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- /**************************************************************************
- * pattern.c
- *
- * This module implements texturing functions that return a value to be
- * used in a pigment or normal.
- *
- * from Persistence of Vision(tm) Ray Tracer
- * Copyright 1996 Persistence of Vision Team
- *---------------------------------------------------------------------------
- * NOTICE: This source code file is provided so that users may experiment
- * with enhancements to POV-Ray and to port the software to platforms other
- * than those supported by the POV-Ray Team. There are strict rules under
- * which you are permitted to use this file. The rules are in the file
- * named POVLEGAL.DOC which should be distributed with this file. If
- * POVLEGAL.DOC is not available or for more info please contact the POV-Ray
- * Team Coordinator by leaving a message in CompuServe's Graphics Developer's
- * Forum. The latest version of POV-Ray may be found there as well.
- *
- * This program is based on the popular DKB raytracer version 2.12.
- * DKBTrace was originally written by David K. Buck.
- * DKBTrace Ver 2.0-2.12 were written by David K. Buck & Aaron A. Collins.
- *
- *****************************************************************************/
-
- /*
- * Some texture ideas garnered from SIGGRAPH '85 Volume 19 Number 3,
- * "An Image Synthesizer" By Ken Perlin.
- * Further Ideas Garnered from "The RenderMan Companion" (Addison Wesley).
- */
-
- #include "frame.h"
- #include "vector.h"
- #include "povproto.h"
- #include "matrices.h"
- #include "pattern.h"
- #include "texture.h"
- #include "image.h"
- #include "txttest.h"
- #include "colour.h"
-
-
-
- /*****************************************************************************
- * Local preprocessor defines
- ******************************************************************************/
-
-
- /*****************************************************************************
- * Static functions
- ******************************************************************************/
-
- static DBL agate PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static DBL brick PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static DBL checker PARAMS((VECTOR EPoint));
- static DBL crackle PARAMS((VECTOR EPoint));
- static DBL gradient PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static DBL granite PARAMS((VECTOR EPoint));
- static DBL leopard PARAMS((VECTOR EPoint));
- static DBL mandel PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static DBL marble PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static DBL onion PARAMS((VECTOR EPoint));
- static DBL radial PARAMS((VECTOR EPoint));
- static DBL spiral1 PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static DBL spiral2 PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static DBL wood PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static DBL hexagon PARAMS((VECTOR EPoint));
- static long PickInCube PARAMS((VECTOR tv, VECTOR p1));
-
- static DBL ripples_pigm PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static DBL waves_pigm PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static DBL dents_pigm PARAMS((VECTOR EPoint));
- static DBL wrinkles_pigm PARAMS((VECTOR EPoint));
- static DBL quilted_pigm PARAMS((VECTOR EPoint, TPATTERN *TPat));
- static TURB *Search_For_Turb PARAMS((WARP *Warps));
- /* static TURB *Copy_Turb PARAMS((TURB *Old)); Unused function [AED] */
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * agate
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern is evaluated.
- * TPat -- Texture pattern struct
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION
- *
- * CHANGES
- * Oct 1994 : adapted from agate pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL agate (EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- register DBL noise, turb_val;
- TURB* Turb;
-
- Turb=Search_For_Turb(TPat->Warps);
-
- turb_val = TPat->Vals.Agate_Turb_Scale * Turbulence(EPoint,Turb);
-
- noise = 0.5 * (cycloidal(1.3 * turb_val + 1.1 * EPoint[Z]) + 1.0);
-
- if (noise < 0.0)
- {
- noise = 0.0;
- }
- else
- {
- noise = min(1.0, noise);
- noise = pow(noise, 0.77);
- }
-
- return(noise);
- }
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * brick
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- * TPat -- Texture pattern struct
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value exactly 0.0 or 1.0
- *
- * AUTHOR
- *
- * Dan Farmer
- *
- * DESCRIPTION
- *
- * CHANGES
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL brick (EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- int ibrickx, ibricky, ibrickz;
- DBL brickheight, brickwidth, brickdepth;
