src/mesa/main/accum.c

/* $Id: accum.c,v 1.37 2001/03/12 00:48:37 gareth Exp $ */

/*
 * Mesa 3-D graphics library
 * Version:  3.5
 *
 * Copyright (C) 1999-2001  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.
 */


#ifdef PC_HEADER
#include "all.h"
#else
#include "glheader.h"
#include "accum.h"
#include "context.h"
#include "macros.h"
#include "mem.h"
#include "state.h"
#include "mtypes.h"
#endif




void
_mesa_ClearAccum( GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha )
{
   GLfloat tmp[4];
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END(ctx);

   tmp[0] = CLAMP( red, -1.0, 1.0 );
   tmp[1] = CLAMP( green, -1.0, 1.0 );
   tmp[2] = CLAMP( blue, -1.0, 1.0 );
   tmp[3] = CLAMP( alpha, -1.0, 1.0 );

   if (TEST_EQ_4V(tmp, ctx->Accum.ClearColor))
      return;

   FLUSH_VERTICES(ctx, _NEW_ACCUM);
   COPY_4FV( ctx->Accum.ClearColor, tmp );
}

/* Should really be a driver-supplied function?
 */
void
_mesa_Accum( GLenum op, GLfloat value )
{
   GET_CURRENT_CONTEXT(ctx);
   GLuint xpos, ypos, width, height;
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (ctx->Visual.accumRedBits == 0 || ctx->DrawBuffer != ctx->ReadBuffer) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glAccum");
      return;
   }

   if (ctx->NewState)
      _mesa_update_state( ctx );

   /* Determine region to operate upon. */
   if (ctx->Scissor.Enabled) {
      xpos = ctx->Scissor.X;
      ypos = ctx->Scissor.Y;
      width = ctx->Scissor.Width;
      height = ctx->Scissor.Height;
   }
   else {
      /* whole window */
      xpos = 0;
      ypos = 0;
      width = ctx->DrawBuffer->Width;
      height = ctx->DrawBuffer->Height;
   }

   ctx->Driver.Accum( ctx, op, value, xpos, ypos, width, height );
}