src/mesa/main/accum.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  *
   5  * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 #include "glheader.h"
  26 #include "accum.h"
  27 #include "context.h"
  28 #include "imports.h"
  29 #include "macros.h"
  30 #include "state.h"
  31 #include "mtypes.h"
  32
  33
  34 void GLAPIENTRY
  35 _mesa_ClearAccum( GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha )
  36 {
  37    GLfloat tmp[4];
  38    GET_CURRENT_CONTEXT(ctx);
  39    ASSERT_OUTSIDE_BEGIN_END(ctx);
  40
  41    tmp[0] = CLAMP( red,   -1.0F, 1.0F );
  42    tmp[1] = CLAMP( green, -1.0F, 1.0F );
  43    tmp[2] = CLAMP( blue,  -1.0F, 1.0F );
  44    tmp[3] = CLAMP( alpha, -1.0F, 1.0F );
  45
  46    if (TEST_EQ_4V(tmp, ctx->Accum.ClearColor))
  47       return;
  48
  49    FLUSH_VERTICES(ctx, _NEW_ACCUM);
  50    COPY_4FV( ctx->Accum.ClearColor, tmp );
  51 }
  52
  53
  54 void GLAPIENTRY
  55 _mesa_Accum( GLenum op, GLfloat value )
  56 {
  57    GET_CURRENT_CONTEXT(ctx);
  58    GLuint xpos, ypos, width, height;
  59    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
  60
  61    if (ctx->Visual.accumRedBits == 0 || ctx->DrawBuffer != ctx->ReadBuffer) {
  62       _mesa_error(ctx, GL_INVALID_OPERATION, "glAccum");
  63       return;
  64    }
  65
  66    switch (op) {
  67    case GL_ADD:
  68    case GL_MULT:
  69    case GL_ACCUM:
  70    case GL_LOAD:
  71    case GL_RETURN:
  72       /* OK */
  73       break;
  74    default:
  75       _mesa_error(ctx, GL_INVALID_ENUM, "glAccum(op)");
  76       return;
  77    }
  78
  79    if (ctx->DrawBuffer != ctx->ReadBuffer) {
  80       /* See GLX_SGI_make_current_read or WGL_ARB_make_current_read */
  81       _mesa_error(ctx, GL_INVALID_OPERATION,
  82                   "glAccum(different read/draw buffers)");
  83       return;
  84    }
  85
  86    if (ctx->NewState)
  87       _mesa_update_state( ctx );
  88
  89    if (ctx->RenderMode != GL_RENDER) {
  90       /* no-op */
  91       return;
  92    }
  93
  94    /* Determine region to operate upon. */
  95    if (ctx->Scissor.Enabled) {
  96       xpos = ctx->Scissor.X;
  97       ypos = ctx->Scissor.Y;
  98       width = ctx->Scissor.Width;
  99       height = ctx->Scissor.Height;
 100    }
 101    else {
 102       /* whole window */
 103       xpos = 0;
 104       ypos = 0;
 105       width = ctx->DrawBuffer->Width;
 106       height = ctx->DrawBuffer->Height;
 107    }
 108
 109    ctx->Driver.Accum( ctx, op, value, xpos, ypos, width, height );
 110 }
 111
 112
 113
 114 void
 115 _mesa_init_accum( GLcontext *ctx )
 116 {
 117    /* Accumulate buffer group */
 118    ASSIGN_4V( ctx->Accum.ClearColor, 0.0, 0.0, 0.0, 0.0 );
 119 }