APPLE: Basis curves on Metal - Updated mega PR

pxr/imaging/hd/tokens.h

@@ -185,6 +185,7 @@ PXR_NAMESPACE_OPEN_SCOPE
 
 #define HD_SHADER_TOKENS                        \
     (alphaThreshold)                            \
+    (centroid)                                  \
     (clipPlanes)                                \
     (commonShaderSource)                        \
     (computeShader)                             \
@@ -214,6 +215,7 @@ PXR_NAMESPACE_OPEN_SCOPE
     (wireframeColor)                            \
     (worldToViewMatrix)                         \
     (worldToViewInverseMatrix)                  \
+    (sample)                                    \
     (stepSize)                                  \
     (stepSizeLighting)
 

pxr/imaging/hdSt/basisCurves.cpp

@@ -289,16 +289,9 @@ HdStBasisCurves::_UpdateDrawItemGeometricShader(
         std::static_pointer_cast<HdStResourceRegistry>(
             renderIndex.GetResourceRegistry());
 
-    // For the time being, don't use complex curves on Metal. Support for this
-    // is planned for the future.
-    const bool hasMetalTessellation =
-        resourceRegistry->GetHgi()->GetCapabilities()->
-        IsSet(HgiDeviceCapabilitiesBitsMetalTessellation);
-
     TfToken curveType = _topology->GetCurveType();
     TfToken curveBasis = _topology->GetCurveBasis();
-    bool supportsRefinement = _SupportsRefinement(_refineLevel) &&
-        !hasMetalTessellation;
+    bool supportsRefinement = _SupportsRefinement(_refineLevel);
     if (!supportsRefinement) {
         // XXX: Rendering non-linear (i.e., cubic) curves as linear segments
         // when unrefined can be confusing. Should we continue to do this?
@@ -329,8 +322,7 @@ HdStBasisCurves::_UpdateDrawItemGeometricShader(
     case HdBasisCurvesGeomStylePatch:
     {
         if (_SupportsRefinement(_refineLevel) &&
-            _SupportsUserWidths(drawItem) &&
-            !hasMetalTessellation) {
+            _SupportsUserWidths(drawItem)) {
             if (_SupportsUserNormals(drawItem)){
                 drawStyle = HdSt_BasisCurvesShaderKey::RIBBON;
                 normalStyle = HdSt_BasisCurvesShaderKey::ORIENTED;
@@ -380,6 +372,9 @@ HdStBasisCurves::_UpdateDrawItemGeometricShader(
             shadingTerminal = HdBasisCurvesReprDescTokens->surfaceShaderUnlit;
         }
     }
+     bool hasPostTessVertexSupport = resourceRegistry->GetHgi()
+        ->GetCapabilities()->IsSet(HgiDeviceCapabilitiesBitsMetalTessellation);
+
 
     HdSt_BasisCurvesShaderKey shaderKey(curveType,
                                         curveBasis,
@@ -389,7 +384,8 @@ HdStBasisCurves::_UpdateDrawItemGeometricShader(
                                         _basisNormalInterpolation,
                                         shadingTerminal,
                                         hasAuthoredTopologicalVisiblity,
-                                        _pointsShadingEnabled);
+                                        _pointsShadingEnabled,
+                                        hasPostTessVertexSupport);
 
     TF_DEBUG(HD_RPRIM_UPDATED).
             Msg("HdStBasisCurves(%s) - Shader Key PrimType: %s\n ",

pxr/imaging/hdSt/basisCurvesComputations.cpp

@@ -28,11 +28,34 @@
 
 #include "pxr/base/gf/vec2i.h"
 #include "pxr/base/gf/vec4i.h"
+#include "pxr/base/gf/half.h"
+
 
 #include <algorithm>
 
 PXR_NAMESPACE_OPEN_SCOPE
 
+int32_t GetOneOnePacked() {
+    int32_t one = 0;
+    uint16_t const oneHalf =
+        reinterpret_cast<uint16_t>(GfHalf(1.0f).bits());
+    one |= oneHalf;
+    int32_t oneScaled = 0;
+    oneScaled |= (one << 16);
+    int32_t oneone = 0;
+    oneone |= (one | oneScaled);
+    return oneone;
+}
+
+int32_t GetZeroZeroPacked() {
+    int32_t zero = 0;
+    uint16_t const zeroHalf =
+        reinterpret_cast<uint16_t>(GfHalf(0.0f).bits());
+    zero |= zeroHalf;
+    int32_t zerozero = 0;
+    zerozero |= (zero << 16) | zero;
+    return zerozero;
+}
 
 HdSt_BasisCurvesIndexBuilderComputation::HdSt_BasisCurvesIndexBuilderComputation(
     HdBasisCurvesTopology *topology, bool forceLines)
@@ -60,6 +83,8 @@ HdSt_BasisCurvesIndexBuilderComputation::GetBufferSpecs(
     // XXX: we currently create it even when the curve has no uniform primvars
     specs->emplace_back(HdTokens->primitiveParam,
                         HdTupleType{HdTypeInt32, 1});
+    specs->emplace_back(HdTokens->tessFactors,
+                        HdTupleType{HdTypeInt32Vec3, 1});
 }
 
 HdSt_BasisCurvesIndexBuilderComputation::IndexAndPrimIndex
@@ -108,12 +133,24 @@ HdSt_BasisCurvesIndexBuilderComputation::_BuildLinesIndexArray()
         }
     }
 
