1/**
2 * \file stencil.h
3 * Stencil operations.
4 */
5
6/*
7 * Mesa 3-D graphics library
8 *
9 * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
10 *
11 * Permission is hereby granted, free of charge, to any person obtaining a
12 * copy of this software and associated documentation files (the "Software"),
13 * to deal in the Software without restriction, including without limitation
14 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15 * and/or sell copies of the Software, and to permit persons to whom the
16 * Software is furnished to do so, subject to the following conditions:
17 *
18 * The above copyright notice and this permission notice shall be included
19 * in all copies or substantial portions of the Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
22 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
24 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
25 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
26 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
27 * OTHER DEALINGS IN THE SOFTWARE.
28 */
29
30
31#ifndef STENCIL_H
32#define STENCIL_H
33
34
35#include "glheader.h"
36#include "macros.h"
37
38struct gl_context;
39
40extern void GLAPIENTRY
41_mesa_ClearStencil( GLint s );
42
43
44void GLAPIENTRY
45_mesa_StencilFunc_no_error(GLenum func, GLint ref, GLuint mask);
46
47extern void GLAPIENTRY
48_mesa_StencilFunc(GLenum func, GLint ref, GLuint mask);
49
50
51extern void GLAPIENTRY
52_mesa_StencilMask( GLuint mask );
53
54void GLAPIENTRY
55_mesa_StencilOp_no_error(GLenum fail, GLenum zfail, GLenum zpass);
56
57extern void GLAPIENTRY
58_mesa_StencilOp(GLenum fail, GLenum zfail, GLenum zpass);
59
60
61extern void GLAPIENTRY
62_mesa_ActiveStencilFaceEXT(GLenum face);
63
64void GLAPIENTRY
65_mesa_StencilOpSeparate_no_error(GLenum face, GLenum fail, GLenum zfail,
66                                 GLenum zpass);
67
68extern void GLAPIENTRY
69_mesa_StencilOpSeparate(GLenum face, GLenum fail, GLenum zfail, GLenum zpass);
70
71
72void GLAPIENTRY
73_mesa_StencilFuncSeparate_no_error(GLenum face, GLenum func, GLint ref,
74                                   GLuint mask);
75
76extern void GLAPIENTRY
77_mesa_StencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask);
78
79
80extern void GLAPIENTRY
81_mesa_StencilFuncSeparateATI(GLenum frontfunc, GLenum backfunc, GLint ref, GLuint mask);
82
83void GLAPIENTRY
84_mesa_StencilMaskSeparate_no_error(GLenum face, GLuint mask);
85
86extern void GLAPIENTRY
87_mesa_StencilMaskSeparate(GLenum face, GLuint mask);
88
89extern void
90_mesa_init_stencil( struct gl_context * ctx );
91
92/* From the GL 4.3 spec, 17.3.5:
93 *    "Stencil comparison operations and queries of <ref> clamp its value
94 *    to the range [0, 2^s-1], where <s> is the number of bits in the
95 *    stencil buffer attached to the draw framebuffer."
96 */
97
98static inline GLint
99_mesa_get_stencil_ref(struct gl_context const *ctx, int face)
100{
101   GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
102   GLint ref = ctx->Stencil.Ref[face];
103   return CLAMP(ref, 0, stencilMax);
104}
105
106static inline bool
107_mesa_stencil_is_enabled(const struct gl_context *ctx)
108{
109   return ctx->Stencil.Enabled &&
110          ctx->DrawBuffer->Visual.stencilBits > 0;
111}
112
113static inline bool
114_mesa_stencil_is_two_sided(const struct gl_context *ctx)
115{
116   const int face = ctx->Stencil._BackFace;
117
118   return _mesa_stencil_is_enabled(ctx) &&
119          (ctx->Stencil.Function[0] != ctx->Stencil.Function[face] ||
120           ctx->Stencil.FailFunc[0] != ctx->Stencil.FailFunc[face] ||
121           ctx->Stencil.ZPassFunc[0] != ctx->Stencil.ZPassFunc[face] ||
122           ctx->Stencil.ZFailFunc[0] != ctx->Stencil.ZFailFunc[face] ||
123           ctx->Stencil.Ref[0] != ctx->Stencil.Ref[face] ||
124           ctx->Stencil.ValueMask[0] != ctx->Stencil.ValueMask[face] ||
125           ctx->Stencil.WriteMask[0] != ctx->Stencil.WriteMask[face]);
126}
127
128static inline bool
129_mesa_stencil_is_write_enabled(const struct gl_context *ctx, bool is_two_sided)
130{
131   return _mesa_stencil_is_enabled(ctx) &&
132          (ctx->Stencil.WriteMask[0] != 0 ||
133           (is_two_sided &&
134            ctx->Stencil.WriteMask[ctx->Stencil._BackFace] != 0));
135}
136
137#endif
138