Main: use 4D position buffer for stencil shadows

instead of splitting W into separate buffer. Works on D3D9 as well for me. Adapt support code to work with 4D positions.
OGRECave · Jun 22, 2021 · adba82e · adba82e
1 parent 1a38f7e
commit adba82e
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Showing 22 changed files with 143 additions and 295 deletions.
diff --git a/Components/MeshLodGenerator/include/OgreLod0Stripifier.h b/Components/MeshLodGenerator/include/OgreLod0Stripifier.h
@@ -207,7 +207,6 @@ namespace Ogre
 		vertexData->vertexStart = 0;
 		vertexData->vertexCount = remapInfo.usedCount;
 
-		vertexData->hardwareShadowVolWBuffer = HardwareVertexBufferSharedPtr(); // TODO: check this
 		vertexData->hwAnimationDataList.clear(); // TODO: check this
 		vertexData->hwAnimDataItemsUsed = 0; // TODO: check this
 	}

diff --git a/Media/Main/ShadowExtrudeDirLight.vert b/Media/Main/ShadowExtrudeDirLight.vert
@@ -5,14 +5,13 @@ uniform mat4 worldviewproj_matrix;
 uniform vec4 light_position_object_space; // homogenous, object space
 
 MAIN_PARAMETERS
-IN(vec4 uv0, TEXCOORD0)
 IN(vec4 position, POSITION)
 MAIN_DECLARATION
 {
     // Extrusion in object space
     // Vertex unmodified if w==1, extruded if w==0
     vec4 newpos =
-        (uv0.xxxx * (position + light_position_object_space)) - light_position_object_space;
+        (position.wwww * (position + light_position_object_space)) - light_position_object_space;
 
     gl_Position = mul(worldviewproj_matrix, newpos);
 }
diff --git a/Media/Main/ShadowExtrudeDirLightFinite.vert b/Media/Main/ShadowExtrudeDirLightFinite.vert
@@ -6,7 +6,6 @@ uniform vec4 light_position_object_space; // homogenous, object space
 uniform float shadow_extrusion_distance;  // how far to extrude
 
 MAIN_PARAMETERS
-IN(vec4 uv0, TEXCOORD0)
 IN(vec4 position, POSITION)
 MAIN_DECLARATION
 {
@@ -16,7 +15,7 @@ MAIN_DECLARATION
     extrusionDir = normalize(extrusionDir);
 
     vec4 newpos = vec4(position.xyz +
-        ((1.0 - uv0.x) * shadow_extrusion_distance * extrusionDir), 1.0);
+        ((1.0 - position.w) * shadow_extrusion_distance * extrusionDir), 1.0);
 
     gl_Position = mul(worldviewproj_matrix, newpos);
 }
diff --git a/Media/Main/ShadowExtrudePointLight.vert b/Media/Main/ShadowExtrudePointLight.vert
@@ -5,14 +5,13 @@ uniform mat4 worldviewproj_matrix;
 uniform vec4 light_position_object_space; // homogenous, object space
 
 MAIN_PARAMETERS
-IN(vec4 uv0, TEXCOORD0)
 IN(vec4 position, POSITION)
 MAIN_DECLARATION
 {
     // Extrusion in object space
     // Vertex unmodified if w==1, extruded if w==0
     vec4 newpos =
-        (uv0.xxxx * light_position_object_space) +
+        (position.wwww * light_position_object_space) +
         vec4(position.xyz - light_position_object_space.xyz, 0.0);
 
     gl_Position = mul(worldviewproj_matrix, newpos);

diff --git a/Media/Main/ShadowExtrudePointLightFinite.vert b/Media/Main/ShadowExtrudePointLightFinite.vert
@@ -6,7 +6,6 @@ uniform vec4 light_position_object_space; // homogenous, object space
 uniform float shadow_extrusion_distance; // how far to extrude
 
