/* $Xorg: miLight.h,v 1.3 2000/08/17 19:47:03 cpqbld Exp $ */ /* Copyright 1989, 1990, 1991, 1998 The Open Group All Rights Reserved. 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 THE OPEN GROUP 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. Except as contained in this notice, the name of The Open Group shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from The Open Group. Copyright 1989, 1990, 1991 by Sun Microsystems, Inc. All Rights Reserved Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of Sun Microsystems, not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. SUN MICROSYSTEMS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL SUN MICROSYSTEMS BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* $XFree86: xc/programs/Xserver/PEX5/ddpex/mi/include/miLight.h,v 1.5 2001/01/17 22:12:20 dawes Exp $ */ #ifndef MI_LIGHT_H #define MI_LIGHT_H /* Macros for lighting calculations */ /**** * * Name: NEAR_ZERO * Synopsis: determine if a floating point ia approximately 0. * ****/ #define ZERO_TOLERANCE 1.0e-30 #define NEAR_ZERO(a) \ ( ((a) < 0) ? ((a) > -ZERO_TOLERANCE) : ((a) < ZERO_TOLERANCE) ) /**** * * Name: DOT_PRODUCT * Synopsis: Compute the Dot (or inner) product of two vectors * ****/ #define DOT_PRODUCT(v1, v2, v1_dot_v2) \ { \ ddFLOAT *t1, *t2; \ t1 = (ddFLOAT *) (v1); \ t2 = (ddFLOAT *) (v2); \ (v1_dot_v2) = (*(t1++) * *(t2++)); \ (v1_dot_v2) += (*(t1++) * *(t2++)); \ (v1_dot_v2) += (*(t1 ) * *(t2 )); \ } /**** * * Name: CROSS_PRODUCT * Synopsis: Give three points p0, p1, p2, compute the cross product * of the two vectors (p1p0)x(p1p2). This corresponds to * computing the geomtric normal of a facet whose coordinates * are specified in counter-clockwise order. * ****/ #define CROSS_PRODUCT(p0, p1, p2, v) \ { \ register ddFLOAT *t; \ t = (ddFLOAT *) (v); \ *(t++) = (((p2->y-p1->y)*(p0->z-p1->z))-((p0->y-p1->y)*(p2->z-p1->z))); \ *(t++) = -(((p2->x-p1->x)*(p0->z-p1->z))-((p0->x-p1->x)*(p2->z-p1->z))); \ *(t ) = (((p2->x-p1->x)*(p0->y-p1->y))-((p0->x-p1->x)*(p2->y-p1->y))); \ } /**** * * Name: COPY_VECTOR * Synopsis: Copy a 3-component vector. * ****/ #define COPY_VECTOR(dest, src) \ { \ register ddFLOAT *d, *s; \ d = (ddFLOAT *) (dest); \ s = (ddFLOAT *) (src); \ *(d++) = *(s++); \ *(d++) = *(s++); \ *(d ) = *(s ); \ } /**** * * Name: NEGATE_VECTOR * Synopsis: Reverse direction of a 3-component vector. * ****/ #define NEGATE_VECTOR(dest, src) \ { \ register ddFLOAT *d, *s; \ d = (ddFLOAT *) (dest); \ s = (ddFLOAT *) (src); \ *(d++) = -(*(s++)); \ *(d++) = -(*(s++)); \ *(d ) = -(*(s )); \ } /**** * * Name: NORMALIZE_VECTOR * Synopsis: Normalize a 3-component vector. * Description: Replace arbitrary vector with unit vector (same direction) * and also return the original length. * ****/ #define NORMALIZE_VECTOR(vector, length) \ { \ ddFLOAT *v; \ v = (ddFLOAT *) (vector); \ DOT_PRODUCT(v, v, (length)); \ (length) = sqrt ((length)); \ if (length != 0.0) { \ *(v++) /= (length); \ *(v++) /= (length); \ *(v ) /= (length); \ } \ } /**** * * Name: CALCULATE_REFLECTION_VECTOR * Synopsis: Calculates the