OpenSubdiv: Re-work C-API integration

Main goal is to make API simpler to follow (at least ion terms what
is defined/declared where, as opposite of handful big headers which
includes all the declarations), and also avoid a big set of long and
obscure functions.

Now C-API files are split into smaller ones, following OpenSubdiv
behavior more closely, and also function pointers in structures
used a lot more, which shortens functions names,

UV integration part in GL Mesh is mainly stripped away, it needs
to be done differently. On a related topic, UV coordinates API in
converter needs to be removed as well, we do not need coordinates,
only island connectivity information there.

Additional changes:

- Varying interpolation in evaluator API are temporarily disabled,
  need to extend API somewhere (probably, evaluator's API) to inform
  layout information of vertex data (whether it contains varying
  data, width, stride and such).

- Evaluator now can interpolate face-varying data.
  Only works for adaptive refiner, since some issues in OpenSubdiv
  itself.

Planned changes:

- Remove uv coordinates from TopologyConverter.
- Support evaluation of patches (as opposite to individual coordinates
  as it happens currently).
- Support more flexible layout of varying and face-varying data.
  It is stupid to assume varying is 3 floats and face-varying 2 floats.
- Support of second order derivatives.
- Everything else what i'm missing in this list.

1 files changed, 287 insertions, 0 deletions

diff --git a/intern/opensubdiv/internal/opensubdiv_gl_mesh.cc b/intern/opensubdiv/internal/opensubdiv_gl_mesh.cc
new file mode 100644
index 00000000000..34d27591d0b
--- /dev/null
+++ b/intern/opensubdiv/internal/opensubdiv_gl_mesh.cc
@@ -0,0 +1,287 @@
+// Copyright 2013 Blender Foundation. All rights reserved.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software Foundation,
+// Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+//
+// Author: Sergey Sharybin
+// Contributor(s): Brecht van Lommel
+
+#include "opensubdiv_gl_mesh_capi.h"
+
+#ifdef _MSC_VER
+#  include <iso646.h>
+#endif
+
+#include <opensubdiv/far/stencilTable.h>
+#include <opensubdiv/osd/glMesh.h>
+#include <opensubdiv/osd/glPatchTable.h>
+
+using OpenSubdiv::Far::StencilTable;
+using OpenSubdiv::Osd::GLMeshInterface;
+using OpenSubdiv::Osd::GLPatchTable;
+using OpenSubdiv::Osd::Mesh;
+using OpenSubdiv::Osd::MeshBitset;
+
+// CPU backend.
+#include <opensubdiv/osd/cpuEvaluator.h>
+#include <opensubdiv/osd/cpuGLVertexBuffer.h>
+using OpenSubdiv::Osd::CpuGLVertexBuffer;
+using OpenSubdiv::Osd::CpuEvaluator;
+typedef Mesh<CpuGLVertexBuffer,
+             StencilTable,
+             CpuEvaluator,
+             GLPatchTable> OsdCpuMesh;
+// OpenMP backend.
+#ifdef OPENSUBDIV_HAS_OPENMP
+#  include <opensubdiv/osd/ompEvaluator.h>
+using OpenSubdiv::Osd::OmpEvaluator;
+typedef Mesh<CpuGLVertexBuffer,
+             StencilTable,
+             OmpEvaluator,
+             GLPatchTable> OsdOmpMesh;
+#endif
+// OpenCL backend.
+#ifdef OPENSUBDIV_HAS_OPENCL
+#  include <opensubdiv/osd/clEvaluator.h>
+#  include <opensubdiv/osd/clGLVertexBuffer.h>
+#  include "opensubdiv_device_context_opencl.h"
+using OpenSubdiv::Osd::CLEvaluator;
+using OpenSubdiv::Osd::CLGLVertexBuffer;
+using OpenSubdiv::Osd::CLStencilTable;
+/* TODO(sergey): Use CLDeviceContext similar to OSD examples? */
+typedef Mesh<CLGLVertexBuffer,
+             CLStencilTable,
+             CLEvaluator,
+             GLPatchTable,
+             CLDeviceContext> OsdCLMesh;
+static CLDeviceContext g_cl_device_context;
+#endif
+// CUDA backend.
+#ifdef OPENSUBDIV_HAS_CUDA
+#  include <opensubdiv/osd/cudaEvaluator.h>
+#  include <opensubdiv/osd/cudaGLVertexBuffer.h>
+#  include "opensubdiv_device_context_cuda.h"
+using OpenSubdiv::Osd::CudaEvaluator;
