Add option to mjspec for creating a texture directly from a buffer.

PiperOrigin-RevId: 662186527
Change-Id: I469c876681d52964ac971c0bb2ec3517224d3a3d

include/mujoco/mjspec.h

@@ -22,6 +22,7 @@
 
 // this is a C-API
 #ifdef __cplusplus
+#include <cstddef>
 #include <string>
 #include <vector>
 
@@ -32,6 +33,7 @@ extern "C" {
 
 #ifdef __cplusplus
   // C++: defined to be compatible with corresponding std types
+  using mjBuffer      = std::vector<std::byte>;
   using mjString      = std::string;
   using mjStringVec   = std::vector<std::string>;
   using mjIntVec      = std::vector<int>;
@@ -41,6 +43,7 @@ extern "C" {
   using mjDoubleVec   = std::vector<double>;
 #else
   // C: opaque types
+  typedef void mjBuffer;
   typedef void mjString;
   typedef void mjStringVec;
   typedef void mjIntVec;
@@ -511,6 +514,9 @@ typedef struct mjsTexture_ {       // texture specification
   // method 3: separate files
   mjStringVec* cubefiles;          // different file for each side of the cube
 
+  // method 4: from buffer read by user
+  mjBuffer* data;                  // texture data
+
   // flip options
   mjtByte hflip;                   // horizontal flip
   mjtByte vflip;                   // vertical flip

include/mujoco/mujoco.h

@@ -1629,6 +1629,9 @@ MJAPI mjsMaterial* mjs_asMaterial(mjsElement* element);
 
 //---------------------------------- Attribute setters ---------------------------------------------
 
+// Copy buffer.
+MJAPI void mjs_setBuffer(mjBuffer* dest, const void* array, int size);
+
 // Copy text to string.
 MJAPI void mjs_setString(mjString* dest, const char* text);