Fix VAOs and client side arrays

gpu/command_buffer/client/vertex_array_object_manager.cc

Index: gpu/command_buffer/client/vertex_array_object_manager.cc
diff --git a/gpu/command_buffer/client/vertex_array_object_manager.cc b/gpu/command_buffer/client/vertex_array_object_manager.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4c76fb56899d7651c8acdf82228ba1e4364abfbc
--- /dev/null
+++ b/gpu/command_buffer/client/vertex_array_object_manager.cc
@@ -0,0 +1,632 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "../client/vertex_array_object_manager.h"
+
+#include "../client/gles2_cmd_helper.h"
+#include "../client/gles2_implementation.h"
+#include "../common/logging.h"
+
+#if defined(__native_client__) && !defined(GLES2_SUPPORT_CLIENT_SIDE_ARRAYS)
+#define GLES2_SUPPORT_CLIENT_SIDE_ARRAYS
+#endif
+
+namespace gpu {
+namespace gles2 {
+
+#if defined(GLES2_SUPPORT_CLIENT_SIDE_ARRAYS)
+
+static GLsizei RoundUpToMultipleOf4(GLsizei size) {
+  return (size + 3) & ~3;
+}
+
+#endif  // defined(GLES2_SUPPORT_CLIENT_SIDE_ARRAYS)
+
+// A 32-bit and 64-bit compatible way of converting a pointer to a GLuint.
+static GLuint ToGLuint(const void* ptr) {
+  return static_cast<GLuint>(reinterpret_cast<size_t>(ptr));
+}
+
+// This class tracks VertexAttribPointers and helps emulate client side buffers.
+//
+// The way client side buffers work is we shadow all the Vertex Attribs so we
+// know which ones are pointing to client side buffers.
+//
+// At Draw time, for any attribs pointing to client side buffers we copy them
+// to a special VBO and reset the actual vertex attrib pointers to point to this
+// VBO.
+//
+// This also means we have to catch calls to query those values so that when
+// an attrib is a client side buffer we pass the info back the user expects.
+
+class GLES2_IMPL_EXPORT VertexArrayObject {
+ public:
+  // Info about Vertex Attributes. This is used to track what the user currently
+  // has bound on each Vertex Attribute so we can simulate client side buffers
+  // at glDrawXXX time.
+  class VertexAttrib {
+   public:
+    VertexAttrib()
+        : enabled_(false),
+          buffer_id_(0),
+          size_(4),
+          type_(GL_FLOAT),
+          normalized_(GL_FALSE),
+          pointer_(NULL),
+          gl_stride_(0),
+          divisor_(0) {
+    }
+
+    bool enabled() const {
+      return enabled_;
+    }
+
+    void set_enabled(bool enabled) {
+      enabled_ = enabled;
+    }
+
+    GLuint buffer_id() const {
+      return buffer_id_;
+    }
+
+    void set_buffer_id(GLuint id) {
+      buffer_id_ = id;
+    }
+
+    GLenum type() const {
+      return type_;
+    }
+
+    GLint size() const {
+      return size_;
+    }
+
+    GLsizei stride() const {
+      return gl_stride_;
+    }
+
+    GLboolean normalized() const {
+      return normalized_;
+    }
+
+    const GLvoid* pointer() const {
+      return pointer_;
+    }
+
+    bool IsClientSide() const {
+      return buffer_id_ == 0;
+    }
+
+    GLuint divisor() const {
+      return divisor_;
+    }
+
+    void SetInfo(
+        GLuint buffer_id,
+        GLint size,
+        GLenum type,
+        GLboolean normalized,
+        GLsizei gl_stride,
+        const GLvoid* pointer) {
+      buffer_id_ = buffer_id;
+      size_ = size;
+      type_ = type;
+      normalized_ = normalized;
+      gl_stride_ = gl_stride;
+      pointer_ = pointer;
+    }
+
+    void SetDivisor(GLuint divisor) {
+      divisor_ = divisor;
+    }
+
+   private:
+    // Whether or not this attribute is enabled.
