+GLuint ResourcePool::create_fbo(GLuint texture_num)
+{
+ void *context = get_gl_context_identifier();
+
+ pthread_mutex_lock(&lock);
+ if (fbo_freelist.count(context) != 0) {
+ // See if there's an FBO on the freelist we can use.
+ for (list<GLuint>::iterator freelist_it = fbo_freelist[context].begin();
+ freelist_it != fbo_freelist[context].end();
+ ++freelist_it) {
+ GLuint fbo_num = *freelist_it;
+ map<pair<void *, GLuint>, FBO>::const_iterator format_it =
+ fbo_formats.find(make_pair(context, fbo_num));
+ assert(format_it != fbo_formats.end());
+ if (format_it->second.texture_num == texture_num) {
+ fbo_freelist[context].erase(freelist_it);
+ pthread_mutex_unlock(&lock);
+ return fbo_num;
+ }
+ }
+ }
+
+ // Create a new one.
+ GLuint fbo_num;
+ glGenFramebuffers(1, &fbo_num);
+ check_error();
+ glBindFramebuffer(GL_FRAMEBUFFER, fbo_num);
+ check_error();
+ glFramebufferTexture2D(
+ GL_FRAMEBUFFER,
+ GL_COLOR_ATTACHMENT0,
+ GL_TEXTURE_2D,
+ texture_num,
+ 0);
+ check_error();
+ GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+ assert(status == GL_FRAMEBUFFER_COMPLETE);
+ glBindFramebuffer(GL_FRAMEBUFFER, 0);
+ check_error();
+
+ FBO fbo_format;
+ fbo_format.texture_num = texture_num;
+ pair<void *, GLuint> key(context, fbo_num);
+ assert(fbo_formats.count(key) == 0);
+ fbo_formats.insert(make_pair(key, fbo_format));
+
+ pthread_mutex_unlock(&lock);
+ return fbo_num;
+}
+
+void ResourcePool::release_fbo(GLuint fbo_num)
+{
+ void *context = get_gl_context_identifier();
+
+ pthread_mutex_lock(&lock);
+ fbo_freelist[context].push_front(fbo_num);
+ assert(fbo_formats.count(make_pair(context, fbo_num)) != 0);
+
+ // Now that we're in this context, free up any FBOs that are connected
+ // to deleted textures (in release_2d_texture).
+ cleanup_unlinked_fbos(context);
+
+ shrink_fbo_freelist(context, fbo_freelist_max_length);
+ pthread_mutex_unlock(&lock);
+}
+
+void ResourcePool::clean_context()
+{
+ void *context = get_gl_context_identifier();
+
+ // Currently, we only need to worry about FBOs, as they are the only
+ // non-shareable resource we hold.
+ shrink_fbo_freelist(context, 0);
+ fbo_freelist.erase(context);
+}
+
+void ResourcePool::cleanup_unlinked_fbos(void *context)
+{
+ for (list<GLuint>::iterator freelist_it = fbo_freelist[context].begin();
+ freelist_it != fbo_freelist[context].end(); ) {
+ GLuint fbo_num = *freelist_it;
+ pair<void *, GLuint> key(context, fbo_num);
+ assert(fbo_formats.count(key) != 0);
+ if (fbo_formats[key].texture_num == 0) {
+ fbo_formats.erase(key);
+ glDeleteFramebuffers(1, &fbo_num);
+ check_error();
+ fbo_freelist[context].erase(freelist_it++);
+ } else {
+ freelist_it++;
+ }
+ }
+}
+
+void ResourcePool::shrink_fbo_freelist(void *context, size_t max_length)
+{
+ while (fbo_freelist[context].size() > max_length) {
+ GLuint free_fbo_num = fbo_freelist[context].back();
+ pair<void *, GLuint> key(context, free_fbo_num);
+ fbo_freelist[context].pop_back();
+ assert(fbo_formats.count(key) != 0);
+ fbo_formats.erase(key);
+ glDeleteFramebuffers(1, &free_fbo_num);
+ check_error();
+ }
+}
+