CalculateInstance
It returns the minimum size the buffers should be. This is only the case
when the pointer is given, all arguments are allowed to be nullptr.
Note: This function needs to be called directly before UpdateVertexBuffer(),
UpdateIndexBuffer() and UpdateTransformationBuffer().
Syntax
// // Strong typing definition // int64_t CalculateInstance( OwlInstance owlInstance, int64_t * vertexBufferSize, int64_t * indexBufferSize, int64_t * transformationBufferSize ); static inline int64_t CalculateInstance( OwlInstance owlInstance, int64_t * vertexBufferSize, int64_t * indexBufferSize ) { return CalculateInstance( owlInstance, vertexBufferSize, indexBufferSize, nullptr // transformationBufferSize ); } static inline int64_t CalculateInstance( OwlInstance owlInstance ) { return CalculateInstance( owlInstance, nullptr, // vertexBufferSize nullptr, // indexBufferSize nullptr // transformationBufferSize ); } // // Weak typing definition // int64_t __declspec(dllexport) __stdcall CalculateInstance( int64_t owlInstance, int64_t * vertexBufferSize, int64_t * indexBufferSize, int64_t * transformationBufferSize ); static inline int64_t CalculateInstance( int64_t owlInstance, int64_t * vertexBufferSize, int64_t * indexBufferSize ) { return CalculateInstance( owlInstance, vertexBufferSize, indexBufferSize, nullptr // transformationBufferSize ); } static inline int64_t CalculateInstance( int64_t owlInstance ) { return CalculateInstance( owlInstance, nullptr, // vertexBufferSize nullptr, // indexBufferSize nullptr // transformationBufferSize ); }
Property owlInstance
Size: 64 bit / 8 byte (value)Property vertexBufferSize
Size: 64 bit / 8 byte (reference)Property indexBufferSize
Size: 64 bit / 8 byte (reference)Property transformationBufferSize
Size: 64 bit / 8 byte (reference)
Example (based on pure API calls)
Here you can find code snippits that show how the API call CalculateInstance can be used.
#include "./include/engine.h" static const uint64_t flagbit0 = 1; // 2^^0 0000.0000..0000.0001 static const uint64_t flagbit1 = 2; // 2^^1 0000.0000..0000.0010 static const uint64_t flagbit2 = 4; // 2^^2 0000.0000..0000.0100 static const uint64_t flagbit3 = 8; // 2^^3 0000.0000..0000.1000 static const uint64_t flagbit4 = 16; // 2^^4 0000.0000..0001.0000 static const uint64_t flagbit5 = 32; // 2^^5 0000.0000..0010.0000 static const uint64_t flagbit6 = 64; // 2^^6 0000.0000..0100.0000 static const uint64_t flagbit7 = 128; // 2^^7 0000.0000..1000.0000 static const uint64_t flagbit8 = 256; // 2^^8 0000.0001..0000.0000 static const uint64_t flagbit9 = 512; // 2^^9 0000.0010..0000.0000 static const uint64_t flagbit10 = 1024; // 2^^10 0000.0100..0000.0000 static const uint64_t flagbit11 = 2048; // 2^^11 0000.1000..0000.0000 static const uint64_t flagbit12 = 4096; // 2^^12 0001.0000..0000.0000 static const uint64_t flagbit13 = 8192; // 2^^13 0010.0000..0000.0000 static const uint64_t flagbit14 = 16384; // 2^^14 0100.0000..0000.0000 static const uint64_t flagbit15 = 32768; // 2^^15 1000.0000..0000.0000 ... int64_t model = CreateModel(); if (model) { // // Classes // int64_t classCollection = GetClassByName(model, "Collection"), classCylinder = GetClassByName(model, "Cylinder"), classLine3D = GetClassByName(model, "Line3D"), classPoint3D = GetClassByName(model, "Point3D"); // // Object Properties (relations) // int64_t propertyObjects = GetPropertyByName(model, "objects"); // // Datatype Properties (attributes) // int64_t propertyCoordinates = GetPropertyByName(model, "coordinates"), propertyLength = GetPropertyByName(model, "length"), propertyPoints = GetPropertyByName(model, "points"), propertyRadius = GetPropertyByName(model, "radius"), propertySegmentationParts = GetPropertyByName(model, "segmentationParts"); // // Instances (creating) // int64_t instanceCollection = CreateInstance(classCollection, nullptr), instanceCylinder = CreateInstance(classCylinder, nullptr), instanceLine3D = CreateInstance(classLine3D, nullptr), instancePoint3D_I = CreateInstance(classPoint3D, nullptr), instancePoint3D_II = CreateInstance(classPoint3D, nullptr); int64_t objects[6] = { instancePoint3D_I, instanceLine3D, instanceLine3D, instancePoint3D_II, instanceCylinder, instancePoint3D_I }; SetObjectProperty(instanceCollection, propertyObjects, objects, 6); double coordinates_I[3] = { 1., 2., 3. }, coordinates_II[3] = { 4., 5., 6. }, length = 4., points[6] = { 0., 0., -1., 5., 3., 0. }, radius = 2.; int64_t segmentationParts = 36; SetDatatypeProperty(instanceCylinder, propertyLength, &length, 