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 */
35void 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 */
66void
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 */
91void
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}
101