Working around vertex array problem

panda/src/glstuff/glGraphicsStateGuardian_src.I

@@ -102,6 +102,16 @@ get_gl_renderer() const {
   return _gl_renderer;
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: CLP(GraphicsStateGuardian)::get_gl_version
+//       Access: Public
+//  Description: Returns the GL version string reported by the driver.
+////////////////////////////////////////////////////////////////////
+INLINE const string &CLP(GraphicsStateGuardian)::
+get_gl_version() const {
+  return _gl_version;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: CLP(GraphicsStateGuardian)::get_gl_version_major
 //       Access: Public

panda/src/glstuff/glGraphicsStateGuardian_src.cxx

@@ -571,6 +571,17 @@ reset() {
 
   _supports_multitexture = false;
 
+  _supports_vertex_arrays = true;
+  if (_gl_version == "1.2 (1.5 Mesa 6.4.2)") {
+    // We suspect this particular version of Mesa, which appears to
+    // be installed by default on every Linux implementation, has
+    // real problems rendering with vertex arrays.  Therefore,
+    // disable vertex arrays by default.
+    GLCAT.debug()
+      << "Buggy Mesa version detected; vertex array support is doubted.\n";
+    _supports_vertex_arrays = false;
+  }
+
   _supports_tex_non_pow2 =
     has_extension("GL_ARB_texture_non_power_of_two");
 
@@ -1702,6 +1713,9 @@ begin_draw_primitives(const GeomPipelineReader *geom_reader,
   // extra vertex arrays used by the previous rendering mode.
 #ifdef SUPPORT_IMMEDIATE_MODE
   _use_sender = !vertex_arrays;
+  if (!_supports_vertex_arrays) {
+    _use_sender = true;
+  }
 #endif
   if (_vertex_array_shader_context==0) {
     if (_current_shader_context==0) {
@@ -4325,6 +4339,7 @@ void CLP(GraphicsStateGuardian)::
 query_gl_version() {
   _gl_vendor = show_gl_string("GL_VENDOR", GL_VENDOR);
   _gl_renderer = show_gl_string("GL_RENDERER", GL_RENDERER);
+  _gl_version = show_gl_string("GL_VERSION", GL_VERSION);
 
   _gl_version_major = 0;
   _gl_version_minor = 0;
@@ -4361,18 +4376,6 @@ query_gl_version() {
         << _gl_version_major << "." << _gl_version_minor
         << "." << _gl_version_release << "\n";
     }
-
-    if (version == "1.2 (1.5 Mesa 6.4.2)") {
-      // We suspect this particular version of Mesa, which appears to
-      // be installed by default on every Linux implementation, has
-      // real problems rendering with vertex arrays.  Therefore,
-      // disable vertex arrays by default.
-      GLCAT.debug()
-        << "Buggy Mesa version detected; vertex array support is doubted.\n";
-      if (!vertex_arrays.has_value()) {
-        load_prc_file_data("mesa-hack", "vertex-arrays 0");
-      }
-    }
   }
 }
 

panda/src/glstuff/glGraphicsStateGuardian_src.h

@@ -195,6 +195,7 @@ public:
 
   INLINE const string &get_gl_vendor() const;
   INLINE const string &get_gl_renderer() const;
+  INLINE const string &get_gl_version() const;
   INLINE int get_gl_version_major() const;
   INLINE int get_gl_version_minor() const;
   INLINE int get_gl_version_release() const;
@@ -386,6 +387,7 @@ protected:
 
   string _gl_vendor;
   string _gl_renderer;
+  string _gl_version;
   int _gl_version_major, _gl_version_minor, _gl_version_release;
   pset<string> _extensions;
 
@@ -421,7 +423,8 @@ public:
 
   bool _supports_bgr;
   bool _supports_rescale_normal;
-
+  bool _supports_vertex_arrays;
+  
   bool _supports_multitexture;
   PFNGLACTIVETEXTUREPROC _glActiveTexture;
   PFNGLCLIENTACTIVETEXTUREPROC _glClientActiveTexture;