+/**
+ * Is 'mode' a valid value for glBegin(), glDrawArrays(), glDrawElements(),
+ * etc? The set of legal values depends on whether geometry shaders/programs
+ * are supported.
+ */
+GLboolean
+_mesa_valid_prim_mode(const struct gl_context *ctx, GLenum mode)
+{
+ if (ctx->Extensions.ARB_geometry_shader4 &&
+ mode > GL_TRIANGLE_STRIP_ADJACENCY_ARB) {
+ return GL_FALSE;
+ }
+ else if (mode > GL_POLYGON) {
+ return GL_FALSE;
+ }
+ else {
+ return GL_TRUE;
+ }
+}
+
+