src/mesa/main/accum.c

   1 /* $Id: accum.c,v 1.39 2002/10/24 23:57:19 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  4.1
   6  *
   7  * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27 #include "glheader.h"
  28 #include "accum.h"
  29 #include "context.h"
  30 #include "imports.h"
  31 #include "macros.h"
  32 #include "state.h"
  33 #include "mtypes.h"
  34
  35
  36 void
  37 _mesa_ClearAccum( GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha )
  38 {
  39    GLfloat tmp[4];
  40    GET_CURRENT_CONTEXT(ctx);
  41    ASSERT_OUTSIDE_BEGIN_END(ctx);
  42
  43    tmp[0] = CLAMP( red,   -1.0F, 1.0F );
  44    tmp[1] = CLAMP( green, -1.0F, 1.0F );
  45    tmp[2] = CLAMP( blue,  -1.0F, 1.0F );
  46    tmp[3] = CLAMP( alpha, -1.0F, 1.0F );
  47
  48    if (TEST_EQ_4V(tmp, ctx->Accum.ClearColor))
  49       return;
  50
  51    FLUSH_VERTICES(ctx, _NEW_ACCUM);
  52    COPY_4FV( ctx->Accum.ClearColor, tmp );
  53 }
  54
  55 /* Should really be a driver-supplied function?
  56  */
  57 void
  58 _mesa_Accum( GLenum op, GLfloat value )
  59 {
  60    GET_CURRENT_CONTEXT(ctx);
  61    GLuint xpos, ypos, width, height;
  62    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
  63
  64    if (ctx->Visual.accumRedBits == 0 || ctx->DrawBuffer != ctx->ReadBuffer) {
  65       _mesa_error(ctx, GL_INVALID_OPERATION, "glAccum");
  66       return;
  67    }
  68
  69    if (ctx->NewState)
  70       _mesa_update_state( ctx );
  71
  72    /* Determine region to operate upon. */
  73    if (ctx->Scissor.Enabled) {
  74       xpos = ctx->Scissor.X;
  75       ypos = ctx->Scissor.Y;
  76       width = ctx->Scissor.Width;
  77       height = ctx->Scissor.Height;
  78    }
  79    else {
  80       /* whole window */
  81       xpos = 0;
  82       ypos = 0;
  83       width = ctx->DrawBuffer->Width;
  84       height = ctx->DrawBuffer->Height;
  85    }
  86
  87    ctx->Driver.Accum( ctx, op, value, xpos, ypos, width, height );
  88 }