 MAIN_PARAMETERS
-IN(vec4 uv0, TEXCOORD0)
 IN(vec4 position, POSITION)
 MAIN_DECLARATION
 {
@@ -16,7 +15,7 @@ MAIN_DECLARATION
     extrusionDir = normalize(extrusionDir);
 
     vec4 newpos = vec4(position.xyz +
-        ((1.0 - uv0.x) * shadow_extrusion_distance * extrusionDir), 1.0);
+        ((1.0 - position.w) * shadow_extrusion_distance * extrusionDir), 1.0);
 
     gl_Position = mul(worldviewproj_matrix, newpos);
 }
diff --git a/OgreMain/include/OgreEntity.h b/OgreMain/include/OgreEntity.h
@@ -324,8 +324,6 @@ namespace Ogre {
             Entity* mParent;
             /// Shared link to position buffer.
             HardwareVertexBufferSharedPtr mPositionBuffer;
-            /// Shared link to w-coord buffer (optional).
-            HardwareVertexBufferSharedPtr mWBuffer;
             /// Link to current vertex data used to bind (maybe changes).
             const VertexData* mCurrentVertexData;
             /// Link to SubEntity, only present if SubEntity has it's own geometry.
@@ -343,7 +341,6 @@ namespace Ogre {
             void _createSeparateLightCap();
             void getWorldTransforms(Matrix4* xform) const override;
             HardwareVertexBufferSharedPtr getPositionBuffer(void) { return mPositionBuffer; }
-            HardwareVertexBufferSharedPtr getWBuffer(void) { return mWBuffer; }
             /// Rebind the source positions (for temp buffer users).
             void rebindPositionBuffer(const VertexData* vertexData, bool force);
             bool isVisible(void) const override;

diff --git a/OgreMain/include/OgreManualObject.h b/OgreMain/include/OgreManualObject.h
@@ -623,8 +623,6 @@ namespace Ogre
             ManualObject* mParent;
             // Shared link to position buffer
             HardwareVertexBufferSharedPtr mPositionBuffer;
-            // Shared link to w-coord buffer (optional)
-            HardwareVertexBufferSharedPtr mWBuffer;
 
         public:
             ManualObjectSectionShadowRenderable(ManualObject* parent, 
@@ -633,7 +631,6 @@ namespace Ogre
             ~ManualObjectSectionShadowRenderable();
             void getWorldTransforms(Matrix4* xform) const override;
             HardwareVertexBufferSharedPtr getPositionBuffer(void) { return mPositionBuffer; }
-            HardwareVertexBufferSharedPtr getWBuffer(void) { return mWBuffer; }
             virtual void rebindIndexBuffer(const HardwareIndexBufferSharedPtr& indexBuffer) override;
 
 

diff --git a/OgreMain/include/OgreOptimisedUtil.h b/OgreMain/include/OgreOptimisedUtil.h
@@ -155,12 +155,14 @@ namespace Ogre {
         @param faceNormals The array of Vector4 used to store triangles face normal,
             Must be aligned to SIMD alignment.
         @param numTriangles Number of triangles to calculate face normal.
+        @param components Number of components in positions buffer. Must be 3 or 4
         */
         virtual void calculateFaceNormals(
             const float *positions,
             const EdgeData::Triangle *triangles,
             Vector4 *faceNormals,
-            size_t numTriangles) = 0;
+            size_t numTriangles,
+            int components = 3) = 0;
 
