Specification doesn't define behaviour for rotation of 0-vector. But khronos.org says that vector has to be normalized. As workaround assumed that for 0-vector x-position will be defined as 1.0f.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100960 Signed-off-by: Sergii Romantsov <sergii.romant...@globallogic.com> --- src/mesa/main/matrix.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/mesa/main/matrix.c b/src/mesa/main/matrix.c index 8065a83..631b203 100644 --- a/src/mesa/main/matrix.c +++ b/src/mesa/main/matrix.c @@ -415,6 +415,11 @@ _mesa_Rotatef( GLfloat angle, GLfloat x, GLfloat y, GLfloat z ) FLUSH_VERTICES(ctx, 0); if (angle != 0.0F) { + /* khronos.org says that ||( x,y,z )|| = 1 (if not, the GL will normalize this vector) + * So that is kind of workaround for empty-vectors. + * */ + if (x == 0 && y == 0 && z == 0) + x = 1.0f; _math_matrix_rotate( ctx->CurrentStack->Top, angle, x, y, z); ctx->NewState |= ctx->CurrentStack->DirtyFlag; } -- 2.7.4 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