- DBL brickmortar, mortarheight, mortarwidth, mortardepth;
- DBL brickx, bricky, brickz;
- DBL x, y, z, fudgit;
-
- fudgit=Small_Tolerance+TPat->Vals.Brick.Mortar;
-
- x = EPoint[X]+fudgit;
- y = EPoint[Y]+fudgit;
- z = EPoint[Z]+fudgit;
-
- brickwidth = TPat->Vals.Brick.Size[X];
- brickheight = TPat->Vals.Brick.Size[Y];
- brickdepth = TPat->Vals.Brick.Size[Z];
- brickmortar = (DBL)TPat->Vals.Brick.Mortar;
-
- mortarwidth = brickmortar / brickwidth;
- mortarheight = brickmortar / brickheight;
- mortardepth = brickmortar / brickdepth;
-
- /* 1) Check mortar layers in the X-Z plane (ie: top view) */
-
- bricky = y / brickheight;
- ibricky = (int) bricky;
- bricky -= (DBL) ibricky;
-
- if (bricky < 0.0)
- {
- bricky += 1.0;
- }
-
- if (bricky <= mortarheight)
- {
- return(0.0);
- }
-
- bricky = (y / brickheight) * 0.5;
- ibricky = (int) bricky;
- bricky -= (DBL) ibricky;
-
- if (bricky < 0.0)
- {
- bricky += 1.0;
- }
-
-
- /* 2) Check ODD mortar layers in the Y-Z plane (ends) */
-
- brickx = (x / brickwidth);
- ibrickx = (int) brickx;
- brickx -= (DBL) ibrickx;
-
- if (brickx < 0.0)
- {
- brickx += 1.0;
- }
-
- if ((brickx <= mortarwidth) && (bricky <= 0.5))
- {
- return(0.0);
- }
-
- /* 3) Check EVEN mortar layers in the Y-Z plane (ends) */
-
- brickx = (x / brickwidth) + 0.5;
- ibrickx = (int) brickx;
- brickx -= (DBL) ibrickx;
-
- if (brickx < 0.0)
- {
- brickx += 1.0;
- }
-
- if ((brickx <= mortarwidth) && (bricky > 0.5))
- {
- return(0.0);
- }
-
- /* 4) Check ODD mortar layers in the Y-X plane (facing) */
-
- brickz = (z / brickdepth);
- ibrickz = (int) brickz;
- brickz -= (DBL) ibrickz;
-
- if (brickz < 0.0)
- {
- brickz += 1.0;
- }
-
- if ((brickz <= mortardepth) && (bricky > 0.5))
- {
- return(0.0);
- }
-
- /* 5) Check EVEN mortar layers in the X-Y plane (facing) */
-
- brickz = (z / brickdepth) + 0.5;
- ibrickz = (int) brickz;
- brickz -= (DBL) ibrickz;
-
- if (brickz < 0.0)
- {
- brickz += 1.0;
- }
-
- if ((brickz <= mortardepth) && (bricky <= 0.5))
- {
- return(0.0);
- }
-
- /* If we've gotten this far, color me brick. */
-
- return(1.0);
- }
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * checker
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value exactly 0.0 or 1.0
- *
- * AUTHOR
- *
- * POV-Team
- *
- * DESCRIPTION
- *
- * CHANGES
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL checker (EPoint)
- VECTOR EPoint;
- {
- int value;
-
- value = (int)(floor(EPoint[X]+Small_Tolerance) +
- floor(EPoint[Y]+Small_Tolerance) +
- floor(EPoint[Z]+Small_Tolerance));
-
- if (value & 1)
- {
- return (1.0);
- }
- else
- {
- return (0.0);
- }
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * crackle
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * Jim McElhiney
- *
- * DESCRIPTION
- *
- * "crackle":
- *
- * New colour function by Jim McElhiney,
- * CompuServe 71201,1326, aka mcelhiney@acm.org
- *
- * Large scale, without turbulence, makes a pretty good stone wall.
- * Small scale, without turbulence, makes a pretty good crackle ceramic glaze.
- * Highly turbulent (with moderate displacement) makes a good marble, solving
- * the problem of apparent parallel layers in Perlin's method.
- * 2 octaves of full-displacement turbulence make a great "drizzled paint"
- * pattern, like a 1950's counter top.
- * Rule of thumb: put a single colour transition near 0 in your colour map.
- *
- * Mathematically, the set crackle(p)=0 is a 3D Voronoi diagram of a field of
- * semirandom points, and crackle(p)>0 is distance from set along shortest path.
- * (A Voronoi diagram is the locus of points equidistant from their 2 nearest
- * neighbours from a set of disjoint points, like the membranes in suds are
- * to the centres of the bubbles).
- *
- * All "crackle" specific source code and examples are in the public domain.
- *
- * CHANGES
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL crackle (EPoint)
- VECTOR EPoint;
- {
- int i;
- long thisseed;
- DBL sum, minsum, minsum2, tf;
- VECTOR sv, tv, dv, t1, add;
-
- static int cvc;
- static long lastseed = 0x80000000;
- static VECTOR cv[81];
-
- Assign_Vector(tv,EPoint);
-
- /*
- * Check to see if the input point is in the same unit cube as the last
- * call to this function, to use cache of cubelets for speed.
- */
-
- thisseed = PickInCube(tv, t1);
-
- if (thisseed != lastseed)
- {
- /*
- * No, not same unit cube. Calculate the random points for this new
- * cube and its 80 neighbours which differ in any axis by 1 or 2.
- * Why distance of 2? If there is 1 point in each cube, located
- * randomly, it is possible for the closest random point to be in the
- * cube 2 over, or the one two over and one up. It is NOT possible
- * for it to be two over and two up. Picture a 3x3x3 cube with 9 more
- * cubes glued onto each face.