+    bool enabled_;
+
+    // The id of the buffer. 0 = client side buffer.
+    GLuint buffer_id_;
+
+    // Number of components (1, 2, 3, 4).
+    GLint size_;
+
+    // GL_BYTE, GL_FLOAT, etc. See glVertexAttribPointer.
+    GLenum type_;
+
+    // GL_TRUE or GL_FALSE
+    GLboolean normalized_;
+
+    // The pointer/offset into the buffer.
+    const GLvoid* pointer_;
+
+    // The stride that will be used to access the buffer. This is the bogus GL
+    // stride where 0 = compute the stride based on size and type.
+    GLsizei gl_stride_;
+
+    // Divisor, for geometry instancing.
+    GLuint divisor_;
+  };
+
+  typedef std::vector<VertexAttrib> VertexAttribs;
+
+  explicit VertexArrayObject(GLuint max_vertex_attribs);
+
+  void UnbindBuffer(GLuint id);
+
+  bool BindElementArray(GLuint id);
+
+  bool HaveEnabledClientSideBuffers() const;
+
+  void SetAttribEnable(GLuint index, bool enabled);
+
+  void SetAttribPointer(
+    GLuint buffer_id,
+    GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride,
+    const void* ptr);
+
+  bool GetVertexAttrib(
+      GLuint index, GLenum pname, uint32* param) const;
+
+  void SetAttribDivisor(GLuint index, GLuint divisor);
+
+  bool GetAttribPointer(GLuint index, GLenum pname, void** ptr) const;
+
+  const VertexAttribs& vertex_attribs() const {
+    return vertex_attribs_;
+  }
+
+  GLuint bound_element_array_buffer() const {
+    return bound_element_array_buffer_id_;
+  }
+
+ private:
+  const VertexAttrib* GetAttrib(GLuint index) const;
+
+  GLuint num_client_side_pointers_enabled_;
+
+  // The currently bound element array buffer.
+  GLuint bound_element_array_buffer_id_;
+
+  VertexAttribs vertex_attribs_;
+
+  DISALLOW_COPY_AND_ASSIGN(VertexArrayObject);
+};
+
+VertexArrayObject::VertexArrayObject(GLuint max_vertex_attribs)
+    : num_client_side_pointers_enabled_(0),
+      bound_element_array_buffer_id_(0) {
+  vertex_attribs_.resize(max_vertex_attribs);
+}
+
+void VertexArrayObject::UnbindBuffer(GLuint id) {
+  for (size_t ii = 0; ii < vertex_attribs_.size(); ++ii) {
+    VertexAttrib& attrib = vertex_attribs_[ii];
+    if (attrib.buffer_id() == id) {
+      attrib.set_buffer_id(0);
+      if (attrib.enabled()) {
+        ++num_client_side_pointers_enabled_;
+      }
+    }
+  }
+}
+
+bool VertexArrayObject::BindElementArray(GLuint id) {
+  if (id == bound_element_array_buffer_id_) {
+    return false;
+  }
+  bound_element_array_buffer_id_ = id;
+  return true;
+}
+bool VertexArrayObject::HaveEnabledClientSideBuffers() const {
+  return num_client_side_pointers_enabled_ > 0;
+}
+
+void VertexArrayObject::SetAttribEnable(GLuint index, bool enabled) {
+  if (index < vertex_attribs_.size()) {
+    VertexAttrib& attrib = vertex_attribs_[index];
+    if (attrib.enabled() != enabled) {
+      if (attrib.IsClientSide()) {
+        num_client_side_pointers_enabled_ += enabled ? 1 : -1;
+      }
+      attrib.set_enabled(enabled);
+    }
+  }
+}
+
+void VertexArrayObject::SetAttribPointer(
+    GLuint buffer_id,
+    GLuint index,
+    GLint size,
+    GLenum type,
+    GLboolean normalized,
+    GLsizei stride,
+    const void* ptr) {
+  if (index < vertex_attribs_.size()) {
