+/**
+ * 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(struct gl_context *ctx, GLenum mode, const char *name)
+{
+ bool valid_enum;
+
+ switch (mode) {
+ case GL_POINTS:
+ case GL_LINES:
+ case GL_LINE_LOOP:
+ case GL_LINE_STRIP:
+ case GL_TRIANGLES:
+ case GL_TRIANGLE_STRIP:
+ case GL_TRIANGLE_FAN:
+ valid_enum = true;
+ break;
+ case GL_QUADS:
+ case GL_QUAD_STRIP:
+ case GL_POLYGON:
+ valid_enum = (ctx->API == API_OPENGL);
+ break;
+ case GL_LINES_ADJACENCY:
+ case GL_LINE_STRIP_ADJACENCY:
+ case GL_TRIANGLES_ADJACENCY:
+ case GL_TRIANGLE_STRIP_ADJACENCY:
+ valid_enum = _mesa_is_desktop_gl(ctx)
+ && ctx->Extensions.ARB_geometry_shader4;
+ break;
+ default:
+ valid_enum = false;
+ break;
+ }
+
+ if (!valid_enum) {
+ _mesa_error(ctx, GL_INVALID_ENUM, "%s(mode=%x)", name, mode);
+ return GL_FALSE;
+ }
+
+ /* From the GL_EXT_transform_feedback spec:
+ *
+ * "The error INVALID_OPERATION is generated if Begin, or any command
+ * that performs an explicit Begin, is called when:
+ *
+ * * a geometry shader is not active and <mode> does not match the
+ * allowed begin modes for the current transform feedback state as
+ * given by table X.1.
+ *
+ * * a geometry shader is active and the output primitive type of the
+ * geometry shader does not match the allowed begin modes for the
+ * current transform feedback state as given by table X.1.
+ *
+ */
+ if (ctx->TransformFeedback.CurrentObject->Active &&
+ !ctx->TransformFeedback.CurrentObject->Paused) {
+ GLboolean pass = GL_TRUE;
+
+ switch (mode) {
+ case GL_POINTS:
+ pass = ctx->TransformFeedback.Mode == GL_POINTS;
+ break;
+ case GL_LINES:
+ case GL_LINE_STRIP:
+ case GL_LINE_LOOP:
+ pass = ctx->TransformFeedback.Mode == GL_LINES;
+ break;
+ default:
+ pass = ctx->TransformFeedback.Mode == GL_TRIANGLES;
+ break;
+ }
+ if (!pass) {
+ _mesa_error(ctx, GL_INVALID_OPERATION,
+ "%s(mode=%s vs transform feedback %s)",
+ name,
+ _mesa_lookup_prim_by_nr(mode),
+ _mesa_lookup_prim_by_nr(ctx->TransformFeedback.Mode));
+ return GL_FALSE;
+ }
+ }
+
+ return GL_TRUE;
+}
+
+/**
+ * Verify that the element type is valid.
+ *
+ * Generates \c GL_INVALID_ENUM and returns \c false if it is not.
+ */
+static bool
+valid_elements_type(struct gl_context *ctx, GLenum type, const char *name)
+{
+ switch (type) {
+ case GL_UNSIGNED_BYTE:
+ case GL_UNSIGNED_SHORT:
+ case GL_UNSIGNED_INT:
+ return true;
+
+ default:
+ _mesa_error(ctx, GL_INVALID_ENUM, "%s(type = %s)", name,
+ _mesa_lookup_enum_by_nr(type));
+ return false;
+ }
+}
+