rhi: Clean up 1D and 3D texture feature flags

Separate 1D mipmap generation support from rendering into an 1D texture.
Those are two independent features, so have a separate feature flag for
both instead of using just one.

This will then be symmetric with the 3D texture features, where now we
have a new flag to report support for generating mipmap for 3D textures.
(whereas 3D texture as a render target is already covered by
RenderTo3DTextureSlice)

Change-Id: Ie5e1f056a7d1c341d90cd7fc522877a3f2da3290
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

src/gui/rhi/qrhi.cpp

@@ -735,10 +735,10 @@ Q_LOGGING_CATEGORY(QRHI_LOG_INFO, "qt.rhi.general")
     \value OneDimensionalTextures Indicates that 1D textures are supported.
     In practice this feature will be unsupported on OpenGL ES.
 
-    \value OneDimensionalTextureMipmaps Indicates that 1D texture mipmaps and
-    1D texture render targets are supported. In practice this feature will be
-    unsupported on backends that do not report support for
-    \l{OneDimensionalTextures}, and Metal.
+    \value OneDimensionalTextureMipmaps Indicates that generating 1D texture
+    mipmaps are supported. In practice this feature will be unsupported on
+    backends that do not report support for
+    \l{OneDimensionalTextures}, Metal, and Direct 3D 12.
 
     \value HalfAttributes Indicates that specifying input attributes with half
     precision (16bit) floating point types for a shader pipeline is supported.
@@ -750,6 +750,14 @@ Q_LOGGING_CATEGORY(QRHI_LOG_INFO, "qt.rhi.general")
     half3 attributes as half4. To ensure cross platform compatibility, half3
     inputs should be padded to 8 bytes.
 
+    \value RenderToOneDimensionalTexture Indicates that 1D texture render
+    targets are supported. In practice this feature will be unsupported on
+    backends that do not report support for
+    \l{OneDimensionalTextures}, and Metal.
+
+    \value ThreeDimensionalTextureMipmaps Indicates that generating 3D texture
+    mipmaps are supported. In practice this feature will be unsupported with
+    Direct 3D 12.
  */
 
 /*!

src/gui/rhi/qrhi_p.h

@@ -1820,7 +1820,9 @@ public:
         NonFillPolygonMode,
         OneDimensionalTextures,
         OneDimensionalTextureMipmaps,
-        HalfAttributes
+        HalfAttributes,
+        RenderToOneDimensionalTexture,
+        ThreeDimensionalTextureMipmaps
     };
 
     enum BeginFrameFlag {

src/gui/rhi/qrhid3d11.cpp

@@ -530,6 +530,10 @@ bool QRhiD3D11::isFeatureSupported(QRhi::Feature feature) const
         return true;
     case QRhi::HalfAttributes:
         return true;
+    case QRhi::RenderToOneDimensionalTexture:
+        return true;
+    case QRhi::ThreeDimensionalTextureMipmaps:
+        return true;
     default:
         Q_UNREACHABLE();
         return false;

src/gui/rhi/qrhid3d12.cpp

@@ -582,9 +582,13 @@ bool QRhiD3D12::isFeatureSupported(QRhi::Feature feature) const
     case QRhi::OneDimensionalTextures:
         return true;
     case QRhi::OneDimensionalTextureMipmaps:
-        return false;
+        return false; // we generate mipmaps ourselves with compute and this is not implemented
     case QRhi::HalfAttributes:
         return true;
+    case QRhi::RenderToOneDimensionalTexture:
+        return true;
+    case QRhi::ThreeDimensionalTextureMipmaps:
+        return false; // we generate mipmaps ourselves with compute and this is not implemented
     }
     return false;
 }

src/gui/rhi/qrhigles2.cpp

@@ -1323,6 +1323,10 @@ bool QRhiGles2::isFeatureSupported(QRhi::Feature feature) const
         return caps.texture1D;
     case QRhi::HalfAttributes:
         return caps.halfAttributes;
+    case QRhi::RenderToOneDimensionalTexture:
+        return caps.texture1D;
+    case QRhi::ThreeDimensionalTextureMipmaps:
+        return caps.texture3D;
     default:
         Q_UNREACHABLE_RETURN(false);
     }

