If FLAGS_2D_PROJECTION is set, the MVP matrices need updating when changing the viewport.
diff --git a/opengl/libagl/matrix.cpp b/opengl/libagl/matrix.cpp
index 0b68dc0..21ef50e 100644
--- a/opengl/libagl/matrix.cpp
+++ b/opengl/libagl/matrix.cpp
@@ -696,6 +696,8 @@
f[2] = 0; f[6] = 0; f[10] = A; f[14] = B;
f[3] = 0; f[7] = 0; f[11] = 0; f[15] = 1;
c->transforms.dirty |= transform_state_t::VIEWPORT;
+ if (c->transforms.mvp4.flags & transform_t::FLAGS_2D_PROJECTION)
+ c->transforms.dirty |= transform_state_t::MVP;
}
// ----------------------------------------------------------------------------
