Edit Mode overlay: backwire "ghost wireframe" with variable intensity

12 files changed, 410 insertions, 55 deletions

diff --git a/source/blender/draw/CMakeLists.txt b/source/blender/draw/CMakeLists.txt
index ea1d179aa40..cb2681fcf81 100644
--- a/source/blender/draw/CMakeLists.txt
+++ b/source/blender/draw/CMakeLists.txt
@@ -89,6 +89,10 @@ data_to_c_simple(modes/shaders/edit_overlay_geom_edge.glsl SRC)
 data_to_c_simple(modes/shaders/edit_overlay_loosevert_vert.glsl SRC)
 data_to_c_simple(modes/shaders/edit_overlay_facedot_frag.glsl SRC)
 data_to_c_simple(modes/shaders/edit_overlay_facedot_vert.glsl SRC)
+data_to_c_simple(modes/shaders/edit_overlay_mix_frag.glsl SRC)
+data_to_c_simple(modes/shaders/edit_overlay_mix_vert.glsl SRC)
+data_to_c_simple(modes/shaders/edit_overlay_facefill_vert.glsl SRC)
+data_to_c_simple(modes/shaders/edit_overlay_facefill_frag.glsl SRC)
 
 list(APPEND INC
 )
diff --git a/source/blender/draw/engines/clay/clay.c b/source/blender/draw/engines/clay/clay.c
index 7a5beb46482..7f55ee03a3b 100644
--- a/source/blender/draw/engines/clay/clay.c
+++ b/source/blender/draw/engines/clay/clay.c
@@ -689,6 +689,7 @@ static void CLAY_view_draw(RenderEngine *UNUSED(engine), const bContext *context
 	CLAY_FramebufferList *fbl = DRW_engine_framebuffer_list_get();
 
 	CLAY_engine_init();
+	DRW_mode_init();
 
 	/* TODO : tag to refresh by the deps graph */
 	/* ideally only refresh when objects are added/removed */
diff --git a/source/blender/draw/intern/DRW_render.h b/source/blender/draw/intern/DRW_render.h
index a9d831440dc..4c5442cc211 100644
--- a/source/blender/draw/intern/DRW_render.h
+++ b/source/blender/draw/intern/DRW_render.h
@@ -131,6 +131,7 @@ typedef struct DRWFboTexture {
 
 void DRW_framebuffer_init(struct GPUFrameBuffer **fb, int width, int height, DRWFboTexture textures[MAX_FBO_TEX], int texnbr);
 void DRW_framebuffer_bind(struct GPUFrameBuffer *fb);
+void DRW_framebuffer_clear(bool color, bool depth, float clear_col[4]);
 void DRW_framebuffer_texture_attach(struct GPUFrameBuffer *fb, struct GPUTexture *tex, int slot);
 void DRW_framebuffer_texture_detach(struct GPUTexture *tex);
 void DRW_framebuffer_blit(struct GPUFrameBuffer *fb_read, struct GPUFrameBuffer *fb_write, bool depth);
@@ -144,19 +145,20 @@ void DRW_shader_free(struct GPUShader *shader);
 /* Batches */
 
 typedef enum {
-	DRW_STATE_WRITE_DEPTH = (1 << 0),
-	DRW_STATE_WRITE_COLOR = (1 << 1),
-	DRW_STATE_DEPTH_LESS  = (1 << 2),
-	DRW_STATE_DEPTH_EQUAL = (1 << 3),
-	DRW_STATE_CULL_BACK   = (1 << 4),
-	DRW_STATE_CULL_FRONT  = (1 << 5),
-	DRW_STATE_WIRE        = (1 << 6),
-	DRW_STATE_WIRE_LARGE  = (1 << 7),
-	DRW_STATE_POINT       = (1 << 8),
-	DRW_STATE_STIPPLE_2   = (1 << 9),
-	DRW_STATE_STIPPLE_3   = (1 << 10),
-	DRW_STATE_STIPPLE_4   = (1 << 11),
-	DRW_STATE_BLEND       = (1 << 12),
+	DRW_STATE_WRITE_DEPTH   = (1 << 0),
+	DRW_STATE_WRITE_COLOR   = (1 << 1),
+	DRW_STATE_DEPTH_LESS    = (1 << 2),
+	DRW_STATE_DEPTH_EQUAL   = (1 << 3),
+	DRW_STATE_DEPTH_GREATER = (1 << 4),
+	DRW_STATE_CULL_BACK     = (1 << 5),
+	DRW_STATE_CULL_FRONT    = (1 << 6),
+	DRW_STATE_WIRE          = (1 << 7),
+	DRW_STATE_WIRE_LARGE    = (1 << 8),
+	DRW_STATE_POINT         = (1 << 9),
+	DRW_STATE_STIPPLE_2     = (1 << 10),
+	DRW_STATE_STIPPLE_3     = (1 << 11),
+	DRW_STATE_STIPPLE_4     = (1 << 12),
+	DRW_STATE_BLEND         = (1 << 13),
 } DRWState;
 