- */
-
- /* Now store a points for this cube and each of the 80 neighbour cubes. */
-
- cvc = 0;
-
- for (add[X] = -2.0; add[X] < 2.5; add[X] +=1.0)
- {
- for (add[Y] = -2.0; add[Y] < 2.5; add[Y] += 1.0)
- {
- for (add[Z] = -2.0; add[Z] < 2.5; add[Z] += 1.0)
- {
- /* For each cubelet in a 5x5 cube. */
-
- if ((fabs(add[X])>1.5)+(fabs(add[Y])>1.5)+(fabs(add[Z])>1.5) <= 1.0)
- {
- /* Yes, it's within a 3d knight move away. */
-
- VAdd(sv, tv, add);
-
- PickInCube(sv, t1);
-
- cv[cvc][X] = t1[X];
- cv[cvc][Y] = t1[Y];
- cv[cvc][Z] = t1[Z];
- cvc++;
- }
- }
- }
- }
-
- lastseed = thisseed;
- }
-
- /*
- * Find the 2 points with the 2 shortest distances from the input point.
- * Loop invariant: minsum is shortest dist, minsum2 is 2nd shortest
- */
-
- /* Set up the loop so the invariant is true: minsum <= minsum2 */
-
- VSub(dv, cv[0], tv); minsum = VSumSqr(dv);
- VSub(dv, cv[1], tv); minsum2 = VSumSqr(dv);
-
- if (minsum2 < minsum)
- {
- tf = minsum; minsum = minsum2; minsum2 = tf;
- }
-
- /* Loop for the 81 cubelets to find closest and 2nd closest. */
-
- for (i = 2; i < cvc; i++)
- {
- VSub(dv, cv[i], tv);
-
- sum = VSumSqr(dv);
-
- if (sum < minsum)
- {
- minsum2 = minsum;
- minsum = sum;
- }
- else
- {
- if (sum < minsum2)
- {
- minsum2 = sum;
- }
- }
- }
-
- /* Crackle value is absolute value of diff in dist to closest 2 points. */
-
- tf = sqrt(minsum2) - sqrt(minsum); /* minsum is known <= minsum2 */
-
- /*
- * Note that the theoretical range of this function is 0 to root 3.
- * In practice, it rarely exceeds 0.9, and only very rarely 1.0
- */
-
- return min(tf, 1.);
- }
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * gradient
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION
- *
- * Gradient Pattern - gradient based on the fractional values of
- * x, y or z, based on whether or not the given directional vector is
- * a 1.0 or a 0.0.
- * The basic concept of this is from DBW Render, but Dave Wecker's
- * only supports simple Y axis gradients.
- *
- * CHANGES
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL gradient (EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- register int i;
- register DBL temp;
- DBL value = 0.0;
-
- for (i=X; i<=Z; i++)
- {
- if (TPat->Vals.Gradient[i] != 0.0)
- {
- temp = fabs(EPoint[i]);
-
- value += fmod(temp,1.0);
- }
- }
-
- /* Clamp to 1.0. */
-
- value = ((value > 1.0) ? fmod(value, 1.0) : value);
-
- return(value);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * granite
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION
- *
- * Granite - kind of a union of the "spotted" and the "dented" textures,
- * using a 1/f fractal noise function for color values. Typically used
- * with small scaling values. Should work with colour maps for pink granite.
- *
- * CHANGES
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL granite (EPoint)
- VECTOR EPoint;
- {
- register int i;
- register DBL temp, noise = 0.0, freq = 1.0;
- VECTOR tv1,tv2;
-
- VScale(tv1,EPoint,4.0);
-
- for (i = 0; i < 6 ; freq *= 2.0, i++)
- {
- VScale(tv2,tv1,freq);
- temp = 0.5 - Noise (tv2);
-
- temp = fabs(temp);
-
- noise += temp / freq;
- }
-
- return(noise);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * leopard
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * Scott Taylor
- *
- * DESCRIPTION
- *
- * CHANGES
- * Jul 1991 : Creation.
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL leopard (EPoint)
- VECTOR EPoint;
- {
- register DBL value, temp1, temp2, temp3;
-
- /* This form didn't work with Zortech 386 compiler */
- /* value = Sqr((sin(x)+sin(y)+sin(z))/3); */
- /* So we break it down. */
-
- temp1 = sin(EPoint[X]);
- temp2 = sin(EPoint[Y]);
- temp3 = sin(EPoint[Z]);
-
- value = Sqr((temp1 + temp2 + temp3) / 3.0);
-
- return(value);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * mandel
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * submitted by user, name lost (sorry)
- *
- * DESCRIPTION
- * The mandel pattern computes the standard Mandelbrot fractal pattern and
- * projects it onto the X-Y plane. It uses the X and Y coordinates to compute
- * the Mandelbrot set.
- *
- * CHANGES
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL mandel (EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- int it_max, col;
- DBL a, b, cf, a2, b2, x, y;
-
- a = x = EPoint[X]; a2 = Sqr(a);
- b = y = EPoint[Y]; b2 = Sqr(b);
-
- it_max = TPat->Vals.Iterations;
-
- for (col = 0; col < it_max; col++)
- {
- b = 2.0 * a * b + y;
- a = a2 - b2 + x;
-
- a2 = Sqr(a);
- b2 = Sqr(b);
-
- if ((a2 + b2) > 4.0)
- {
- break;
- }
- }
-
- cf = (DBL)col / (DBL)it_max;
-
- return(cf);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * marble
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- * TPat -- Texture pattern struct
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION
- *
- * CHANGES
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL marble (EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- register DBL turb_val;
- TURB *Turb;
-
- if ((Turb=Search_For_Turb(TPat->Warps)) != NULL)
- {
- turb_val = Turb->Turbulence[X] * Turbulence(EPoint,Turb);
- }
- else
- {
- turb_val = 0.0;
- }
-
- return(EPoint[X] + turb_val);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * onion
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * Scott Taylor
- *
- * DESCRIPTION
- *
- * CHANGES
- * Jul 1991 : Creation.
