自学教程：C++ CTX_data_active_object函数代码示例

static int mask_flood_fill_exec(bContext *C, wmOperator *op){	ARegion *ar = CTX_wm_region(C);	Object *ob = CTX_data_active_object(C);	PaintMaskFloodMode mode;	float value;	DerivedMesh *dm;	PBVH *pbvh;	PBVHNode **nodes;	int totnode, i;	mode = RNA_enum_get(op->ptr, "mode");	value = RNA_float_get(op->ptr, "value");	dm = mesh_get_derived_final(CTX_data_scene(C), ob, CD_MASK_BAREMESH);	pbvh = dm->getPBVH(ob, dm);	ob->sculpt->pbvh = pbvh;	BLI_pbvh_search_gather(pbvh, NULL, NULL, &nodes, &totnode);	sculpt_undo_push_begin("Mask flood fill");	for (i = 0; i < totnode; i++) {		PBVHVertexIter vi;		sculpt_undo_push_node(ob, nodes[i], SCULPT_UNDO_MASK);		BLI_pbvh_vertex_iter_begin(pbvh, nodes[i], vi, PBVH_ITER_UNIQUE) {			mask_flood_fill_set_elem(vi.mask, mode, value);		} BLI_pbvh_vertex_iter_end;				BLI_pbvh_node_mark_update(nodes[i]);		if (BLI_pbvh_type(pbvh) == PBVH_GRIDS)			multires_mark_as_modified(ob, MULTIRES_COORDS_MODIFIED);	}

/* Criteria: *  1) There must be an dopesheet/action editor, and it must be in a mode which uses actions... *        OR *     The NLA Editor is active (i.e. Animation Data panel -> new action) *  2) The associated AnimData block must not be in tweakmode */static int action_new_poll(bContext *C){	Scene *scene = CTX_data_scene(C);		/* Check tweakmode is off (as you don't want to be tampering with the action in that case) */	/* NOTE: unlike for pushdown, this operator needs to be run when creating an action from nothing... */		if (ED_operator_action_active(C)) {		SpaceAction *saction = (SpaceAction *)CTX_wm_space_data(C);		Object *ob = CTX_data_active_object(C);				/* For now, actions are only for the active object, and on object and shapekey levels... */		if (saction->mode == SACTCONT_ACTION) {			/* XXX: This assumes that actions are assigned to the active object in this mode */			if (ob) {				if ((ob->adt == NULL) || (ob->adt->flag & ADT_NLA_EDIT_ON) == 0)					return true;			}		}		else if (saction->mode == SACTCONT_SHAPEKEY) {			Key *key = BKE_key_from_object(ob);			if (key) {				if ((key->adt == NULL) || (key->adt->flag & ADT_NLA_EDIT_ON) == 0)					return true;			}		}	}	else if (ED_operator_nla_active(C)) {		if (!(scene->flag & SCE_NLA_EDIT_ON)) {			return true;		}	}		/* something failed... */	return false;}

static int fluid_bake_exec(bContext *C, wmOperator *op){	if (!fluidsimBake(C, op->reports, CTX_data_active_object(C), false))		return OPERATOR_CANCELLED;	return OPERATOR_FINISHED;}

static int pose_select_parent_exec(bContext *C, wmOperator *UNUSED(op)){	Object *ob = BKE_object_pose_armature_get(CTX_data_active_object(C));	bArmature *arm = (bArmature *)ob->data;	bPoseChannel *pchan, *parent;	/* Determine if there is an active bone */	pchan = CTX_data_active_pose_bone(C);	if (pchan) {		parent = pchan->parent;		if ((parent) && !(parent->bone->flag & (BONE_HIDDEN_P | BONE_UNSELECTABLE))) {			parent->bone->flag |= BONE_SELECTED;			arm->act_bone = parent->bone;		}		else {			return OPERATOR_CANCELLED;		}	}	else {		return OPERATOR_CANCELLED;	}		/* updates */	WM_event_add_notifier(C, NC_OBJECT | ND_BONE_SELECT, ob);		if (arm->flag & ARM_HAS_VIZ_DEPS) {		/* mask modifier ('armature' mode), etc. */		DAG_id_tag_update(&ob->id, OB_RECALC_DATA);	}		return OPERATOR_FINISHED;}

