Rendering of mjGEOM_LINE respects size[0] (width argument of mjv_makeconnector), denominated in pixels.

- Before this change, line width was hardcoded to 3 pixels and the width argument of mjv_makeConnector was ignored.
- After this change, the width argument is respected and interpreted in units of pixel. The non-standard width unit is ok since lines can only be drawn programmatically.

PiperOrigin-RevId: 516529265
Change-Id: I27bffabba69cde415d2ada67263a887c9240efbf

src/engine/engine_vis_visualize.c

@@ -14,7 +14,6 @@
 
 #include "engine/engine_vis_visualize.h"
 
-#include <math.h>
 #include <stddef.h>
 #include <string.h>
 
@@ -1591,7 +1590,7 @@ void mjv_addGeoms(const mjModel* m, mjData* d, const mjvOption* vopt,
 
         // make ray
         START
-        mjv_makeConnector(thisgeom, mjGEOM_LINE, .01,
+        mjv_makeConnector(thisgeom, mjGEOM_LINE, 3,
                           d->site_xpos[3*sid],
                           d->site_xpos[3*sid+1],
                           d->site_xpos[3*sid+2],

src/render/render_gl3.c

@@ -390,7 +390,7 @@ static void renderGeom(const mjvGeom* geom, int mode, const float* headpos,
     break;
 
   case mjGEOM_LINE:                           // line
-    glLineWidth(3*con->lineWidth);
+    glLineWidth(size[0]*con->lineWidth);
     lighting = glIsEnabled(GL_LIGHTING);
     glDisable(GL_LIGHTING);
     glBegin(GL_LINES);