-/* $XConsortium: spaces.c,v 1.8 95/06/08 23:20:39 gildea Exp $ */
-/* Copyright International Business Machines, Corp. 1991
- * All Rights Reserved
- * Copyright Lexmark International, Inc. 1991
- * All Rights Reserved
- *
- * License 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 IBM or Lexmark not be
- * used in advertising or publicity pertaining to distribution of the
- * software without specific, written prior permission.
- *
- * IBM AND LEXMARK PROVIDE THIS SOFTWARE "AS IS", WITHOUT ANY WARRANTIES OF
- * ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO ANY
- * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
- * AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. THE ENTIRE RISK AS TO THE
- * QUALITY AND PERFORMANCE OF THE SOFTWARE, INCLUDING ANY DUTY TO SUPPORT
- * OR MAINTAIN, BELONGS TO THE LICENSEE. SHOULD ANY PORTION OF THE
- * SOFTWARE PROVE DEFECTIVE, THE LICENSEE (NOT IBM OR LEXMARK) ASSUMES THE
- * ENTIRE COST OF ALL SERVICING, REPAIR AND CORRECTION. IN NO EVENT SHALL
- * IBM OR LEXMARK 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.
- */
- /* SPACES CWEB V0021 ******** */
-/*
-:h1 id=spaces.SPACES Module - Handles Coordinate Spaces
-
-This module is responsible for handling the TYPE1IMAGER "XYspace" object.
-
-&author. Jeffrey B. Lotspiech (lotspiech@almaden.ibm.com)
-
-
-:h3.Include Files
-*/
-#include "objects.h"
-#include "spaces.h"
-#include "paths.h"
-#include "pictures.h"
-#include "fonts.h"
-#include "arith.h"
-#include "trig.h"
-
-static void FindFfcn();
-static void FindIfcn();
-/*
-:h3.Entry Points Provided to the TYPE1IMAGER User
-*/
-
-/*SHARED LINE(S) ORIGINATED HERE*/
-
-/*
-:h3.Entry Points Provided to Other Modules
-*/
-
-/*
-In addition, other modules call the SPACES module through function
-vectors in the "XYspace" structure. The entry points accessed that
-way are "FConvert()", "IConvert()", and "ForceFloat()".
-*/
-
-/*SHARED LINE(S) ORIGINATED HERE*/
-/*
-:h3.Macros and Typedefs Provided to Other Modules
-
-:h4.Duplicating and Killing Spaces
-
-Destroying XYspaces is so simple we can do it with a
-macro:
-*/
-
-/*SHARED LINE(S) ORIGINATED HERE*/
-/*
-On the other hand, duplicating XYspaces is slightly more difficult
-because of the need to keep a unique ID in the space, see
-:hdref refid=dupspace..
-
-:h4.Fixed Point Pel Representation
-
-We represent pel positions with fixed point numbers. This does NOT
-mean integer, but truly means fixed point, with a certain number
-of binary digits (FRACTBITS) representing the fractional part of the
-pel.
-*/
-
-/*SHARED LINE(S) ORIGINATED HERE*/
-/*
-:h2.Data Structures for Coordinate Spaces and Points
-*/
-/*
-:h3 id=matrix.Matrices
-
-TYPE1IMAGER uses 2x2 transformation matrices. We'll use C notation for
-such a matrix (M[2][2]), the first index being rows, the second columns.
-*/
-
-/*
-:h3.The "doublematrix" Structure
-
-We frequently find it desirable to store both a matrix and its
-inverse. We store these in a "doublematrix" structure.
-*/
-
-/*SHARED LINE(S) ORIGINATED HERE*/
-
-/*
-:h3.The "XYspace" Structure
-
-The XYspace structure represents the XYspace object.