         /** Calculate the light facing state of the triangle's face normals
         @remarks

diff --git a/OgreMain/include/OgreStaticGeometry.h b/OgreMain/include/OgreStaticGeometry.h
@@ -292,17 +292,13 @@ namespace Ogre {
                 LODBucket* mParent;
                 // Shared link to position buffer
                 HardwareVertexBufferSharedPtr mPositionBuffer;
-                // Shared link to w-coord buffer (optional)
-                HardwareVertexBufferSharedPtr mWBuffer;
-
             public:
                 LODShadowRenderable(LODBucket* parent, 
                     HardwareIndexBufferSharedPtr* indexBuffer, const VertexData* vertexData, 
                     bool createSeparateLightCap, bool isLightCap = false);
                 ~LODShadowRenderable();
                 void getWorldTransforms(Matrix4* xform) const override;
                 HardwareVertexBufferSharedPtr getPositionBuffer(void) { return mPositionBuffer; }
-                HardwareVertexBufferSharedPtr getWBuffer(void) { return mWBuffer; }
                 virtual void rebindIndexBuffer(const HardwareIndexBufferSharedPtr& indexBuffer) override;
 
             };

diff --git a/OgreMain/include/OgreVertexIndexData.h b/OgreMain/include/OgreVertexIndexData.h
@@ -144,22 +144,6 @@ namespace Ogre {
         */
         void prepareForShadowVolume(void);
 
-        /** Additional shadow volume vertex buffer storage. 
-        @remarks
-            This additional buffer is only used where we have prepared this VertexData for
-            use in shadow volume construction, and where the current render system supports
-            vertex programs. This buffer contains the 'w' vertex position component which will
-            be used by that program to differentiate between extruded and non-extruded vertices.
-            This 'w' component cannot be included in the original position buffer because
-            DirectX does not allow 4-component positions in the fixed-function pipeline, and the original
-            position buffer must still be usable for fixed-function rendering.
-        @par    
-            Note that we don't store any vertex declaration or vertex buffer binding here because this
-            can be reused in the shadow algorithm.
-        */
-        HardwareVertexBufferSharedPtr hardwareShadowVolWBuffer;
-
-
         /** Reorganises the data in the vertex buffers according to the 
             new vertex declaration passed in. Note that new vertex buffers
             are created and written to, so if the buffers being referenced 

diff --git a/OgreMain/src/OgreEdgeListBuilder.cpp b/OgreMain/src/OgreEdgeListBuilder.cpp
@@ -414,11 +414,11 @@ namespace Ogre {
     void EdgeData::updateFaceNormals(size_t vertexSet, 
         const HardwareVertexBufferSharedPtr& positionBuffer)
     {
-        assert (positionBuffer->getVertexSize() == sizeof(float) * 3
-            && "Position buffer should contain only positions!");
+        OgreAssert(positionBuffer->getVertexSize() == sizeof(float) * 4,
+                   "Position buffer should contain only positions!");
 
         // Triangle face normals should be 1:1 with triangles
-        assert(triangleFaceNormals.size() == triangles.size());
+        OgreAssert(triangleFaceNormals.size() == triangles.size(), "size mismatch");
 
         // Calculate triangles which are using this vertex set
         const EdgeData::EdgeGroup& eg = edgeGroups[vertexSet];
@@ -429,7 +429,8 @@ namespace Ogre {
                 static_cast<float*>(positionsLock.pData),
                 &triangles[eg.triStart],
                 &triangleFaceNormals[eg.triStart],
-                eg.triCount);
+                eg.triCount,
+                4);
         }
     }
     //---------------------------------------------------------------------

