Merge branch 'master' of ssh://ka.blankertz.org/home/matthias/git/openglplayground

VBOManager.cc

@@ -0,0 +1,146 @@
+#include <glbinding/gl/gl.h>
+#include <cassert>
+
+#include "VBOManager.hh"
+
+using namespace gl;
+
+VBOManager::VBOManager()
+{
+}
+
+VBOManager::~VBOManager()
+{
+}
+
+VBOManager::VBOAlloc::~VBOAlloc()
+{
+  if(_vbo)
+    _vbo->free(*this);
+  _vbo = nullptr;
+}
+
+VBOManager::VBOAlloc::VBOAlloc(VBOAlloc&& move)
+  : _vbo(move._vbo), _ofs(move._ofs), _size(move._size)
+{
+  move._vbo = nullptr;
+}
+
+VBOManager::VBOAlloc& VBOManager::VBOAlloc::operator=(VBOAlloc&& move)
+{
+  _vbo = move._vbo;
+  _ofs = move._ofs;
+  _size = move._size;
+  move._vbo = nullptr;
+  return *this;
+}
+    
+VBOManager::VBOAlloc::VBOAlloc()
+  : _vbo(nullptr), _ofs(0), _size(0)
+{
+}
+
+VBOManager::VBOAlloc::VBOAlloc(VBO &vbo, size_t ofs, size_t size)
+  : _vbo(&vbo), _ofs(ofs), _size(size)
+{
+}
+
+VBOManager::VBOAlloc VBOManager::alloc(size_t size, GLenum type)
+{
+  for(auto& vbo : _vbos[type]) {
+    try {
+      return vbo.alloc(size);
+    } catch (AllocFailed &ex) {
+      continue;
+    }
+  }
+  
+  _vbos[type].emplace_back((size>default_size)?size:default_size, type);
+  
+  return _vbos[type].back().alloc(size);
+}
+
+VBOManager::VBO::VBO(size_t size, GLenum type)
+  : _bufID(0)
+{
+  glGenBuffers(1, &_bufID);
+  glBindBuffer(GL_ARRAY_BUFFER, _bufID);
+  glBufferData(GL_ARRAY_BUFFER, size, NULL, type);
+  _allocs.emplace_back(_Entry{size, false});
+}
+
+VBOManager::VBO::VBO(VBO&& move)
+  : _bufID(move._bufID), _allocs(std::move(move._allocs))
+{
+  move._bufID = 0;
+}
+
+VBOManager::VBO& VBOManager::VBO::operator=(VBO&& move)
+{
+  for (auto ent : _allocs) {
+    assert(!ent.used);
+  }
+  if (_bufID)
+    glDeleteBuffers(1, &_bufID);
+  _bufID = move._bufID;
+  move._bufID = 0;
+  _allocs = std::move(move._allocs);
+
+  return *this;
+}
+    
+VBOManager::VBO::~VBO()
+{
+  for (auto ent : _allocs) {
+    assert(!ent.used);
+  }
+  if (_bufID)
+    glDeleteBuffers(1, &_bufID);
+  _bufID = 0;
+}
+
+VBOManager::VBOAlloc VBOManager::VBO::alloc(size_t size)
+{
+  if (size%alignment != 0)
+    size += (alignment - (size%alignment));
+
+  size_t pos = 0;
+  for (auto it = _allocs.begin();it != _allocs.end();++it) {
+    if (!it->used && (it->size >= size)) {
+      size_t leftover = it->size - size;
+      it->used = true;
+      it->size = size;
+      if (leftover > 0)
+	_allocs.insert(++it, _Entry{leftover, false});
+      printf("DEBUG: VBO: Allocated %lu @ %lu in %u\n", size, pos, _bufID);
+      return VBOAlloc(*this, pos, size);
+    }
+    pos += it->size;
+  }
+  
+  throw AllocFailed();
+}
+
+void VBOManager::VBO::free(VBOAlloc& alloc)
+{
+  size_t pos = 0;
+  for (auto it = _allocs.begin();it != _allocs.end();++it) {
+    if (pos == alloc._ofs) {
+      assert(it->size == alloc._size);
+      printf("DEBUG: VBO: Freed %lu @ %lu in %u\n", alloc._size, pos, _bufID);
+      it->used = false;
+      if ((std::next(it) != _allocs.end()) &&
+	  !std::next(it)->used) {
+	it->size += std::next(it)->size;
+	_allocs.erase(std::next(it));
+      }
+      if ((it != _allocs.begin()) &&
+	  !std::prev(it)->used) {
+	it->size += std::prev(it)->size;
+	_allocs.erase(std::prev(it));
+      }
+      return;
+    }
+    pos += it->size;
+  }
+}