Fix #32941: Sequencer Preview shows texture which is apart of the window.

Issue was caused by buffer shadows were binding buffer after offscreen buffers
was bind which lead to some unpredictable results.

Made it so ED_view3d_draw_offscreen wouldn't bind any buffers and for proper
shadows ED_view3d_draw_offscreen_init should be manually be called before
drawing to an offscreen.

This should also make open gl render with AA enabled a bit faster.

Also fixed missing sequencer cache invalidation when open gl render type is
changing.

Material and Rendered modes are still a TODO for sequencer.

4 files changed, 23 insertions, 4 deletions

diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index fc24f68f2d1..479cdef29fc 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -263,6 +263,7 @@ void ED_view3d_init_mats_rv3d_gl(struct Object *ob, struct RegionView3D *rv3d);
 int ED_view3d_scene_layer_set(int lay, const int *values, int *active);
 
 int ED_view3d_context_activate(struct bContext *C);
+void ED_view3d_draw_offscreen_init(struct Scene *scene, struct View3D *v3d);
 void ED_view3d_draw_offscreen(struct Scene *scene, struct View3D *v3d, struct ARegion *ar,
                               int winx, int winy, float viewmat[][4], float winmat[][4], int do_bgpic, int colormanage_background);
 
diff --git a/source/blender/editors/render/render_opengl.c b/source/blender/editors/render/render_opengl.c
index 3cc2f314960..f14b9be3039 100644
--- a/source/blender/editors/render/render_opengl.c
+++ b/source/blender/editors/render/render_opengl.c
@@ -171,6 +171,8 @@ static void screen_opengl_render_apply(OGLRender *oglrender)
 		}
 	}
 	else if (view_context) {
+		ED_view3d_draw_offscreen_init(scene, v3d);
+
 		GPU_offscreen_bind(oglrender->ofs); /* bind */
 
 		/* render 3d view */
diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index 062400ef79e..8ff9b79af1d 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -2371,6 +2371,7 @@ static void gpu_update_lamps_shadows(Scene *scene, View3D *v3d)
 		mult_m4_m4m4(rv3d.persmat, rv3d.winmat, rv3d.viewmat);
 		invert_m4_m4(rv3d.persinv, rv3d.viewinv);
 
+		/* no need to call ED_view3d_draw_offscreen_init since shadow buffers were already updated */
 		ED_view3d_draw_offscreen(scene, v3d, &ar, winsize, winsize, viewmat, winmat, FALSE, FALSE);
 		GPU_lamp_shadow_buffer_unbind(shadow->lamp);
 		
@@ -2508,6 +2509,16 @@ static void view3d_main_area_setup_view(Scene *scene, View3D *v3d, ARegion *ar,
 	glLoadMatrixf(rv3d->viewmat);
 }
 
+void ED_view3d_draw_offscreen_init(Scene *scene, View3D *v3d)
+{
+	/* shadow buffers, before we setup matrices */
+	if (draw_glsl_material(scene, NULL, v3d, v3d->drawtype))
+		gpu_update_lamps_shadows(scene, v3d);
+}
+
+/* ED_view3d_draw_offscreen_init should be called before this to initialize
+ * stuff like shadow buffers
+ */
 void ED_view3d_draw_offscreen(Scene *scene, View3D *v3d, ARegion *ar,
                               int winx, int winy, float viewmat[][4], float winmat[][4],
                               int do_bgpic, int colormanage_background)
@@ -2541,10 +2552,6 @@ void ED_view3d_draw_offscreen(Scene *scene, View3D *v3d, ARegion *ar,
 	/* free images which can have changed on frame-change
 	 * warning! can be slow so only free animated images - campbell */
 	GPU_free_images_anim();
-	
-	/* shadow buffers, before we setup matrices */
-	if (draw_glsl_material(scene, NULL, v3d, v3d->drawtype))
-		gpu_update_lamps_shadows(scene, v3d);
 
 	/* set background color, fallback on the view background color
 	 * (if active clip is set but frame is failed to load fallback to horizon color as background) */
@@ -2687,6 +2694,8 @@ ImBuf *ED_view3d_draw_offscreen_imbuf(Scene *scene, View3D *v3d, ARegion *ar,
 	if (ofs == NULL)
 		return NULL;
 
+	ED_view3d_draw_offscreen_init(scene, v3d);
+
 	GPU_offscreen_bind(ofs);
 
 	/* render 3d view */
diff --git a/source/blender/makesrna/intern/rna_scene.c b/source/blender/makesrna/intern/rna_scene.c
index 9fb83e8597d..c2146a1a812 100644
--- a/source/blender/makesrna/intern/rna_scene.c
+++ b/source/blender/makesrna/intern/rna_scene.c
@@ -1414,6 +1414,12 @@ static void rna_SceneCamera_update(Main *UNUSED(bmain), Scene *UNUSED(scene), Po
 		DAG_id_tag_update(&camera->id, 0);
 }
 
+static void rna_SceneSequencer_update(Main *UNUSED(bmain), Scene *UNUSED(scene), PointerRNA *UNUSED(ptr))
+{
+	BKE_sequencer_cache_cleanup();
+	BKE_sequencer_preprocessed_cache_cleanup();
+}
+
 #else
 
 static void rna_def_transform_orientation(BlenderRNA *brna)
@@ -3948,6 +3954,7 @@ static void rna_def_scene_render_data(BlenderRNA *brna)
 	RNA_def_property_enum_sdna(prop, NULL, "seq_prev_type");
 	RNA_def_property_enum_items(prop, viewport_shade_items);
 	RNA_def_property_ui_text(prop, "Sequencer Preview Shading", "Method to draw in the sequencer view");
+	RNA_def_property_update(prop, NC_SCENE | ND_SEQUENCER, "rna_SceneSequencer_update");
 
 	prop = RNA_def_property(srna, "sequencer_gl_render", PROP_ENUM, PROP_NONE);
 	RNA_def_property_enum_sdna(prop, NULL, "seq_rend_type");