1/* 2 * Mesa 3-D graphics library 3 * 4 * Copyright (C) 1999-2005 Brian Paul All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included 14 * in all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 22 * 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#include "api_exec_decl.h" 34 35#include "state_tracker/st_context.h" 36 37/** 38 * Update derived clip plane state. 39 */ 40void 41_mesa_update_clip_plane(struct gl_context *ctx, GLuint plane) 42{ 43 /* make sure the inverse is up to date */ 44 if (_math_matrix_is_dirty(ctx->ProjectionMatrixStack.Top)) 45 _math_matrix_analyse( ctx->ProjectionMatrixStack.Top ); 46 47 /* Clip-Space Plane = Eye-Space Plane * Projection Matrix */ 48 _mesa_transform_vector(ctx->Transform._ClipUserPlane[plane], 49 ctx->Transform.EyeUserPlane[plane], 50 ctx->ProjectionMatrixStack.Top->inv); 51} 52 53 54void GLAPIENTRY 55_mesa_ClipPlane( GLenum plane, const GLdouble *eq ) 56{ 57 GET_CURRENT_CONTEXT(ctx); 58 GLint p; 59 GLfloat equation[4]; 60 61 p = (GLint) plane - (GLint) GL_CLIP_PLANE0; 62 if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) { 63 _mesa_error( ctx, GL_INVALID_ENUM, "glClipPlane" ); 64 return; 65 } 66 67 equation[0] = (GLfloat) eq[0]; 68 equation[1] = (GLfloat) eq[1]; 69 equation[2] = (GLfloat) eq[2]; 70 equation[3] = (GLfloat) eq[3]; 71 72 /* 73 * The equation is transformed by the transpose of the inverse of the 74 * current modelview matrix and stored in the resulting eye coordinates. 75 * 76 * KW: Eqn is then transformed to the current clip space, where user 77 * clipping now takes place. The clip-space equations are recalculated 78 * whenever the projection matrix changes. 79 */ 80 if (_math_matrix_is_dirty(ctx->ModelviewMatrixStack.Top)) 81 _math_matrix_analyse( ctx->ModelviewMatrixStack.Top ); 82 83 _mesa_transform_vector( equation, equation, 84 ctx->ModelviewMatrixStack.Top->inv ); 85 86 if (TEST_EQ_4V(ctx->Transform.EyeUserPlane[p], equation)) 87 return; 88 89 /* EyeUserPlane is used by program state constants. */ 90 FLUSH_VERTICES(ctx, _NEW_TRANSFORM, GL_TRANSFORM_BIT); 91 ctx->NewDriverState |= ST_NEW_CLIP_STATE; 92 COPY_4FV(ctx->Transform.EyeUserPlane[p], equation); 93 94 if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { 95 _mesa_update_clip_plane(ctx, p); 96 } 97} 98 99 100void GLAPIENTRY 101_mesa_GetClipPlane( GLenum plane, GLdouble *equation ) 102{ 103 GET_CURRENT_CONTEXT(ctx); 104 GLint p; 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