 DRWShadingGroup *DRW_shgroup_create(struct GPUShader *shader, DRWPass *pass);
@@ -210,6 +212,7 @@ void *DRW_render_settings_get(Scene *scene, const char *engine_name);
 #endif /* __DRW_ENGINE_H__ */
 
 /* Cache */
+void DRW_mode_init(void);
 void DRW_mode_cache_init(void);
 void DRW_mode_cache_populate(struct Object *ob);
 void DRW_mode_cache_finish(void);
diff --git a/source/blender/draw/intern/draw_manager.c b/source/blender/draw/intern/draw_manager.c
index 1ffff40fb58..ea14c59bc7f 100644
--- a/source/blender/draw/intern/draw_manager.c
+++ b/source/blender/draw/intern/draw_manager.c
@@ -942,8 +942,7 @@ static void set_state(short flag)
 	}
 
 	/* Depht Test */
-	if (flag & DRW_STATE_DEPTH_LESS ||
-	    flag & DRW_STATE_DEPTH_EQUAL)
+	if (flag & (DRW_STATE_DEPTH_LESS | DRW_STATE_DEPTH_EQUAL | DRW_STATE_DEPTH_GREATER))
 	{
 
 		glEnable(GL_DEPTH_TEST);
@@ -952,6 +951,8 @@ static void set_state(short flag)
 			glDepthFunc(GL_LEQUAL);
 		else if (flag & DRW_STATE_DEPTH_EQUAL)
 			glDepthFunc(GL_EQUAL);
+		else if (flag & DRW_STATE_DEPTH_GREATER)
+			glDepthFunc(GL_GREATER);
 	}
 	else {
 		glDisable(GL_DEPTH_TEST);
@@ -977,6 +978,7 @@ static void set_state(short flag)
 	/* Blending (all buffer) */
 	if (flag & DRW_STATE_BLEND) {
 		glEnable(GL_BLEND);
+		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 	}
 	else {
 		glDisable(GL_BLEND);
@@ -1063,6 +1065,23 @@ void DRW_draw_pass(DRWPass *UNUSED(pass))
 #endif
 
 /* ******************************************* Mode Engine Cache ****************************************** */
+
+void DRW_mode_init(void)
+{
+	const bContext *C = DRW_get_context();
+	int mode = CTX_data_mode_enum(C);
+
+	switch (mode) {
+		case CTX_MODE_EDIT_MESH:
+			EDIT_MESH_init();
+			break;
+		case CTX_MODE_EDIT_ARMATURE:
+			break;
+		case CTX_MODE_OBJECT:
+			break;
+	}
+}
+
 void DRW_mode_cache_init(void)
 {
 	const bContext *C = DRW_get_context();
@@ -1188,6 +1207,8 @@ void *DRW_render_settings_get(Scene *scene, const char *engine_name)
 void DRW_framebuffer_init(struct GPUFrameBuffer **fb, int width, int height, DRWFboTexture textures[MAX_FBO_TEX],
                           int texnbr)
 {
+	BLI_assert(texnbr <= MAX_FBO_TEX);
+
 	if (!*fb) {
 		int color_attachment = -1;
 		*fb = GPU_framebuffer_create();
@@ -1226,6 +1247,19 @@ void DRW_framebuffer_bind(struct GPUFrameBuffer *fb)
 	GPU_framebuffer_bind(fb);
 }
 
+void DRW_framebuffer_clear(bool color, bool depth, float clear_col[4])
+{
+	if (color) {
+		glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+		glClearColor(clear_col[0], clear_col[1], clear_col[2], clear_col[4]);
+	}
+	if (depth) {
+		glDepthMask(GL_TRUE);
+	}
+	glClear(((color) ? GL_COLOR_BUFFER_BIT : 0) |
+	        ((depth) ? GL_DEPTH_BUFFER_BIT : 0));
+}
+
 void DRW_framebuffer_texture_attach(struct GPUFrameBuffer *fb, GPUTexture *tex, int slot)
 {
 	GPU_framebuffer_texture_attach(fb, tex, slot);
diff --git a/source/blender/draw/modes/edit_mesh_mode.c b/source/blender/draw/modes/edit_mesh_mode.c
index 4177e7b843f..c9a998df9a2 100644
--- a/source/blender/draw/modes/edit_mesh_mode.c
+++ b/source/blender/draw/modes/edit_mesh_mode.c
@@ -27,6 +27,7 @@
 #include "DRW_render.h"
 
 #include "GPU_shader.h"
+#include "GPU_viewport.h"
 #include "DNA_view3d_types.h"
 