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL onion (EPoint)
- VECTOR EPoint;
- {
- /* The variable noise is not used as noise in this function */
-
- register DBL noise;
-
- /*
- This ramp goes 0-1,1-0,0-1,1-0...
-
- noise = (fmod(sqrt(Sqr(x)+Sqr(y)+Sqr(z)),2.0)-1.0);
-
- if (noise<0.0) {noise = 0.0-noise;}
- */
-
- /* This ramp goes 0-1, 0-1, 0-1, 0-1 ... */
-
- noise = (fmod(sqrt(Sqr(EPoint[X])+Sqr(EPoint[Y])+Sqr(EPoint[Z])), 1.0));
-
- return(noise);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * radial
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * Chris Young -- new in vers 2.0
- *
- * DESCRIPTION
- *
- * CHANGES
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL radial (EPoint)
- VECTOR EPoint;
- {
- register DBL value;
-
- if ((fabs(EPoint[X])<0.001) && (fabs(EPoint[Z])<0.001))
- {
- value = 0.25;
- }
- else
- {
- value = 0.25 + (atan2(EPoint[X],EPoint[Z]) + M_PI) / (2.0 * M_PI);
- }
-
- return(value);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * spiral1
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- * TPat -- Texture pattern struct
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * Dieter Bayer
- *
- * DESCRIPTION
- * Spiral whirles around z-axis.
- * The number of "arms" is defined in the TPat.
- *
- * CHANGES
- * Aug 1994 : Creation.
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- static DBL spiral1(EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- DBL rad, phi, turb_val;
- DBL x = EPoint[X];
- DBL y = EPoint[Y];
- DBL z = EPoint[Z];
- TURB *Turb;
-
- if ((Turb=Search_For_Turb(TPat->Warps)) != NULL)
- {
- turb_val = Turb->Turbulence[X] * Turbulence(EPoint,Turb);
- }
- else
- {
- turb_val = 0.0;
- }
-
- /* Get distance from z-axis. */
-
- rad = sqrt(x * x + y * y);
-
- /* Get angle in x,y-plane (0...2 PI). */
-
- if (rad == 0.0)
- {
- phi = 0.0;
- }
- else
- {
- if (x < 0.0)
- {
- phi = 1.5 * M_PI - asin(y / rad);
- }
- else
- {
- phi = 0.5 * M_PI + asin(y / rad);
- }
- }
-
- return(z + rad + (DBL)TPat->Vals.Arms * phi / (2.0 * M_PI) + turb_val);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * spiral2
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- * TPat -- Texture pattern struct
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * Dieter Bayer
- *
- * DESCRIPTION
- * Spiral whirles around z-axis.
- * The number of "arms" is defined in the TPat.
- *
- * CHANGES
- * Aug 1994 : Creation.
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
-
- static DBL spiral2(EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- DBL rad, phi, turb_val;
- DBL x = EPoint[X];
- DBL y = EPoint[Y];
- DBL z = EPoint[Z];
- TURB *Turb;
-
- if ((Turb=Search_For_Turb(TPat->Warps)) != NULL)
- {
- turb_val = Turb->Turbulence[X] * Turbulence(EPoint,Turb);
- }
- else
- {
- turb_val = 0.0;
- }
-
- /* Get distance from z-axis. */
-
- rad = sqrt(x * x + y * y);
-
- /* Get angle in x,y-plane (0...2 PI) */
-
- if (rad == 0.0)
- {
- phi = 0.0;
- }
- else
- {
- if (x < 0.0)
- {
- phi = 1.5 * M_PI - asin(y / rad);
- }
- else
- {
- phi = 0.5 * M_PI + asin(y / rad);
- }
- }
-
- turb_val = Triangle_Wave(z + rad + (DBL)TPat->Vals.Arms * phi / (2.0 * M_PI) + turb_val);
-
- return(Triangle_Wave(rad) + turb_val);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * wood
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- * TPat -- Texture pattern struct
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION
- *
- * CHANGES
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
-
- static DBL wood (EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- register DBL length;
- VECTOR WoodTurbulence;
- VECTOR point;
- DBL x=EPoint[X];
- DBL y=EPoint[Y];
- TURB *Turb;
-
- if ((Turb=Search_For_Turb(TPat->Warps)) != NULL)
- {
- DTurbulence (WoodTurbulence, EPoint,Turb);
- point[X] = cycloidal((x + WoodTurbulence[X]) * Turb->Turbulence[X]);
- point[Y] = cycloidal((y + WoodTurbulence[Y]) * Turb->Turbulence[Y]);
- }
- else
- {
- point[X] = 0.0;
- point[Y] = 0.0;
- }
- point[Z] = 0.0;
-
- point[X] += x;
- point[Y] += y;
-
- /* point[Z] += z; Deleted per David Buck -- BP 7/91 */
-
- VLength (length, point);
-
- return(length);
- }
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * hexagon
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value exactly 0.0, 1.0 or 2.0
- *
- * AUTHOR
- *
- * Ernest MacDougal Campbell III
- *
- * DESCRIPTION
- *
- * TriHex pattern -- Ernest MacDougal Campbell III (EMC3) 11/23/92
- *
- * Creates a hexagon pattern in the XZ plane.
