mesa: Remove SGI_color_matrix.

[mesa.git] / src / mesa / state_tracker / st_atom_scissor.c

diff --git a/src/mesa/state_tracker/st_atom_scissor.c b/src/mesa/state_tracker/st_atom_scissor.c
index fb666b8546fb75fff71c8345d80438b147029f50..56b1383ae39017ba80affd875393b2a258e73d0b 100644 (file)
--- 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"
@@ -52,27 +53,34 @@ 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)
          scissor.minx = scissor.miny = scissor.maxx = scissor.maxy = 0;
    }
 
-   /* Now invert Y.  Pipe drivers use the convention Y=0=top for surfaces
+   /* Now invert Y if needed.
+    * Gallium drivers use the convention Y=0=top for surfaces.
     */
-   miny = fb->Height - scissor.maxy;
-   maxy = fb->Height - scissor.miny;
-   scissor.miny = miny;
-   scissor.maxy = maxy;
+   if (st_fb_orientation(fb) == Y_0_TOP) {
+      miny = fb->Height - scissor.maxy;
+      maxy = fb->Height - scissor.miny;
+      scissor.miny = miny;
+      scissor.maxy = maxy;
+   }
 
    if (memcmp(&scissor, &st->state.scissor, sizeof(scissor)) != 0) {
       /* state has changed */