Christmas coding work!

********* Node editor work:

- To enable Nodes for Materials, you have to set the "Use Nodes"
  button, in the new Material buttons "Nodes" Panel or in header
  of the Node editor. Doing this will disable Material-Layers.

- Nodes now execute materials ("shaders"), but still only using the
  previewrender code.

- Nodes have (optional) previews for rendered images.

- Node headers allow to hide buttons and/or preview image

- Nodes can be dragged larger/smaller (right-bottom corner)

- Nodes can be hidden (minimized) with hotkey H

- CTRL+click on an Input Socket gives a popup with default values.

- Changing Material/Texture or Mix node will adjust Node title.

- Click-drag outside of a Node changes cursor to "Knife' and allows to
  draw a rect where to cut Links.

- Added new node types RGBtoBW, Texture, In/Output, ColorRamp

- Material Nodes have options to ouput diffuse or specular, or to use
  a negative normal. The input socket 'Normal' will force the material
  to use that normal, otherwise it uses the normal from the Material
  that has the node tree.

- When drawing a link between two not-matching sockets, Blender inserts
  a converting node (now only for value/rgb combos)

- When drawing a link to an input socket that's already in use, the
  old link will either disappear or flip to another unused socket.

- A click on a Material Node will activate it, and show all its settings
  in the Material Buttons. Active Material Nodes draw the material icon
  in red.

- A click on any node will show its options in the Node Panel in the
  Material buttons.

- Multiple Output Nodes can be used, to sample contents of a tree, but
  only one Output is the real one, which is indicated in a different
  color and red material icon.

- Added ThemeColors for node types

- ALT+C will convert existing Material-Layers to Node... this currently
  only adds the material/mix nodes and connects them. Dunno if this is
  worth a lot of coding work to make perfect?

- Press C to call another "Solve order", which will show all possible
  cyclic conflicts (if there are).

- Technical: nodes now use "Type" structs which define the
  structure of nodes and in/output sockets. The Type structs store all
  fixed info, callbacks, and allow to reconstruct saved Nodes to match
  what is required by Blender.

- Defining (new) nodes now is as simple as filling in a fixed
  Type struct, plus code some callbacks. A doc will be made!

- Node preview images are by default float

********* Icon drawing:

- Cleanup of how old icons were implemented in new system, making
  them 16x16 too, correctly centered *and* scaled.

- Made drawing Icons use float coordinates

- Moved BIF_calcpreview_image() into interface_icons.c, renamed it
  icon_from_image(). Removed a lot of unneeded Imbuf magic here! :)

- Skipped scaling and imbuf copying when icons are OK size


********* Preview render:

- Huge cleanup of code....

- renaming BIF_xxx calls that only were used internally

- BIF_previewrender() now accepts an argument for rendering method,
  so it supports icons, buttonwindow previewrender and node editor

- Only a single BIF_preview_changed() call now exists, supporting all
  signals as needed for buttos and node editor


********* More stuff:

- glutil.c, glaDrawPixelsSafe() and glaDrawPixelsTex() now accept format
  argument for GL_FLOAT rects

- Made the ColorBand become a built-in button for interface.c
  Was a load of cleanup work in buttons_shading.c...

- removed a load of unneeded glBlendFunc() calls

- Fixed bug in calculating text length for buttons (ancient!)

source/blender/blenkernel/BKE_node.h

@@ -37,40 +37,113 @@ struct bNodeTree;
 struct bNode;
 struct bNodeLink;
 struct bNodeSocket;
+struct bNodeStack;
+struct uiBlock;
+struct rctf;
 struct ListBase;
 
 #define SOCK_IN		1
 #define SOCK_OUT	2
 
+/* ************** NODE TYPE DEFINITIONS ***** */
 
-/* ************** GENERIC API *************** */
+typedef struct bNodeSocketType {
+	int type, limit;
+	char *name;
+	float val1, val2, val3, val4;	/* default alloc value for inputs */
+	float min, max;					/* default range for inputs */
+	
+	/* after this line is used internal only */
+	struct bNodeSocket *sock;		/* to verify */
+	
+} bNodeSocketType;
 