-*/
-
-/*SHARED LINE(S) ORIGINATED HERE*/
-#define RESERVED 10 /* 'n' IDs are reserved for invalid & immortal spaces */
-/*
-*/
-#define NEXTID ((SpaceID < RESERVED) ? (SpaceID = RESERVED) : ++SpaceID)
-
-static unsigned int SpaceID = 1;
-
-struct XYspace *CopySpace(S)
- register struct XYspace *S;
-{
- S = (struct XYspace *)Allocate(sizeof(struct XYspace), S, 0);
- S->ID = NEXTID;
- return(S);
-}
-/*
-:h3.The "fractpoint" Structure
-
-A fractional point is just a "fractpel" x and y:
-*/
-
-/*SHARED LINE(S) ORIGINATED HERE*/
-
-/*
-:h3.Lazy Evaluation of Matrix Inverses
-
-Calculating the inverse of a matrix is somewhat involved, and we usually
-do not need them. So, we flag whether or not the space has the inverse
-already calculated:
-*/
-
-#define HASINVERSE(flag) ((flag)&0x80)
-
-/*
-The following macro forces a space to have an inverse:
-*/
-
-#define CoerceInverse(S) if (!HASINVERSE((S)->flag)) { \
- MatrixInvert((S)->tofract.normal, (S)->tofract.inverse); (S)->flag |= HASINVERSE(ON); }
-/*
-:h3.IDENTITY Space
-
-IDENTITY space is (logically) the space corresponding to the identity
-transformation matrix. However, since all our transformation matrices
-have a common FRACTFLOAT scale factor to convert to 'fractpel's, that
-is actually what we store in 'tofract' matrix of IDENTITY:
-*/
-
-static struct XYspace identity = { SPACETYPE, ISPERMANENT(ON) + ISIMMORTAL(ON)
- + HASINVERSE(ON), 2, /* added 3-26-91 PNM */
- NULL, NULL,
- NULL, NULL, NULL, NULL,
- INVALIDID + 1, 0,
- FRACTFLOAT, 0.0, 0.0, FRACTFLOAT,
- 1.0/FRACTFLOAT, 0.0, 0.0, 1.0/FRACTFLOAT,
- 0, 0, 0, 0 };
-struct XYspace *IDENTITY = &identity;
-
-/*
-*/
-#define MAXCONTEXTS 16
-
-static struct doublematrix contexts[MAXCONTEXTS];
-
-#ifdef notdef
-
-static int nextcontext = 1;
-
-/*SHARED LINE(S) ORIGINATED HERE*/
-
-#ifdef __STDC__
-#define pointer void *
-#else
-#define pointer char *
-#endif
-
-/*
-:h3.FindDeviceContext() - Find the Context Given a Device
-
-This routine, given a device, returns the index of the device's
-transformation matrix in the context array. If it cannot find it,
-it will allocate a new array entry and fill it out.
-*/
-
-static int FindDeviceContext(device)
- pointer device; /* device token */
-{
- double M[2][2]; /* temporary matrix */
- float Xres,Yres; /* device resolution */
- int orient = -1; /* device orientation */
- int rc = -1; /* return code for QueryDeviceState */
-
- if (rc != 0) /* we only bother with this check once */
- abort("Context: QueryDeviceState didn't work");
-
- M[0][0] = M[1][0] = M[0][1] = M[1][1] = 0.0;
-
- switch (orient) {
- case 0:
- M[0][0] = Xres; M[1][1] = -Yres;
- break;
- case 1:
- M[1][0] = Yres; M[0][1] = Xres;
- break;
- case 2:
- M[0][0] = -Xres; M[1][1] = Yres;
- break;
- case 3:
- M[1][0] = -Yres; M[0][1] = -Xres;
- break;
- default:
- abort("QueryDeviceState returned invalid orientation");
- }
- return(FindContext(M));
-}
-
-/*
-:h3.FindContext() - Find the Context Given a Matrix
-
-This routine, given a matrix, returns the index of that matrix matrix in
-the context array. If it cannot find it, it will allocate a new array
-entry and fill it out.