static int sculpt_undo_restore_hidden(bContext *C, DerivedMesh *dm,                                      SculptUndoNode *unode){	Object *ob = CTX_data_active_object(C);	SculptSession *ss = ob->sculpt;	int i;	if (unode->maxvert) {		MVert *mvert = ss->mvert;				for (i = 0; i < unode->totvert; i++) {			MVert *v = &mvert[unode->index[i]];			int uval = BLI_BITMAP_GET(unode->vert_hidden, i);			BLI_BITMAP_MODIFY(unode->vert_hidden, i,			                  v->flag & ME_HIDE);			if (uval)				v->flag |= ME_HIDE;			else				v->flag &= ~ME_HIDE;						v->flag |= ME_VERT_PBVH_UPDATE;		}	}	else if (unode->maxgrid && dm->getGridData) {		BLI_bitmap **grid_hidden = dm->getGridHidden(dm);				for (i = 0; i < unode->totgrid; i++) {			SWAP(BLI_bitmap *,			     unode->grid_hidden[i],			     grid_hidden[unode->grids[i]]);					}	}

bool paint_curve_poll(bContext *C){  Object *ob = CTX_data_active_object(C);  Paint *p;  RegionView3D *rv3d = CTX_wm_region_view3d(C);  SpaceImage *sima;  if (rv3d && !(ob && ((ob->mode & OB_MODE_ALL_PAINT) != 0))) {    return false;  }  sima = CTX_wm_space_image(C);  if (sima && sima->mode != SI_MODE_PAINT) {    return false;  }  p = BKE_paint_get_active_from_context(C);  if (p && p->brush && (p->brush->flag & BRUSH_CURVE)) {    return true;  }  return false;}

/* For the object with pose/action: create path curves for selected bones  * This recalculates the WHOLE path within the pchan->pathsf and pchan->pathef range */static int pose_calculate_paths_exec(bContext *C, wmOperator *op){	Object *ob = BKE_object_pose_armature_get(CTX_data_active_object(C));	Scene *scene = CTX_data_scene(C);		if (ELEM(NULL, ob, ob->pose))		return OPERATOR_CANCELLED;		/* grab baking settings from operator settings */	{		bAnimVizSettings *avs = &ob->pose->avs;		PointerRNA avs_ptr;				avs->path_sf = RNA_int_get(op->ptr, "start_frame");		avs->path_ef = RNA_int_get(op->ptr, "end_frame");				RNA_pointer_create(NULL, &RNA_AnimVizMotionPaths, avs, &avs_ptr);		RNA_enum_set(&avs_ptr, "bake_location", RNA_enum_get(op->ptr, "bake_location"));	}		/* set up path data for bones being calculated */	CTX_DATA_BEGIN (C, bPoseChannel *, pchan, selected_pose_bones)	{		/* verify makes sure that the selected bone has a bone with the appropriate settings */		animviz_verify_motionpaths(op->reports, scene, ob, pchan);	}

static int face_select_reveal_exec(bContext *C, wmOperator *UNUSED(op)){	Object *ob = CTX_data_active_object(C);	paintface_reveal(ob);	ED_region_tag_redraw(CTX_wm_region(C));	return OPERATOR_FINISHED;}

static int paint_select_linked_pick_invoke(bContext *C, wmOperator *op, wmEvent *event){	int mode= RNA_boolean_get(op->ptr, "extend") ? 1:0;	select_linked_tfaces(C, CTX_data_active_object(C), event->mval, mode);	ED_region_tag_redraw(CTX_wm_region(C));	return OPERATOR_FINISHED;}

void ED_preview_shader_job(const bContext *C, void *owner, ID *id, ID *parent, MTex *slot, int sizex, int sizey, int method){	Object *ob= CTX_data_active_object(C);	wmJob *steve;	ShaderPreview *sp;	steve= WM_jobs_get(CTX_wm_manager(C), CTX_wm_window(C), owner, "Shader Preview", WM_JOB_EXCL_RENDER);	sp= MEM_callocN(sizeof(ShaderPreview), "shader preview");	/* customdata for preview thread */	sp->scene= CTX_data_scene(C);	sp->owner= owner;	sp->sizex= sizex;	sp->sizey= sizey;	sp->pr_method= method;	sp->id = id;	sp->parent= parent;	sp->slot= slot;	if(ob && ob->totcol) copy_v4_v4(sp->col, ob->col);	else sp->col[0]= sp->col[1]= sp->col[2]= sp->col[3]= 1.0f;		/* setup job */	WM_jobs_customdata(steve, sp, shader_preview_free);	WM_jobs_timer(steve, 0.1, NC_MATERIAL, NC_MATERIAL);	WM_jobs_callbacks(steve, common_preview_startjob, NULL, shader_preview_updatejob, NULL);		WM_jobs_start(CTX_wm_manager(C), steve);}