+    VertexAttrib& attrib = vertex_attribs_[index];
+    if (attrib.IsClientSide() && attrib.enabled()) {
+      --num_client_side_pointers_enabled_;
+    }
+
+    attrib.SetInfo(buffer_id, size, type, normalized, stride, ptr);
+
+    if (attrib.IsClientSide() && attrib.enabled()) {
+      ++num_client_side_pointers_enabled_;
+    }
+  }
+}
+
+bool VertexArrayObject::GetVertexAttrib(
+    GLuint index, GLenum pname, uint32* param) const {
+  const VertexAttrib* attrib = GetAttrib(index);
+  if (!attrib) {
+    return false;
+  }
+
+  switch (pname) {
+    case GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING:
+      *param = attrib->buffer_id();
+      break;
+    case GL_VERTEX_ATTRIB_ARRAY_ENABLED:
+      *param = attrib->enabled();
+      break;
+    case GL_VERTEX_ATTRIB_ARRAY_SIZE:
+      *param = attrib->size();
+      break;
+    case GL_VERTEX_ATTRIB_ARRAY_STRIDE:
+      *param = attrib->stride();
+      break;
+    case GL_VERTEX_ATTRIB_ARRAY_TYPE:
+      *param = attrib->type();
+      break;
+    case GL_VERTEX_ATTRIB_ARRAY_NORMALIZED:
+      *param = attrib->normalized();
+      break;
+    default:
+      return false;  // pass through to service side.
+      break;
+  }
+  return true;
+}
+
+void VertexArrayObject::SetAttribDivisor(GLuint index, GLuint divisor) {
+  if (index < vertex_attribs_.size()) {
+    VertexAttrib& attrib = vertex_attribs_[index];
+    attrib.SetDivisor(divisor);
+  }
+}
+
+// Gets the Attrib pointer for an attrib but only if it's a client side
+// pointer. Returns true if it got the pointer.
+bool VertexArrayObject::GetAttribPointer(
+    GLuint index, GLenum pname, void** ptr) const {
+  const VertexAttrib* attrib = GetAttrib(index);
+  if (attrib && pname == GL_VERTEX_ATTRIB_ARRAY_POINTER) {
+    *ptr = const_cast<void*>(attrib->pointer());
+    return true;
+  }
+  return false;
+}
+
+// Gets an attrib if it's in range and it's client side.
+const VertexArrayObject::VertexAttrib* VertexArrayObject::GetAttrib(
+    GLuint index) const {
+  if (index < vertex_attribs_.size()) {
+    const VertexAttrib* attrib = &vertex_attribs_[index];
+    return attrib;
+  }
+  return NULL;
+}
+
+VertexArrayObjectManager::VertexArrayObjectManager(
+    GLuint max_vertex_attribs,
+    GLuint array_buffer_id,
+    GLuint element_array_buffer_id)
+    : max_vertex_attribs_(max_vertex_attribs),
+      array_buffer_id_(array_buffer_id),
+      array_buffer_size_(0),
+      array_buffer_offset_(0),
+      element_array_buffer_id_(element_array_buffer_id),
+      element_array_buffer_size_(0),
+      collection_buffer_size_(0),
+      default_vertex_array_object_(new VertexArrayObject(max_vertex_attribs)),
+      bound_vertex_array_object_(default_vertex_array_object_) {
+}
+
+VertexArrayObjectManager::~VertexArrayObjectManager() {
+  for (VertexArrayObjectMap::iterator it = vertex_array_objects_.begin();
+       it != vertex_array_objects_.end(); ++it) {
+    delete it->second;
+  }
+  delete default_vertex_array_object_;
+}
+
+bool VertexArrayObjectManager::IsReservedId(GLuint id) const {
+  return (id != 0 &&
+          (id == array_buffer_id_ || id == element_array_buffer_id_));
+}
+