+typedef struct bNodeType {
+	int type;
+	char *name;
+	float width, minwidth, maxwidth;
+	short nclass, flag;
+	
+	bNodeSocketType *inputs, *outputs;
+	
+	char storagename[64];			/* struct name for DNA */
+	
+	void (*execfunc)(void *data, struct bNode *, struct bNodeStack **, struct bNodeStack **);
+	
+	/* after this line is set on startup of blender */
+	int (*butfunc)(struct uiBlock *, struct bNode *, rctf *);
+
+} bNodeType;
+
+/* nodetype->nclass, also for themes */
+#define NODE_CLASS_INPUT		0
+#define NODE_CLASS_OUTPUT		1
+#define NODE_CLASS_GENERATOR	2
+#define NODE_CLASS_OPERATOR		3
+
+/* ************** GENERIC API, TREES *************** */
+
+struct bNodeTree *ntreeAddTree(int type);
+void			ntreeInitTypes(struct bNodeTree *ntree);
+void			ntreeFreeTree(struct bNodeTree *ntree);
+struct bNodeTree *ntreeCopyTree(struct bNodeTree *ntree, int internal_select);
+
+void			ntreeSolveOrder(struct bNodeTree *ntree);
+
+void			ntreeBeginExecTree(struct bNodeTree *ntree, int xsize, int ysize);
+void			ntreeExecTree(struct bNodeTree *ntree);
+void			ntreeEndExecTree(struct bNodeTree *ntree);
+void			ntreeClearPixelTree(struct bNodeTree *, int, int);
+
+/* ************** GENERIC API, NODES *************** */
+
+void			nodeAddToPreview(struct bNode *, float *, int, int);
+
+struct bNode	*nodeAddNodeType(struct bNodeTree *ntree, int type);
 void			nodeFreeNode(struct bNodeTree *ntree, struct bNode *node);
-void			nodeFreeTree(struct bNodeTree *ntree);
-
-struct bNode	*nodeAddNode(struct bNodeTree *ntree, char *name);
-struct bNodeLink *nodeAddLink(struct bNodeTree *ntree, struct bNode *fromnode, struct bNodeSocket *fromsock, struct bNode *tonode, struct bNodeSocket *tosock);
 struct bNode	*nodeCopyNode(struct bNodeTree *ntree, struct bNode *node);
 
-struct bNodeSocket *nodeAddSocket(struct bNode *node, int type, int where, int limit, char *name);
+struct bNodeLink *nodeAddLink(struct bNodeTree *ntree, struct bNode *fromnode, struct bNodeSocket *fromsock, struct bNode *tonode, struct bNodeSocket *tosock);
+void			nodeRemLink(struct bNodeTree *ntree, struct bNodeLink *link);
 
 struct bNodeLink *nodeFindLink(struct bNodeTree *ntree, struct bNodeSocket *from, struct bNodeSocket *to);
 int				nodeCountSocketLinks(struct bNodeTree *ntree, struct bNodeSocket *sock);
-
-void			nodeSolveOrder(struct bNodeTree *ntree);
-void			nodeExecTree(struct bNodeTree *ntree);
+struct bNode	*nodeGetActive(struct bNodeTree *ntree);
+struct bNode	*nodeGetActiveID(struct bNodeTree *ntree, short idtype);
 
 /* ************** SHADER NODES *************** */
 
-/* types are needed to restore callbacks */
-#define SH_NODE_TEST		0
-#define SH_NODE_RGB			1
-#define SH_NODE_VALUE		2
-#define SH_NODE_MIX_RGB		3
-#define SH_NODE_SHOW_RGB	4
+struct ShadeInput;
+struct ShadeResult;
 
-struct bNode	*node_shader_add(struct bNodeTree *ntree, int type);
-void			node_shader_set_execfunc(struct bNode *node);
+/* note: types are needed to restore callbacks, don't change values */
+#define SH_NODE_INPUT		0
+#define SH_NODE_OUTPUT		1
+
+#define SH_NODE_MATERIAL	100
+#define SH_NODE_RGB			101
+#define SH_NODE_VALUE		102
+#define SH_NODE_MIX_RGB		103
+#define SH_NODE_VALTORGB	104
+#define SH_NODE_RGBTOBW		105
+#define SH_NODE_TEXTURE		106
+
+/* custom defines: options for Material node */
+#define SH_NODE_MAT_DIFF	1
+#define SH_NODE_MAT_SPEC	2
+#define SH_NODE_MAT_NEG		4
+
+/* the type definitions array */
+extern bNodeType *node_all_shaders[];
+
+/* API */
+struct bNode	*nodeShaderAdd(struct bNodeTree *ntree, int type);
+void			nodeShaderSetExecfunc(struct bNode *node);
+
+void			ntreeShaderExecTree(struct bNodeTree *ntree, struct ShadeInput *shi, struct ShadeResult *shr);
+
+				/* switch material render loop */
+void			set_node_shader_lamp_loop(void (*lamp_loop_func)(struct ShadeInput *, struct ShadeResult *));
 
 #endif