-*/
-
-int FindContext(M)
- double M[2][2]; /* array to search for */
-{
- register int i; /* loop variable for search */
- for (i=0; i < nextcontext; i++)
- if (M[0][0] == contexts[i].normal[0][0] && M[1][0] == contexts[i].normal[1][0]
- && M[0][1] == contexts[i].normal[0][1] && M[1][1] == contexts[i].normal[1][1])
- break;
-
- if (i >= nextcontext) {
- if (i >= MAXCONTEXTS)
- abort("Context: out of them");
- LONGCOPY(contexts[i].normal, M, sizeof(contexts[i].normal));
- MatrixInvert(M, contexts[i].inverse);
- nextcontext++;
- }
-
- return(i);
-}
-
-/*
-:h3.Context() - Create a Coordinate Space for a Device
-
-This user operator is implemented by first finding the device context
-array index, then transforming IDENTITY space to create an appropriate
-cooridnate space.
-*/
-
-struct XYspace *Context(device, units)
- pointer device; /* device token */
- double units; /* multiples of one inch */
-{
- double M[2][2]; /* device transformation matrix */
- register int n; /* will hold device context number */
- register struct XYspace *S; /* XYspace constructed */
-
- IfTrace2((MustTraceCalls),"Context(%x, %f)\n", device, &units);
-
- ARGCHECK((device == NULL), "Context of NULLDEVICE not allowed",
- NULL, IDENTITY, (0), struct XYspace *);
- ARGCHECK((units == 0.0), "Context: bad units", NULL, IDENTITY, (0), struct XYspace *);
-
- n = FindDeviceContext(device);
-
- LONGCOPY(M, contexts[n].normal, sizeof(M));
-
- M[0][0] *= units;
- M[0][1] *= units;
- M[1][0] *= units;
- M[1][1] *= units;
-
- S = (struct XYspace *)Xform(IDENTITY, M);
-
- S->context = n;
- return(S);
-}
-#endif
-
-/*
-:h3.ConsiderContext() - Adjust a Matrix to Take Out Device Transform
-
-Remember, we have :f/x times U times D/ and :f/M/ and and we want :f/x
-times U times M times D/. An easy way to do this is to calculate
-:f/D sup <-1> times M times D/, because:
-:formula.
-x times U times D times D sup <-1> times M times D = x times U times M times D
-:formula.
-So this subroutine, given an :f/M/and an object, finds the :f/D/ for that
-object and modifies :f/M/ so it is :f/D sup <-1> times M times D/.
-*/
-
-static void ConsiderContext(obj, M)
- register struct xobject *obj; /* object to be transformed */
- register double M[2][2]; /* matrix (may be changed) */
-{
- register int context; /* index in contexts array */
-
- if (obj == NULL) return;
-
- if (ISPATHTYPE(obj->type)) {
- struct segment *path = (struct segment *) obj;
-
- context = path->context;
- }
- else if (obj->type == SPACETYPE) {
- struct XYspace *S = (struct XYspace *) obj;
-
- context = S->context;
- }
- else if (obj->type == PICTURETYPE) {
-
- }
- else
- context = NULLCONTEXT;
-
- if (context != NULLCONTEXT) {
- MatrixMultiply(contexts[context].inverse, M, M);
- MatrixMultiply(M, contexts[context].normal, M);
- }
-}
-
-/*
-:h2.Conversion from User's X,Y to "fractpel" X,Y
-
-When the user is building paths (lines, moves, curves, etc.) he passes
-the control points (x,y) for the paths together with an XYspace. We
-must convert from the user's (x,y) to our internal representation
-which is in pels (fractpels, actually). This involves transforming
-the user's (x,y) under the coordinate space transformation. It is
-important that we do this quickly. So, we store pointers to different
-conversion functions right in the XYspace structure. This allows us
-to have simpler special case functions for the more commonly
-encountered types of transformations.
-
-:h3.Convert(), IConvert(), and ForceFloat() - Called Through "XYspace" Structure
-
-These are functions that fit in the "convert" and "iconvert" function
-pointers in the XYspace structure. They call the "xconvert", "yconvert",
-"ixconvert", and "iyconvert" as appropriate to actually do the work.
