RenderViewport: Texture Format

When doing viewport rendering the color management happens on the CPU.
This has overhead in downloading a float texture from the gpu and
performing color management on the CPU.

Based on the scene fileformat bit depth the result will be rendered to
a byte texture where the colormanagement happens on the GPU or a float
texture where the colormanagement happens on the CPU.

This is only done during `Viewport Render Animation` in other
cases a float texture is being used.

Baseline (HD render of wanderer.blend workbench engine no samples) 15.688038 s
After changes: 9.412880s

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D6195

1 files changed, 10 insertions, 4 deletions

diff --git a/source/blender/editors/render/render_opengl.c b/source/blender/editors/render/render_opengl.c
index f419d30a17e..0d0e183e480 100644
--- a/source/blender/editors/render/render_opengl.c
+++ b/source/blender/editors/render/render_opengl.c
@@ -18,7 +18,7 @@
  */
 
 /** \file
- * \ingroup edrend
+ * \ingroup render
  */
 
 #include <math.h>
@@ -77,7 +77,7 @@
 #include "render_intern.h"
 
 /* Define this to get timing information. */
-// #undef DEBUG_TIME
+// #define DEBUG_TIME
 
 #ifdef DEBUG_TIME
 #  include "PIL_time.h"
@@ -138,6 +138,8 @@ typedef struct OGLRender {
   TaskPool *task_pool;
   bool pool_ok;
   bool is_animation;
+
+  eImageFormatDepth color_depth;
   SpinLock reports_lock;
   unsigned int num_scheduled_frames;
   ThreadMutex task_mutex;
@@ -356,6 +358,7 @@ static void screen_opengl_render_doit(const bContext *C, OGLRender *oglrender, R
     char err_out[256] = "unknown";
     ImBuf *ibuf_view;
     const int alpha_mode = (draw_sky) ? R_ADDSKY : R_ALPHAPREMUL;
+    int output_flags = oglrender->color_depth <= R_IMF_CHAN_DEPTH_8 ? IB_rect : IB_rectfloat;
 
     if (view_context) {
       ibuf_view = ED_view3d_draw_offscreen_imbuf(depsgraph,
@@ -365,7 +368,7 @@ static void screen_opengl_render_doit(const bContext *C, OGLRender *oglrender, R
                                                  ar,
                                                  sizex,
                                                  sizey,
-                                                 IB_rectfloat,
+                                                 output_flags,
                                                  alpha_mode,
                                                  oglrender->ofs_samples,
                                                  viewname,
@@ -385,7 +388,7 @@ static void screen_opengl_render_doit(const bContext *C, OGLRender *oglrender, R
                                                         scene->camera,
                                                         oglrender->sizex,
                                                         oglrender->sizey,
-                                                        IB_rectfloat,
+                                                        output_flags,
                                                         V3D_OFSDRAW_SHOW_ANNOTATION,
                                                         alpha_mode,
                                                         oglrender->ofs_samples,
@@ -528,6 +531,8 @@ static bool screen_opengl_render_init(bContext *C, wmOperator *op)
   const bool is_animation = RNA_boolean_get(op->ptr, "animation");
   const bool is_sequencer = RNA_boolean_get(op->ptr, "sequencer");
   const bool is_write_still = RNA_boolean_get(op->ptr, "write_still");
+  const eImageFormatDepth color_depth = (is_animation) ? scene->r.im_format.depth :
+                                                         R_IMF_CHAN_DEPTH_32;
   const int samples = U.ogl_multisamples;
   char err_out[256] = "unknown";
 
@@ -600,6 +605,7 @@ static bool screen_opengl_render_init(bContext *C, wmOperator *op)
 
   oglrender->write_still = is_write_still && !is_animation;
   oglrender->is_animation = is_animation;
+  oglrender->color_depth = color_depth;
 
   oglrender->views_len = BKE_scene_multiview_num_views_get(&scene->r);