Support reversed Z rendering and float32 offscreen depth buffer

Combined, both options greatly improve camera depth accuracy compared to
OpenGL default Z mapping and int24 depth buffer.

Requires GL_ARB_clip_control and ARB_depth_buffer_float extensions

introspect/enums.py

@@ -621,6 +621,24 @@ ENUMS: Mapping[str, EnumDecl] = dict([
              ('mjFB_OFFSCREEN', 1),
          ]),
      )),
+    ('mjtDepthMapping',
+     EnumDecl(
+         name='mjtDepthMapping',
+         declname='enum mjtDepthMapping_',
+         values=dict([
+             ('mjDB_NEGONETOONE', 0),
+             ('mjDB_ONETOZERO', 1),
+         ]),
+     )),
+    ('mjtDepthPrecision',
+     EnumDecl(
+         name='mjtDepthPrecision',
+         declname='enum mjtDepthPrecision_',
+         values=dict([
+             ('mjDB_INT24', 0),
+             ('mjDB_FLOAT32', 1),
+         ]),
+     )),
     ('mjtFontScale',
      EnumDecl(
          name='mjtFontScale',

introspect/structs.py

@@ -7126,6 +7126,16 @@ STRUCTS: Mapping[str, StructDecl] = dict([
                  type=ValueType(name='int'),
                  doc='default color pixel format for mjr_readPixels',
              ),
+             StructFieldDecl(
+                 name='depthMapping',
+                 type=ValueType(name='int'),
+                 doc='depth buffer mapping from [znear zfar] to normalized device coordinates: mjDB_NEGONETOONE or mjDB_ONETOZERO',  # pylint: disable=line-too-long
+             ),
+             StructFieldDecl(
+                 name='depthPrecision',
+                 type=ValueType(name='int'),
+                 doc='depth buffer precision: mjDB_INT24 or mjDB_FLOAT32',
+             ),
          ),
      )),
     ('mjuiState',