From 4c251b88613ae3650a7b9eb255b79a95d0c837a7 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Fri, 21 Jan 2011 17:35:08 -0700 Subject: st/mesa: update comment, use st_fb_orientation() --- src/mesa/state_tracker/st_atom_rasterizer.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/src/mesa/state_tracker/st_atom_rasterizer.c b/src/mesa/state_tracker/st_atom_rasterizer.c index f92ca13d5e4..8bccceeec53 100644 --- a/src/mesa/state_tracker/st_atom_rasterizer.c +++ b/src/mesa/state_tracker/st_atom_rasterizer.c @@ -70,14 +70,16 @@ static void update_raster_state( struct st_context *st ) { raster->front_ccw = (ctx->Polygon.FrontFace == GL_CCW); - /* XXX - * I think the intention here is that user-created framebuffer objects - * use Y=0=TOP layout instead of OpenGL's normal Y=0=bottom layout. - * Flipping Y changes CW to CCW and vice-versa. - * But this is an implementation/driver-specific artifact - remove... + /* + * Gallium's surfaces are Y=0=TOP orientation. OpenGL is the + * opposite. Window system surfaces are Y=0=TOP. Mesa's FBOs + * must match OpenGL conventions so FBOs use Y=0=BOTTOM. In that + * case, we must invert Y and flip the notion of front vs. back. */ - if (ctx->DrawBuffer && ctx->DrawBuffer->Name != 0) + if (st_fb_orientation(ctx->DrawBuffer) == Y_0_BOTTOM) { + /* Drawing to an FBO. The viewport will be inverted. */ raster->front_ccw ^= 1; + } } /* _NEW_LIGHT -- cgit v1.2.3