Fix T89204: slow repeated rendering with GPUOffscreen.draw_view3d

Cache the GPUViewport so the framebuffers and associated textures are not
reallocated each time.

2 files changed, 18 insertions, 1 deletions

diff --git a/source/blender/python/gpu/gpu_py_offscreen.c b/source/blender/python/gpu/gpu_py_offscreen.c
index 0d29bc98a31..1ccac003e97 100644
--- a/source/blender/python/gpu/gpu_py_offscreen.c
+++ b/source/blender/python/gpu/gpu_py_offscreen.c
@@ -44,6 +44,7 @@
 #include "GPU_context.h"
 #include "GPU_framebuffer.h"
 #include "GPU_texture.h"
+#include "GPU_viewport.h"
 
 #include "ED_view3d.h"
 #include "ED_view3d_offscreen.h"
@@ -342,6 +343,10 @@ static PyObject *pygpu_offscreen_draw_view3d(BPyGPUOffScreen *self, PyObject *ar
 
   GPU_offscreen_bind(self->ofs, true);
 
+  if (!self->viewport) {
+    self->viewport = GPU_viewport_create();
+  }
+
   ED_view3d_draw_offscreen(depsgraph,
                            scene,
                            v3d->shading.type,
@@ -357,7 +362,7 @@ static PyObject *pygpu_offscreen_draw_view3d(BPyGPUOffScreen *self, PyObject *ar
                            false,
                            true,
                            self->ofs,
-                           NULL);
+                           self->viewport);
 
   GPU_offscreen_unbind(self->ofs, true);
 
@@ -378,6 +383,10 @@ static PyObject *pygpu_offscreen_free(BPyGPUOffScreen *self)
 {
   BPY_GPU_OFFSCREEN_CHECK_OBJ(self);
 
+  if (self->viewport) {
+    GPU_viewport_free(self->viewport);
+    self->viewport = NULL;
+  }
   GPU_offscreen_free(self->ofs);
   self->ofs = NULL;
   Py_RETURN_NONE;
@@ -386,6 +395,9 @@ static PyObject *pygpu_offscreen_free(BPyGPUOffScreen *self)
 
 static void BPyGPUOffScreen__tp_dealloc(BPyGPUOffScreen *self)
 {
+  if (self->viewport) {
+    GPU_viewport_free(self->viewport);
+  }
   if (self->ofs) {
     GPU_offscreen_free(self->ofs);
   }
@@ -456,6 +468,7 @@ PyObject *BPyGPUOffScreen_CreatePyObject(GPUOffScreen *ofs)
 
   self = PyObject_New(BPyGPUOffScreen, &BPyGPUOffScreen_Type);
   self->ofs = ofs;
+  self->viewport = NULL;
 
   return (PyObject *)self;
 }
diff --git a/source/blender/python/gpu/gpu_py_offscreen.h b/source/blender/python/gpu/gpu_py_offscreen.h
index f551730cf54..203c8c69f73 100644
--- a/source/blender/python/gpu/gpu_py_offscreen.h
+++ b/source/blender/python/gpu/gpu_py_offscreen.h
@@ -26,8 +26,12 @@ extern PyTypeObject BPyGPUOffScreen_Type;
 
 #define BPyGPUOffScreen_Check(v) (Py_TYPE(v) == &BPyGPUOffScreen_Type)
 
+struct GPUOffscreen;
+struct GPUViewport;
+
 typedef struct BPyGPUOffScreen {
   PyObject_HEAD struct GPUOffScreen *ofs;
+  struct GPUViewport *viewport;
 } BPyGPUOffScreen;
 
 PyObject *BPyGPUOffScreen_CreatePyObject(struct GPUOffScreen *ofs) ATTR_NONNULL(1);