 #include "draw_mode_pass.h"
@@ -40,14 +41,37 @@ typedef struct EDIT_MESH_PassList {
 	struct DRWPass *wire_outline_pass;
 	struct DRWPass *depth_pass_hidden_wire;
 	struct DRWPass *edit_face_overlay_pass;
+	struct DRWPass *edit_face_occluded_pass;
+	struct DRWPass *mix_occlude_pass;
+	struct DRWPass *facefill_occlude_pass;
 } EDIT_MESH_PassList;
 
+/* keep it under MAX_BUFFERS */
+typedef struct EDIT_MESH_FramebufferList {
+	struct GPUFrameBuffer *occlude_wire_fb;
+	struct GPUFrameBuffer *occlude_face_fb;
+} EDIT_MESH_FramebufferList;
+
+/* keep it under MAX_TEXTURES */
+typedef struct EDIT_MESH_TextureList {
+	struct GPUTexture *occlude_wire_depth_tx;
+	struct GPUTexture *occlude_wire_color_tx;
+	struct GPUTexture *occlude_face_color_tx;
+} EDIT_MESH_TextureList;
+
 static DRWShadingGroup *depth_shgrp_hidden_wire;
+
 static DRWShadingGroup *face_overlay_shgrp;
 static DRWShadingGroup *ledges_overlay_shgrp;
 static DRWShadingGroup *lverts_overlay_shgrp;
 static DRWShadingGroup *facedot_overlay_shgrp;
 
+static DRWShadingGroup *face_occluded_shgrp;
+static DRWShadingGroup *ledges_occluded_shgrp;
+static DRWShadingGroup *lverts_occluded_shgrp;
+static DRWShadingGroup *facedot_occluded_shgrp;
+static DRWShadingGroup *facefill_occluded_shgrp;
+
 extern struct GPUUniformBuffer *globals_ubo; /* draw_mode_pass.c */
 
 static struct GPUShader *overlay_tri_sh = NULL;
@@ -58,6 +82,8 @@ static struct GPUShader *overlay_edge_sh = NULL;
 static struct GPUShader *overlay_edge_vcol_sh = NULL;
 static struct GPUShader *overlay_vert_sh = NULL;
 static struct GPUShader *overlay_facedot_sh = NULL;
+static struct GPUShader *overlay_mix_sh = NULL;
+static struct GPUShader *overlay_facefill_sh = NULL;
 
 extern char datatoc_edit_overlay_frag_glsl[];
 extern char datatoc_edit_overlay_vert_glsl[];
@@ -66,19 +92,28 @@ extern char datatoc_edit_overlay_geom_edge_glsl[];
 extern char datatoc_edit_overlay_loosevert_vert_glsl[];
 extern char datatoc_edit_overlay_facedot_frag_glsl[];
 extern char datatoc_edit_overlay_facedot_vert_glsl[];
+extern char datatoc_edit_overlay_mix_vert_glsl[];
+extern char datatoc_edit_overlay_mix_frag_glsl[];
+extern char datatoc_edit_overlay_facefill_vert_glsl[];
+extern char datatoc_edit_overlay_facefill_frag_glsl[];
 
-void EDIT_MESH_cache_init(void)
+void EDIT_MESH_init(void)
 {
-	EDIT_MESH_PassList *psl = DRW_mode_pass_list_get();
-	static struct GPUShader *depth_sh, *tri_sh, *ledge_sh;
+	EDIT_MESH_TextureList *txl = DRW_mode_texture_list_get();
+	EDIT_MESH_FramebufferList *fbl = DRW_mode_framebuffer_list_get();
 
-	const struct bContext *C = DRW_get_context();
-	struct RegionView3D *rv3d = CTX_wm_region_view3d(C);
-	Scene *scene = CTX_data_scene(C);
-	ToolSettings *ts = scene->toolsettings;
+	float *viewport_size = DRW_viewport_size_get();
 
-	if (!depth_sh)
-		depth_sh = DRW_shader_create_3D_depth_only();
+	DRWFboTexture tex[2] = {{&txl->occlude_wire_depth_tx, DRW_BUF_DEPTH_24},
+	                        {&txl->occlude_wire_color_tx, DRW_BUF_RGBA_8}};
+	DRW_framebuffer_init(&fbl->occlude_wire_fb,
+	                     (int)viewport_size[0], (int)viewport_size[1],
+	                     tex, 2);
+
+	DRWFboTexture tex2 = {&txl->occlude_face_color_tx, DRW_BUF_RGBA_8};
+	DRW_framebuffer_init(&fbl->occlude_face_fb,
+	                     (int)viewport_size[0], (int)viewport_size[1],
+	                     &tex2, 1);
 