reflection vector as determined by * the laws of geometrical optics. * ****/ #define CALCULATE_REFLECTION_VECTOR(refl, n_dot_l, normal, light) \ { \ ddFLOAT *r, *n, *l; \ ddFLOAT temp; \ r = (ddFLOAT *) (refl); \ temp = 2.0 * (n_dot_l); \ n = (ddFLOAT *) (normal); \ l = (ddFLOAT *) (light); \ *(r++) = temp * (*(n++)) - *(l++); \ *(r++) = temp * (*(n++)) - *(l++); \ *(r ) = temp * (*(n )) - *(l ); \ } /**** * * Name: CALCULATE_DIRECTION_VECTOR * Synopsis: Calculates the direction vector (without normalization) * from one position to another. * ****/ #define CALCULATE_DIRECTION_VECTOR(to, from, dir) \ { \ register ddFLOAT *d, *t, *f; \ d = (ddFLOAT *) (dir); \ t = (ddFLOAT *) (to); \ f = (ddFLOAT *) (from); \ *(d++) = *(t++) - *(f++); \ *(d++) = *(t++) - *(f++); \ *(d ) = *(t ) - *(f ); \ } /**** * * Name: APPLY_DEPTH_CUING * Synopsis: Applies depth cueing calculation to a colour * value according to the suggested equations of * the PHIGS spec, "Annex E - Informative" * ****/ #define APPLY_DEPTH_CUEING(dcue_entry, pt_depth, in_color, out_color) \ { \ float tmp1, tmp2; \ \ if ((pt_depth) > (dcue_entry).frontPlane) { \ tmp1 = (1.0 - ((dcue_entry).frontScaling)); \ (out_color)->red = \ ((dcue_entry).frontScaling * (in_color)->red) + \ ((tmp1) * (dcue_entry).depthCueColour.colour.rgbFloat.red); \ \ (out_color)->green = \ ((dcue_entry).frontScaling * (in_color)->green) + \ ((tmp1) * (dcue_entry).depthCueColour.colour.rgbFloat.green);\ \ (out_color)->blue = \ ((dcue_entry).frontScaling * (in_color)->blue) + \ ((tmp1) * (dcue_entry).depthCueColour.colour.rgbFloat.blue); \ \ } else if ((pt_depth) < (dcue_entry).backPlane) { \ tmp1 = (1.0 - ((dcue_entry).backScaling)); \ (out_color)->red = \ ((dcue_entry).backScaling * (in_color)->red) + \ ((tmp1) * (dcue_entry).depthCueColour.colour.rgbFloat.red); \ \ (out_color)->green = \ ((dcue_entry).backScaling * (in_color)->green) + \ ((tmp1) * (dcue_entry).depthCueColour.colour.rgbFloat.green);\ \ (out_color)->blue = \ ((dcue_entry).backScaling * (in_color)->blue) + \ ((tmp1) * (dcue_entry).depthCueColour.colour.rgbFloat.blue); \ \ } else { /* between front and back planes */ \ \ tmp1 = ((dcue_entry).backScaling + \ (((pt_depth) - (dcue_entry).backPlane) * \ (((dcue_entry).frontScaling-(dcue_entry).backScaling) / \ ((dcue_entry).frontPlane-(dcue_entry).backPlane)) ) ); \ \ tmp2 = (1.0 - tmp1); \ \ (out_color)->red = (((tmp1) * (in_color)->red) + \ (tmp2 * (dcue_entry).depthCueColour.colour.rgbFloat.red)); \ \ (out_color)->green = (((tmp1) * (in_color)->green) + \ (tmp2 * (dcue_entry).depthCueColour.colour.rgbFloat.green)); \ \ (out_color)->blue = (((tmp1) * (in_color)->blue) + \ (tmp2 * (dcue_entry).depthCueColour.colour.rgbFloat.blue)); \ } \ } /* * * Name: AVERAGE * Synopsis: Give three points p0, p1, p2, compute the average * position in world coordinates * ****/ #define AVERAGE(p0, p1, p2, avg) \ { \ register ddFLOAT *t; \ t = (ddFLOAT *) (avg); \ *(t++) = ((p0->x) + (p1->x) + (p2->x)) / 3.0; \ *(t++) = ((p0->y) + (p1->y) + (p2->y)) / 3.0; \ *(t ) = ((p0->z) + (p1->z) + (p2->z)) / 3.0; \ } #endif