Multi-View and Stereo 3D

Official Documentation:
http://www.blender.org/manual/render/workflows/multiview.html

Implemented Features
====================
Builtin Stereo Camera
* Convergence Mode
* Interocular Distance
* Convergence Distance
* Pivot Mode

Viewport
* Cameras
* Plane
* Volume

Compositor
* View Switch Node
* Image Node Multi-View OpenEXR support

Sequencer
* Image/Movie Strips 'Use Multiview'

UV/Image Editor
* Option to see Multi-View images in Stereo-3D or its individual images
* Save/Open Multi-View (OpenEXR, Stereo3D, individual views) images

I/O
* Save/Open Multi-View (OpenEXR, Stereo3D, individual views) images

Scene Render Views
* Ability to have an arbitrary number of views in the scene

Missing Bits
============
First rule of Multi-View bug report: If something is not working as it should *when Views is off* this is a severe bug, do mention this in the report.

Second rule is, if something works *when Views is off* but doesn't (or crashes) when *Views is on*, this is a important bug. Do mention this in the report.

Everything else is likely small todos, and may wait until we are sure none of the above is happening.

Apart from that there are those known issues:
* Compositor Image Node poorly working for Multi-View OpenEXR
(this was working prefectly before the 'Use Multi-View' functionality)
* Selecting camera from Multi-View when looking from camera is problematic
* Animation Playback (ctrl+F11) doesn't support stereo formats
* Wrong filepath when trying to play back animated scene
* Viewport Rendering doesn't support Multi-View
* Overscan Rendering
* Fullscreen display modes need to warn the user
* Object copy should be aware of views suffix

Acknowledgments
===============
* Francesco Siddi for the help with the original feature specs and design
* Brecht Van Lommel for the original review of the code and design early on
* Blender Foundation for the Development Fund to support the project wrap up

Final patch reviewers:
* Antony Riakiotakis (psy-fi)
* Campbell Barton (ideasman42)
* Julian Eisel (Severin)
* Sergey Sharybin (nazgul)
* Thomas Dinged (dingto)

Code contributors of the original branch in github:
* Alexey Akishin
* Gabriel Caraballo

1 files changed, 247 insertions, 37 deletions

diff --git a/source/blender/windowmanager/intern/wm_draw.c b/source/blender/windowmanager/intern/wm_draw.c
index 7440570f4a0..16fe9ca5142 100644
--- a/source/blender/windowmanager/intern/wm_draw.c
+++ b/source/blender/windowmanager/intern/wm_draw.c
@@ -48,9 +48,11 @@
 #include "BIF_gl.h"
 
 #include "BKE_context.h"
+#include "BKE_image.h"
 
 #include "GHOST_C-api.h"
 
+#include "ED_node.h"
 #include "ED_view3d.h"
 #include "ED_screen.h"
 
@@ -165,6 +167,7 @@ static void wm_method_draw_full(bContext *C, wmWindow *win)
 			if (ar->swinid) {
 				CTX_wm_region_set(C, ar);
 				ED_region_do_draw(C, ar);
+				ar->do_draw = false;
 				wm_paintcursor_draw(C, ar);
 				CTX_wm_region_set(C, NULL);
 			}
@@ -175,12 +178,14 @@ static void wm_method_draw_full(bContext *C, wmWindow *win)
 	}
 
 	ED_screen_draw(win);
+	win->screen->do_draw = false;
 
 	/* draw overlapping regions */
 	for (ar = screen->regionbase.first; ar; ar = ar->next) {
 		if (ar->swinid) {
 			CTX_wm_menu_set(C, ar);
 			ED_region_do_draw(C, ar);
+			ar->do_draw = false;
 			CTX_wm_menu_set(C, NULL);
 		}
 	}
@@ -278,6 +283,7 @@ static void wm_method_draw_overlap_all(bContext *C, wmWindow *win, int exchange)
 				if (ar->do_draw) {
 					CTX_wm_region_set(C, ar);
 					ED_region_do_draw(C, ar);
+					ar->do_draw = false;
 					wm_paintcursor_draw(C, ar);
 					CTX_wm_region_set(C, NULL);
 
