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

1 files changed, 198 insertions, 38 deletions

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