Graph Editor: F-Curve Colouring

Now F-Curve channels in channels region are drawn with the same colour as their respective curve is drawn in the curves area. I've had to make a compromise to store such colour info in F-Curves themselves, which is not terribly ideal if the F-Curve gets reused in some way. However, for now, this will do (special tweaks can be made to make this work better though).

I've also added a colour-determination mode per curve which should in future allow more control over this. By default, all curves still use the old 'rainbow' style. The available types area:
* Old Rainbow - Colour is determined 'automatically' using a magic method which uses curve position + total curves to generate a colour.
* Auto RGB - Color is determined using the 'array index' stored in F-Curve for data-access. An unresolved issue with this is that all the curves with this will end up with exactly the same colour, leading to confusion (i.e. all location.x and scale.x properties could potentially all be the same red colour).
* Custom colour - self explanatory

Currently, there's a minor bug when loading old files where the colours don't get initialised yet. For now, just clicking in the Graph Editor after file-load will solve any of these problems.
Ton: it looks like area->refresh() isn't getting called after file read.

1 files changed, 73 insertions, 0 deletions

diff --git a/source/blender/editors/space_graph/space_graph.c b/source/blender/editors/space_graph/space_graph.c
index 7651dd37538..50c8bcaa1ea 100644
--- a/source/blender/editors/space_graph/space_graph.c
+++ b/source/blender/editors/space_graph/space_graph.c
@@ -43,6 +43,7 @@
 
 #include "BKE_context.h"
 #include "BKE_screen.h"
+#include "BKE_utildefines.h"
 
 #include "ED_space_api.h"
 #include "ED_screen.h"
@@ -343,9 +344,12 @@ static void graph_listener(ScrArea *sa, wmNotifier *wmn)
 	}
 }
 
+
+
 static void graph_refresh(const bContext *C, ScrArea *sa)
 {
 	SpaceIpo *sipo = (SpaceIpo *)sa->spacedata.first;
+	bAnimContext ac;
 	
 	/* updates to data needed depends on Graph Editor mode... */
 	switch (sipo->mode) {
@@ -364,6 +368,75 @@ static void graph_refresh(const bContext *C, ScrArea *sa)
 	
 	/* region updates? */
 	// XXX resizing y-extents of tot should go here?
+	
+	/* init/adjust F-Curve colors */
+	if (ANIM_animdata_get_context(C, &ac)) {
+		ListBase anim_data = {NULL, NULL};
+		bAnimListElem *ale;
+		int filter;
+		int items, i;
+		
+		/* build list of F-Curves which will be visible as channels in channel-region
+		 * 	- we don't include ANIMFILTER_CURVEVISIBLE filter, as that will result in a 
+		 * 	  mismatch between channel-colors and the drawn curves
+		 */
+		filter= (ANIMFILTER_VISIBLE|ANIMFILTER_CURVESONLY);
+		items= ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
+		
+		/* loop over F-Curves, assigning colors */
+		for (ale=anim_data.first, i=0; ale; ale= ale->next, i++) {
+			FCurve *fcu= (FCurve *)ale->data;
+			
+			/* set color of curve here */
+			switch (fcu->color_mode) {
+				case FCURVE_COLOR_CUSTOM:
+					/* User has defined a custom color for this curve already (we assume it's not going to cause clashes with text colors),
+					 * which should be left alone... Nothing needs to be done here.
+					 */
+					break;
+					
+				case FCURVE_COLOR_AUTO_RGB:
+				{
+					/* F-Curve's array index is automatically mapped to RGB values. This works best of 3-value vectors. 
+					 * TODO: find a way to module the hue so that not all curves have same color...
+					 */
+					
+					/* standard table of colors to use */
+					const float _colorsets[4][3]= 
+					{
+						{1.0f, 0.0f, 0.0f}, /* red */
+						{0.0f, 1.0f, 0.0f}, /* green */
+						{0.0f, 0.0f, 1.0f}, /* blue */
+						{0.3f, 0.8f, 1.0f}, /* 'unknown' color - bluish so as to not conflict with handles */
+					};
+					
+					/* simply copy the relevant color over to the F-Curve */
+					if ((fcu->array_index >= 0) && (fcu->array_index < 3)) {
+						/* if the index is within safe bounds, use index to access table */
+						VECCOPY(fcu->color, _colorsets[fcu->array_index]);
+					}
+					else {
+						/* use the 'unknown' color... */
+						VECCOPY(fcu->color, _colorsets[3]);
+					}
+				}
+					break;
+				
+				case FCURVE_COLOR_AUTO_RAINBOW:
+				default:
+				{
+					/* determine color 'automatically' using 'magic function' which uses the given args
+					 * of current item index + total items to determine some RGB color
+					 */
+					ipo_rainbow(i, items, fcu->color);
+				}
+					break;
+			}
+		}
+		
+		/* free temp list */
+		BLI_freelistN(&anim_data);
+	}
 }
 
 /* only called once, from space/spacetypes.c */