@@ -288,6 +294,7 @@ static void wm_method_draw_overlap_all(bContext *C, wmWindow *win, int exchange)
 					if (ar->swap == WIN_FRONT_OK) {
 						CTX_wm_region_set(C, ar);
 						ED_region_do_draw(C, ar);
+						ar->do_draw = false;
 						wm_paintcursor_draw(C, ar);
 						CTX_wm_region_set(C, NULL);
 
@@ -300,7 +307,7 @@ static void wm_method_draw_overlap_all(bContext *C, wmWindow *win, int exchange)
 				}
 			}
 		}
-		
+
 		wm_area_mark_invalid_backbuf(sa);
 		CTX_wm_area_set(C, NULL);
 	}
@@ -308,6 +315,7 @@ static void wm_method_draw_overlap_all(bContext *C, wmWindow *win, int exchange)
 	/* after area regions so we can do area 'overlay' drawing */
 	if (screen->do_draw) {
 		ED_screen_draw(win);
+		win->screen->do_draw = false;
 
 		if (exchange)
 			screen->swap = WIN_FRONT_OK;
@@ -315,6 +323,7 @@ static void wm_method_draw_overlap_all(bContext *C, wmWindow *win, int exchange)
 	else if (exchange) {
 		if (screen->swap == WIN_FRONT_OK) {
 			ED_screen_draw(win);
+			win->screen->do_draw = false;
 			screen->swap = WIN_BOTH_OK;
 		}
 		else if (screen->swap == WIN_BACK_OK)
@@ -328,6 +337,7 @@ static void wm_method_draw_overlap_all(bContext *C, wmWindow *win, int exchange)
 		if (ar->swinid && ar->do_draw) {
 			CTX_wm_menu_set(C, ar);
 			ED_region_do_draw(C, ar);
+			ar->do_draw = false;
 			CTX_wm_menu_set(C, NULL);
 		}
 	}
@@ -360,15 +370,6 @@ static void wm_method_draw_damage(bContext *C, wmWindow *win)
 /*   used. if not, multiple smaller ones are used, with   */
 /*   worst case wasted space being 23.4% for 3x3 textures */
 
-#define MAX_N_TEX 3
-
-typedef struct wmDrawTriple {
-	GLuint bind[MAX_N_TEX * MAX_N_TEX];
-	int x[MAX_N_TEX], y[MAX_N_TEX];
-	int nx, ny;
-	GLenum target;
-} wmDrawTriple;
-
 static void split_width(int x, int n, int *splitx, int *nx)
 {
 	int a, newnx, waste;
@@ -405,16 +406,13 @@ static void split_width(int x, int n, int *splitx, int *nx)
 	}
 }
 
-static void wm_draw_triple_free(wmWindow *win)
+static void wm_draw_triple_free(wmDrawTriple *triple)
 {
-	if (win->drawdata) {
-		wmDrawTriple *triple = win->drawdata;
+	if (triple) {
 
 		glDeleteTextures(triple->nx * triple->ny, triple->bind);
 
 		MEM_freeN(triple);
-
-		win->drawdata = NULL;
 	}
 }
 
@@ -499,7 +497,7 @@ static int wm_triple_gen_textures(wmWindow *win, wmDrawTriple *triple)
 	return 1;
 }
 
-static void wm_triple_draw_textures(wmWindow *win, wmDrawTriple *triple, float alpha)
+void wm_triple_draw_textures(wmWindow *win, wmDrawTriple *triple, float alpha)
 {
 	const int winsize_x = WM_window_pixels_x(win);
 	const int winsize_y = WM_window_pixels_y(win);
@@ -571,7 +569,7 @@ static void wm_triple_copy_textures(wmWindow *win, wmDrawTriple *triple)
 	glBindTexture(triple->target, 0);
 }
 
-static void wm_draw_region_blend(wmWindow *win, ARegion *ar)
+static void wm_draw_region_blend(wmWindow *win, ARegion *ar, wmDrawTriple *triple)
 {
 	float fac = ED_region_blend_factor(ar);
 	