+GLuint VertexArrayObjectManager::bound_element_array_buffer() const {
+  return bound_vertex_array_object_->bound_element_array_buffer();
+}
+
+void VertexArrayObjectManager::UnbindBuffer(GLuint id) {
+  bound_vertex_array_object_->UnbindBuffer(id);
+}
+
+bool VertexArrayObjectManager::BindElementArray(GLuint id) {
+  return  bound_vertex_array_object_->BindElementArray(id);
+}
+
+void VertexArrayObjectManager::GenVertexArrays(
+    GLsizei n, const GLuint* arrays) {
+  GPU_DCHECK_GE(n, 0);
+  for (GLsizei i = 0; i < n; ++i) {
+    std::pair<VertexArrayObjectMap::iterator, bool> result =
+        vertex_array_objects_.insert(std::make_pair(
+            arrays[i], new VertexArrayObject(max_vertex_attribs_)));
+    GPU_DCHECK(result.second);
+  }
+}
+
+void VertexArrayObjectManager::DeleteVertexArrays(
+    GLsizei n, const GLuint* arrays) {
+  GPU_DCHECK_GE(n, 0);
+  for (GLsizei i = 0; i < n; ++i) {
+    GLuint id = arrays[i];
+    if (id) {
+      VertexArrayObjectMap::iterator it = vertex_array_objects_.find(id);
+      if (it != vertex_array_objects_.end()) {
+        if (bound_vertex_array_object_ == it->second) {
+          bound_vertex_array_object_ = default_vertex_array_object_;
+        }
+        delete it->second;
+        vertex_array_objects_.erase(it);
+      }
+    }
+  }
+}
+
+bool VertexArrayObjectManager::BindVertexArray(GLuint array, bool* changed) {
+  *changed = false;
+  VertexArrayObject* vertex_array_object = default_vertex_array_object_;
+  if (array != 0) {
+    VertexArrayObjectMap::iterator it = vertex_array_objects_.find(array);
+    if (it == vertex_array_objects_.end()) {
+      return false;
+    }
+    vertex_array_object = it->second;
+  }
+  *changed = vertex_array_object != bound_vertex_array_object_;
+  bound_vertex_array_object_ = vertex_array_object;
+  return true;
+}
+
+bool VertexArrayObjectManager::HaveEnabledClientSideBuffers() const {
+  return bound_vertex_array_object_->HaveEnabledClientSideBuffers();
+}
+
+void VertexArrayObjectManager::SetAttribEnable(GLuint index, bool enabled) {
+  bound_vertex_array_object_->SetAttribEnable(index, enabled);
+}
+
+bool VertexArrayObjectManager::GetVertexAttrib(
+    GLuint index, GLenum pname, uint32* param) {
+  return bound_vertex_array_object_->GetVertexAttrib(index, pname, param);
+}
+
+bool VertexArrayObjectManager::GetAttribPointer(
+    GLuint index, GLenum pname, void** ptr) const {
+  return bound_vertex_array_object_->GetAttribPointer(index, pname, ptr);
+}
+
+bool VertexArrayObjectManager::SetAttribPointer(
+    GLuint buffer_id,
+    GLuint index,
+    GLint size,
+    GLenum type,
+    GLboolean normalized,
+    GLsizei stride,
+    const void* ptr) {
+  // Client side arrays are not allowed in vaos.
+  if (buffer_id == 0 && !IsDefaultVAOBound()) {
+    return false;
+  }
+  bound_vertex_array_object_->SetAttribPointer(
+      buffer_id, index, size, type, normalized, stride, ptr);
+  return true;
+}
+
+void VertexArrayObjectManager::SetAttribDivisor(GLuint index, GLuint divisor) {
+  bound_vertex_array_object_->SetAttribDivisor(index, divisor);
+}
+
+// Collects the data into the collection buffer and returns the number of
+// bytes collected.
