stencil_state.back_stencil_state.pass_op];
                 backStencilDescriptor.depthFailureOperation = SDLToMetal_StencilOp[createinfo->depth_stencil_state.back_stencil_state.depth_fail_op];
                 backStencilDescriptor.readMask = createinfo->depth_stencil_state.compare_mask;
                 backStencilDescriptor.writeMask = createinfo->depth_stencil_state.write_mask;
+            } else {
+                // This is just a safe default that avoids doing anything to the stencil buffer
+
+                frontStencilDescriptor.stencilCompareFunction = MTLCompareFunctionNever;
+                frontStencilDescriptor.stencilFailureOperation = MTLStencilOperationKeep;
+                frontStencilDescriptor.depthStencilPassOperation = MTLStencilOperationKeep;
+                frontStencilDescriptor.depthFailureOperation = MTLStencilOperationKeep;
+                frontStencilDescriptor.readMask = createinfo->depth_stencil_state.compare_mask;
+                frontStencilDescriptor.writeMask = createinfo->depth_stencil_state.write_mask;
+
+                backStencilDescriptor.stencilCompareFunction = MTLCompareFunctionNever;
+                backStencilDescriptor.stencilFailureOperation = MTLStencilOperationKeep;
+                backStencilDescriptor.depthStencilPassOperation = MTLStencilOperationKeep;
+                backStencilDescriptor.depthFailureOperation = MTLStencilOperationKeep;
+                backStencilDescriptor.readMask = createinfo->depth_stencil_state.compare_mask;
+                backStencilDescriptor.writeMask = createinfo->depth_stencil_state.write_mask;
             }
 
             depthStencilDescriptor = [MTLDepthStencilDescriptor new];