@@ -580,7 +578,7 @@ static void wm_draw_region_blend(wmWindow *win, ARegion *ar)
 		wmSubWindowScissorSet(win, win->screen->mainwin, &ar->winrct, true);
 
 		glEnable(GL_BLEND);
-		wm_triple_draw_textures(win, win->drawdata, 1.0f - fac);
+		wm_triple_draw_textures(win, triple, 1.0f - fac);
 		glDisable(GL_BLEND);
 	}
 }
@@ -589,29 +587,46 @@ static void wm_method_draw_triple(bContext *C, wmWindow *win)
 {
 	wmWindowManager *wm = CTX_wm_manager(C);
 	wmDrawTriple *triple;
+	wmDrawData *dd, *dd_next, *drawdata = win->drawdata.first;
 	bScreen *screen = win->screen;
 	ScrArea *sa;
 	ARegion *ar;
-	int copytex = 0;
+	int copytex = false;
 
-	if (win->drawdata) {
+	if (drawdata && drawdata->triple) {
 		glClearColor(0, 0, 0, 0);
 		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
 		wmSubWindowSet(win, screen->mainwin);
 
-		wm_triple_draw_textures(win, win->drawdata, 1.0f);
+		wm_triple_draw_textures(win, drawdata->triple, 1.0f);
 	}
 	else {
-		win->drawdata = MEM_callocN(sizeof(wmDrawTriple), "wmDrawTriple");
+		/* we run it when we start OR when we turn stereo on */
+		if (drawdata == NULL) {
+			drawdata = MEM_callocN(sizeof(wmDrawData), "wmDrawData");
+			BLI_addhead(&win->drawdata, drawdata);
+		}
+
+		drawdata->triple = MEM_callocN(sizeof(wmDrawTriple), "wmDrawTriple");
 
-		if (!wm_triple_gen_textures(win, win->drawdata)) {
+		if (!wm_triple_gen_textures(win, drawdata->triple)) {
 			wm_draw_triple_fail(C, win);
 			return;
 		}
 	}
 
-	triple = win->drawdata;
+	/* it means stereo was just turned off */
+	/* note: we are removing all drawdatas that are not the first */
+	for (dd = drawdata->next; dd; dd = dd_next) {
+		dd_next = dd->next;
+
+		BLI_remlink(&win->drawdata, dd);
+		wm_draw_triple_free(dd->triple);
+		MEM_freeN(dd);
+	}
+
+	triple = drawdata->triple;
 
 	/* draw marked area regions */
 	for (sa = screen->areabase.first; sa; sa = sa->next) {
@@ -619,16 +634,17 @@ static void wm_method_draw_triple(bContext *C, wmWindow *win)
 
 		for (ar = sa->regionbase.first; ar; ar = ar->next) {
 			if (ar->swinid && ar->do_draw) {
-				
-				if (ar->overlap == 0) {
+
+				if (ar->overlap == false) {
 					CTX_wm_region_set(C, ar);
 					ED_region_do_draw(C, ar);
+					ar->do_draw = false;
 					CTX_wm_region_set(C, NULL);
-					copytex = 1;
+					copytex = true;
 				}
 			}
 		}
-		
+
 		wm_area_mark_invalid_backbuf(sa);
 		CTX_wm_area_set(C, NULL);
 	}
@@ -662,14 +678,15 @@ static void wm_method_draw_triple(bContext *C, wmWindow *win)
 	/* draw overlapping area regions (always like popups) */
 	for (sa = screen->areabase.first; sa; sa = sa->next) {
 		CTX_wm_area_set(C, sa);
-		
+
 		for (ar = sa->regionbase.first; ar; ar = ar->next) {
 			if (ar->swinid && ar->overlap) {
 				CTX_wm_region_set(C, ar);
 				ED_region_do_draw(C, ar);
+				ar->do_draw = false;
 				CTX_wm_region_set(C, NULL);
-				
-				wm_draw_region_blend(win, ar);
+
+				wm_draw_region_blend(win, ar, triple);
 			}
 		}
 
@@ -678,12 +695,14 @@ static void wm_method_draw_triple(bContext *C, wmWindow *win)
 
 	/* after area regions so we can do area 'overlay' drawing */
 	ED_screen_draw(win);
+	win->screen->do_draw = false;
 