-These secondary routines come in many flavors to handle different
-special cases as quickly as possible.
-*/
-
-static void FXYConvert(pt, S, x, y)
- register struct fractpoint *pt; /* point to set */
- register struct XYspace *S; /* relevant coordinate space */
- register double x,y; /* user's coordinates of point */
-{
- pt->x = (*S->xconvert)(S->tofract.normal[0][0], S->tofract.normal[1][0], x, y);
- pt->y = (*S->yconvert)(S->tofract.normal[0][1], S->tofract.normal[1][1], x, y);
-}
-
-static void IXYConvert(pt, S, x, y)
- register struct fractpoint *pt; /* point to set */
- register struct XYspace *S; /* relevant coordinate space */
- register long x,y; /* user's coordinates of point */
-{
- pt->x = (*S->ixconvert)(S->itofract[0][0], S->itofract[1][0], x, y);
- pt->y = (*S->iyconvert)(S->itofract[0][1], S->itofract[1][1], x, y);
-}
-
-/*
-ForceFloat is a substitute for IConvert(), when we just do not have
-enough significant digits in the coefficients to get high enough
-precision in the answer with fixed point arithmetic. So, we force the
-integers to floats, and do the arithmetic all with floats:
-*/
-
-static void ForceFloat(pt, S, x, y)
- register struct fractpoint *pt; /* point to set */
- register struct XYspace *S; /* relevant coordinate space */
- register long x,y; /* user's coordinates of point */
-{
- (*S->convert)(pt, S, (double) x, (double) y);
-}
-
-/*
-:h3.FXYboth(), FXonly(), FYonly() - Floating Point Conversion
-
-These are the routines we use when the user has given us floating
-point numbers for x and y. FXYboth() is the general purpose routine;
-FXonly() and FYonly() are special cases when one of the coefficients
-is 0.0.
-*/
-
-static fractpel FXYboth(cx, cy, x, y)
- register double cx,cy; /* x and y coefficients */
- register double x,y; /* user x,y */
-{
- register double r; /* temporary float */
-
- r = x * cx + y * cy;
- return((fractpel) r);
-}
-
-/*ARGSUSED*/
-static fractpel FXonly(cx, cy, x, y)
- register double cx,cy; /* x and y coefficients */
- register double x,y; /* user x,y */
-{
- register double r; /* temporary float */
-
- r = x * cx;
- return((fractpel) r);
-}
-
-/*ARGSUSED*/
-static fractpel FYonly(cx, cy, x, y)
- register double cx,cy; /* x and y coefficients */
- register double x,y; /* user x,y */
-{
- register double r; /* temporary float */
-
- r = y * cy;
- return((fractpel) r);
-}
-
-/*
-:h3.IXYboth(), IXonly(), IYonly() - Simple Integer Conversion
-
-These are the routines we use when the user has given us integers for
-x and y, and the coefficients have enough significant digits to
-provide precise answers with only "long" (32 bit?) multiplication.
-IXYboth() is the general purpose routine; IXonly() and IYonly() are
-special cases when one of the coefficients is 0.
-*/
-
-static fractpel IXYboth(cx, cy, x, y)
- register fractpel cx,cy; /* x and y coefficients */
- register long x,y; /* user x,y */
-{
- return(x * cx + y * cy);
-}
-
-/*ARGSUSED*/
-static fractpel IXonly(cx, cy, x, y)
- register fractpel cx,cy; /* x and y coefficients */
- register long x,y; /* user x,y */
-{
- return(x * cx);
-}
-
-/*ARGSUSED*/
-static fractpel IYonly(cx, cy, x, y)
- register fractpel cx,cy; /* x and y coefficients */
- register long x,y; /* user x,y */
-{
- return(y * cy);
-}
-
-
-/*
-:h3.FPXYboth(), FPXonly(), FPYonly() - More Involved Integer Conversion
-
-These are the routines we use when the user has given us integers for
-x and y, but the coefficients do not have enough significant digits to
-provide precise answers with only "long" (32 bit?) multiplication.