diff --git a/OgreMain/src/OgreEntity.cpp b/OgreMain/src/OgreEntity.cpp
@@ -1987,8 +1987,10 @@ namespace Ogre {
                         // Lock, we'll be locking the (suppressed hardware update) shadow buffer
                         HardwareBufferLockGuard posLock(esrPositionBuffer, HardwareBuffer::HBL_NORMAL);
                         float* pSrc = static_cast<float*>(posLock.pData);
-                        float* pDest = pSrc + (egi->vertexData->vertexCount * 3);
-                        memcpy(pDest, pSrc, sizeof(float) * 3 * egi->vertexData->vertexCount);
+                        float* pDest = pSrc + (egi->vertexData->vertexCount * 4);
+                        memcpy(pDest, pSrc, sizeof(float) * 4 * egi->vertexData->vertexCount);
+                        for (size_t i = 0; i < egi->vertexData->vertexCount; i++)
+                            pDest[i * 4 + 3] = 0; // second part needs w=0
                     }
                     if (egi->vertexData == mMesh->sharedVertexData)
                     {
@@ -2121,18 +2123,11 @@ namespace Ogre {
         // Create vertex data which just references position component (and 2 component)
         mRenderOp.vertexData = OGRE_NEW VertexData();
         // Map in position data
-        mRenderOp.vertexData->vertexDeclaration->addElement(0,0,VET_FLOAT3, VES_POSITION);
+        mRenderOp.vertexData->vertexDeclaration->addElement(0,0,VET_FLOAT4, VES_POSITION);
         mOriginalPosBufferBinding =
             vertexData->vertexDeclaration->findElementBySemantic(VES_POSITION)->getSource();
         mPositionBuffer = vertexData->vertexBufferBinding->getBuffer(mOriginalPosBufferBinding);
         mRenderOp.vertexData->vertexBufferBinding->setBinding(0, mPositionBuffer);
-        // Map in w-coord buffer (if present)
-        if(vertexData->hardwareShadowVolWBuffer)
-        {
-            mRenderOp.vertexData->vertexDeclaration->addElement(1,0,VET_FLOAT1, VES_TEXTURE_COORDINATES, 0);
-            mWBuffer = vertexData->hardwareShadowVolWBuffer;
-            mRenderOp.vertexData->vertexBufferBinding->setBinding(1, mWBuffer);
-        }
         // Use same vertex start as input
         mRenderOp.vertexData->vertexStart = vertexData->vertexStart;
 

diff --git a/OgreMain/src/OgreHardwareBufferManager.cpp b/OgreMain/src/OgreHardwareBufferManager.cpp
@@ -476,7 +476,7 @@ namespace Ogre {
         if (positions && !destPositionBuffer)
         {
             destPositionBuffer = srcPositionBuffer->getManager()->allocateVertexBufferCopy(srcPositionBuffer, 
-                HardwareBufferManagerBase::BLT_AUTOMATIC_RELEASE, this);
+                HardwareBufferManagerBase::BLT_AUTOMATIC_RELEASE, this, true); // copy contents to keep W-coord for stencil shadows
         }
         if (normals && !posNormalShareBuffer && srcNormalBuffer && !destNormalBuffer)
         {

diff --git a/OgreMain/src/OgreManualObject.cpp b/OgreMain/src/OgreManualObject.cpp
@@ -773,18 +773,11 @@ ManualObject::ManualObject(const String& name)
         // Create vertex data which just references position component (and 2 component)
         mRenderOp.vertexData = OGRE_NEW VertexData();
         // Map in position data
-        mRenderOp.vertexData->vertexDeclaration->addElement(0,0,VET_FLOAT3, VES_POSITION);
+        mRenderOp.vertexData->vertexDeclaration->addElement(0,0,VET_FLOAT4, VES_POSITION);
         ushort origPosBind =
             vertexData->vertexDeclaration->findElementBySemantic(VES_POSITION)->getSource();
         mPositionBuffer = vertexData->vertexBufferBinding->getBuffer(origPosBind);
         mRenderOp.vertexData->vertexBufferBinding->setBinding(0, mPositionBuffer);
-        // Map in w-coord buffer (if present)
-        if(vertexData->hardwareShadowVolWBuffer)
-        {
-            mRenderOp.vertexData->vertexDeclaration->addElement(1,0,VET_FLOAT1, VES_TEXTURE_COORDINATES, 0);
-            mWBuffer = vertexData->hardwareShadowVolWBuffer;
-            mRenderOp.vertexData->vertexBufferBinding->setBinding(1, mWBuffer);
-        }
         // Use same vertex start as input
         mRenderOp.vertexData->vertexStart = vertexData->vertexStart;
 

diff --git a/OgreMain/src/OgreMesh.cpp b/OgreMain/src/OgreMesh.cpp
@@ -1993,10 +1993,8 @@ namespace Ogre {
 
