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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 55 | pj | 1 | /* $Id: clip.c,v 1.1 2003-02-28 11:41:58 pj Exp $ */ |
| 2 | |||
| 3 | /* |
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| 4 | * Mesa 3-D graphics library |
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| 5 | * Version: 3.5 |
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| 6 | * |
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| 7 | * Copyright (C) 1999-2001 Brian Paul All Rights Reserved. |
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| 8 | * |
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| 9 | * Permission is hereby granted, free of charge, to any person obtaining a |
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| 10 | * copy of this software and associated documentation files (the "Software"), |
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| 11 | * to deal in the Software without restriction, including without limitation |
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| 12 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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| 13 | * and/or sell copies of the Software, and to permit persons to whom the |
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| 14 | * Software is furnished to do so, subject to the following conditions: |
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| 15 | * |
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| 16 | * The above copyright notice and this permission notice shall be included |
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| 17 | * in all copies or substantial portions of the Software. |
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| 18 | * |
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| 19 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
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| 20 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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| 21 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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| 22 | * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN |
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| 23 | * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
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| 24 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
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| 25 | */ |
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| 26 | |||
| 27 | |||
| 28 | #include "glheader.h" |
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| 29 | #include "clip.h" |
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| 30 | #include "context.h" |
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| 31 | #include "macros.h" |
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| 32 | #include "mmath.h" |
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| 33 | #include "mtypes.h" |
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| 34 | |||
| 35 | #include "math/m_xform.h" |
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| 36 | #include "math/m_matrix.h" |
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| 37 | |||
| 38 | |||
| 39 | |||
| 40 | /**********************************************************************/ |
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| 41 | /* Get/Set User clip-planes. */ |
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| 42 | /**********************************************************************/ |
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| 43 | |||
| 44 | |||
| 45 | |||
| 46 | void |
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| 47 | _mesa_ClipPlane( GLenum plane, const GLdouble *eq ) |
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| 48 | { |
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| 49 | GET_CURRENT_CONTEXT(ctx); |
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| 50 | GLint p; |
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| 51 | GLfloat equation[4]; |
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| 52 | ASSERT_OUTSIDE_BEGIN_END(ctx); |
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| 53 | |||
| 54 | p = (GLint) plane - (GLint) GL_CLIP_PLANE0; |
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| 55 | if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) { |
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| 56 | _mesa_error( ctx, GL_INVALID_ENUM, "glClipPlane" ); |
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| 57 | return; |
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| 58 | } |
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| 59 | |||
| 60 | equation[0] = (GLfloat) eq[0]; |
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| 61 | equation[1] = (GLfloat) eq[1]; |
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| 62 | equation[2] = (GLfloat) eq[2]; |
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| 63 | equation[3] = (GLfloat) eq[3]; |
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| 64 | |||
| 65 | /* |
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| 66 | * The equation is transformed by the transpose of the inverse of the |
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| 67 | * current modelview matrix and stored in the resulting eye coordinates. |
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| 68 | * |
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| 69 | * KW: Eqn is then transformed to the current clip space, where user |
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| 70 | * clipping now takes place. The clip-space equations are recalculated |
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| 71 | * whenever the projection matrix changes. |
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| 72 | */ |
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| 73 | if (ctx->ModelviewMatrixStack.Top->flags & MAT_DIRTY) |
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| 74 | _math_matrix_analyse( ctx->ModelviewMatrixStack.Top ); |
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| 75 | |||
| 76 | _mesa_transform_vector( equation, equation, |
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| 77 | ctx->ModelviewMatrixStack.Top->inv ); |
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| 78 | |||
| 79 | if (TEST_EQ_4V(ctx->Transform.EyeUserPlane[p], equation)) |
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| 80 | return; |
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| 81 | |||
| 82 | FLUSH_VERTICES(ctx, _NEW_TRANSFORM); |
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| 83 | COPY_4FV(ctx->Transform.EyeUserPlane[p], equation); |
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| 84 | |||
| 85 | /* Update derived state. This state also depends on the projection |
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| 86 | * matrix, and is recalculated on changes to the projection matrix by |
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| 87 | * code in _mesa_update_state(). |
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| 88 | */ |
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| 89 | if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { |
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| 90 | if (ctx->ProjectionMatrixStack.Top->flags & MAT_DIRTY) |
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| 91 | _math_matrix_analyse( ctx->ProjectionMatrixStack.Top ); |
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| 92 | |||
| 93 | _mesa_transform_vector( ctx->Transform._ClipUserPlane[p], |
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| 94 | ctx->Transform.EyeUserPlane[p], |
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| 95 | ctx->ProjectionMatrixStack.Top->inv ); |
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| 96 | } |
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| 97 | |||
| 98 | if (ctx->Driver.ClipPlane) |
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| 99 | ctx->Driver.ClipPlane( ctx, plane, equation ); |
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| 100 | } |
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| 101 | |||
| 102 | |||
| 103 | void |
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| 104 | _mesa_GetClipPlane( GLenum plane, GLdouble *equation ) |
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| 105 | { |
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| 106 | GET_CURRENT_CONTEXT(ctx); |
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| 107 | GLint p; |
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| 108 | ASSERT_OUTSIDE_BEGIN_END(ctx); |
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| 109 | |||
| 110 | p = (GLint) (plane - GL_CLIP_PLANE0); |
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| 111 | if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) { |
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| 112 | _mesa_error( ctx, GL_INVALID_ENUM, "glGetClipPlane" ); |
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| 113 | return; |
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| 114 | } |
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| 115 | |||
| 116 | equation[0] = (GLdouble) ctx->Transform.EyeUserPlane[p][0]; |
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| 117 | equation[1] = (GLdouble) ctx->Transform.EyeUserPlane[p][1]; |
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| 118 | equation[2] = (GLdouble) ctx->Transform.EyeUserPlane[p][2]; |
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| 119 | equation[3] = (GLdouble) ctx->Transform.EyeUserPlane[p][3]; |
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| 120 | } |