- *
- * This algorithm is hard to explain. First it scales the point to make
- * a few of the later calculations easier, then maps some points to be
- * closer to the Origin. A small area in the first quadrant is subdivided
- * into a 6 x 6 grid. The position of the point mapped into that grid
- * determines its color. For some points, just the grid location is enough,
- * but for others, we have to calculate which half of the block it's in
- * (this is where the atan2() function comes in handy).
- *
- * CHANGES
- * Nov 1992 : Creation.
- * Oct 1994 : adapted from pigment by [CY]
- *
- ******************************************************************************/
-
- #define xfactor 0.5; /* each triangle is split in half for the grid */
- #define zfactor 0.866025404; /* sqrt(3)/2 -- Height of an equilateral triangle */
-
- static DBL hexagon (EPoint)
- VECTOR EPoint;
- {
- int xm, zm;
- int brkindx;
- DBL xs, zs, xl, zl, value = 0.0;
- DBL x=EPoint[X];
- DBL z=EPoint[Z];
-
-
- /* Keep all numbers positive. Also, if z is negative, map it in such a
- * way as to avoid mirroring across the x-axis. The value 5.196152424
- * is (sqrt(3)/2) * 6 (because the grid is 6 blocks high)
- */
-
- x = fabs(x);
-
- /* Avoid mirroring across x-axis. */
-
- z = z < 0.0 ? 5.196152424 - fabs(z) : z;
-
- /* Scale point to make calcs easier. */
-
- xs = x/xfactor;
- zs = z/zfactor;
-
- /* Map points into the 6 x 6 grid where the basic formula works. */
-
- xs -= floor(xs/6.0) * 6.0;
- zs -= floor(zs/6.0) * 6.0;
-
- /* Get a block in the 6 x 6 grid. */
-
- xm = (int) FLOOR(xs) % 6;
- zm = (int) FLOOR(zs) % 6;
-
- switch (xm)
- {
- /* These are easy cases: Color depends only on xm and zm. */
-
- case 0:
- case 5:
-
- switch (zm)
- {
- case 0:
- case 5: value = 0; break;
-
- case 1:
- case 2: value = 1; break;
-
- case 3:
- case 4: value = 2; break;
- }
-
- break;
-
- case 2:
- case 3:
-
- switch (zm)
- {
- case 0:
- case 1: value = 2; break;
-
- case 2:
- case 3: value = 0; break;
-
- case 4:
- case 5: value = 1; break;
- }
-
- break;
-
- /* These cases are harder. These blocks are divided diagonally
- * by the angled edges of the hexagons. Some slope positive, and
- * others negative. We flip the x value of the negatively sloped
- * pieces. Then we check to see if the point in question falls
- * in the upper or lower half of the block. That info, plus the
- * z status of the block determines the color.
- */
-
- case 1:
- case 4:
-
- /* Map the point into the block at the origin. */
-
- xl = xs-xm;
- zl = zs-zm;
-
- /* These blocks have negative slopes so we flip it horizontally. */
-
- if (((xm + zm) % 2) == 1)
- {
- xl = 1.0 - xl;
- }
-
- /* Avoid a divide-by-zero error. */
-
- if (xl == 0.0)
- {
- xl = 0.0001;
- }
-
- /* Is the angle less-than or greater-than 45 degrees? */
-
- brkindx = (zl / xl) < 1.0;
-
- /* was...
- * brkindx = (atan2(zl,xl) < (45 * M_PI/180));
- * ...but because of the mapping, it's easier and cheaper,
- * CPU-wise, to just use a good ol' slope.
- */
-
- switch (brkindx)
- {
- case TRUE:
-
- switch (zm)
- {
- case 0:
- case 3: value = 0; break;
-
- case 2:
- case 5: value = 1; break;
-
- case 1:
- case 4: value = 2; break;
- }
-
- break;
-
- case FALSE:
-
- switch (zm)
- {
- case 0:
- case 3: value = 2; break;
-
- case 2:
- case 5: value = 0; break;
-
- case 1:
- case 4: value = 1; break;
- }
-
- break;
- }
- }
-
- value = fmod(value, 3.0);
-
- return(value);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * PickInCube(tv, p1)
- *
- * INPUT
- *
- * ?
- *
- * OUTPUT
- *
- * RETURNS
- *
- * long integer hash function used, to speed up cacheing.
- *
- * AUTHOR
- *
- * Jim McElhiney
- *
- * DESCRIPTION
- *
- * A subroutine to go with crackle.