+GLsizei VertexArrayObjectManager::CollectData(
+    const void* data,
+    GLsizei bytes_per_element,
+    GLsizei real_stride,
+    GLsizei num_elements) {
+  GLsizei bytes_needed = bytes_per_element * num_elements;
+  if (collection_buffer_size_ < bytes_needed) {
+    collection_buffer_.reset(new int8[bytes_needed]);
+    collection_buffer_size_ = bytes_needed;
+  }
+  const int8* src = static_cast<const int8*>(data);
+  int8* dst = collection_buffer_.get();
+  int8* end = dst + bytes_per_element * num_elements;
+  for (; dst < end; src += real_stride, dst += bytes_per_element) {
+    memcpy(dst, src, bytes_per_element);
+  }
+  return bytes_needed;
+}
+
+bool VertexArrayObjectManager::IsDefaultVAOBound() const {
+  return bound_vertex_array_object_ == default_vertex_array_object_;
+}
+
+// Returns true if buffers were setup.
+bool VertexArrayObjectManager::SetupSimulatedClientSideBuffers(
+    const char* function_name,
+    GLES2Implementation* gl,
+    GLES2CmdHelper* gl_helper,
+    GLsizei num_elements,
+    GLsizei primcount,
+    bool* simulated) {
+  *simulated = false;
+#if defined(GLES2_SUPPORT_CLIENT_SIDE_ARRAYS)
+  if (!bound_vertex_array_object_->HaveEnabledClientSideBuffers()) {
+    return true;
+  }
+  if (!IsDefaultVAOBound()) {
+    gl->SetGLError(
+        GL_INVALID_OPERATION, function_name,
+        "client side arrays not allowed with vertex array object");
+    return false;
+  }
+  *simulated = true;
+  GLsizei total_size = 0;
+  // Compute the size of the buffer we need.
+  const VertexArrayObject::VertexAttribs& vertex_attribs =
+      bound_vertex_array_object_->vertex_attribs();
+  for (GLuint ii = 0; ii < vertex_attribs.size(); ++ii) {
+    const VertexArrayObject::VertexAttrib& attrib = vertex_attribs[ii];
+    if (attrib.IsClientSide() && attrib.enabled()) {
+      size_t bytes_per_element =
+          GLES2Util::GetGLTypeSizeForTexturesAndBuffers(attrib.type()) *
+          attrib.size();
+      GLsizei elements = (primcount && attrib.divisor() > 0) ?
+          ((primcount - 1) / attrib.divisor() + 1) : num_elements;
+      total_size += RoundUpToMultipleOf4(bytes_per_element * elements);
+    }
+  }
+  gl_helper->BindBuffer(GL_ARRAY_BUFFER, array_buffer_id_);
+  array_buffer_offset_ = 0;
+  if (total_size > array_buffer_size_) {
+    gl->BufferDataHelper(GL_ARRAY_BUFFER, total_size, NULL, GL_DYNAMIC_DRAW);
+    array_buffer_size_ = total_size;
+  }
+  for (GLuint ii = 0; ii < vertex_attribs.size(); ++ii) {
+    const VertexArrayObject::VertexAttrib& attrib = vertex_attribs[ii];
+    if (attrib.IsClientSide() && attrib.enabled()) {
+      size_t bytes_per_element =
+          GLES2Util::GetGLTypeSizeForTexturesAndBuffers(attrib.type()) *
+          attrib.size();
+      GLsizei real_stride = attrib.stride() ?
+          attrib.stride() : static_cast<GLsizei>(bytes_per_element);
+      GLsizei elements = (primcount && attrib.divisor() > 0) ?
