Initial revision

1 files changed, 163 insertions, 0 deletions

diff --git a/xc/lib/GL/mesa/src/alpha.c b/xc/lib/GL/mesa/src/alpha.c
new file mode 100644
index 000000000..e03610223
--- /dev/null
+++ b/xc/lib/GL/mesa/src/alpha.c
@@ -0,0 +1,163 @@
+/* Id: alpha.c,v 1.3 1999/02/26 08:52:30 martin Exp $ */
+
+/*
+ * Mesa 3-D graphics library
+ * Version:  3.1
+ * 
+ * Copyright (C) 1999  Brian Paul   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, sublicense,
+ * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL 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.
+ */
+/* $XFree86: xc/lib/GL/mesa/src/alpha.c,v 1.2 1999/04/04 00:20:18 dawes Exp $ */
+
+/*
+ * Log: alpha.c,v $
+ * Revision 1.3  1999/02/26 08:52:30  martin
+ * Updated Mesa to the official version checked into the Mesa cvs archive
+ * Cleaned up the XMesa interface
+ * Fixed support for standalone Mesa
+ * Removed several unused files in the lib/GL/mesa/src subdirectory
+ * Moved glcore.h back to include/GL/internal/glcore.h
+ *
+ * Revision 3.6  1999/02/24 22:48:04  jens
+ * Added header file to get XMesa to compile standalone and inside XFree86
+ *
+ * Revision 3.5  1999/02/14 03:46:34  brianp
+ * new copyright
+ *
+ * Revision 3.4  1998/11/17 02:51:35  brianp
+ * added a bunch of new device driver functions (Keith Harrison)
+ *
+ * Revision 3.3  1998/07/29 04:02:30  brianp
+ * fixed rounding error in computing integer alpha reference value
+ *
+ * Revision 3.2  1998/03/28 03:57:13  brianp
+ * added CONST macro to fix IRIX compilation problems
+ *
+ * Revision 3.1  1998/02/13 03:23:04  brianp
+ * AlphaRef is now a GLubyte
+ *
+ * Revision 3.0  1998/01/31 20:44:19  brianp
+ * initial rev
+ *
+ */
+
+
+#ifdef PC_HEADER
+#include "all.h"
+#else
+#ifdef XFree86Server
+#include "GL/xf86glx.h"
+#endif
+#include "alpha.h"
+#include "context.h"
+#include "types.h"
+#include "macros.h"
+#endif
+
+
+
+void gl_AlphaFunc( GLcontext* ctx, GLenum func, GLclampf ref )
+{
+   if (INSIDE_BEGIN_END(ctx)) {
+      gl_error( ctx, GL_INVALID_OPERATION, "glAlphaFunc" );
+      return;
+   }
+   switch (func) {
+      case GL_NEVER:
+      case GL_LESS:
+      case GL_EQUAL:
+      case GL_LEQUAL:
+      case GL_GREATER:
+      case GL_NOTEQUAL:
+      case GL_GEQUAL:
+      case GL_ALWAYS:
+         ctx->Color.AlphaFunc = func;
+         ctx->Color.AlphaRef = (GLubyte) (CLAMP(ref, 0.0F, 1.0F) * 255.0F + 0.5F);
+         if (ctx->Driver.AlphaFunc) {
+            (*ctx->Driver.AlphaFunc)(ctx, func, ctx->Color.AlphaRef);
+         }
+         break;
+      default:
+         gl_error( ctx, GL_INVALID_ENUM, "glAlphaFunc(func)" );
+         break;
+   }
+}
+
+
+
+
+/*
+ * Apply the alpha test to a span of pixels.
+ * In:  rgba - array of pixels
+ * In/Out:  mask - current pixel mask.  Pixels which fail the alpha test
+ *                 will set the corresponding mask flag to 0.
+ * Return:  0 = all pixels in the span failed the alpha test.
+ *          1 = one or more pixels passed the alpha test.
+ */
+GLint gl_alpha_test( const GLcontext* ctx,
+                     GLuint n, CONST GLubyte rgba[][4], GLubyte mask[] )
+{
+   GLuint i;
+   GLubyte ref = ctx->Color.AlphaRef;
+
+   /* switch cases ordered from most frequent to less frequent */
+   switch (ctx->Color.AlphaFunc) {
+      case GL_LESS:
+         for (i=0;i<n;i++) {
+	    mask[i] &= (rgba[i][ACOMP] < ref);
+	 }
+	 return 1;
+      case GL_LEQUAL:
+         for (i=0;i<n;i++) {
+	    mask[i] &= (rgba[i][ACOMP] <= ref);
+	 }
+	 return 1;
+      case GL_GEQUAL:
+         for (i=0;i<n;i++) {
+	    mask[i] &= (rgba[i][ACOMP] >= ref);
+	 }
+	 return 1;
+      case GL_GREATER:
+         for (i=0;i<n;i++) {
+	    mask[i] &= (rgba[i][ACOMP] > ref);
+	 }
+	 return 1;
+      case GL_NOTEQUAL:
+         for (i=0;i<n;i++) {
+	    mask[i] &= (rgba[i][ACOMP] != ref);
+	 }
+	 return 1;
+      case GL_EQUAL:
+         for (i=0;i<n;i++) {
+	    mask[i] &= (rgba[i][ACOMP] == ref);
+	 }
+	 return 1;
+      case GL_ALWAYS:
+	 /* do nothing */
+	 return 1;
+      case GL_NEVER:
+         /* caller should check for zero! */
+	 return 0;
+      default:
+	 gl_problem( ctx, "Invalid alpha test in gl_alpha_test" );
+         return 0;
+   }
+   /* Never get here */
+   /*return 1;*/
+}