- *
- * Pick a random point in the same unit-sized cube as tv, in a
- * predictable way, so that when called again with another point in
- * the same unit cube, p1 is picked to be the same.
- *
- * CHANGES
- *
- ******************************************************************************/
-
- static long PickInCube(tv, p1)
- VECTOR tv, p1;
- {
- int seed;
- VECTOR flo;
-
- /*
- * This uses floor() not FLOOR, so it will not be a mirror
- * image about zero in the range -1.0 to 1.0. The viewer
- * won't see an artefact around the origin.
- */
-
- flo[X] = floor(tv[X] - EPSILON);
- flo[Y] = floor(tv[Y] - EPSILON);
- flo[Z] = floor(tv[Z] - EPSILON);
-
- seed = Hash3d((int)flo[X], (int)flo[Y], (int)flo[Z]);
-
- POV_SRAND(seed);
-
- p1[X] = flo[X] + FRAND();
- p1[Y] = flo[Y] + FRAND();
- p1[Z] = flo[Z] + FRAND();
-
- return((long)seed);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * Evaluate_Pattern
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- * TPat -- Texture pattern struct
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL result usual 0.0 to 1.0 but may be 2.0 in hexagon
- *
- * AUTHOR
- *
- * adapted from Add_Pigment by Chris Young
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- DBL Evaluate_TPat (TPat, EPoint)
- TPATTERN *TPat;
- VECTOR EPoint;
- {
- DBL value = 0.0;
- VECTOR TPoint;
-
- Warp_EPoint (TPoint, EPoint, TPat);
-
- switch (TPat->Type)
- {
- case AGATE_PATTERN: value = agate (TPoint, TPat); break;
-
- case BOZO_PATTERN:
- case SPOTTED_PATTERN:
- case BUMPS_PATTERN: value = Noise (TPoint); break;
-
- case BRICK_PATTERN: value = brick (TPoint, TPat); break;
- case CHECKER_PATTERN: value = checker (TPoint); break;
- case CRACKLE_PATTERN: value = crackle (TPoint); break;
- case GRADIENT_PATTERN: value = gradient (TPoint, TPat); break;
- case GRANITE_PATTERN: value = granite (TPoint); break;
- case HEXAGON_PATTERN: value = hexagon (TPoint); break;
- case LEOPARD_PATTERN: value = leopard (TPoint); break;
- case MANDEL_PATTERN: value = mandel (TPoint, TPat); break;
- case MARBLE_PATTERN: value = marble (TPoint, TPat); break;
- case ONION_PATTERN: value = onion (TPoint); break;
- case RADIAL_PATTERN: value = radial (TPoint); break;
- case SPIRAL1_PATTERN: value = spiral1 (TPoint, TPat); break;
- case SPIRAL2_PATTERN: value = spiral2 (TPoint, TPat); break;
- case PATTERN1_PATTERN: value = pattern1 (TPoint, TPat); break;
- case PATTERN2_PATTERN: value = pattern2 (TPoint, TPat); break;
- case PATTERN3_PATTERN: value = pattern3 (TPoint, TPat); break;
- case WOOD_PATTERN: value = wood (TPoint, TPat); break;
-
- case WAVES_PATTERN: value = waves_pigm (TPoint, TPat); break;
- case RIPPLES_PATTERN: value = ripples_pigm (TPoint, TPat); break;
- case WRINKLES_PATTERN: value = wrinkles_pigm (TPoint); break;
- case DENTS_PATTERN: value = dents_pigm (TPoint); break;
- case QUILTED_PATTERN: value = quilted_pigm (TPoint, TPat); break;
- default: Error("Problem in Evaluate_TPat.");
- }
-
- if (TPat->Frequency !=0.0)
- {
- value = fmod(value * TPat->Frequency + TPat->Phase, 1.00001);
- }
-
- /* allow negative Frequency */
-
- if (value < 0.0)
- {
- value -= floor(value);
- }
-
- switch (TPat->Wave_Type)
- {
- case RAMP_WAVE:
- break;
-
- case SINE_WAVE:
- value = (1.0+cycloidal(value))*0.5;
- break;
-
- case TRIANGLE_WAVE:
- value = Triangle_Wave(value);
- break;
-
- case SCALLOP_WAVE:
- value = fabs(cycloidal(value*0.5));
- break;
-
- default: Error("Unknown Wave Type %d.",TPat->Wave_Type);
- }
-
- return(value);
- }
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- void Init_TPat_Fields (Tpat)
- TPATTERN *Tpat;
- {
- Tpat->Type = NO_PATTERN;
- Tpat->Wave_Type = RAMP_WAVE;
- Tpat->Flags = NO_FLAGS;
- Tpat->References = 1;
- Tpat->Frequency = 1.0;
- Tpat->Phase = 0.0;
- Tpat->Warps = NULL;
- Tpat->Next = NULL;
- Tpat->Blend_Map = NULL;
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- void Copy_TPat_Fields (New, Old)
- TPATTERN *New, *Old;
- {
- *New = *Old;
-
- /* Copy warp chain */
- New->Warps = Copy_Warps(Old->Warps);
-
- New->Blend_Map = Copy_Blend_Map(Old->Blend_Map);
-
- /* Note, cannot copy Old->Next because we don't know what kind of
- thing this is. It must be copied by Copy_Pigment, Copy_Tnormal etc.