+    VtVec3iArray finalTessFactors(finalIndices.size());
+    int32_t oneone = GetOneOnePacked();
+    int32_t zerozero = GetZeroZeroPacked();
+    for (size_t i = 0; i < indices.size(); i++) {
+        finalTessFactors[i][0] = oneone;
+        finalTessFactors[i][1] = oneone;
+        finalTessFactors[i][2] = zerozero;
+    }
+
+
     VtIntArray finalPrimIndices(primIndices.size());
     std::copy(  primIndices.begin(), 
                 primIndices.end(), 
                 finalPrimIndices.begin());
 
-    return IndexAndPrimIndex(VtValue(finalIndices), VtValue(finalPrimIndices));
+    return IndexAndPrimIndex(VtValue(finalIndices),
+                             VtValue(finalPrimIndices),
+                             VtValue(finalTessFactors));
 }
 
 HdSt_BasisCurvesIndexBuilderComputation::IndexAndPrimIndex
@@ -181,12 +218,24 @@ HdSt_BasisCurvesIndexBuilderComputation::_BuildLineSegmentIndexArray()
         }
     }
 
+    VtVec3iArray finalTessFactors(finalIndices.size());
+    int32_t oneone = GetOneOnePacked();
+    int32_t zerozero = GetZeroZeroPacked();
+    for (size_t i = 0; i < indices.size(); i++) {
+        finalTessFactors[i][0] = oneone;
+        finalTessFactors[i][1] = oneone;
+        finalTessFactors[i][2] = zerozero;
+    }
+
+
     VtIntArray finalPrimIndices(primIndices.size());
     std::copy(  primIndices.begin(),
                 primIndices.end(),
                 finalPrimIndices.begin());
 
-    return IndexAndPrimIndex(VtValue(finalIndices), VtValue(finalPrimIndices));
+    return IndexAndPrimIndex(VtValue(finalIndices),
+                             VtValue(finalPrimIndices),
+                             VtValue(finalTessFactors));
 }
 
 HdSt_BasisCurvesIndexBuilderComputation::IndexAndPrimIndex
@@ -384,10 +433,23 @@ HdSt_BasisCurvesIndexBuilderComputation::_BuildCubicIndexArray()
         }
     }
 
+    VtVec3iArray finalTessFactors(finalIndices.size());
+    int32_t oneone = GetOneOnePacked();
+    int32_t zerozero = GetZeroZeroPacked();
+    for (size_t i = 0; i < indices.size(); i++) {
+        finalTessFactors[i][0] = oneone;
+        finalTessFactors[i][1] = oneone;
+        finalTessFactors[i][2] = zerozero;
+    }
+
     VtIntArray finalPrimIndices(primIndices.size());
-    std::copy(primIndices.begin(), primIndices.end(), finalPrimIndices.begin());    
+    std::copy(primIndices.begin(), primIndices.end(), finalPrimIndices.begin());
+
+    return IndexAndPrimIndex(
+            VtValue(finalIndices),
+            VtValue(finalPrimIndices),
+            VtValue(finalTessFactors));
 
-    return IndexAndPrimIndex(VtValue(finalIndices), VtValue(finalPrimIndices));
 }
 
 bool
@@ -413,6 +475,10 @@ HdSt_BasisCurvesIndexBuilderComputation::Resolve()
                                 HdTokens->indices, 
                                 VtValue(result._indices)));
 
+    _tessFactorsParam.reset(new HdVtBufferSource(
+                HdTokens->tessFactors,
+                VtValue(result._tessFactors)));
+
     // the primitive param buffer is used only when the basis curve
     // has uniform primvars.
     // XXX: we currently create it even when the curve has no uniform primvars
@@ -439,7 +505,7 @@ HdSt_BasisCurvesIndexBuilderComputation::HasChainedBuffer() const
 HdBufferSourceSharedPtrVector
 HdSt_BasisCurvesIndexBuilderComputation::GetChainedBuffers() const
 {
-    return { _primitiveParam };
+    return { _primitiveParam, _tessFactorsParam };
 }
 
 

pxr/imaging/hdSt/basisCurvesComputations.h

@@ -61,16 +61,21 @@ class HdSt_BasisCurvesIndexBuilderComputation : public HdComputedBufferSource {
     virtual bool _CheckValid() const override;
 
 public:
-    // For building index and primitive index arrays
+    // For building index, primitive index and tessFactor arrays
     struct IndexAndPrimIndex {
         // default constructor results in empty VtValue's
         IndexAndPrimIndex() {}
 
-        IndexAndPrimIndex(VtValue indices, VtValue primIndices) :
-            _indices(indices), _primIndices(primIndices) {}
+        IndexAndPrimIndex(VtValue indices,
+                          VtValue primIndices,
+                          VtValue tessFactors) :
+                     _indices(indices),
+                     _primIndices(primIndices),
+                     _tessFactors(tessFactors) {}
 
         VtValue _indices;
         VtValue _primIndices;
+        VtValue _tessFactors;
     };
 private:
     IndexAndPrimIndex _BuildLinesIndexArray();
@@ -80,7 +85,8 @@ class HdSt_BasisCurvesIndexBuilderComputation : public HdComputedBufferSource {
     HdBasisCurvesTopology *_topology;
     bool _forceLines;
 
-    HdBufferSourceSharedPtr _primitiveParam;    
+    HdBufferSourceSharedPtr _primitiveParam;
+    HdBufferSourceSharedPtr _tessFactorsParam;
 };