static int vert_select_all_exec(bContext *C, wmOperator *op){	Object *ob = CTX_data_active_object(C);	paintvert_deselect_all_visible(ob, RNA_enum_get(op->ptr, "action"), true);	ED_region_tag_redraw(CTX_wm_region(C));	return OPERATOR_FINISHED;}

/* Check if context data is suitable for the given absolute Keying Set */short keyingset_context_ok_poll (bContext *C, KeyingSet *ks){	ScrArea *sa= CTX_wm_area(C);		/* data retrieved from context depends on active editor */	if (sa == NULL) return 0;			switch (sa->spacetype) {		case SPACE_VIEW3D:		{			Object *obact= CTX_data_active_object(C);						/* if in posemode, check if 'pose-channels' requested for in KeyingSet */			if ((obact && obact->pose) && (obact->mode & OB_MODE_POSE)) {				/* check for posechannels */							}			else {				/* check for selected object */							}		}			break;	}			return 1;}

/* draw keyframe lines for timeline */static void time_draw_keyframes(const bContext *C, ARegion *ar){	Scene *scene = CTX_data_scene(C);	Object *ob = CTX_data_active_object(C);	View2D *v2d = &ar->v2d;	bool onlysel = ((scene->flag & SCE_KEYS_NO_SELONLY) == 0);		/* set this for all keyframe lines once and for all */	glLineWidth(1.0);		/* draw grease pencil keyframes (if available) */		UI_ThemeColor(TH_TIME_GP_KEYFRAME);	if (scene->gpd) {		time_draw_idblock_keyframes(v2d, (ID *)scene->gpd, onlysel);	}	if (ob && ob->gpd) {		time_draw_idblock_keyframes(v2d, (ID *)ob->gpd, onlysel);	}		/* draw scene keyframes first 	 *	- don't try to do this when only drawing active/selected data keyframes,	 *	  since this can become quite slow	 */	if (onlysel == 0) {		/* set draw color */		UI_ThemeColorShade(TH_TIME_KEYFRAME, -50);		time_draw_idblock_keyframes(v2d, (ID *)scene, onlysel);	}		/* draw keyframes from selected objects 	 *  - only do the active object if in posemode (i.e. showing only keyframes for the bones)	 *    OR the onlysel flag was set, which means that only active object's keyframes should	 *    be considered	 */	UI_ThemeColor(TH_TIME_KEYFRAME);		if (ob && ((ob->mode == OB_MODE_POSE) || onlysel)) {		/* draw keyframes for active object only */		time_draw_idblock_keyframes(v2d, (ID *)ob, onlysel);	}	else {		bool active_done = false;				/* draw keyframes from all selected objects */		CTX_DATA_BEGIN (C, Object *, obsel, selected_objects)		{			/* last arg is 0, since onlysel doesn't apply here... */			time_draw_idblock_keyframes(v2d, (ID *)obsel, 0);						/* if this object is the active one, set flag so that we don't draw again */			if (obsel == ob)				active_done = true;		}		CTX_DATA_END;				/* if active object hasn't been done yet, draw it... */		if (ob && (active_done == 0))			time_draw_idblock_keyframes(v2d, (ID *)ob, 0);	}

static int face_select_hide_exec(bContext *C, wmOperator *op){	const bool unselected = RNA_boolean_get(op->ptr, "unselected");	Object *ob = CTX_data_active_object(C);	paintface_hide(ob, unselected);	ED_region_tag_redraw(CTX_wm_region(C));	return OPERATOR_FINISHED;}

static int paint_select_linked_pick_invoke(bContext *C, wmOperator *op, const wmEvent *event){	const bool select = !RNA_boolean_get(op->ptr, "deselect");	view3d_operator_needs_opengl(C);	paintface_select_linked(C, CTX_data_active_object(C), event->mval, select);	ED_region_tag_redraw(CTX_wm_region(C));	return OPERATOR_FINISHED;}

static int make_regular_poll(bContext *C){	Object *ob;	if (ED_operator_editlattice(C)) return 1;	ob = CTX_data_active_object(C);	return (ob && ob->type == OB_LATTICE);}