- */
-
- if (Old->Type == BITMAP_PATTERN)
- {
- New->Vals.Image = Copy_Image(Old->Vals.Image);
- }
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- void Destroy_TPat_Fields(Tpat)
- TPATTERN *Tpat;
- {
- Destroy_Warps(Tpat->Warps);
- Destroy_Blend_Map(Tpat->Blend_Map);
- /* Note, cannot destroy Tpat->Next nor pattern itself because we don't
- know what kind of thing this is. It must be destroied by Destroy_Pigment, etc.
- */
-
- if (Tpat->Type == BITMAP_PATTERN)
- {
- Destroy_Image(Tpat->Vals.Image);
- }
- }
-
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- TURB *Create_Turb()
- {
- TURB *New;
-
- New = POV_MALLOC(sizeof(TURB),"turbulence struct");
-
- Make_Vector(New->Turbulence, 0.0, 0.0, 0.0);
-
- New->Octaves = 6;
- New->Omega = 0.5;
- New->Lambda = 2.0;
-
- return(New);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- #if 0 /* Unused function [AED] */
- static TURB *Copy_Turb(Old)
- TURB *Old;
- {
- TURB *New;
-
- if (Old != NULL)
- {
- New = Create_Turb();
-
- *New = *Old;
- }
- else
- {
- New=NULL;
- }
-
- return(New);
- }
- #endif
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * Translate_Tpattern
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- void Translate_Tpattern(Tpattern,Vector)
- TPATTERN *Tpattern;
- VECTOR Vector;
- {
- TRANSFORM Trans;
-
- if (Tpattern != NULL)
- {
- Compute_Translation_Transform (&Trans, Vector);
-
- Transform_Tpattern (Tpattern, &Trans);
- }
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * Rotate_Tpattern
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- void Rotate_Tpattern(Tpattern,Vector)
- TPATTERN *Tpattern;
- VECTOR Vector;
- {
- TRANSFORM Trans;
-
- if (Tpattern != NULL)
- {
- Compute_Rotation_Transform (&Trans, Vector);
-
- Transform_Tpattern (Tpattern, &Trans);
- }
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * Scale_Tpattern
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- void Scale_Tpattern(Tpattern,Vector)
- TPATTERN *Tpattern;
- VECTOR Vector;
- {
- TRANSFORM Trans;
-
- if (Tpattern != NULL)
- {
- Compute_Scaling_Transform (&Trans, Vector);
-
- Transform_Tpattern (Tpattern, &Trans);
- }
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * Transform_Tpattern
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- void Transform_Tpattern(Tpattern,Trans)
- TPATTERN *Tpattern;
- TRANSFORM *Trans;
- {
- WARP *Temp;
-
- if (Tpattern != NULL)
- {
- if (Tpattern->Warps == NULL)
- {
- Tpattern->Warps=Create_Warp(TRANSFORM_WARP);
- }
- else
- {
- if (Tpattern->Warps->Warp_Type != TRANSFORM_WARP)
- {
- Temp=Tpattern->Warps;
-
- Tpattern->Warps=Create_Warp(TRANSFORM_WARP);
-
- Tpattern->Warps->Next_Warp=Temp;
- }
- }
-
- Compose_Transforms (&( ((TRANS *)(Tpattern->Warps))->Trans), Trans);
- }
- }
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * ripples_pigm
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- * TPat -- Texture pattern struct
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION : Note this pattern is only used for pigments and textures.
- * Normals have a specialized pattern for this.
- *
- * CHANGES
- * Nov 1994 : adapted from normal by [CY]
- *
- ******************************************************************************/
-
- static DBL ripples_pigm (EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- register unsigned int i;
- register DBL length, index;
- DBL scalar =0.0;
- VECTOR point;
-
- for (i = 0 ; i < Number_Of_Waves ; i++)
- {
- VSub (point, EPoint, Wave_Sources[i]);
- VLength (length, point);
-
- if (length == 0.0)
- length = 1.0;
-
- index = length * TPat->Frequency + TPat->Phase;
-
- scalar += cycloidal(index);
- }
-
- scalar = 0.5*(1.0+(scalar / (DBL)Number_Of_Waves));
-
- return(scalar);
- }
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * waves_pigm
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- * TPat -- Texture pattern struct
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION : Note this pattern is only used for pigments and textures.
- * Normals have a specialized pattern for this.
- *
- * CHANGES
- * Nov 1994 : adapted from normal by [CY]
- *
- ******************************************************************************/
-
- static DBL waves_pigm (EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- register unsigned int i;
- register DBL length, index;
- DBL scalar = 0.0;
- VECTOR point;
-
- for (i = 0 ; i < Number_Of_Waves ; i++)
- {
- VSub (point, EPoint, Wave_Sources[i]);
- VLength (length, point);
-
- if (length == 0.0)
- {
- length = 1.0;
- }
-
- index = length * TPat->Frequency * frequency[i] + TPat->Phase;
-
- scalar += cycloidal(index)/frequency[i];
- }
-
- scalar = 0.2*(2.5+(scalar / (DBL)Number_Of_Waves));
-
- return(scalar);
- }
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * dents_pigm
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION : Note this pattern is only used for pigments and textures.
