[Bf-blender-cvs] [2e908156d0c] master: Fix T77564: VSE (and compositor background) lost stereoscopy preview

[Clément Foucault]

Commit: 2e908156d0c744e526e165b386c61a0a4d0e8ed0
Author: Clément Foucault
Date:   Tue Aug 18 14:43:18 2020 +0200
Branches: master
https://developer.blender.org/rB2e908156d0c744e526e165b386c61a0a4d0e8ed0

Fix T77564: VSE (and compositor background) lost stereoscopy preview

Issue introduced on fe045b2b77dc6d7f0b552619fe824b496d34db6c.

Since the stereoscopy compositing (anaglyph, ...) is only done for
viewports the VSE preview and compositor need to use viewports.

Reviewed by: dfelinto

Differential Revision: https://developer.blender.org/D8472

===================================================================

M	source/blender/editors/space_node/node_draw.c
M	source/blender/editors/space_sequencer/sequencer_draw.c
M	source/blender/gpu/GPU_framebuffer.h
M	source/blender/gpu/intern/gpu_framebuffer.cc
M	source/blender/windowmanager/intern/wm_draw.c

===================================================================

diff --git a/source/blender/editors/space_node/node_draw.c b/source/blender/editors/space_node/node_draw.c
index 9d048bf7c3c..df1a24eb71a 100644
--- a/source/blender/editors/space_node/node_draw.c
+++ b/source/blender/editors/space_node/node_draw.c
@@ -52,6 +52,7 @@
 #include "GPU_immediate_util.h"
 #include "GPU_matrix.h"
 #include "GPU_state.h"
+#include "GPU_viewport.h"
 
 #include "WM_api.h"
 #include "WM_types.h"
@@ -1755,6 +1756,12 @@ void drawnodespace(const bContext *C, ARegion *region)
   SpaceNode *snode = CTX_wm_space_node(C);
   View2D *v2d = &region->v2d;
 
+  /* Setup offscreen buffers. */
+  GPUViewport *viewport = WM_draw_region_get_viewport(region);
+
+  GPUFrameBuffer *framebuffer_overlay = GPU_viewport_framebuffer_overlay_get(viewport);
+  GPU_framebuffer_bind_no_srgb(framebuffer_overlay);
+
   UI_ThemeClearColor(TH_BACK);
   GPU_clear(GPU_COLOR_BIT);
 
diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index 0f4690c11d5..b784104e9ce 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -56,6 +56,7 @@
 #include "GPU_matrix.h"
 #include "GPU_state.h"
 #include "GPU_vertex_buffer.h"
+#include "GPU_viewport.h"
 
 #include "ED_anim_api.h"
 #include "ED_gpencil.h"
@@ -1537,7 +1538,7 @@ static void sequencer_preview_clear(void)
   float col[3];
 
   UI_GetThemeColor3fv(TH_SEQ_PREVIEW, col);
-  GPU_clear_color(col[0], col[1], col[2], 0.0);
+  GPU_clear_color(col[0], col[1], col[2], 1.0f);
   GPU_clear(GPU_COLOR_BIT);
 }
 
@@ -1780,6 +1781,12 @@ void sequencer_draw_preview(const bContext *C,
     return;
   }
 
+  /* Setup offscreen buffers. */
+  GPUViewport *viewport = WM_draw_region_get_viewport(region);
+
+  GPUFrameBuffer *framebuffer_overlay = GPU_viewport_framebuffer_overlay_get(viewport);
+  GPU_framebuffer_bind_no_srgb(framebuffer_overlay);
+
   /* Setup view. */
   sequencer_display_size(scene, viewrect);
   UI_view2d_totRect_set(v2d, viewrect[0] + 0.5f, viewrect[1] + 0.5f);
@@ -1798,6 +1805,9 @@ void sequencer_draw_preview(const bContext *C,
   ibuf = sequencer_ibuf_get(
       bmain, depsgraph, scene, sseq, cfra, frame_ofs, names[sseq->multiview_eye]);
 
+  /* sequencer_ibuf_get can call GPU_framebuffer_bind. So disable srgb framebuffer again. */
+  GPU_framebuffer_bind_no_srgb(framebuffer_overlay);
+
   if (ibuf) {
     scope = sequencer_get_scope(scene, sseq, ibuf, draw_backdrop);
 
diff --git a/source/blender/gpu/GPU_framebuffer.h b/source/blender/gpu/GPU_framebuffer.h
index 9dc07fefd4e..7103317e4d6 100644
--- a/source/blender/gpu/GPU_framebuffer.h
+++ b/source/blender/gpu/GPU_framebuffer.h
@@ -61,6 +61,7 @@ typedef struct GPUOffScreen GPUOffScreen;
 GPUFrameBuffer *GPU_framebuffer_create(void);
 void GPU_framebuffer_free(GPUFrameBuffer *fb);
 void GPU_framebuffer_bind(GPUFrameBuffer *fb);
+void GPU_framebuffer_bind_no_srgb(GPUFrameBuffer *fb);
 void GPU_framebuffer_restore(void);
 
 bool GPU_framebuffer_bound(GPUFrameBuffer *fb);
diff --git a/source/blender/gpu/intern/gpu_framebuffer.cc b/source/blender/gpu/intern/gpu_framebuffer.cc
index 5f3089b2ffb..627f417e0c3 100644
--- a/source/blender/gpu/intern/gpu_framebuffer.cc
+++ b/source/blender/gpu/intern/gpu_framebuffer.cc
@@ -555,6 +555,18 @@ void GPU_framebuffer_bind(GPUFrameBuffer *fb)
   glViewport(0, 0, fb->width, fb->height);
 }
 
+/* Workaround for binding a srgb framebuffer without doing the srgb transform. */
+void GPU_framebuffer_bind_no_srgb(GPUFrameBuffer *fb)
+{
+  GPU_framebuffer_bind(fb);
+
+  glDisable(GL_FRAMEBUFFER_SRGB);
+
+  GPUTexture *first_target = fb->attachments[GPU_FB_COLOR_ATTACHMENT0].tex;
+  const bool is_srgb_target = (first_target && (GPU_texture_format(first_target) == GPU_SRGB8_A8));
+  GPU_shader_set_framebuffer_srgb_target(!is_srgb_target);
+}
+
 void GPU_framebuffer_restore(void)
 {
   if (GPU_framebuffer_active_get() != NULL) {
diff --git a/source/blender/windowmanager/intern/wm_draw.c b/source/blender/windowmanager/intern/wm_draw.c
index b8cb5432a49..bfc155dce16 100644
--- a/source/blender/windowmanager/intern/wm_draw.c
+++ b/source/blender/windowmanager/intern/wm_draw.c
@@ -307,7 +307,9 @@ static void wm_region_test_xr_do_draw(const wmWindowManager *wm,
 
 static bool wm_region_use_viewport_by_type(short space_type, short region_type)
 {
-  return (ELEM(space_type, SPACE_VIEW3D, SPACE_IMAGE) && region_type == RGN_TYPE_WINDOW);
+  return (ELEM(space_type, SPACE_VIEW3D, SPACE_IMAGE, SPACE_NODE) &&
+          region_type == RGN_TYPE_WINDOW) ||
+         ((space_type == SPACE_SEQ) && region_type == RGN_TYPE_PREVIEW);
 }
 
 bool WM_region_use_viewport(ScrArea *area, ARegion *region)