 	/* draw floating regions (menus) */
 	for (ar = screen->regionbase.first; ar; ar = ar->next) {
 		if (ar->swinid) {
 			CTX_wm_menu_set(C, ar);
 			ED_region_do_draw(C, ar);
+			ar->do_draw = false;
 			CTX_wm_menu_set(C, NULL);
 		}
 	}
@@ -691,13 +710,188 @@ static void wm_method_draw_triple(bContext *C, wmWindow *win)
 	/* always draw, not only when screen tagged */
 	if (win->gesture.first)
 		wm_gesture_draw(win);
-	
+
 	/* needs pixel coords in screen */
 	if (wm->drags.first) {
 		wm_drags_draw(C, win, NULL);
 	}
 }
 
+static void wm_method_draw_triple_multiview(bContext *C, wmWindow *win, StereoViews sview)
+{
+	wmWindowManager *wm = CTX_wm_manager(C);
+	wmDrawData *drawdata;
+	wmDrawTriple *triple_data, *triple_all;
+	bScreen *screen = win->screen;
+	ScrArea *sa;
+	ARegion *ar;
+	int copytex = false;
+	int id;
+
+	/* we store the triple_data in sequence to triple_all */
+	for (id = 0; id < 2; id++) {
+		drawdata = BLI_findlink(&win->drawdata, (sview * 2) + id);
+
+		if (drawdata && drawdata->triple) {
+			if (id == 0) {
+				glClearColor(0, 0, 0, 0);
+				glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+				wmSubWindowSet(win, screen->mainwin);
+
+				wm_triple_draw_textures(win, drawdata->triple, 1.0f);
+			}
+		}
+		else {
+			/* we run it when we start OR when we turn stereo on */
+			if (drawdata == NULL) {
+				drawdata = MEM_callocN(sizeof(wmDrawData), "wmDrawData");
+				BLI_addtail(&win->drawdata, drawdata);
+			}
+
+			drawdata->triple = MEM_callocN(sizeof(wmDrawTriple), "wmDrawTriple");
+
+			if (!wm_triple_gen_textures(win, drawdata->triple)) {
+				wm_draw_triple_fail(C, win);
+				return;
+			}
+		}
+	}
+
+	triple_data = ((wmDrawData *) BLI_findlink(&win->drawdata, sview * 2))->triple;
+	triple_all  = ((wmDrawData *) BLI_findlink(&win->drawdata, (sview * 2) + 1))->triple;
+
+	/* draw marked area regions */
+	for (sa = screen->areabase.first; sa; sa = sa->next) {
+		CTX_wm_area_set(C, sa);
+
+		switch (sa->spacetype) {
+			case SPACE_IMAGE:
+			{
+				SpaceImage *sima = sa->spacedata.first;
+				sima->iuser.multiview_eye = sview;
+				break;
+			}
+			case SPACE_VIEW3D:
+			{
+				View3D *v3d = sa->spacedata.first;
+				BGpic *bgpic = v3d->bgpicbase.first;
+				v3d->multiview_eye = sview;
+				if (bgpic) bgpic->iuser.multiview_eye = sview;
+				break;
+			}
+			case SPACE_NODE:
+			{
+				SpaceNode *snode = sa->spacedata.first;
+				if ((snode->flag & SNODE_BACKDRAW) && ED_node_is_compositor(snode)) {
+					Image *ima = BKE_image_verify_viewer(IMA_TYPE_COMPOSITE, "Viewer Node");
+					ima->eye = sview;
+				}
+				break;
+			}
+			case SPACE_SEQ:
+			{
+				SpaceSeq *sseq = sa->spacedata.first;
+				sseq->multiview_eye = sview;
+				break;
+			}
+		}
+
+		/* draw marked area regions */
+		for (ar = sa->regionbase.first; ar; ar = ar->next) {
+			if (ar->swinid && ar->do_draw) {
+
+				if (ar->overlap == false) {
+					CTX_wm_region_set(C, ar);
+					ED_region_do_draw(C, ar);
+
+					if (sview == STEREO_RIGHT_ID)
+						ar->do_draw = false;
+
+					CTX_wm_region_set(C, NULL);
+					copytex = true;
+				}
+			}
+		}
+
+		wm_area_mark_invalid_backbuf(sa);
+		CTX_wm_area_set(C, NULL);
+	}
+
+	if (copytex) {
+		wmSubWindowSet(win, screen->mainwin);
+
+		wm_triple_copy_textures(win, triple_data);
+	}
+
+	if (wm->paintcursors.first) {
+		for (sa = screen->areabase.first; sa; sa = sa->next) {
+			for (ar = sa->regionbase.first; ar; ar = ar->next) {
+				if (ar->swinid && ar->swinid == screen->subwinactive) {
+					CTX_wm_area_set(C, sa);
+					CTX_wm_region_set(C, ar);
+
+					/* make region ready for draw, scissor, pixelspace */
+					ED_region_set(C, ar);
+					wm_paintcursor_draw(C, ar);
+
+					CTX_wm_region_set(C, NULL);
+					CTX_wm_area_set(C, NULL);
+				}
+			}
+		}
+
+		wmSubWindowSet(win, screen->mainwin);
+	}
+
+	/* draw overlapping area regions (always like popups) */
+	for (sa = screen->areabase.first; sa; sa = sa->next) {
+		CTX_wm_area_set(C, sa);
+
+		for (ar = sa->regionbase.first; ar; ar = ar->next) {
+			if (ar->swinid && ar->overlap) {
+				CTX_wm_region_set(C, ar);
+				ED_region_do_draw(C, ar);
+				if (sview == STEREO_RIGHT_ID)
+					ar->do_draw = false;
+				CTX_wm_region_set(C, NULL);
+
+				wm_draw_region_blend(win, ar, triple_data);
+			}
+		}
+
+		CTX_wm_area_set(C, NULL);
+	}
+
+	/* after area regions so we can do area 'overlay' drawing */
+	ED_screen_draw(win);
+	if (sview == STEREO_RIGHT_ID)
+		win->screen->do_draw = false;
+
+	/* draw floating regions (menus) */
+	for (ar = screen->regionbase.first; ar; ar = ar->next) {
+		if (ar->swinid) {
+			CTX_wm_menu_set(C, ar);
+			ED_region_do_draw(C, ar);
+			if (sview == STEREO_RIGHT_ID)
+				ar->do_draw = false;
+			CTX_wm_menu_set(C, NULL);
+		}
+	}
+
+	/* always draw, not only when screen tagged */
+	if (win->gesture.first)
+		wm_gesture_draw(win);
+
+	/* needs pixel coords in screen */
+	if (wm->drags.first) {
+		wm_drags_draw(C, win, NULL);
+	}
+
+	/* copy the ui + overlays */
+	wmSubWindowSet(win, screen->mainwin);
+	wm_triple_copy_textures(win, triple_all);
+}
 