 	if (!overlay_tri_sh) {
 		overlay_tri_sh = DRW_shader_create(datatoc_edit_overlay_vert_glsl,
@@ -119,6 +154,25 @@ void EDIT_MESH_cache_init(void)
 		overlay_facedot_sh = DRW_shader_create(datatoc_edit_overlay_facedot_vert_glsl, NULL,
 		                                       datatoc_edit_overlay_facedot_frag_glsl, NULL);
 	}
+	if (!overlay_mix_sh) {
+		overlay_mix_sh = DRW_shader_create(datatoc_edit_overlay_mix_vert_glsl, NULL,
+		                                   datatoc_edit_overlay_mix_frag_glsl, NULL);
+	}
+	if (!overlay_facefill_sh) {
+		overlay_facefill_sh = DRW_shader_create(datatoc_edit_overlay_facefill_vert_glsl, NULL,
+		                                        datatoc_edit_overlay_facefill_frag_glsl, NULL);
+	}
+}
+
+static DRWPass *edit_mesh_create_overlay_pass(DRWShadingGroup **face_shgrp, DRWShadingGroup **ledges_shgrp,
+                                              DRWShadingGroup **lverts_shgrp, DRWShadingGroup **facedot_shgrp,
+                                              float *faceAlpha, DRWState statemod)
+{
+	static struct GPUShader *tri_sh, *ledge_sh;
+	const struct bContext *C = DRW_get_context();
+	RegionView3D *rv3d = CTX_wm_region_view3d(C);
+	Scene *scene = CTX_data_scene(C);
+	ToolSettings *ts = scene->toolsettings;
 
 	if ((ts->selectmode & SCE_SELECT_VERTEX) != 0) {
 		ledge_sh = overlay_edge_vcol_sh;
@@ -137,25 +191,78 @@ void EDIT_MESH_cache_init(void)
 			tri_sh = overlay_tri_sh;
 	}
 
-	psl->depth_pass_hidden_wire = DRW_pass_create("Depth Pass Hidden Wire", DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS | DRW_STATE_CULL_BACK);
-	depth_shgrp_hidden_wire = DRW_shgroup_create(depth_sh, psl->depth_pass_hidden_wire);
-
-	psl->edit_face_overlay_pass = DRW_pass_create("Edit Mesh Face Overlay Pass", DRW_STATE_WRITE_DEPTH | DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_LESS | DRW_STATE_BLEND | DRW_STATE_POINT);
+	DRWPass *pass = DRW_pass_create("Edit Mesh Face Overlay Pass", DRW_STATE_WRITE_COLOR | DRW_STATE_POINT | statemod);
 
-	face_overlay_shgrp = DRW_shgroup_create(tri_sh, psl->edit_face_overlay_pass);
-	DRW_shgroup_uniform_block(face_overlay_shgrp, "globalsBlock", globals_ubo, 0);
-	DRW_shgroup_uniform_vec2(face_overlay_shgrp, "viewportSize", DRW_viewport_size_get(), 1);
+	*face_shgrp = DRW_shgroup_create(tri_sh, pass);
+	DRW_shgroup_uniform_block(*face_shgrp, "globalsBlock", globals_ubo, 0);
+	DRW_shgroup_uniform_vec2(*face_shgrp, "viewportSize", DRW_viewport_size_get(), 1);
+	DRW_shgroup_uniform_float(*face_shgrp, "faceAlphaMod", faceAlpha, 1);
 
-	ledges_overlay_shgrp = DRW_shgroup_create(ledge_sh, psl->edit_face_overlay_pass);
-	DRW_shgroup_uniform_vec2(ledges_overlay_shgrp, "viewportSize", DRW_viewport_size_get(), 1);
+	*ledges_shgrp = DRW_shgroup_create(ledge_sh, pass);
+	DRW_shgroup_uniform_vec2(*ledges_shgrp, "viewportSize", DRW_viewport_size_get(), 1);
 
 	if ((ts->selectmode & (SCE_SELECT_VERTEX)) != 0) {
-		lverts_overlay_shgrp = DRW_shgroup_create(overlay_vert_sh, psl->edit_face_overlay_pass);
-		DRW_shgroup_uniform_vec2(lverts_overlay_shgrp, "viewportSize", DRW_viewport_size_get(), 1);
+		*lverts_shgrp = DRW_shgroup_create(overlay_vert_sh, pass);
+		DRW_shgroup_uniform_vec2(*lverts_shgrp, "viewportSize", DRW_viewport_size_get(), 1);
 	}
 