1); SetDatatypeProperty(instanceCylinder, propertyRadius, &radius, 1); SetDatatypeProperty(instanceCylinder, propertySegmentationParts, &segmentationParts, 1); SetDatatypeProperty(instanceLine3D, propertyPoints, points, 6); SetDatatypeProperty(instancePoint3D_I, propertyCoordinates, coordinates_I, 3); SetDatatypeProperty(instancePoint3D_II, propertyCoordinates, coordinates_II, 3); int64_t myInstance = instanceCollection; ... ... // create, load or edit myInstance, in this case a simple Collection is used as input ... // // Initializing the mask with all possible options // int64_t setting = 0, mask = GetFormat(0, 0); setting += 0 * flagbit2; // SINGLE / DOUBLE PRECISION (float / double) setting += 0 * flagbit3; // 32 / 63 BIT INDEX ARRAY (int32_t / int64_t) setting += 1 * flagbit4; // OFF / ON VECTORS (x, y, z) setting += 1 * flagbit5; // OFF / ON NORMALS (Nx, Ny, Nz) setting += 1 * flagbit8; // OFF / ON TRIANGLES setting += 1 * flagbit9; // OFF / ON LINES setting += 1 * flagbit10; // OFF / ON POINTS setting += 0 * flagbit12; // OFF / ON WIREFRAME FACES setting += 0 * flagbit13; // OFF / ON WIREFRAME CONCEPTUAL FACES int64_t vertexElementSizeInBytes = SetFormat(model, setting, mask); assert(vertexElementSizeInBytes == (3 + 3) * sizeof(float)); ... int64_t vertexBufferSize = 0, indexBufferSize = 0; CalculateInstance(myInstance, &vertexBufferSize, &indexBufferSize, nullptr); if (vertexBufferSize && indexBufferSize) { float * vertices = new float[(int_t) vertexBufferSize * ((int_t) vertexElementSizeInBytes / sizeof(float))]; int32_t * indices = new int32_t[(int_t) indexBufferSize]; UpdateInstanceVertexBuffer(myInstance, vertices); UpdateInstanceIndexBuffer(myInstance, indices); int64_t triangleCnt = 0, lineCnt = 0, pointCnt = 0, conceptualFaceCnt = GetConceptualFaceCnt(myInstance); for (int64_t index = 0; index < conceptualFaceCnt; index++) { int64_t startIndexTriangles = 0, noIndicesTriangles = 0, startIndexLines = 0, noIndicesLines = 0, startIndexPoints = 0, noIndicesPoints = 0; GetConceptualFace( myInstance, index, &startIndexTriangles, &noIndicesTriangles, &startIndexLines, &noIndicesLines, &startIndexPoints, &noIndicesPoints, 0, 0, 0, 0 ); // // Calculate space required for arrays // triangleCnt += noIndicesTriangles / 3; lineCnt += noIndicesLines / 2; pointCnt += noIndicesPoints; } int32_t * triangleIndices = triangleCnt ? new int32_t[(int_t) 3 * triangleCnt] : nullptr, * lineIndices = lineCnt ? new int32_t[(int_t) 2 * lineCnt] : nullptr, * pointIndices = pointCnt ? new int32_t[(int_t) pointCnt] : nullptr; int64_t triangleIndicesOffset = 0, lineIndicesOffset = 0, pointIndicesOffset = 0; for (int64_t index = 0; index < conceptualFaceCnt; index++) { int64_t startIndexTriangles = 0, noIndicesTriangles = 0, startIndexLines = 0, noIndicesLines = 0, startIndexPoints = 0, noIndicesPoints = 0; GetConceptualFace( myInstance, index, &startIndexTriangles, &noIndicesTriangles, &startIndexLines, &noIndicesLines, &startIndexPoints, &noIndicesPoints, 0, 0, 0, 0 ); if (noIndicesTriangles) { memcpy(&triangleIndices[triangleIndicesOffset], &indices[startIndexTriangles], noIndicesTriangles * sizeof(int32_t)); triangleIndicesOffset += noIndicesTriangles; } if (noIndicesLines) { memcpy(&lineIndices[lineIndicesOffset], &indices[startIndexLines], noIndicesLines * sizeof(int32_t)); lineIndicesOffset += noIndicesLines; } if (noIndicesPoints) { memcpy(&pointIndices[pointIndicesOffset], &indices[startIndexPoints], noIndicesPoints * sizeof(int32_t)); pointIndicesOffset += noIndicesPoints; } } delete[] indices; assert(triangleIndicesOffset == triangleCnt * 3 && lineIndicesOffset == lineCnt * 2 && pointIndicesOffset == pointCnt); // // Now the index arrays for triagles, lines and points are ready // triangleIndices // lineIndices // pointIndices // all three are using the same vertex array // vertices // // // Based on the Collection we should find // // assert(triangleCnt == 36 * 2 + 2 * (36 - 2)); // The collection contained 1 cylinder (with segmentation parts 36) assert(lineCnt == 2); // The collection contained 2 lines assert(pointCnt == 3); // The collection contained 3 points ... ... // use the vertex and index array for visualization, QTO, conversion etc. ... delete[] vertices; if (triangleIndices) { delete[] triangleIndices; } if (lineIndices) { delete[] lineIndices; } if (pointIndices) { delete[] pointIndices; } } // // The resulting model can be viewed in 3D-Editor.exe // SaveModel(model, "c:\\created\\myFile.bin"); CloseModel(model); }