 /****************** main update call **********************/
 
@@ -848,8 +1042,16 @@ void wm_draw_update(bContext *C)
 				wm_method_draw_overlap_all(C, win, 0);
 			else if (drawmethod == USER_DRAW_OVERLAP_FLIP)
 				wm_method_draw_overlap_all(C, win, 1);
-			else // if (drawmethod == USER_DRAW_TRIPLE)
-				wm_method_draw_triple(C, win);
+			else { /* USER_DRAW_TRIPLE */
+				if ((WM_stereo3d_enabled(win, false)) == false) {
+					wm_method_draw_triple(C, win);
+				}
+				else {
+					wm_method_draw_triple_multiview(C, win, STEREO_LEFT_ID);
+					wm_method_draw_triple_multiview(C, win, STEREO_RIGHT_ID);
+					wm_method_draw_stereo3d(C, win);
+				}
+			}
 
 			win->screen->do_draw_gesture = false;
 			win->screen->do_draw_paintcursor = false;
@@ -862,15 +1064,23 @@ void wm_draw_update(bContext *C)
 	}
 }
 
+void wm_draw_data_free(wmWindow *win)
+{
+	wmDrawData *dd;
+
+	for (dd = win->drawdata.first; dd; dd = dd->next) {
+		wm_draw_triple_free(dd->triple);
+	}
+	BLI_freelistN(&win->drawdata);
+}
+
 void wm_draw_window_clear(wmWindow *win)
 {
 	bScreen *screen = win->screen;
 	ScrArea *sa;
 	ARegion *ar;
-	int drawmethod = wm_automatic_draw_method(win);
 
-	if (drawmethod == USER_DRAW_TRIPLE)
-		wm_draw_triple_free(win);
+	wm_draw_data_free(win);
 
 	/* clear screen swap flags */
 	if (screen) {