-We have increased the number of significant bits in the coefficients
-by FRACTBITS; therefore we must use "double long" (64 bit?)
-multiplication by calling FPmult(). FPXYboth() is the general purpose
-routine; FPXonly() and FPYonly() are special cases when one of the
-coefficients is 0.
-
-Note that it is perfectly possible for us to calculate X with the
-"FP" method and Y with the "I" method, or vice versa. It all depends
-on how the functions in the XYspace structure are filled out.
-*/
-
-static fractpel FPXYboth(cx, cy, x, y)
- register fractpel cx,cy; /* x and y coefficients */
- register long x,y; /* user x,y */
-{
- return( FPmult(x, cx) + FPmult(y, cy) );
-}
-
-/*ARGSUSED*/
-static fractpel FPXonly(cx, cy, x, y)
- register fractpel cx,cy; /* x and y coefficients */
- register long x,y; /* user x,y */
-{
- return( FPmult(x, cx) );
-}
-
-/*ARGSUSED*/
-static fractpel FPYonly(cx, cy, x, y)
- register fractpel cx,cy; /* x and y coefficients */
- register long x,y; /* user x,y */
-{
- return( FPmult(y, cy) );
-}
-
-
-
-/*
-:h3.FillOutFcns() - Determine the Appropriate Functions to Use for Conversion
-
-This function fills out the "convert" and "iconvert" function pointers
-in an XYspace structure, and also fills the "helper"
-functions that actually do the work.
-*/
-
-static void FillOutFcns(S)
- register struct XYspace *S; /* functions will be set in this structure */
-{
- S->convert = FXYConvert;
- S->iconvert = IXYConvert;
-
- FindFfcn(S->tofract.normal[0][0], S->tofract.normal[1][0], &S->xconvert);
- FindFfcn(S->tofract.normal[0][1], S->tofract.normal[1][1], &S->yconvert);
- FindIfcn(S->tofract.normal[0][0], S->tofract.normal[1][0],
- &S->itofract[0][0], &S->itofract[1][0], &S->ixconvert);
- FindIfcn(S->tofract.normal[0][1], S->tofract.normal[1][1],
- &S->itofract[0][1], &S->itofract[1][1], &S->iyconvert);
-
- if (S->ixconvert == NULL || S->iyconvert == NULL)
- S->iconvert = ForceFloat;
-}
-
-/*
-:h4.FindFfcn() - Subroutine of FillOutFcns() to Fill Out Floating Functions
-
-This function tests for the special case of one of the coefficients
-being zero:
-*/
-
-static void FindFfcn(cx, cy, fcnP)
- register double cx,cy; /* x and y coefficients */
- register fractpel (**fcnP)(); /* pointer to function to set */
-{
- if (cx == 0.0)
- *fcnP = FYonly;
- else if (cy == 0.0)
- *fcnP = FXonly;
- else
- *fcnP = FXYboth;
-}
-
-/*
-:h4.FindIfcn() - Subroutine of FillOutFcns() to Fill Out Integer Functions
-
-There are two types of integer functions, the 'I' type and the 'FP' type.
-We use the I type functions when we are satisfied with simple integer
-arithmetic. We used the FP functions when we feel we need higher
-precision (but still fixed point) arithmetic. If all else fails,
-we store a NULL indicating that this we should do the conversion in
-floating point.
-*/
-
-static void FindIfcn(cx, cy, icxP, icyP, fcnP)
- register double cx,cy; /* x and y coefficients */
- register fractpel *icxP,*icyP; /* fixed point coefficients to set */
- register fractpel (**fcnP)(); /* pointer to function to set */
-{
- register fractpel imax; /* maximum of cx and cy */
-
- *icxP = cx;
- *icyP = cy;
-
- if (cx != (float) (*icxP) || cy != (float) (*icyP)) {
-/*
-At this point we know our integer approximations of the coefficients
-are not exact. However, we will still use them if the maximum
-coefficient will not fit in a 'fractpel'. Of course, we have little
-choice at that point, but we haven't lost that much precision by
-staying with integer arithmetic. We have enough significant digits
-so that
-any error we introduce is less than one part in 2:sup/16/.