 	if ((ts->selectmode & (SCE_SELECT_FACE)) != 0) {
-		facedot_overlay_shgrp = DRW_shgroup_create(overlay_facedot_sh, psl->edit_face_overlay_pass);
+		*facedot_shgrp = DRW_shgroup_create(overlay_facedot_sh, pass);
+	}
+
+	return pass;
+}
+
+static float backwire_opacity;
+static float face_mod;
+
+void EDIT_MESH_cache_init(void)
+{
+	EDIT_MESH_PassList *psl = DRW_mode_pass_list_get();
+	const struct bContext *C = DRW_get_context();
+	View3D *v3d = CTX_wm_view3d(C);
+
+	bool do_zbufclip = ((v3d->flag & V3D_ZBUF_SELECT) == 0);
+
+	static float zero = 0.0f;
+	static struct GPUShader *depth_sh;
+
+	if (!depth_sh)
+		depth_sh = DRW_shader_create_3D_depth_only();
+
+	psl->depth_pass_hidden_wire = DRW_pass_create("Depth Pass Hidden Wire", DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS | DRW_STATE_CULL_BACK);
+	depth_shgrp_hidden_wire = DRW_shgroup_create(depth_sh, psl->depth_pass_hidden_wire);
+
+	if (!do_zbufclip) {
+		psl->edit_face_overlay_pass = edit_mesh_create_overlay_pass(&face_overlay_shgrp, &ledges_overlay_shgrp, &lverts_overlay_shgrp,
+		                                                            &facedot_overlay_shgrp, &face_mod, DRW_STATE_DEPTH_LESS | DRW_STATE_WRITE_DEPTH | DRW_STATE_BLEND);
+	}
+	else {
+		/* We render all wires with depth and opaque to a new fbo and blend the result based on depth values */
+		psl->edit_face_occluded_pass = edit_mesh_create_overlay_pass(&face_occluded_shgrp, &ledges_occluded_shgrp, &lverts_occluded_shgrp,
+		                                                             &facedot_occluded_shgrp, &zero,  DRW_STATE_DEPTH_LESS | DRW_STATE_WRITE_DEPTH);
+
+		/* however we loose the front faces value (because we need the depth of occluded wires and
+		 * faces are alpha blended ) so we recover them in a new pass. */
+		psl->facefill_occlude_pass = DRW_pass_create("Front Face Color", DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_LESS);
+		facefill_occluded_shgrp = DRW_shgroup_create(overlay_facefill_sh, psl->facefill_occlude_pass);
+		DRW_shgroup_uniform_block(facefill_occluded_shgrp, "globalsBlock", globals_ubo, 0);
+
+		/* we need a full screen pass to combine the result */
+		EDIT_MESH_TextureList *txl = DRW_mode_texture_list_get();
+		DefaultTextureList *dtxl = DRW_engine_texture_list_get();
+		struct Batch *quad = DRW_cache_fullscreen_quad_get();
+		static float mat[4][4]; /* not even used but avoid crash */
+
+
+		psl->mix_occlude_pass = DRW_pass_create("Mix Occluded Wires", DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND);
+		DRWShadingGroup *mix_shgrp = DRW_shgroup_create(overlay_mix_sh, psl->mix_occlude_pass);
+		DRW_shgroup_call_add(mix_shgrp, quad, mat);
+		DRW_shgroup_uniform_float(mix_shgrp, "alpha", &backwire_opacity, 1);
+		DRW_shgroup_uniform_buffer(mix_shgrp, "wireColor", &txl->occlude_wire_color_tx, 0);
+		DRW_shgroup_uniform_buffer(mix_shgrp, "faceColor", &txl->occlude_face_color_tx, 1);
+		DRW_shgroup_uniform_buffer(mix_shgrp, "wireDepth", &txl->occlude_wire_depth_tx, 2);
+		DRW_shgroup_uniform_buffer(mix_shgrp, "sceneDepth", &dtxl->depth, 3);
 	}
 
 	DRW_mode_passes_setup(NULL,
@@ -167,37 +274,58 @@ void EDIT_MESH_cache_init(void)
 	                      NULL);
 }
 
-void EDIT_MESH_cache_populate(Object *ob)
+static void edit_mesh_add_ob_to_pass(Scene *scene, Object *ob, DRWShadingGroup *face_shgrp, DRWShadingGroup *ledges_shgrp,
+                              DRWShadingGroup *lverts_shgrp, DRWShadingGroup *facedot_shgrp, DRWShadingGroup *facefill_shgrp)
 {
-	struct Batch *geom;
 	struct Batch *geo_ovl_tris, *geo_ovl_ledges, *geo_ovl_lverts, *geo_ovl_fcenter;
+	ToolSettings *ts = scene->toolsettings;
+
+	DRW_cache_wire_overlay_get(ob, &geo_ovl_tris, &geo_ovl_ledges, &geo_ovl_lverts);
+	DRW_shgroup_call_add(face_shgrp, geo_ovl_tris, ob->obmat);
+	DRW_shgroup_call_add(ledges_shgrp, geo_ovl_ledges, ob->obmat);
+
+	if (facefill_shgrp)
+		DRW_shgroup_call_add(facefill_shgrp, geo_ovl_tris, ob->obmat);
+
+	if ((ts->selectmode & SCE_SELECT_VERTEX) != 0)
+		DRW_shgroup_call_add(lverts_shgrp, geo_ovl_lverts, ob->obmat);
+
+	if ((ts->selectmode & SCE_SELECT_FACE) != 0) {
+		geo_ovl_fcenter = DRW_cache_face_centers_get(ob);
+		DRW_shgroup_call_add(facedot_shgrp, geo_ovl_fcenter, ob->obmat);
+	}
+}
+
+void EDIT_MESH_cache_populate(Object *ob)
+{
 	const struct bContext *C = DRW_get_context();
+	View3D *v3d = CTX_wm_view3d(C);
 	Scene *scene = CTX_data_scene(C);
 	Object *obedit = scene->obedit;
-	ToolSettings *ts = scene->toolsettings;
+	struct Batch *geom;
 
