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/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',