-*/
-
- imax = MAX(ABS(*icxP), ABS(*icyP));
- if (imax < (fractpel) (1<<(FRACTBITS-1)) ) {
-/*
-At this point we know our integer approximations just do not have
-enough significant digits for accuracy. We will add FRACTBITS
-significant digits to the coefficients (by multiplying them by
-1<<FRACTBITS) and go to the "FP" form of the functions. First, we
-check to see if we have ANY significant digits at all (that is, if
-imax == 0). If we don't, we suspect that adding FRACTBITS digits
-won't help, so we punt the whole thing.
-*/
- if (imax == 0) {
- *fcnP = NULL;
- return;
- }
- cx *= FRACTFLOAT;
- cy *= FRACTFLOAT;
- *icxP = cx;
- *icyP = cy;
- *fcnP = FPXYboth;
- }
- else
- *fcnP = IXYboth;
- }
- else
- *fcnP = IXYboth;
-/*
-Now we check for special cases where one coefficient is zero (after
-integer conversion):
-*/
- if (*icxP == 0)
- *fcnP = (*fcnP == FPXYboth) ? FPYonly : IYonly;
- else if (*icyP == 0)
- *fcnP = (*fcnP == FPXYboth) ? FPXonly : IXonly;
-}
-/*
-:h3.UnConvert() - Find User Coordinates From FractPoints
-
-The interesting thing with this routine is that we avoid calculating
-the matrix inverse of the device transformation until we really need
-it, which is to say, until this routine is called for the first time
-with a given coordinate space.
-
-We also only calculate it only once. If the inverted matrix is valid,
-we don't calculate it; if not, we do. We never expect matrices with
-zero determinants, so by convention, we mark the matrix is invalid by
-marking both X terms zero.
-*/
-
-void UnConvert(S, pt, xp, yp)
- register struct XYspace *S; /* relevant coordinate space */
- register struct fractpoint *pt; /* device coordinates */
- double *xp,*yp; /* where to store resulting x,y */
-{
- double x,y;
-
- CoerceInverse(S);
- x = pt->x;
- y = pt->y;
- *xp = S->tofract.inverse[0][0] * x + S->tofract.inverse[1][0] * y;
- *yp = S->tofract.inverse[0][1] * x + S->tofract.inverse[1][1] * y;
-}
-
-/*
-:h2.Transformations
-*/
-/*
-:h3 id=xform.Xform() - Transform Object in X and Y
-
-TYPE1IMAGER wants transformations of objects like paths to be identical
-to transformations of spaces. For example, if you scale a line(1,1)
-by 10 it should yield the same result as generating the line(1,1) in
-a coordinate space that has been scaled by 10.
-
-We handle fonts by storing the accumulated transform, for example, SR
-(accumulating on the right). Then when we map the font through space TD,
-for example, we multiply the accumulated font transform on the left by
-the space transform on the right, yielding SRTD in this case. We will
-get the same result if we did S, then R, then T on the space and mapping
-an unmodified font through that space.
-*/
-
-struct xobject *t1_Xform(obj, M)
- register struct xobject *obj; /* object to transform */
- register double M[2][2]; /* transformation matrix */
-{
- if (obj == NULL)
- return(NULL);
-
- if (obj->type == FONTTYPE) {
- register struct font *F = (struct font *) obj;
-
- F = UniqueFont(F);
- return((struct xobject*)F);
- }
- if (obj->type == PICTURETYPE) {
-/*
-In the case of a picture, we choose both to update the picture's
-transformation matrix and keep the handles up to date.