 	CollectionEngineSettings *ces_mode_ed = BKE_object_collection_engine_get(ob, COLLECTION_MODE_EDIT, "");
 	bool do_occlude_wire = BKE_collection_engine_property_value_get_bool(ces_mode_ed, "show_occlude_wire");
+	backwire_opacity = BKE_collection_engine_property_value_get_float(ces_mode_ed, "backwire_opacity"); /* should be done only once */
+
+	face_mod = (do_occlude_wire) ? 0.0f : 1.0f;
 
 	switch (ob->type) {
 		case OB_MESH:
-			if (ob == obedit) {
-				DRW_cache_wire_overlay_get(ob, &geo_ovl_tris, &geo_ovl_ledges, &geo_ovl_lverts);
-				DRW_shgroup_call_add(face_overlay_shgrp, geo_ovl_tris, ob->obmat);
-				DRW_shgroup_call_add(ledges_overlay_shgrp, geo_ovl_ledges, ob->obmat);
-
-				if ((ts->selectmode & SCE_SELECT_VERTEX) != 0)
-					DRW_shgroup_call_add(lverts_overlay_shgrp, geo_ovl_lverts, ob->obmat);
-
-				if ((ts->selectmode & SCE_SELECT_FACE) != 0) {
-					geo_ovl_fcenter = DRW_cache_face_centers_get(ob);
-					DRW_shgroup_call_add(facedot_overlay_shgrp, geo_ovl_fcenter, ob->obmat);
-				}
-
+			if (ob == obedit) {	
 				if (do_occlude_wire) {
 					geom = DRW_cache_surface_get(ob);
 					DRW_shgroup_call_add(depth_shgrp_hidden_wire, geom, ob->obmat);
 				}
+
+				if ((v3d->flag & V3D_ZBUF_SELECT) == 0) {
+					edit_mesh_add_ob_to_pass(scene, ob, face_occluded_shgrp, ledges_occluded_shgrp,
+					                         lverts_occluded_shgrp, facedot_occluded_shgrp, facefill_occluded_shgrp);
+				}
+				else {
+					edit_mesh_add_ob_to_pass(scene, ob, face_overlay_shgrp, ledges_overlay_shgrp,
+					                         lverts_overlay_shgrp, facedot_overlay_shgrp, NULL);
+				}
 			}
 			break;
 		case OB_LAMP:
@@ -229,9 +357,36 @@ void EDIT_MESH_cache_finish(void)
 void EDIT_MESH_draw(void)
 {
 	EDIT_MESH_PassList *psl = DRW_mode_pass_list_get();
+	EDIT_MESH_FramebufferList *fbl = DRW_mode_framebuffer_list_get();
+	DefaultFramebufferList *dfbl = DRW_engine_framebuffer_list_get();
+	DefaultTextureList *dtxl = DRW_engine_texture_list_get();
 
 	DRW_draw_pass(psl->depth_pass_hidden_wire);
-	DRW_draw_pass(psl->edit_face_overlay_pass);
+
+	if (psl->edit_face_occluded_pass) {
+		float clearcol[4] = {0.0f, 0.0f, 0.0f, 0.0f};
+		/* render facefill */
+		DRW_framebuffer_texture_detach(dtxl->depth);
+		DRW_framebuffer_texture_attach(fbl->occlude_face_fb, dtxl->depth, 0);
+		DRW_framebuffer_bind(fbl->occlude_face_fb);
+		DRW_framebuffer_clear(true, false, clearcol);
+		DRW_draw_pass(psl->facefill_occlude_pass);
+		DRW_framebuffer_texture_detach(dtxl->depth);
+		
+		/* Render wires on a separate framebuffer */
+		DRW_framebuffer_bind(fbl->occlude_wire_fb);
+		DRW_framebuffer_clear(true, true, clearcol);
+		DRW_draw_pass(psl->edit_face_occluded_pass);
+
+		/* Combine with scene buffer */
+		DRW_framebuffer_bind(dfbl->default_fb);
+		DRW_draw_pass(psl->mix_occlude_pass);
+		DRW_framebuffer_texture_attach(dfbl->default_fb, dtxl->depth, 0);
+	}
+	else {
+		DRW_draw_pass(psl->edit_face_overlay_pass);
+	}
+
 	DRW_draw_pass(psl->wire_outline_pass);
 	DRW_draw_pass(psl->non_meshes_pass);
 	DRW_draw_pass(psl->ob_center_pass);
@@ -241,6 +396,7 @@ void EDIT_MESH_collection_settings_create(CollectionEngineSettings *ces)
 {
 	BLI_assert(ces);
 	BKE_collection_engine_property_add_int(ces, "show_occlude_wire", false);
+	BKE_collection_engine_property_add_float(ces, "backwire_opacity", 0.5);
 }
 
