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

doc/APIreference/functions.rst

@@ -1436,6 +1436,7 @@ mjv_makeConnector
 
 Set (type, size, pos, mat) for connector-type geom between given points.
 Assume that mjv_initGeom was already called to set all other properties.
+Width of mjGEOM_LINE is denominated in pixels.
 
 .. _mjv_defaultScene:
 

include/mujoco/mujoco.h

@@ -587,6 +587,7 @@ MJAPI void mjv_initGeom(mjvGeom* geom, int type, const mjtNum size[3],
 
 // Set (type, size, pos, mat) for connector-type geom between given points.
 // Assume that mjv_initGeom was already called to set all other properties.
+// Width of mjGEOM_LINE is denominated in pixels.
 MJAPI void mjv_makeConnector(mjvGeom* geom, int type, mjtNum width,
                              mjtNum a0, mjtNum a1, mjtNum a2,
                              mjtNum b0, mjtNum b1, mjtNum b2);

introspect/functions.py

@@ -3630,7 +3630,7 @@ FUNCTIONS: Mapping[str, FunctionDecl] = dict([
                  type=ValueType(name='mjtNum'),
              ),
          ),
-         doc='Set (type, size, pos, mat) for connector-type geom between given points. Assume that mjv_initGeom was already called to set all other properties.',  # pylint: disable=line-too-long
+         doc='Set (type, size, pos, mat) for connector-type geom between given points. Assume that mjv_initGeom was already called to set all other properties. Width of mjGEOM_LINE is denominated in pixels.',  # pylint: disable=line-too-long
      )),
     ('mjv_defaultScene',
      FunctionDecl(

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);