/* Temporary wrapper for driver operators for buttons to make it easier to create * such drivers by rerouting all paths through the active object instead so that * they will get picked up by the dependency system. * * < C: context pointer - for getting active data  * <> ptr: RNA pointer for property's datablock. May be modified as result of path remapping. * < prop: RNA definition of property to add for * * > returns: MEM_alloc'd string representing the path to the property from the given PointerRNA */static char *get_driver_path_hack(bContext *C, PointerRNA *ptr, PropertyRNA *prop){	ID *id = (ID *)ptr->id.data;	ScrArea *sa = CTX_wm_area(C);		/* get standard path which may be extended */	char *basepath = RNA_path_from_ID_to_property(ptr, prop);	char *path = basepath; /* in case no remapping is needed */			/* Remapping will only be performed in the Properties Editor, as only this 	 * restricts the subspace of options to the 'active' data (a manageable state)	 */	// TODO: watch out for pinned context?	if ((sa) && (sa->spacetype == SPACE_BUTS)) {		Object *ob = CTX_data_active_object(C);				if (ob && id) {			/* only id-types which can be remapped to go through objects should be considered */			switch (GS(id->name)) {				case ID_TE: /* textures */				{					Material *ma = give_current_material(ob, ob->actcol);					Tex *tex = give_current_material_texture(ma);										/* assumes: texture will only be shown if it is active material's active texture it's ok */					if ((ID *)tex == id) {						char name_esc_ma[(sizeof(ma->id.name) - 2) * 2];						char name_esc_tex[(sizeof(tex->id.name) - 2) * 2];						BLI_strescape(name_esc_ma, ma->id.name + 2, sizeof(name_esc_ma));						BLI_strescape(name_esc_tex, tex->id.name + 2, sizeof(name_esc_tex));						/* create new path */						// TODO: use RNA path functions to construct step by step instead?						// FIXME: maybe this isn't even needed anymore...						path = BLI_sprintfN("material_slots[/"%s/"].material.texture_slots[/"%s/"].texture.%s", 						                    name_esc_ma, name_esc_tex, basepath);													/* free old one */						MEM_freeN(basepath);					}					break;				}			}						/* fix RNA pointer, as we've now changed the ID root by changing the paths */			if (basepath != path) {				/* rebase provided pointer so that it starts from object... */				RNA_pointer_create(&ob->id, ptr->type, ptr->data, ptr);			}		}	}		/* the path should now have been corrected for use */	return path;}

static int ED_operator_rigidbody_con_active_poll(bContext *C){	if (ED_operator_object_active_editable(C)) {		Object *ob = CTX_data_active_object(C);		return (ob && ob->rigidbody_constraint);	}	else		return 0;}

static int fluid_bake_exec(bContext *C, wmOperator *op){	Object *ob= CTX_data_active_object(C);	// XXX TODO redraw, escape, non-blocking, ..	if(!fluidsimBake(C, op->reports, ob))		return OPERATOR_CANCELLED;	return OPERATOR_FINISHED;}

static int vertex_color_set_exec(bContext *C, wmOperator *UNUSED(op)){	Scene *scene = CTX_data_scene(C);	Object *obact = CTX_data_active_object(C);	unsigned int paintcol = vpaint_get_current_col(scene->toolsettings->vpaint);	vpaint_fill(obact, paintcol);		ED_region_tag_redraw(CTX_wm_region(C)); // XXX - should redraw all 3D views	return OPERATOR_FINISHED;}

static int buttons_shading_context(const bContext *C, int mainb){	Object *ob = CTX_data_active_object(C);	if (ELEM(mainb, BCONTEXT_MATERIAL, BCONTEXT_WORLD, BCONTEXT_TEXTURE))		return 1;	if (mainb == BCONTEXT_DATA && ob && ELEM(ob->type, OB_LAMP, OB_CAMERA))		return 1;		return 0;}

static int fluid_bake_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event)){	/* only one bake job at a time */	if (WM_jobs_test(CTX_wm_manager(C), CTX_data_scene(C), WM_JOB_TYPE_OBJECT_SIM_FLUID))		return OPERATOR_CANCELLED;	if (!fluidsimBake(C, op->reports, CTX_data_active_object(C), true))		return OPERATOR_CANCELLED;	return OPERATOR_FINISHED;}