reactos/dll/opengl/mesa/main/clip.c

108 lines
3.6 KiB
C

/*
* Mesa 3-D graphics library
* Version: 6.3
*
* Copyright (C) 1999-2005 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <precomp.h>
/**
* Update derived clip plane state.
*/
void
_mesa_update_clip_plane(struct gl_context *ctx, GLuint plane)
{
if (_math_matrix_is_dirty(ctx->ProjectionMatrixStack.Top))
_math_matrix_analyse( ctx->ProjectionMatrixStack.Top );
/* Clip-Space Plane = Eye-Space Plane * Projection Matrix */
_mesa_transform_vector(ctx->Transform._ClipUserPlane[plane],
ctx->Transform.EyeUserPlane[plane],
ctx->ProjectionMatrixStack.Top->inv);
}
void GLAPIENTRY
_mesa_ClipPlane( GLenum plane, const GLdouble *eq )
{
GET_CURRENT_CONTEXT(ctx);
GLint p;
GLfloat equation[4];
ASSERT_OUTSIDE_BEGIN_END(ctx);
p = (GLint) plane - (GLint) GL_CLIP_PLANE0;
if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) {
_mesa_error( ctx, GL_INVALID_ENUM, "glClipPlane" );
return;
}
equation[0] = (GLfloat) eq[0];
equation[1] = (GLfloat) eq[1];
equation[2] = (GLfloat) eq[2];
equation[3] = (GLfloat) eq[3];
/*
* The equation is transformed by the transpose of the inverse of the
* current modelview matrix and stored in the resulting eye coordinates.
*
* KW: Eqn is then transformed to the current clip space, where user
* clipping now takes place. The clip-space equations are recalculated
* whenever the projection matrix changes.
*/
if (_math_matrix_is_dirty(ctx->ModelviewMatrixStack.Top))
_math_matrix_analyse( ctx->ModelviewMatrixStack.Top );
_mesa_transform_vector( equation, equation,
ctx->ModelviewMatrixStack.Top->inv );
if (TEST_EQ_4V(ctx->Transform.EyeUserPlane[p], equation))
return;
FLUSH_VERTICES(ctx, _NEW_TRANSFORM);
COPY_4FV(ctx->Transform.EyeUserPlane[p], equation);
if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
_mesa_update_clip_plane(ctx, p);
}
if (ctx->Driver.ClipPlane)
ctx->Driver.ClipPlane( ctx, plane, equation );
}
void GLAPIENTRY
_mesa_GetClipPlane( GLenum plane, GLdouble *equation )
{
GET_CURRENT_CONTEXT(ctx);
GLint p;
ASSERT_OUTSIDE_BEGIN_END(ctx);
p = (GLint) (plane - GL_CLIP_PLANE0);
if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) {
_mesa_error( ctx, GL_INVALID_ENUM, "glGetClipPlane" );
return;
}
equation[0] = (GLdouble) ctx->Transform.EyeUserPlane[p][0];
equation[1] = (GLdouble) ctx->Transform.EyeUserPlane[p][1];
equation[2] = (GLdouble) ctx->Transform.EyeUserPlane[p][2];
equation[3] = (GLdouble) ctx->Transform.EyeUserPlane[p][3];
}