- * Normals have a specialized pattern for this.
- *
- * CHANGES
- * Nov 1994 : adapted from normal by [CY]
- *
- ******************************************************************************/
-
- static DBL dents_pigm (EPoint)
- VECTOR EPoint;
- {
- DBL noise;
-
- noise = Noise (EPoint);
-
- return(noise * noise * noise);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * wrinkles_pigm
- *
- * INPUT
- *
- * EPoint -- The point in 3d space at which the pattern
- * is evaluated.
- *
- * OUTPUT
- *
- * RETURNS
- *
- * DBL value in the range 0.0 to 1.0
- *
- * AUTHOR
- *
- * POV-Ray Team
- *
- * DESCRIPTION : Note this pattern is only used for pigments and textures.
- * Normals have a specialized pattern for this.
- *
- * CHANGES
- * Nov 1994 : adapted from normal by [CY]
- *
- ******************************************************************************/
-
-
- static DBL wrinkles_pigm (EPoint)
- VECTOR EPoint;
- {
- register int i;
- DBL lambda = 2.0;
- DBL omega = 0.5;
- DBL value;
- VECTOR temp;
-
- value = Noise(EPoint);
-
- for (i = 1; i < 10; i++)
- {
- VScale(temp,EPoint,lambda);
-
- value += omega * Noise(temp);
-
- lambda *= 2.0;
-
- omega *= 0.5;
- }
-
- return(value/2.0);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * quilted_pigm
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * Dan Farmer & Chris Young
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- static DBL quilted_pigm (EPoint, TPat)
- VECTOR EPoint;
- TPATTERN *TPat;
- {
- VECTOR value;
- DBL t;
-
- value[X] = EPoint[X]-FLOOR(EPoint[X])-0.5;
- value[Y] = EPoint[Y]-FLOOR(EPoint[Y])-0.5;
- value[Z] = EPoint[Z]-FLOOR(EPoint[Z])-0.5;
-
- t = sqrt(value[X]*value[X]+value[Y]*value[Y]+value[Z]*value[Z]);
-
- t = quilt_cubic(t, TPat->Vals.Quilted.Control0, TPat->Vals.Quilted.Control1);
-
- value[X] *= t;
- value[Y] *= t;
- value[Z] *= t;
-
- return((fabs(value[X])+fabs(value[Y])+fabs(value[Z]))/3.0);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- #define INV_SQRT_3_4 1.154700538
- DBL quilt_cubic(t,p1,p2)
- DBL t,p1,p2;
- {
- DBL it=(1-t);
- DBL itsqrd=it*it;
- /* DBL itcubed=it*itsqrd; */
- DBL tsqrd=t*t;
- DBL tcubed=t*tsqrd;
- DBL val;
-
- /* Originally coded as...
-
- val= (DBL)(itcubed*n1+(tcubed)*n2+3*t*(itsqrd)*p1+3*(tsqrd)*(it)*p2);
-
- re-written by CEY to optimise because n1=0 n2=1 always.
-
- */
-
- val = (tcubed + 3.0*t*itsqrd*p1 + 3.0*tsqrd*it*p2) * INV_SQRT_3_4;
-
- return(val);
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- void Search_Blend_Map (value,Blend_Map,Prev,Cur)
- DBL value;
- BLEND_MAP *Blend_Map;
- BLEND_MAP_ENTRY **Prev, **Cur;
- {
- BLEND_MAP_ENTRY *P, *C;
- int Max_Ent=Blend_Map->Number_Of_Entries-1;
-
- /* if greater than last, use last. */
-
- if (value >= Blend_Map->Blend_Map_Entries[Max_Ent].value)
- {
- P = C = &(Blend_Map->Blend_Map_Entries[Max_Ent]);
- }
- else
- {
- P = C = &(Blend_Map->Blend_Map_Entries[0]);
-
- while (value > C->value)
- {
- P = C++;
- }
- }
-
- if (value == C->value)
- {
- P = C;
- }
-
- *Prev = P;
- *Cur = C;
- }
-
-
-
- /*****************************************************************************
- *
- * FUNCTION
- *
- * INPUT
- *
- * OUTPUT
- *
- * RETURNS
- *
- * AUTHOR
- *
- * DESCRIPTION
- *
- * CHANGES
- *
- ******************************************************************************/
-
- static TURB *Search_For_Turb(Warps)
- WARP *Warps;
- {
- WARP* Temp=Warps;
-
- if (Temp!=NULL)
- {
- while (Temp->Next_Warp != NULL)
- {
- Temp=Temp->Next_Warp;
- }
-
- if (Temp->Warp_Type != CLASSIC_TURB_WARP)
- {
- Temp=NULL;
- }
- }
-
- return ((TURB *)Temp);
- }
-