+using OpenSubdiv::Osd::CudaGLVertexBuffer;
+using OpenSubdiv::Osd::CudaStencilTable;
+typedef Mesh<CudaGLVertexBuffer,
+             CudaStencilTable,
+             CudaEvaluator,
+             GLPatchTable> OsdCudaMesh;
+static CudaDeviceContext g_cuda_device_context;
+#endif
+// Transform feedback backend.
+#ifdef OPENSUBDIV_HAS_GLSL_TRANSFORM_FEEDBACK
+#  include <opensubdiv/osd/glVertexBuffer.h>
+#  include <opensubdiv/osd/glXFBEvaluator.h>
+using OpenSubdiv::Osd::GLXFBEvaluator;
+using OpenSubdiv::Osd::GLStencilTableTBO;
+using OpenSubdiv::Osd::GLVertexBuffer;
+typedef Mesh<GLVertexBuffer,
+             GLStencilTableTBO,
+             GLXFBEvaluator,
+             GLPatchTable> OsdGLSLTransformFeedbackMesh;
+#endif
+// GLSL compute backend.
+#ifdef OPENSUBDIV_HAS_GLSL_COMPUTE
+#  include <opensubdiv/osd/glComputeEvaluator.h>
+#  include <opensubdiv/osd/glVertexBuffer.h>
+using OpenSubdiv::Osd::GLComputeEvaluator;
+using OpenSubdiv::Osd::GLStencilTableSSBO;
+using OpenSubdiv::Osd::GLVertexBuffer;
+typedef Mesh<GLVertexBuffer,
+             GLStencilTableSSBO,
+             GLComputeEvaluator,
+             GLPatchTable> OsdGLSLComputeMesh;
+#endif
+
+#include <string>
+#include <vector>
+
+#include "MEM_guardedalloc.h"
+
+#include "opensubdiv_topology_refiner_capi.h"
+#include "internal/opensubdiv_gl_mesh_draw.h"
+#include "internal/opensubdiv_gl_mesh_fvar.h"
+#include "internal/opensubdiv_gl_mesh_internal.h"
+#include "internal/opensubdiv_topology_refiner_internal.h"
+
+namespace {
+
+GLMeshInterface* createGLMeshInterface(
+    OpenSubdiv::Far::TopologyRefiner* topology_refiner,
+    const MeshBitset& bits,
+    const int num_vertex_elements,
+    const int num_varying_elements,
+    const int level,
+    eOpenSubdivEvaluator evaluator_type) {
+  GLMeshInterface* mesh = NULL;
+  switch (evaluator_type) {
+#define CHECK_EVALUATOR_TYPE(type, class)                                \
+  case OPENSUBDIV_EVALUATOR_##type:                                      \
+    mesh = new class(topology_refiner,                                   \
+                     num_vertex_elements,                                \
+                     num_varying_elements,                               \
+                     level,                                              \
+                     bits);                                              \
+    break;
+
+#define CHECK_EVALUATOR_TYPE_STUB(type)                                  \
+  case OPENSUBDIV_EVALUATOR_##type:                                      \
+    mesh = NULL;                                                         \
+    break;
+
+    CHECK_EVALUATOR_TYPE(CPU, OsdCpuMesh)
+#ifdef OPENSUBDIV_HAS_OPENMP
+    CHECK_EVALUATOR_TYPE(OPENMP, OsdOmpMesh)
+#else
+    CHECK_EVALUATOR_TYPE_STUB(OPENMP)
+#endif
+#ifdef OPENSUBDIV_HAS_OPENCL
+    CHECK_EVALUATOR_TYPE(OPENCL, OsdCLMesh)
+#else
+    CHECK_EVALUATOR_TYPE_STUB(OPENCL)
+#endif
+#ifdef OPENSUBDIV_HAS_CUDA
+    CHECK_EVALUATOR_TYPE(CUDA, OsdCudaMesh)
+#else
+    CHECK_EVALUATOR_TYPE_STUB(CUDA)
+#endif
+#ifdef OPENSUBDIV_HAS_GLSL_TRANSFORM_FEEDBACK
+    CHECK_EVALUATOR_TYPE(GLSL_TRANSFORM_FEEDBACK, OsdGLSLTransformFeedbackMesh)
+#else
+    CHECK_EVALUATOR_TYPE_STUB(GLSL_TRANSFORM_FEEDBACK)
+#endif
+#ifdef OPENSUBDIV_HAS_GLSL_COMPUTE
+    CHECK_EVALUATOR_TYPE(GLSL_COMPUTE, OsdGLSLComputeMesh)
+#else
+    CHECK_EVALUATOR_TYPE_STUB(GLSL_COMPUTE)
+#endif
+
+#undef CHECK_EVALUATOR_TYPE
+#undef CHECK_EVALUATOR_TYPE_STUB
+  }
+  return mesh;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// GLMesh structure "methods".
+
+opensubdiv_capi::GLMeshFVarData* createFVarData(
+    OpenSubdiv::Far::TopologyRefiner* topology_refiner,
+    GLMeshInterface* mesh,
+    const float *fvar_src_buffer) {
+  using opensubdiv_capi::GLMeshFVarData;
