Partial fix to Multi-View single eye issues in viewport

Handling depth loop for now (3d cursor positioning). Selection is a bit
more tricky.

Reported on 51354

1 files changed, 47 insertions, 36 deletions

diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index 8f2ea86f836..05f18a6771f 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -105,6 +105,7 @@
 #include "view3d_intern.h"  /* own include */
 
 /* prototypes */
+static bool view3d_stereo3d_active(wmWindow *win, Scene *scene, View3D *v3d, RegionView3D *rv3d);
 static void view3d_stereo3d_setup(Scene *scene, View3D *v3d, ARegion *ar);
 static void view3d_stereo3d_setup_offscreen(Scene *scene, View3D *v3d, ARegion *ar,
                                             float winmat[4][4], const char *viewname);
@@ -2369,19 +2370,12 @@ float view3d_depth_near(ViewDepths *d)
 void ED_view3d_draw_depth_gpencil(Scene *scene, ARegion *ar, View3D *v3d)
 {
 	short zbuf = v3d->zbuf;
-	RegionView3D *rv3d = ar->regiondata;
-
-	view3d_winmatrix_set(ar, v3d, NULL);
-	view3d_viewmatrix_set(scene, v3d, rv3d);  /* note: calls BKE_object_where_is_calc for camera... */
 
-	mul_m4_m4m4(rv3d->persmat, rv3d->winmat, rv3d->viewmat);
-	invert_m4_m4(rv3d->persinv, rv3d->persmat);
-	invert_m4_m4(rv3d->viewinv, rv3d->viewmat);
+	/* Setup view matrix. */
+	ED_view3d_draw_setup_view(NULL, scene, ar, v3d);
 
 	glClear(GL_DEPTH_BUFFER_BIT);
 
-	glLoadMatrixf(rv3d->viewmat);
-
 	v3d->zbuf = true;
 	glEnable(GL_DEPTH_TEST);
 
@@ -2390,7 +2384,6 @@ void ED_view3d_draw_depth_gpencil(Scene *scene, ARegion *ar, View3D *v3d)
 	}
 	
 	v3d->zbuf = zbuf;
-
 }
 
 static void view3d_draw_depth_loop(Scene *scene, ARegion *ar, View3D *v3d)
@@ -2489,17 +2482,11 @@ void ED_view3d_draw_depth(Scene *scene, ARegion *ar, View3D *v3d, bool alphaover
 	U.glalphaclip = alphaoverride ? 0.5f : glalphaclip; /* not that nice but means we wont zoom into billboards */
 	U.obcenter_dia = 0;
 	
-	view3d_winmatrix_set(ar, v3d, NULL);
-	view3d_viewmatrix_set(scene, v3d, rv3d);  /* note: calls BKE_object_where_is_calc for camera... */
-	
-	mul_m4_m4m4(rv3d->persmat, rv3d->winmat, rv3d->viewmat);
-	invert_m4_m4(rv3d->persinv, rv3d->persmat);
-	invert_m4_m4(rv3d->viewinv, rv3d->viewmat);
+	/* Setup view matrix. */
+	ED_view3d_draw_setup_view(NULL, scene, ar, v3d);
 	
 	glClear(GL_DEPTH_BUFFER_BIT);
 	
-	glLoadMatrixf(rv3d->viewmat);
-	
 	if (rv3d->rflag & RV3D_CLIPPING) {
 		ED_view3d_clipping_set(rv3d);
 	}
@@ -3265,6 +3252,22 @@ void ED_view3d_draw_offscreen(
 }
 
 /**
+ * Set the correct matrices
+ */
+void ED_view3d_draw_setup_view(wmWindow *win, Scene *scene, ARegion *ar, View3D *v3d)
+{
+	RegionView3D *rv3d = ar->regiondata;
+
+	/* Setup the view matrix. */
+	if (view3d_stereo3d_active(win, scene, v3d, rv3d)) {
+		view3d_stereo3d_setup(scene, v3d, ar);
+	}
+	else {
+		view3d_main_region_setup_view(scene, v3d, ar, NULL, NULL);
+	}
+}
+
+/**
  * Utility func for ED_view3d_draw_offscreen
  *
  * \param ofs: Optional off-screen buffer, can be NULL.
@@ -3698,26 +3701,37 @@ static void view3d_main_region_draw_engine_info(View3D *v3d, RegionView3D *rv3d,
 	ED_region_info_draw(ar, rv3d->render_engine->text, fill_color, true);
 }
 
-static bool view3d_stereo3d_active(const bContext *C, Scene *scene, View3D *v3d, RegionView3D *rv3d)
+static bool view3d_stereo3d_active(wmWindow *win, Scene *scene, View3D *v3d, RegionView3D *rv3d)
 {
-	wmWindow *win = CTX_wm_window(C);
-
-	if ((scene->r.scemode & R_MULTIVIEW) == 0)
-		return false;
-
-	if (WM_stereo3d_enabled(win, true) == false)
+	if ((scene->r.scemode & R_MULTIVIEW) == 0) {
 		return false;
+	}
 
-	if ((v3d->camera == NULL) || (v3d->camera->type != OB_CAMERA) || rv3d->persp != RV3D_CAMOB)
+	if ((v3d->camera == NULL) || (v3d->camera->type != OB_CAMERA) || rv3d->persp != RV3D_CAMOB) {
 		return false;
+	}
 
-	if (scene->r.views_format & SCE_VIEWS_FORMAT_MULTIVIEW) {
-		if (v3d->stereo3d_camera == STEREO_MONO_ID)
+	switch (v3d->stereo3d_camera) {
+		case STEREO_MONO_ID:
 			return false;
-
-		return BKE_scene_multiview_is_stereo3d(&scene->r);
+			break;
+		case STEREO_3D_ID:
+			/* win will be NULL when calling this from the selection or draw loop. */
+			if ((win == NULL) || (WM_stereo3d_enabled(win, true) == false)) {
+				return false;
+			}
+			if (((scene->r.views_format & SCE_VIEWS_FORMAT_MULTIVIEW) != 0) &&
+			    !BKE_scene_multiview_is_stereo3d(&scene->r))
+			{
+				return false;
+			}
+			break;
+		/* We always need the stereo calculation for left and right cameras. */
+		case STEREO_LEFT_ID:
+		case STEREO_RIGHT_ID:
+		default:
+			break;
 	}
-
 	return true;
 }
 
@@ -3830,11 +3844,8 @@ static void view3d_main_region_draw_objects(const bContext *C, Scene *scene, Vie
 		GPU_default_lights();
 	}
 
-	/* setup the view matrix */
-	if (view3d_stereo3d_active(C, scene, v3d, rv3d))
-		view3d_stereo3d_setup(scene, v3d, ar);
-	else
-		view3d_main_region_setup_view(scene, v3d, ar, NULL, NULL);
+	/* Setup the view matrix. */
+	ED_view3d_draw_setup_view(CTX_wm_window(C), scene, ar, v3d);
 
 	rv3d->rflag &= ~RV3D_IS_GAME_ENGINE;
 #ifdef WITH_GAMEENGINE