From 47d30b0c2c36f952cc14deefb9f937f1b0a9b531 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Sun, 24 Jan 2010 18:18:17 -0700 Subject: st/mesa: fix int->uint conversion for negative scissor bound values Based on a patch by Xavier Chantry : If x+width or y+height is negative, then maxx or maxy will get a bogus value when converting that to unsigned. Fix this by setting 0 as minimal value. This was also triggered by teeworlds, but only with some combination of resolution and map section. For example upper part of dm2 at 1280x1024. --- src/mesa/state_tracker/st_atom_scissor.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'src') diff --git a/src/mesa/state_tracker/st_atom_scissor.c b/src/mesa/state_tracker/st_atom_scissor.c index fb666b8546..5e0c51cff0 100644 --- a/src/mesa/state_tracker/st_atom_scissor.c +++ b/src/mesa/state_tracker/st_atom_scissor.c @@ -31,6 +31,7 @@ */ +#include "main/macros.h" #include "st_context.h" #include "pipe/p_context.h" #include "st_atom.h" @@ -52,15 +53,19 @@ update_scissor( struct st_context *st ) scissor.maxy = fb->Height; if (st->ctx->Scissor.Enabled) { + /* need to be careful here with xmax or ymax < 0 */ + GLint xmax = MAX2(0, st->ctx->Scissor.X + st->ctx->Scissor.Width); + GLint ymax = MAX2(0, st->ctx->Scissor.Y + st->ctx->Scissor.Height); + if (st->ctx->Scissor.X > (GLint)scissor.minx) scissor.minx = st->ctx->Scissor.X; if (st->ctx->Scissor.Y > (GLint)scissor.miny) scissor.miny = st->ctx->Scissor.Y; - if (st->ctx->Scissor.X + st->ctx->Scissor.Width < (GLint)scissor.maxx) - scissor.maxx = st->ctx->Scissor.X + st->ctx->Scissor.Width; - if (st->ctx->Scissor.Y + st->ctx->Scissor.Height < (GLint)scissor.maxy) - scissor.maxy = st->ctx->Scissor.Y + st->ctx->Scissor.Height; + if (xmax < (GLint) scissor.maxx) + scissor.maxx = xmax; + if (ymax < (GLint) scissor.maxy) + scissor.maxy = ymax; /* check for null space */ if (scissor.minx >= scissor.maxx || scissor.miny >= scissor.maxy) -- cgit v1.2.3