reactos/dll/opengl/mesa/main/scissor.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2007  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
  26 #include "main/glheader.h"
  27 #include "main/context.h"
  28 #include "main/mtypes.h"
  29 #include "main/scissor.h"
  30
  31
  32 /**
  33  * Called via glScissor
  34  */
  35 void GLAPIENTRY
  36 _mesa_Scissor( GLint x, GLint y, GLsizei width, GLsizei height )
  37 {
  38    GET_CURRENT_CONTEXT(ctx);
  39    ASSERT_OUTSIDE_BEGIN_END(ctx);
  40
  41    if (MESA_VERBOSE & VERBOSE_API)
  42       _mesa_debug(ctx, "glScissor %d %d %d %d\n", x, y, width, height);
  43
  44    if (width < 0 || height < 0) {
  45       _mesa_error( ctx, GL_INVALID_VALUE, "glScissor" );
  46       return;
  47    }
  48
  49    _mesa_set_scissor(ctx, x, y, width, height);
  50 }
  51
  52
  53 /**
  54  * Define the scissor box.
  55  *
  56  * \param x, y coordinates of the scissor box lower-left corner.
  57  * \param width width of the scissor box.
  58  * \param height height of the scissor box.
  59  *
  60  * \sa glScissor().
  61  *
  62  * Verifies the parameters and updates __struct gl_contextRec::Scissor. On a
  63  * change flushes the vertices and notifies the driver via
  64  * the dd_function_table::Scissor callback.
  65  */
  66 void
  67 _mesa_set_scissor(struct gl_context *ctx,
  68                   GLint x, GLint y, GLsizei width, GLsizei height)
  69 {
  70    if (x == ctx->Scissor.X &&
  71        y == ctx->Scissor.Y &&
  72        width == ctx->Scissor.Width &&
  73        height == ctx->Scissor.Height)
  74       return;
  75
  76    FLUSH_VERTICES(ctx, _NEW_SCISSOR);
  77    ctx->Scissor.X = x;
  78    ctx->Scissor.Y = y;
  79    ctx->Scissor.Width = width;
  80    ctx->Scissor.Height = height;
  81
  82    if (ctx->Driver.Scissor)
  83       ctx->Driver.Scissor( ctx, x, y, width, height );
  84 }
  85
  86
  87 /**
  88  * Initialize the context's scissor state.
  89  * \param ctx  the GL context.
  90  */
  91 void
  92 _mesa_init_scissor(struct gl_context *ctx)
  93 {
  94    /* Scissor group */
  95    ctx->Scissor.Enabled = GL_FALSE;
  96    ctx->Scissor.X = 0;
  97    ctx->Scissor.Y = 0;
  98    ctx->Scissor.Width = 0;
  99    ctx->Scissor.Height = 0;
 100 }