From 313553b1edb02660361ebc281516fe8b6c122b7f Mon Sep 17 00:00:00 2001
From: Joshua Leung <aligorith@gmail.com>
Date: Thu, 22 Nov 2007 00:58:57 +0000
Subject: [PATCH] == Armature Path Drawing Tweak ==

Peach Request: Bone path lines are now drawn using two colours to show the parts of the path before and after the current frame. Those before the current frame are drawn darker, while those after are drawn in a blue colour.
---
 source/blender/src/drawarmature.c | 43 ++++++++++++++++++++++++-------
 1 file changed, 33 insertions(+), 10 deletions(-)

diff --git a/source/blender/src/drawarmature.c b/source/blender/src/drawarmature.c
index c424a24718b..c907bab5a23 100644
--- a/source/blender/src/drawarmature.c
+++ b/source/blender/src/drawarmature.c
@@ -1737,8 +1737,8 @@ static void draw_pose_paths(Object *ob)
 	CfraElem *ce;
 	ListBase ak;
 	float *fp;
-	int a;
-	int stepsize, sfra;
+	int a, stepsize;
+	int sfra, efra;
 	
 	if(G.vd->zbuf) glDisable(GL_DEPTH_TEST);
 	
@@ -1758,16 +1758,39 @@ static void draw_pose_paths(Object *ob)
 					pchan->pathef= EFRA;
 				}
 				
-				/* get start frame of calculated range */
+				/* get frame ranges */
 				sfra= pchan->pathsf;
+				efra = sfra + pchan->pathlen;
 				
 				/* draw curve-line of path */
-				// TODO: show before/after with slight difference in colour intensity
-				BIF_ThemeColorBlend(TH_WIRE, TH_BACK, 0.7);
-				glBegin(GL_LINE_STRIP);
-				for(a=0, fp= pchan->path; a<pchan->pathlen; a++, fp+=3)
-					glVertex3fv(fp);
-				glEnd();
+				if ((CFRA > sfra) && (CFRA < efra)) {
+					/* Show before/after current frame with slight difference in colour intensity 
+					 * This is done in two loops, as there seems to be some problems with changing color
+					 * or something during a loop (noted somewhere in the codebase)
+					 */
+					
+					/* 	before cfra (darker) */
+					BIF_ThemeColorBlend(TH_WIRE, TH_BACK, 0.2);
+					glBegin(GL_LINE_STRIP);
+					for (a=0, fp=pchan->path; (sfra+a)<=CFRA; a++, fp+=3)
+						glVertex3fv(fp);
+					glEnd();
+					
+					/* after cfra (lighter) - backtrack a bit so that we don't have gaps */
+					BIF_ThemeColorBlend(TH_WIRE, TH_BONE_POSE, 0.7);
+					glBegin(GL_LINE_STRIP);
+					for (--a, fp-=3; a<pchan->pathlen; a++, fp+=3)
+						glVertex3fv(fp);
+					glEnd();
+				}
+				else {
+					/* show both directions with same intensity (cfra somewhere else) */
+					BIF_ThemeColorBlend(TH_WIRE, TH_BACK, 0.7);
+					glBegin(GL_LINE_STRIP);
+					for (a=0, fp= pchan->path; a<pchan->pathlen; a++, fp+=3)
+						glVertex3fv(fp);
+					glEnd();
+				}
 				
 				glPointSize(1.0);
 				
@@ -1791,7 +1814,7 @@ static void draw_pose_paths(Object *ob)
 					for(a=0, fp= pchan->path; a<pchan->pathlen; a+=stepsize, fp+=(stepsize*3)) {
 						char str[32];
 						
-						/* only draw framenum if several consecutive highlighted points occur on same point */
+						/* only draw framenum if several consecutive highlighted points don't occur on same point */
 						if (a == 0) {
 							glRasterPos3fv(fp);
 							sprintf(str, "  %d\n", (a+sfra));