 void EDIT_MESH_engine_free(void)
@@ -261,4 +417,8 @@ void EDIT_MESH_engine_free(void)
 		DRW_shader_free(overlay_vert_sh);
 	if (overlay_facedot_sh)
 		DRW_shader_free(overlay_facedot_sh);
+	if (overlay_mix_sh)
+		DRW_shader_free(overlay_mix_sh);
+	if (overlay_facefill_sh)
+		DRW_shader_free(overlay_facefill_sh);
 }
\ No newline at end of file
diff --git a/source/blender/draw/modes/edit_mesh_mode.h b/source/blender/draw/modes/edit_mesh_mode.h
index 9eee473917b..508685bd033 100644
--- a/source/blender/draw/modes/edit_mesh_mode.h
+++ b/source/blender/draw/modes/edit_mesh_mode.h
@@ -28,6 +28,8 @@
 
 struct Object;
 
+void EDIT_MESH_init(void);
+
 void EDIT_MESH_cache_init(void);
 void EDIT_MESH_cache_populate(struct Object *ob);
 void EDIT_MESH_cache_finish(void);
diff --git a/source/blender/draw/modes/shaders/edit_overlay_facedot_frag.glsl b/source/blender/draw/modes/shaders/edit_overlay_facedot_frag.glsl
index 9b99247efec..0bcc8aafc1f 100644
--- a/source/blender/draw/modes/shaders/edit_overlay_facedot_frag.glsl
+++ b/source/blender/draw/modes/shaders/edit_overlay_facedot_frag.glsl
@@ -49,7 +49,7 @@ out vec4 FragColor;
 void main()
 {
 	if (isSelected != 0)
-		FragColor = vec4(colorFaceDot.rgb, 1.0);
+		FragColor = colorFaceDot;
 	else
-		FragColor = vec4(colorWireEdit.rgb, 1.0);
+		FragColor = colorWireEdit;
 }
diff --git a/source/blender/draw/modes/shaders/edit_overlay_facefill_frag.glsl b/source/blender/draw/modes/shaders/edit_overlay_facefill_frag.glsl
new file mode 100644
index 00000000000..fa0197573ff
--- /dev/null
+++ b/source/blender/draw/modes/shaders/edit_overlay_facefill_frag.glsl
@@ -0,0 +1,27 @@
+
+/* Solid Wirefram implementation
+ * Mike Erwin, Clément Foucault */
+
+/* This shader follows the principles of
+ * http://developer.download.nvidia.com/SDK/10/direct3d/Source/SolidWireframe/Doc/SolidWireframe.pdf */
+
+flat in vec4 faceColor;
+flat in int faceActive;
+
+out vec4 FragColor;
+
+const mat4 stipple_matrix = mat4(vec4(1.0, 0.0, 0.0, 0.0),
+                                 vec4(0.0, 0.0, 0.0, 0.0),
+                                 vec4(0.0, 0.0, 1.0, 0.0),
+                                 vec4(0.0, 0.0, 0.0, 0.0));
+
+void main()
+{
+	FragColor = faceColor;
+
+	if (faceActive == 1) {
+		int x = int(gl_FragCoord.x) & 0x3; /* mod 4 */
+		int y = int(gl_FragCoord.y) & 0x3; /* mod 4 */
+		FragColor *= stipple_matrix[x][y];
+	}
+}
diff --git a/source/blender/draw/modes/shaders/edit_overlay_facefill_vert.glsl b/source/blender/draw/modes/shaders/edit_overlay_facefill_vert.glsl
new file mode 100644
index 00000000000..be4cd4568cd
--- /dev/null
+++ b/source/blender/draw/modes/shaders/edit_overlay_facefill_vert.glsl
@@ -0,0 +1,72 @@
+
+uniform mat4 ModelViewProjectionMatrix;
+
+/* keep in sync with GlobalsUboStorage */
+layout(std140) uniform globalsBlock {
+	vec4 colorWire;
+	vec4 colorWireEdit;
+	vec4 colorActive;
+	vec4 colorSelect;
+	vec4 colorTransform;
+	vec4 colorGroupActive;
+	vec4 colorGroup;
+	vec4 colorLamp;
+	vec4 colorSpeaker;
+	vec4 colorCamera;
+	vec4 colorEmpty;
+	vec4 colorVertex;
+	vec4 colorVertexSelect;
+	vec4 colorEditMeshActive;
+	vec4 colorEdgeSelect;
+	vec4 colorEdgeSeam;
+	vec4 colorEdgeSharp;
+	vec4 colorEdgeCrease;
+	vec4 colorEdgeBWeight;
+	vec4 colorEdgeFaceSelect;
+	vec4 colorFace;
+	vec4 colorFaceSelect;
+	vec4 colorNormal;
+	vec4 colorVNormal;
+	vec4 colorLNormal;
+	vec4 colorFaceDot;
+
+	vec4 colorDeselect;
+	vec4 colorOutline;
+	vec4 colorLampNoAlpha;
+
+	float sizeLampCenter;
+	float sizeLampCircle;
+	float sizeLampCircleShadow;
+	float sizeVertex;
+	float sizeEdge;
+	float sizeEdgeFix;
+	float sizeNormal;
+	float sizeFaceDot;
+};
+
+in vec3 pos;
+in ivec4 data;
+
+flat out vec4 faceColor;
+flat out int faceActive;
+
+#define FACE_ACTIVE     (1 << 2)
+#define FACE_SELECTED   (1 << 3)
+
+void main()
+{
+	gl_Position = ModelViewProjectionMatrix * vec4(pos, 1.0);
+
+	if ((data.x & FACE_ACTIVE) != 0) {
+		faceColor = colorEditMeshActive;
+		faceActive = 1;
+	}
+	else if ((data.x & FACE_SELECTED) != 0) {
+		faceColor = colorFaceSelect;
+		faceActive = 0;
+	}
+	else {
+		faceColor = colorFace;
+		faceActive = 0;
+	}
+}
diff --git a/source/blender/draw/modes/shaders/edit_overlay_frag.glsl b/source/blender/draw/modes/shaders/edit_overlay_frag.glsl
index a3deaa237ee..43b3e412b9d 100644
--- a/source/blender/draw/modes/shaders/edit_overlay_frag.glsl
+++ b/source/blender/draw/modes/shaders/edit_overlay_frag.glsl
@@ -48,6 +48,8 @@ layout(std140) uniform globalsBlock {
 	float sizeFaceDot;
 };
 