+          ((primcount - 1) / attrib.divisor() + 1) : num_elements;
+      GLsizei bytes_collected = CollectData(
+          attrib.pointer(), bytes_per_element, real_stride, elements);
+      gl->BufferSubDataHelper(
+          GL_ARRAY_BUFFER, array_buffer_offset_, bytes_collected,
+          collection_buffer_.get());
+      gl_helper->VertexAttribPointer(
+          ii, attrib.size(), attrib.type(), attrib.normalized(), 0,
+          array_buffer_offset_);
+      array_buffer_offset_ += RoundUpToMultipleOf4(bytes_collected);
+      GPU_DCHECK_LE(array_buffer_offset_, array_buffer_size_);
+    }
+  }
+#endif  // defined(GLES2_SUPPORT_CLIENT_SIDE_ARRAYS)
+  return true;
+}
+
+// Copies in indices to the service and returns the highest index accessed + 1
+bool VertexArrayObjectManager::SetupSimulatedIndexAndClientSideBuffers(
+    const char* function_name,
+    GLES2Implementation* gl,
+    GLES2CmdHelper* gl_helper,
+    GLsizei count,
+    GLenum type,
+    GLsizei primcount,
+    const void* indices,
+    GLuint* offset,
+    bool* simulated) {
+  *simulated = false;
+  *offset = ToGLuint(indices);
+#if defined(GLES2_SUPPORT_CLIENT_SIDE_ARRAYS)
+  GLsizei num_elements = 0;
+  if (bound_vertex_array_object_->bound_element_array_buffer() == 0) {
+    *simulated = true;
+    *offset = 0;
+    GLsizei max_index = -1;
+    switch (type) {
+      case GL_UNSIGNED_BYTE: {
+        const uint8* src = static_cast<const uint8*>(indices);
+        for (GLsizei ii = 0; ii < count; ++ii) {
+          if (src[ii] > max_index) {
+            max_index = src[ii];
+          }
+        }
+        break;
+      }
+      case GL_UNSIGNED_SHORT: {
+        const uint16* src = static_cast<const uint16*>(indices);
+        for (GLsizei ii = 0; ii < count; ++ii) {
+          if (src[ii] > max_index) {
+            max_index = src[ii];
+          }
+        }
+        break;
+      }
+      case GL_UNSIGNED_INT: {
+        uint32 max_glsizei = static_cast<uint32>(
+            std::numeric_limits<GLsizei>::max());
+        const uint32* src = static_cast<const uint32*>(indices);
+        for (GLsizei ii = 0; ii < count; ++ii) {
+          // Other parts of the API use GLsizei (signed) to store limits.
+          // As such, if we encounter a index that cannot be represented with
+          // an unsigned int we need to flag it as an error here.
+          if(src[ii] > max_glsizei) {
+            gl->SetGLError(
+                GL_INVALID_OPERATION, function_name, "index too large.");
+            return false;
+          }
+          GLsizei signed_index = static_cast<GLsizei>(src[ii]);
+          if (signed_index > max_index) {
+            max_index = signed_index;
+          }
+        }
+        break;
+      }
+      default:
+        break;
+    }
+    gl_helper->BindBuffer(GL_ELEMENT_ARRAY_BUFFER, element_array_buffer_id_);
+    GLsizei bytes_per_element =
+        GLES2Util::GetGLTypeSizeForTexturesAndBuffers(type);
+    GLsizei bytes_needed = bytes_per_element * count;
+    if (bytes_needed > element_array_buffer_size_) {
+      element_array_buffer_size_ = bytes_needed;
+      gl->BufferDataHelper(
+          GL_ELEMENT_ARRAY_BUFFER, bytes_needed, NULL, GL_DYNAMIC_DRAW);
+    }
+    gl->BufferSubDataHelper(
+        GL_ELEMENT_ARRAY_BUFFER, 0, bytes_needed, indices);
+
+    num_elements = max_index + 1;
+  } else if (bound_vertex_array_object_->HaveEnabledClientSideBuffers()) {
+    // Index buffer is GL buffer. Ask the service for the highest vertex
+    // that will be accessed. Note: It doesn't matter if another context
+    // changes the contents of any of the buffers. The service will still
+    // validate the indices. We just need to know how much to copy across.
+    num_elements = gl->GetMaxValueInBufferCHROMIUMHelper(
+        bound_vertex_array_object_->bound_element_array_buffer(),
+        count, type, ToGLuint(indices)) + 1;
+  }
+
+  bool simulated_client_side_buffers = false;
+  SetupSimulatedClientSideBuffers(
+      function_name, gl, gl_helper, num_elements, primcount,
+      &simulated_client_side_buffers);
+  *simulated = *simulated || simulated_client_side_buffers;
+#endif  // defined(GLES2_SUPPORT_CLIENT_SIDE_ARRAYS)
+  return true;
+}
+
+}  // namespace gles2
+}  // namespace gpu
+
+