Metal: Fix depth/stencil FBO attachments validation

Simplified and fixed depth/stencil attachments
validation to match Metal behavior;
added a new error message.

Updated allowSeparateDepthStencilBuffers feature
condition to enable it on Apple silicon Macs.

Fixed: angleproject:362901599
Change-Id: Ib60020f157976240ebfd652254d63380341cddbd
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5823534
Reviewed-by: Geoff Lang <[email protected]>
Reviewed-by: Kimmo Kinnunen <[email protected]>
Commit-Queue: Alexey Knyazev <[email protected]>

Author: lexaknyazev

src/libANGLE/ErrorStrings.h

@@ -199,6 +199,7 @@ MSG kFramebufferIncompleteSurfaceless = "Framebuffer is incomplete: Framebuffer
 MSG kFramebufferIncompleteUnsupportedMissmatchedDimensions = "Framebuffer is incomplete: Mismatched attachment sizes are unsupported.";
 MSG kFramebufferIncompleteUnsupportedNonUniqueAttachments = "Framebuffer is incomplete: Non-unique attachments are unsupported.";
 MSG kFramebufferIncompleteUnsupportedSeparateDepthStencilBuffers = "Framebuffer is incomplete: Separate depth and stencil buffers are unsupported.";
+MSG kFramebufferIncompleteUnsupportedSeparateDepthStencilBuffersCombinedFormat = "Framebuffer is incomplete: Combined depth/stencil formats cannot be used with separate depth and stencil buffers.";
 MSG kFramebufferIncompleteWebGLDepthStencilInconsistant = "Framebuffer is incomplete: WebGL depth stencil state is inconsistent.";
 MSG kFramebufferTextureInvalidLayer = "Layer invalid for framebuffer texture attachment.";
 MSG kFramebufferTextureInvalidMipLevel = "Mip level invalid for framebuffer texture attachment.";

src/libANGLE/renderer/metal/DisplayMtl.mm

@@ -1245,7 +1245,7 @@ bool IsMetalDisplayAvailable()
                             isOSX || isCatalyst || supportsAppleGPUFamily(4));
 
     ANGLE_FEATURE_CONDITION((&mFeatures), allowSeparateDepthStencilBuffers,
-                            !isOSX && !isCatalyst && !isSimulator);
+                            supportsAppleGPUFamily(1) && !isSimulator);
     ANGLE_FEATURE_CONDITION((&mFeatures), emulateTransformFeedback, true);
 
     ANGLE_FEATURE_CONDITION((&mFeatures), intelExplicitBoolCastWorkaround,

src/libANGLE/renderer/metal/FrameBufferMtl.h

@@ -129,7 +129,6 @@ class FramebufferMtl : public FramebufferImpl
 
   private:
     void reset();
-    gl::FramebufferStatus checkPackedDepthStencilAttachment() const;
     angle::Result invalidateImpl(const gl::Context *context,
                                  size_t count,
                                  const GLenum *attachments);

src/libANGLE/renderer/metal/FrameBufferMtl.mm

@@ -654,67 +654,35 @@ void RoundValueAndAdjustCorrespondingValue(float a,
 
 gl::FramebufferStatus FramebufferMtl::checkStatus(const gl::Context *context) const
 {
-    ContextMtl *contextMtl = mtl::GetImpl(context);
-    if (!contextMtl->getDisplay()->getFeatures().allowSeparateDepthStencilBuffers.enabled &&
-        mState.hasSeparateDepthAndStencilAttachments())
-    {
-        return gl::FramebufferStatus::Incomplete(
-            GL_FRAMEBUFFER_UNSUPPORTED,
-            gl::err::kFramebufferIncompleteUnsupportedSeparateDepthStencilBuffers);
-    }
-
-    if (mState.getDepthAttachment() && mState.getDepthAttachment()->getFormat().info->depthBits &&
-        mState.getDepthAttachment()->getFormat().info->stencilBits)
+    if (mState.hasSeparateDepthAndStencilAttachments())
     {
-        return checkPackedDepthStencilAttachment();
-    }
-
-    if (mState.getStencilAttachment() &&
-        mState.getStencilAttachment()->getFormat().info->depthBits &&
-        mState.getStencilAttachment()->getFormat().info->stencilBits)
-    {
-        return checkPackedDepthStencilAttachment();
-    }
-
-    if (!totalBitsUsedIsLessThanOrEqualToMaxBitsSupported(context))
-    {
-        return gl::FramebufferStatus::Incomplete(
-            GL_FRAMEBUFFER_UNSUPPORTED,
-            gl::err::kFramebufferIncompleteColorBitsUsedExceedsMaxColorBitsSupported);
-    }
-
-    return gl::FramebufferStatus::Complete();
-}
-
-gl::FramebufferStatus FramebufferMtl::checkPackedDepthStencilAttachment() const
-{
-    if (ANGLE_APPLE_AVAILABLE_XCI(10.14, 13.1, 12.0))
-    {
-        // If depth/stencil attachment has depth & stencil bits, then depth & stencil must not have
-        // separate attachment. i.e. They must be the same texture or one of them has no
-        // attachment.
-        if (mState.hasSeparateDepthAndStencilAttachments())
+        ContextMtl *contextMtl = mtl::GetImpl(context);
+        if (!contextMtl->getDisplay()->getFeatures().allowSeparateDepthStencilBuffers.enabled)
         {
-            WARN() << "Packed depth stencil texture/buffer must not be mixed with other "
-                      "texture/buffer.";
             return gl::FramebufferStatus::Incomplete(
                 GL_FRAMEBUFFER_UNSUPPORTED,
                 gl::err::kFramebufferIncompleteUnsupportedSeparateDepthStencilBuffers);
         }
-    }
-    else
-    {
-        // Metal 2.0 and below doesn't allow packed depth stencil texture to be attached only as
-        // depth or stencil buffer. i.e. None of the depth & stencil attachment can be null.
-        if (!mState.getDepthStencilAttachment())
+
+        ASSERT(mState.getDepthAttachment()->getFormat().info->depthBits > 0);
+        ASSERT(mState.getStencilAttachment()->getFormat().info->stencilBits > 0);
+        if (mState.getDepthAttachment()->getFormat().info->stencilBits != 0 ||
+            mState.getStencilAttachment()->getFormat().info->depthBits != 0)
         {
-            WARN() << "Packed depth stencil texture/buffer must be bound to both depth & stencil "
-                      "attachment point.";
             return gl::FramebufferStatus::Incomplete(
                 GL_FRAMEBUFFER_UNSUPPORTED,
-                gl::err::kFramebufferIncompleteUnsupportedSeparateDepthStencilBuffers);
+                gl::err::
+                    kFramebufferIncompleteUnsupportedSeparateDepthStencilBuffersCombinedFormat);
         }
     }
+
+    if (!totalBitsUsedIsLessThanOrEqualToMaxBitsSupported(context))
+    {
+        return gl::FramebufferStatus::Incomplete(
+            GL_FRAMEBUFFER_UNSUPPORTED,
+            gl::err::kFramebufferIncompleteColorBitsUsedExceedsMaxColorBitsSupported);
+    }
+
     return gl::FramebufferStatus::Complete();
 }