Bugfix 18671 revisted

Node editor didn't support editing non-material texture node trees.
Campbell pointed me to fact it's been used already, like for brush
painting. However, this only worked via linking the texture to a
material... hackish stuff.

Now the Node Editor supports all other Textures too, with three extra
icon buttons to define which.

- Active Object: for textures linked to Materials or Lamps
- World: textures from Scene world.
- Brush: textures from active Brush 

The latter can only be set and used when in Paint or Sculpt mode:

- Paint mode: in Image window, Paint Tool panel, set active brush
- Sculpt mode: in EditButtons, Texture panel, select empty slot, add texture.

Note that refreshes of previews in Node Editor is not always happening on
switching contextes. Just click a socket to refresh view.

source/blender/makesdna/DNA_space_types.h

@@ -356,7 +356,8 @@ typedef struct SpaceNode {
 	float xof, yof;	/* offset for drawing the backdrop */
 	
 	struct bNodeTree *nodetree, *edittree;
-	int treetype, pad;			/* treetype: as same nodetree->type */
+	int treetype;			/* treetype: as same nodetree->type */
+	short texfrom, pad;		/* texfrom object, world or brush */
 	
 	struct bGPdata *gpd;		/* grease-pencil data */
 } SpaceNode;
@@ -366,6 +367,11 @@ typedef struct SpaceNode {
 #define SNODE_BACKDRAW		2
 #define SNODE_DISPGP		4
 
+/* snode->texfrom */
+#define SNODE_TEX_OBJECT	0
+#define SNODE_TEX_WORLD		1
+#define SNODE_TEX_BRUSH		2
+
 typedef struct SpaceImaSel {
 	SpaceLink *next, *prev;
 	int spacetype;

source/blender/src/buttons_shading.c

@@ -1705,8 +1705,7 @@ static void texture_panel_texture(MTex *actmtex, Material *ma, World *wrld, Lamp
 			uiDefButS(block, MENU, B_TEXTYPE, textypes,	160, 125, 140, 25, &tex->type, 0,0,0,0, "Select texture type");
 		}
 		
-		if(ma)
-			uiDefButC(block, TOG, B_TEX_USENODES, "Nodes", 160, 100, 140, 25, &tex->use_nodes, 0.0f, 0.0f, 0, 0, "");
+		uiDefButC(block, TOG, B_TEX_USENODES, "Nodes", 160, 100, 140, 25, &tex->use_nodes, 0.0f, 0.0f, 0, 0, "");
 
 	}
 	else {

source/blender/src/editnode.c

@@ -35,6 +35,7 @@
 #include "MEM_guardedalloc.h"
 
 #include "DNA_action_types.h"
+#include "DNA_brush_types.h"
 #include "DNA_color_types.h"
 #include "DNA_image_types.h"
 #include "DNA_ipo_types.h"
@@ -583,14 +584,42 @@ void snode_set_context(SpaceNode *snode)
 		snode->nodetree= G.scene->nodetree;
 	}
 	else if(snode->treetype==NTREE_TEXTURE) {
-		if(ob) {
-			Tex *tx= give_current_texture(ob, ob->actcol);
-			if(tx) {
-				snode->from= (ID*)ob; /* please check this; i have no idea what 'from' is. */
-				snode->id= &tx->id;
-				snode->nodetree= tx->nodetree;
+		Tex *tx= NULL;
+
+		if(snode->texfrom==SNODE_TEX_OBJECT) {
+			if(ob) {
+				tx= give_current_texture(ob, ob->actcol);
+				snode->from= (ID *)ob;
 			}
 		}
+		else if(snode->texfrom==SNODE_TEX_WORLD) {
+			tx= give_current_world_texture();
+			snode->from= (ID *)G.scene->world;
+		}
+		else {
+			MTex *mtex= NULL;
+			
+			if(G.f & G_SCULPTMODE) {
+				SculptData *sd= &G.scene->sculptdata;
+				if(sd->texact != -1)
+					mtex= sd->mtex[sd->texact];
+			}
+			else {
+				Brush *br= G.scene->toolsettings->imapaint.brush;
+				if(br) 
+					mtex= br->mtex[br->texact];
+			}
+			
+			if(mtex) {
+				snode->from= (ID *)G.scene;
+				tx= mtex->tex;
+			}
+		}
+		
+		if(tx) {
+			snode->id= &tx->id;
+			snode->nodetree= tx->nodetree;
+		}
 	}
 	
 	/* find editable group */

source/blender/src/header_node.c

@@ -756,8 +756,26 @@ void node_buttons(ScrArea *sa)
 	uiDefIconButI(block, ROW, B_REDR, ICON_TEXTURE_DEHLT, xco,2,XIC,YIC-2,
 				  &(snode->treetype), 2, 2, 0, 0, "Texture Nodes");
 	xco+= 2*XIC;
+	
 	uiBlockEndAlign(block);
 	
+	if(snode->treetype==NTREE_TEXTURE) {
+		
+		uiBlockBeginAlign(block);
+		uiDefIconButS(block, ROW, B_REDR, ICON_OBJECT, xco,2,XIC,YIC-2,
+					  &(snode->texfrom), 3, SNODE_TEX_OBJECT, 0, 0, "Texture Nodes from Object");
+		xco+= XIC;
+		uiDefIconButS(block, ROW, B_REDR, ICON_WORLD_DEHLT, xco,2,XIC,YIC-2,
+					  &(snode->texfrom), 3, SNODE_TEX_WORLD, 0, 0, "Texture Nodes from World");
+		xco+= XIC;
+		uiDefIconButS(block, ROW, B_REDR, ICON_TPAINT_DEHLT, xco,2,XIC,YIC-2,
+					  &(snode->texfrom), 3, SNODE_TEX_BRUSH, 0, 0, "Texture Nodes from Active Brush or Sculpt Data");
+		xco+= 2*XIC;
+		
+		uiBlockEndAlign(block);
+		
+	}
+	
 	/* find and set the context */
 	snode_set_context(snode);
 	
@@ -785,8 +803,9 @@ void node_buttons(ScrArea *sa)
 	else if(snode->treetype==NTREE_TEXTURE) {
 		if(snode->from) {
 			
+			/* can't use unlink etc here, code requires buttons context */
 			xco= std_libbuttons(block, xco, 0, 0, NULL, B_TEXBROWSE, ID_TE, 1, snode->id, snode->from, &(snode->menunr), 
-					   B_TEXALONE, B_TEXLOCAL, B_TEXDELETE, B_AUTOTEXNAME, B_KEEPDATA);
+					   0, 0, 0, B_AUTOTEXNAME, B_KEEPDATA);
 			
 			if(snode->id) {
 				Tex *tx= (Tex *)snode->id;