src/gui/rhi/qrhimetal.mm

@@ -796,6 +796,10 @@ bool QRhiMetal::isFeatureSupported(QRhi::Feature feature) const
         return false;
     case QRhi::HalfAttributes:
         return true;
+    case QRhi::RenderToOneDimensionalTexture:
+        return false;
+    case QRhi::ThreeDimensionalTextureMipmaps:
+        return true;
     default:
         Q_UNREACHABLE();
         return false;

src/gui/rhi/qrhivulkan.cpp

@@ -4267,6 +4267,10 @@ bool QRhiVulkan::isFeatureSupported(QRhi::Feature feature) const
         return true;
     case QRhi::HalfAttributes:
         return true;
+    case QRhi::RenderToOneDimensionalTexture:
+        return true;
+    case QRhi::ThreeDimensionalTextureMipmaps:
+        return true;
     default:
         Q_UNREACHABLE_RETURN(false);
     }

tests/auto/gui/rhi/qrhi/tst_qrhi.cpp

@@ -410,7 +410,12 @@ void tst_QRhi::create()
             QRhi::Tessellation,
             QRhi::GeometryShader,
             QRhi::TextureArrayRange,
-            QRhi::NonFillPolygonMode
+            QRhi::NonFillPolygonMode,
+            QRhi::OneDimensionalTextures,
+            QRhi::OneDimensionalTextureMipmaps,
+            QRhi::HalfAttributes,
+            QRhi::RenderToOneDimensionalTexture,
+            QRhi::ThreeDimensionalTextureMipmaps
         };
         for (size_t i = 0; i <sizeof(features) / sizeof(QRhi::Feature); ++i)
             rhi->isFeatureSupported(features[i]);
@@ -4758,7 +4763,7 @@ void tst_QRhi::threeDimTexture()
     }
 
     // mipmaps
-    {
+    if (rhi->isFeatureSupported(QRhi::ThreeDimensionalTextureMipmaps)) {
         QScopedPointer<QRhiTexture> texture(rhi->newTexture(QRhiTexture::RGBA8, WIDTH, HEIGHT, DEPTH,
                                                             1, QRhiTexture::MipMapped | QRhiTexture::UsedWithGenerateMips));
         QVERIFY(texture->create());
@@ -4801,11 +4806,10 @@ void tst_QRhi::threeDimTexture()
         // Some software-based OpenGL implementations, such as Mesa llvmpipe builds that are
         // used both in Qt CI and are shipped with the official Qt binaries also seem to have
         // problems with this.
-        if (impl != QRhi::Null && impl != QRhi::OpenGLES2) {
-            // temporarily skip for D3D12 as well since 3D texture mipmap generation is not implemented there
-            if (impl != QRhi::D3D12)
-                QVERIFY(imageRGBAEquals(result, referenceImage, 2));
-        }
+        if (impl != QRhi::Null && impl != QRhi::OpenGLES2)
+            QVERIFY(imageRGBAEquals(result, referenceImage, 2));
+    } else {
+        qDebug("Skipping 3D texture mipmap generation test because it is reported as unsupported");
     }
 
     // render target (one slice)
@@ -5175,9 +5179,11 @@ void tst_QRhi::oneDimTexture()
     }
 
     // mipmaps and 1D render target
-    if (!rhi->isFeatureSupported(QRhi::OneDimensionalTextureMipmaps))
-        QSKIP("Skipping testing 1D texture mipmaps and 1D render target because they are reported "
-              "as unsupported");
+    if (!rhi->isFeatureSupported(QRhi::OneDimensionalTextureMipmaps)
+            || !rhi->isFeatureSupported(QRhi::RenderToOneDimensionalTexture))
+    {
+        QSKIP("Skipping testing 1D texture mipmaps and 1D render target because they are reported as unsupported");
+    }
 
     {
         QScopedPointer<QRhiTexture> texture(