-*/
- register struct picture *P = (struct picture *) obj;
- register struct segment *handles; /* temporary path to transform handles */
-
- P = UniquePicture(P);
- handles = PathSegment(LINETYPE, P->origin.x, P->origin.y);
- handles = Join(handles,
- PathSegment(LINETYPE, P->ending.x, P->ending.y) );
- handles = (struct segment *)Xform((struct xobject *) handles, M);
- P->origin = handles->dest;
- P->ending = handles->link->dest;
- KillPath(handles);
- return((struct xobject *)P);
- }
-
- if (ISPATHTYPE(obj->type)) {
- struct XYspace pseudo; /* local temporary space */
- PseudoSpace(&pseudo, M);
- return((struct xobject *) PathTransform(obj, &pseudo));
- }
-
-
- if (obj->type == SPACETYPE) {
- register struct XYspace *S = (struct XYspace *) obj;
-
-/* replaced ISPERMANENT(S->flag) with S->references > 1 3-26-91 PNM */
- if (S->references > 1)
- S = CopySpace(S);
- else
- S->ID = NEXTID;
-
- MatrixMultiply(S->tofract.normal, M, S->tofract.normal);
- /*
- * mark inverted matrix invalid:
- */
- S->flag &= ~HASINVERSE(ON);
-
- FillOutFcns(S);
- return((struct xobject *) S);
- }
-
- return(ArgErr("Untransformable object", obj, obj));
-}
-
-/*
-:h3.Transform() - Transform an Object
-
-This is the external user's entry point.
-*/
-struct xobject *t1_Transform(obj, cxx, cyx, cxy, cyy)
- struct xobject *obj;
- double cxx,cyx,cxy,cyy; /* 2x2 transform matrix elements in row order */
-{
- double M[2][2];
-
- IfTrace1((MustTraceCalls),"Transform(%z,", obj);
- IfTrace4((MustTraceCalls)," %f %f %f %f)\n", &cxx, &cyx, &cxy, &cyy);
-
- M[0][0] = cxx;
- M[0][1] = cyx;
- M[1][0] = cxy;
- M[1][1] = cyy;
- ConsiderContext(obj, M);
- return(Xform(obj, M));
-}
-/*
-:h3.Scale() - Special Case of Transform()
-
-This is a user operator.
-*/
-
-struct xobject *t1_Scale(obj, sx, sy)
- struct xobject *obj; /* object to scale */
- double sx,sy; /* scale factors in x and y */
-{
- double M[2][2];
- IfTrace3((MustTraceCalls),"Scale(%z, %f, %f)\n", obj, &sx, &sy);
- M[0][0] = sx;
- M[1][1] = sy;
- M[1][0] = M[0][1] = 0.0;
- ConsiderContext(obj, M);
- return(Xform(obj, M));
-}
-
-/*
-:h3 id=rotate.Rotate() - Special Case of Transform()
-
-We special-case different settings of 'degrees' for performance
-and accuracy within the DegreeSin() and DegreeCos() routines themselves.
-*/
-
-#ifdef notdef
-struct xobject *xiRotate(obj, degrees)
- struct xobject *obj; /* object to be transformed */
- double degrees; /* degrees of COUNTER-clockwise rotation */
-{
- double M[2][2];
-
-
- IfTrace2((MustTraceCalls),"Rotate(%z, %f)\n", obj, °rees);
-
- M[0][0] = M[1][1] = DegreeCos(degrees);
- M[1][0] = - (M[0][1] = DegreeSin(degrees));
- ConsiderContext(obj, M);
- return(Xform(obj, M));
-}
-#endif
-
-/*
-:h3.PseudoSpace() - Build a Coordinate Space from a Matrix
-
-Since we have built all this optimized code that, given an (x,y) and
-a coordinate space, yield transformed (x,y), it seems a shame not to
-use the same logic when we need to multiply an (x,y) by an arbitrary
-matrix that is not (initially) part of a coordinate space. This
-subroutine takes the arbitrary matrix and builds a coordinate
-space, with all its nifty function pointers.