 
         // Lock destination buffers for writing
-        HardwareBufferLockGuard destPosLock(destPosBuf,
-            (destNormBuf != destPosBuf && destPosBuf->getVertexSize() == destElemPos->getSize()) ||
-            (destNormBuf == destPosBuf && destPosBuf->getVertexSize() == destElemPos->getSize() + destElemNorm->getSize()) ?
-            HardwareBuffer::HBL_DISCARD : HardwareBuffer::HBL_NORMAL);
+        // HBL_NORMAL to keep W-coord for stencil shadows
+        HardwareBufferLockGuard destPosLock(destPosBuf, HardwareBuffer::HBL_NORMAL);
         destElemPos->baseVertexPointerToElement(destPosLock.pData, &pDestPos);
         HardwareBufferLockGuard destNormLock;
         if (includeNormals)

diff --git a/OgreMain/src/OgreOptimisedUtil.cpp b/OgreMain/src/OgreOptimisedUtil.cpp
@@ -202,7 +202,8 @@ namespace Ogre {
             const float *positions,
             const EdgeData::Triangle *triangles,
             Vector4 *faceNormals,
-            size_t numTriangles)
+            size_t numTriangles,
+            int components)
         {
             static ProfileItems results;
             static size_t index;
@@ -215,7 +216,8 @@ namespace Ogre {
                 positions,
                 triangles,
                 faceNormals,
-                numTriangles);
+                numTriangles,
+                components);
             profile.end();
 
             //

diff --git a/OgreMain/src/OgreOptimisedUtilGeneral.cpp b/OgreMain/src/OgreOptimisedUtilGeneral.cpp
@@ -75,7 +75,8 @@ namespace Ogre {
             const float *positions,
             const EdgeData::Triangle *triangles,
             Vector4 *faceNormals,
-            size_t numTriangles);
+            size_t numTriangles,
+            int components);
 
         /// @copydoc OptimisedUtil::calculateLightFacing
         virtual void calculateLightFacing(
@@ -286,20 +287,21 @@ namespace Ogre {
         const float *positions,
         const EdgeData::Triangle *triangles,
         Vector4 *faceNormals,
-        size_t numTriangles)
+        size_t numTriangles,
+        int components)
     {
         for ( ; numTriangles; --numTriangles)
         {
             const EdgeData::Triangle& t = *triangles++;
             size_t offset;
 
-            offset = t.vertIndex[0] * 3;
+            offset = t.vertIndex[0] * components;
             Vector3 v1(positions[offset+0], positions[offset+1], positions[offset+2]);
 
-            offset = t.vertIndex[1] * 3;
+            offset = t.vertIndex[1] * components;
             Vector3 v2(positions[offset+0], positions[offset+1], positions[offset+2]);
 
-            offset = t.vertIndex[2] * 3;
+            offset = t.vertIndex[2] * components;
             Vector3 v3(positions[offset+0], positions[offset+1], positions[offset+2]);
 
             *faceNormals++ = Math::calculateFaceNormalWithoutNormalize(v1, v2, v3);
@@ -341,6 +343,7 @@ namespace Ogre {
                 *pDestPos++ = *pSrcPos++ + extrusionDir.x;
                 *pDestPos++ = *pSrcPos++ + extrusionDir.y;
                 *pDestPos++ = *pSrcPos++ + extrusionDir.z;
+                pDestPos++, pSrcPos++;
             }
         }
         else
@@ -360,6 +363,7 @@ namespace Ogre {
                 *pDestPos++ = *pSrcPos++ + extrusionDir.x;
                 *pDestPos++ = *pSrcPos++ + extrusionDir.y;
                 *pDestPos++ = *pSrcPos++ + extrusionDir.z;
+                pDestPos++, pSrcPos++;
             }
         }
     }