1 files changed, 281 insertions, 0 deletions
diff --git a/source/blender/gpu/intern/gpu_context.cc b/source/blender/gpu/intern/gpu_context.cc
new file mode 100644
index 00000000000..e04631910c1
--- /dev/null
+++ b/source/blender/gpu/intern/gpu_context.cc
@@ -0,0 +1,281 @@
+/*
+ * 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.
+ *
+ * The Original Code is Copyright (C) 2016 by Mike Erwin.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ *
+ * Manage GL vertex array IDs in a thread-safe way
+ * Use these instead of glGenBuffers & its friends
+ * - alloc must be called from a thread that is bound
+ *   to the context that will be used for drawing with
+ *   this vao.
+ * - free can be called from any thread
+ */
+
+/* TODO Create cmake option. */
+#define WITH_OPENGL_BACKEND 1
+
+#include "BLI_assert.h"
+#include "BLI_utildefines.h"
+
+#include "GPU_context.h"
+#include "GPU_framebuffer.h"
+
+#include "GHOST_C-api.h"
+
+#include "gpu_backend.hh"
+#include "gpu_batch_private.hh"
+#include "gpu_context_private.hh"
+#include "gpu_matrix_private.h"
+
+#ifdef WITH_OPENGL_BACKEND
+#  include "gl_backend.hh"
+#  include "gl_context.hh"
+#endif
+
+#include <mutex>
+#include <vector>
+
+using namespace blender::gpu;
+
+static thread_local GPUContext *active_ctx = NULL;
+
+/* -------------------------------------------------------------------- */
+/** \name GPUContext methods
+ * \{ */
+
+GPUContext::GPUContext()
+{
+  thread_ = pthread_self();
+  is_active_ = false;
+  matrix_state = GPU_matrix_state_create();
+}
+
+GPUContext::~GPUContext()
+{
+  GPU_matrix_state_discard(matrix_state);
+}
+
+bool GPUContext::is_active_on_thread(void)
+{
+  return (this == active_ctx) && pthread_equal(pthread_self(), thread_);
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+
+GPUContext *GPU_context_create(void *ghost_window)
+{
+  if (GPUBackend::get() == NULL) {
+    /* TODO move where it make sense. */
+    GPU_backend_init(GPU_BACKEND_OPENGL);
+  }
+
+  GPUContext *ctx = GPUBackend::get()->context_alloc(ghost_window);
+
+  GPU_context_active_set(ctx);
+  return ctx;
+}
+
+/* to be called after GPU_context_active_set(ctx_to_destroy) */
+void GPU_context_discard(GPUContext *ctx)
+{
+  delete ctx;
+  active_ctx = NULL;
+}
+
+/* ctx can be NULL */
+void GPU_context_active_set(GPUContext *ctx)
+{
+  if (active_ctx) {
+    active_ctx->deactivate();
+  }
+
+  active_ctx = ctx;
+
+  if (ctx) {
+    ctx->activate();
+  }
+}
+
+GPUContext *GPU_context_active_get(void)
+{
+  return active_ctx;
+}
+
+GLuint GPU_vao_default(void)
+{
+  BLI_assert(active_ctx); /* need at least an active context */
+  return static_cast<GLContext *>(active_ctx)->default_vao_;
+}
+
+GLuint GPU_framebuffer_default(void)
+{
+  BLI_assert(active_ctx); /* need at least an active context */
+  return static_cast<GLContext *>(active_ctx)->default_framebuffer_;
+}
+
+GLuint GPU_vao_alloc(void)
+{
+  GLuint new_vao_id = 0;
+  glGenVertexArrays(1, &new_vao_id);
+  return new_vao_id;
+}
+
+GLuint GPU_fbo_alloc(void)
+{
+  GLuint new_fbo_id = 0;
+  glGenFramebuffers(1, &new_fbo_id);
+  return new_fbo_id;
+}
+
+GLuint GPU_buf_alloc(void)
+{
+  GLuint new_buffer_id = 0;
+  glGenBuffers(1, &new_buffer_id);
+  return new_buffer_id;
+}
+
+GLuint GPU_tex_alloc(void)
+{
+  GLuint new_texture_id = 0;
+  glGenTextures(1, &new_texture_id);
+  return new_texture_id;
+}
+
+void GPU_vao_free(GLuint vao_id, GPUContext *ctx)
+{
+  static_cast<GLContext *>(ctx)->vao_free(vao_id);
+}
+
+void GPU_fbo_free(GLuint fbo_id, GPUContext *ctx)
+{
+  static_cast<GLContext *>(ctx)->fbo_free(fbo_id);
+}
+
+void GPU_buf_free(GLuint buf_id)
+{
+  /* TODO avoid using backend */
+  GPUBackend *backend = GPUBackend::get();
+  static_cast<GLBackend *>(backend)->buf_free(buf_id);
+}
+
+void GPU_tex_free(GLuint tex_id)
+{
+  /* TODO avoid using backend */
+  GPUBackend *backend = GPUBackend::get();
+  static_cast<GLBackend *>(backend)->tex_free(tex_id);
+}
+
+/* GPUBatch & GPUFrameBuffer contains respectively VAO & FBO indices
+ * which are not shared across contexts. So we need to keep track of
+ * ownership. */
+
+void gpu_context_add_framebuffer(GPUContext *ctx, GPUFrameBuffer *fb)
+{
+#ifdef DEBUG
+  BLI_assert(ctx);
+  static_cast<GLContext *>(ctx)->framebuffer_register(fb);
+#else
+  UNUSED_VARS(ctx, fb);
+#endif
+}
+
+void gpu_context_remove_framebuffer(GPUContext *ctx, GPUFrameBuffer *fb)
+{
+#ifdef DEBUG
+  BLI_assert(ctx);
+  static_cast<GLContext *>(ctx)->framebuffer_unregister(fb);
+#else
+  UNUSED_VARS(ctx, fb);
+#endif
+}
+
+void gpu_context_active_framebuffer_set(GPUContext *ctx, GPUFrameBuffer *fb)
+{
+  ctx->current_fbo = fb;
+}
+
+GPUFrameBuffer *gpu_context_active_framebuffer_get(GPUContext *ctx)
+{
+  return ctx->current_fbo;
+}
+
+struct GPUMatrixState *gpu_context_active_matrix_state_get()
+{
+  BLI_assert(active_ctx);
+  return active_ctx->matrix_state;
+}
+
+/* -------------------------------------------------------------------- */
+/** \name Main context global mutex
+ *
+ * Used to avoid crash on some old drivers.
+ * \{ */
+
+static std::mutex main_context_mutex;
+
+void GPU_context_main_lock(void)
+{
+  main_context_mutex.lock();
+}
+
+void GPU_context_main_unlock(void)
+{
+  main_context_mutex.unlock();
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Backend selection
+ * \{ */
+
+static GPUBackend *g_backend;
+
+void GPU_backend_init(eGPUBackendType backend_type)
+{
+  BLI_assert(g_backend == NULL);
+
+  switch (backend_type) {
+#if WITH_OPENGL_BACKEND
+    case GPU_BACKEND_OPENGL:
+      g_backend = new GLBackend;
+      break;
+#endif
+    default:
+      BLI_assert(0);
+      break;
+  }
+}
+
+void GPU_backend_exit(void)
+{
+  /* TODO assert no resource left. Currently UI textures are still not freed in their context
+   * correctly. */
+  delete g_backend;
+}
+
+GPUBackend *GPUBackend::get(void)
+{
+  return g_backend;
+}
+
+/** \} */