+uniform float faceAlphaMod;
+
 flat in vec3 edgesCrease;
 flat in vec3 edgesBweight;
 flat in ivec3 flag;
@@ -175,6 +177,9 @@ void main()
 		int y = int(gl_FragCoord.y) & 0x3; /* mod 4 */
 		FragColor *= stipple_matrix[x][y];
 	}
+	else {
+		FragColor.a *= faceAlphaMod;
+	}
 
 	/* Edges */
 	for (int v = 0; v < 3; ++v) {
diff --git a/source/blender/draw/modes/shaders/edit_overlay_mix_frag.glsl b/source/blender/draw/modes/shaders/edit_overlay_mix_frag.glsl
new file mode 100644
index 00000000000..67687c7fc2f
--- /dev/null
+++ b/source/blender/draw/modes/shaders/edit_overlay_mix_frag.glsl
@@ -0,0 +1,40 @@
+
+out vec4 FragColor;
+
+uniform sampler2D wireColor;
+uniform sampler2D wireDepth;
+uniform sampler2D faceColor;
+uniform sampler2D sceneDepth;
+uniform float alpha;
+
+vec4 linear(vec4 col)
+{
+	const float fac = 0.45454545;
+	return vec4(pow(col.r,fac), pow(col.g,fac), pow(col.b,fac), col.a);
+}
+
+vec4 srgb(vec4 col)
+{
+	const float fac = 2.2;
+	return vec4(pow(col.r,fac), pow(col.g,fac), pow(col.b,fac), col.a);
+}
+
+void main()
+{
+	ivec2 co = ivec2(gl_FragCoord.xy);
+	float wire_depth = texelFetch(wireDepth, co, 0).r;
+	float scene_depth = texelFetch(sceneDepth, co, 0).r;
+	vec4 wire_color = texelFetch(wireColor, co, 0).rgba;
+	vec4 face_color = texelFetch(faceColor, co, 0).rgba;
+
+	/* this works because not rendered depth is 1.0 and the
+	 * following test is always true even when no wires */
+	if (wire_depth > scene_depth) {
+		wire_color.a *= alpha;
+		FragColor.rgb = mix(face_color.rgb, wire_color.rgb, wire_color.a);
+		FragColor.a = face_color.a + wire_color.a;
+	}
+	else {
+		FragColor = wire_color;
+	}
+}
diff --git a/source/blender/draw/modes/shaders/edit_overlay_mix_vert.glsl b/source/blender/draw/modes/shaders/edit_overlay_mix_vert.glsl
new file mode 100644
index 00000000000..ef3d5d717bc
--- /dev/null
+++ b/source/blender/draw/modes/shaders/edit_overlay_mix_vert.glsl
@@ -0,0 +1,7 @@
+
+in vec2 pos;
+
+void main()
+{
+	gl_Position = vec4(pos, 0.0, 1.0);
+}