+  GLMeshFVarData* fvar_data = new GLMeshFVarData();
+  fvar_data->create(topology_refiner,
+                    mesh->GetFarPatchTable(),
+                    2,
+                    fvar_src_buffer);
+  return fvar_data;
+}
+
+unsigned int getPatchIndexBuffer(OpenSubdiv_GLMesh* gl_mesh) {
+  return gl_mesh->internal->mesh_interface
+             ->GetPatchTable()
+             ->GetPatchIndexBuffer();
+}
+
+void bindVertexBuffer(OpenSubdiv_GLMesh* gl_mesh) {
+  gl_mesh->internal->mesh_interface->BindVertexBuffer();
+}
+
+void setCoarsePositions(OpenSubdiv_GLMesh* gl_mesh,
+                        const float* positions,
+                        const int start_vertex,
+                        const int num_vertices) {
+  gl_mesh->internal->mesh_interface->UpdateVertexBuffer(positions,
+                                                        start_vertex,
+                                                        num_vertices);
+}
+
+void refine(OpenSubdiv_GLMesh* gl_mesh) {
+  gl_mesh->internal->mesh_interface->Refine();
+}
+
+void synchronize(struct OpenSubdiv_GLMesh* gl_mesh) {
+  gl_mesh->internal->mesh_interface->Synchronize();
+}
+
+void assignFunctionPointers(OpenSubdiv_GLMesh* gl_mesh) {
+  gl_mesh->getPatchIndexBuffer = getPatchIndexBuffer;
+  gl_mesh->bindVertexBuffer = bindVertexBuffer;
+  gl_mesh->setCoarsePositions = setCoarsePositions;
+  gl_mesh->refine = refine;
+  gl_mesh->synchronize = synchronize;
+
+  gl_mesh->prepareDraw = opensubdiv_capi::GLMeshDisplayPrepare;
+  gl_mesh->drawPatches = opensubdiv_capi::GLMeshDisplayDrawPatches;
+}
+
+}  // namespace
+
+struct OpenSubdiv_GLMesh *openSubdiv_createOsdGLMeshFromTopologyRefiner(
+    OpenSubdiv_TopologyRefiner* topology_refiner,
+    eOpenSubdivEvaluator evaluator_type) {
+  using OpenSubdiv::Far::TopologyRefiner;
+  TopologyRefiner* osd_topology_refiner =
+      topology_refiner->internal->osd_topology_refiner;
+  // TODO(sergey): Query this from refiner.
+  const bool is_adaptive = false;
+  MeshBitset bits;
+  bits.set(OpenSubdiv::Osd::MeshAdaptive, is_adaptive);
+  bits.set(OpenSubdiv::Osd::MeshUseSingleCreasePatch, 0);
+  bits.set(OpenSubdiv::Osd::MeshInterleaveVarying, 1);
+  bits.set(OpenSubdiv::Osd::MeshFVarData, 1);
+  bits.set(OpenSubdiv::Osd::MeshEndCapBSplineBasis, 1);
+  const int num_vertex_elements = 3;
+  const int num_varying_elements = 3;
+  GLMeshInterface* mesh = createGLMeshInterface(
+      osd_topology_refiner,
+      bits,
+      num_vertex_elements,
+      num_varying_elements,
+      osd_topology_refiner->GetMaxLevel(),
+      evaluator_type);
+  if (mesh == NULL) {
+    return NULL;
+  }
+  OpenSubdiv_GLMesh* gl_mesh = OBJECT_GUARDED_NEW(OpenSubdiv_GLMesh);
+  assignFunctionPointers(gl_mesh);
+  gl_mesh->internal = new OpenSubdiv_GLMeshInternal();
+  gl_mesh->internal->evaluator_type = evaluator_type;
+  gl_mesh->internal->mesh_interface = mesh;
+  // Face-varying support.
+  // TODO(sergey): This part needs to be re-done.
+  if (osd_topology_refiner->GetNumFVarChannels() > 0) {
+    // TODO(sergey): This is a temporary stub to get things compiled. Need
+    // to store base level UVs somewhere else.
+    std::vector<float> uvs;
+    std::vector<float> fvar_data_buffer;
+    opensubdiv_capi::interpolateFVarData(*osd_topology_refiner,
+                                         uvs,
+                                         &fvar_data_buffer);
+    gl_mesh->internal->fvar_data = createFVarData(osd_topology_refiner,
+                                                  mesh,
+                                                  &fvar_data_buffer[0]);
+  } else {
+    gl_mesh->internal->fvar_data = NULL;
+  }
+  return gl_mesh;
+}
+
+void openSubdiv_deleteOsdGLMesh(OpenSubdiv_GLMesh *gl_mesh) {
+  delete gl_mesh->internal;
+  OBJECT_GUARDED_DELETE(gl_mesh, OpenSubdiv_GLMesh);
+}