util: new funcs for triming/validating primitives

diff --git a/src/gallium/auxiliary/util/u_prim.h b/src/gallium/auxiliary/util/u_prim.h
new file mode 100644 (file)
index 0000000..e45e84d
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_prim.h
@@ -0,0 +1,122 @@
+/**************************************************************************
+ *
+ * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+
+#ifndef U_BLIT_H
+#define U_BLIT_H
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "pipe/p_defines.h"
+
+static INLINE boolean u_validate_pipe_prim( unsigned pipe_prim, unsigned nr )
+{
+   boolean ok = TRUE;
+
+   switch (pipe_prim) {
+   case PIPE_PRIM_POINTS:
+      ok = (nr >= 1);
+      break;
+   case PIPE_PRIM_LINES:
+      ok = (nr >= 2);
+      break;
+   case PIPE_PRIM_LINE_STRIP:
+   case PIPE_PRIM_LINE_LOOP:
+      ok = (nr >= 2);
+      break;
+   case PIPE_PRIM_TRIANGLES:
+      ok = (nr >= 3);
+      break;
+   case PIPE_PRIM_TRIANGLE_STRIP:
+   case PIPE_PRIM_TRIANGLE_FAN:
+   case PIPE_PRIM_POLYGON:
+      ok = (nr >= 3);
+      break;
+   case PIPE_PRIM_QUADS:
+      ok = (nr >= 4);
+      break;
+   case PIPE_PRIM_QUAD_STRIP:
+      ok = (nr >= 4);
+      break;
+   default:
+      ok = 0;
+      break;
+   }
+
+   return ok;
+}
+
+
+static INLINE boolean u_trim_pipe_prim( unsigned pipe_prim, unsigned *nr )
+{
+   boolean ok = TRUE;
+
+   switch (pipe_prim) {
+   case PIPE_PRIM_POINTS:
+      ok = (*nr >= 1);
+      break;
+   case PIPE_PRIM_LINES:
+      ok = (*nr >= 2);
+      *nr -= (*nr % 2);
+      break;
+   case PIPE_PRIM_LINE_STRIP:
+   case PIPE_PRIM_LINE_LOOP:
+      ok = (*nr >= 2);
+      break;
+   case PIPE_PRIM_TRIANGLES:
+      ok = (*nr >= 3);
+      *nr -= (*nr % 3);
+      break;
+   case PIPE_PRIM_TRIANGLE_STRIP:
+   case PIPE_PRIM_TRIANGLE_FAN:
+   case PIPE_PRIM_POLYGON:
+      ok = (*nr >= 3);
+      break;
+   case PIPE_PRIM_QUADS:
+      ok = (*nr >= 4);
+      *nr -= (*nr % 4);
+      break;
+   case PIPE_PRIM_QUAD_STRIP:
+      ok = (*nr >= 4);
+      *nr -= (*nr % 2);
+      break;
+   default:
+      ok = 0;
+      break;
+   }
+
+   if (!ok)
+      *nr = 0;
+
+   return ok;
+}
+
+
+#endif