1 /* 2 * Mesa 3-D graphics library 3 * Version: 6.3 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 26 #include "glheader.h" 27 #include "clip.h" 28 #include "context.h" 29 #include "macros.h" 30 #include "mtypes.h" 31 32 #include "math/m_matrix.h" 33 34 35 /** 36 * Update derived clip plane state. 37 */ 38 void 39 _mesa_update_clip_plane(struct gl_context *ctx, GLuint plane) 40 { 41 if (_math_matrix_is_dirty(ctx->ProjectionMatrixStack.Top)) 42 _math_matrix_analyse( ctx->ProjectionMatrixStack.Top ); 43 44 /* Clip-Space Plane = Eye-Space Plane * Projection Matrix */ 45 _mesa_transform_vector(ctx->Transform._ClipUserPlane[plane], 46 ctx->Transform.EyeUserPlane[plane], 47 ctx->ProjectionMatrixStack.Top->inv); 48 } 49 50 51 void GLAPIENTRY 52 _mesa_ClipPlane( GLenum plane, const GLdouble *eq ) 53 { 54 GET_CURRENT_CONTEXT(ctx); 55 GLint p; 56 GLfloat equation[4]; 57 ASSERT_OUTSIDE_BEGIN_END(ctx); 58 59 p = (GLint) plane - (GLint) GL_CLIP_PLANE0; 60 if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) { 61 _mesa_error( ctx, GL_INVALID_ENUM, "glClipPlane" ); 62 return; 63 } 64 65 equation[0] = (GLfloat) eq[0]; 66 equation[1] = (GLfloat) eq[1]; 67 equation[2] = (GLfloat) eq[2]; 68 equation[3] = (GLfloat) eq[3]; 69 70 /* 71 * The equation is transformed by the transpose of the inverse of the 72 * current modelview matrix and stored in the resulting eye coordinates. 73 * 74 * KW: Eqn is then transformed to the current clip space, where user 75 * clipping now takes place. The clip-space equations are recalculated 76 * whenever the projection matrix changes. 77 */ 78 if (_math_matrix_is_dirty(ctx->ModelviewMatrixStack.Top)) 79 _math_matrix_analyse( ctx->ModelviewMatrixStack.Top ); 80 81 _mesa_transform_vector( equation, equation, 82 ctx->ModelviewMatrixStack.Top->inv ); 83 84 if (TEST_EQ_4V(ctx->Transform.EyeUserPlane[p], equation)) 85 return; 86 87 FLUSH_VERTICES(ctx, _NEW_TRANSFORM); 88 COPY_4FV(ctx->Transform.EyeUserPlane[p], equation); 89 90 if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { 91 _mesa_update_clip_plane(ctx, p); 92 } 93 94 if (ctx->Driver.ClipPlane) 95 ctx->Driver.ClipPlane( ctx, plane, equation ); 96 } 97 98 99 void GLAPIENTRY 100 _mesa_GetClipPlane( GLenum plane, GLdouble *equation ) 101 { 102 GET_CURRENT_CONTEXT(ctx); 103 GLint p; 104 ASSERT_OUTSIDE_BEGIN_END(ctx); 105 106 p = (GLint) (plane - GL_CLIP_PLANE0); 107 if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) { 108 _mesa_error( ctx, GL_INVALID_ENUM, "glGetClipPlane" ); 109 return; 110 } 111 112 equation[0] = (GLdouble) ctx->Transform.EyeUserPlane[p][0]; 113 equation[1] = (GLdouble) ctx->Transform.EyeUserPlane[p][1]; 114 equation[2] = (GLdouble) ctx->Transform.EyeUserPlane[p][2]; 115 equation[3] = (GLdouble) ctx->Transform.EyeUserPlane[p][3]; 116 } 117