-*/
-
-void PseudoSpace(S, M)
- struct XYspace *S; /* coordinate space structure to fill out */
- double M[2][2]; /* matrix that will become 'tofract.normal' */
-{
- S->type = SPACETYPE;
- S->flag = ISPERMANENT(ON) + ISIMMORTAL(ON);
- S->references = 2; /* 3-26-91 added PNM */
- S->tofract.normal[0][0] = M[0][0];
- S->tofract.normal[1][0] = M[1][0];
- S->tofract.normal[0][1] = M[0][1];
- S->tofract.normal[1][1] = M[1][1];
-
- FillOutFcns(S);
-}
-
-/*
-:h2 id=matrixa.Matrix Arithmetic
-
-Following the convention in Newman and Sproull, :hp1/Interactive
-Computer Graphics/,
-matrices are organized:
-:xmp.
- | cxx cyx |
- | cxy cyy |
-:exmp.
-A point is horizontal, for example:
-:xmp.
- [ x y ]
-:exmp.
-This means that:
-:formula/x prime = cxx times x + cxy times y/
-:formula/y prime = cyx times x + cyy times y/
-I've seen the other convention, where transform matrices are
-transposed, equally often in the literature.
-*/
-
-/*
-:h3.MatrixMultiply() - Implements Multiplication of Two Matrices
-
-Implements matrix multiplication, A * B = C.
-
-To remind myself, matrix multiplication goes rows of A times columns
-of B.
-The output matrix may be the same as one of the input matrices.
-*/
-void MatrixMultiply(A, B, C)
- register double A[2][2],B[2][2]; /* input matrices */
- register double C[2][2]; /* output matrix */
-{
- register double txx,txy,tyx,tyy;
-
- txx = A[0][0] * B[0][0] + A[0][1] * B[1][0];
- txy = A[1][0] * B[0][0] + A[1][1] * B[1][0];
- tyx = A[0][0] * B[0][1] + A[0][1] * B[1][1];
- tyy = A[1][0] * B[0][1] + A[1][1] * B[1][1];
-
- C[0][0] = txx;
- C[1][0] = txy;
- C[0][1] = tyx;
- C[1][1] = tyy;
-}
-/*
-:h3.MatrixInvert() - Invert a Matrix
-
-My reference for matrix inversion was :hp1/Elementary Linear Algebra/
-by Paul C. Shields, Worth Publishers, Inc., 1968.
-*/
-void MatrixInvert(M, Mprime)
- double M[2][2]; /* input matrix */
- double Mprime[2][2]; /* output inverted matrix */
-{
- register double D; /* determinant of matrix M */
- register double txx,txy,tyx,tyy;
-
- txx = M[0][0];
- txy = M[1][0];
- tyx = M[0][1];
- tyy = M[1][1];
-
- D = M[1][1] * M[0][0] - M[1][0] * M[0][1];
- if (D == 0.0)
- abort("MatrixInvert: can't");
-
- Mprime[0][0] = tyy / D;
- Mprime[1][0] = -txy / D;
- Mprime[0][1] = -tyx / D;
- Mprime[1][1] = txx / D;
-}
-/*
-:h2.Initialization, Queries, and Debug
-*/
-/*
-:h3.InitSpaces() - Initialize Constant Spaces
-
-For compatibility, we initialize a coordinate space called USER which
-maps 72nds of an inch to pels on the default device.
-*/
-
-struct XYspace *USER = &identity;
-
-void InitSpaces()
-{
- extern char *DEFAULTDEVICE;
-
- IDENTITY->type = SPACETYPE;
- FillOutFcns(IDENTITY);
-
- contexts[NULLCONTEXT].normal[1][0]
- = contexts[NULLCONTEXT].normal[0][1]
- = contexts[NULLCONTEXT].inverse[1][0]
- = contexts[NULLCONTEXT].inverse[0][1] = 0.0;
- contexts[NULLCONTEXT].normal[0][0]
- = contexts[NULLCONTEXT].normal[1][1]
- = contexts[NULLCONTEXT].inverse[0][0]
- = contexts[NULLCONTEXT].inverse[1][1] = 1.0;
-
- USER->flag |= ISIMMORTAL(ON);
- CoerceInverse(USER);
-}
-/*
-:h3.QuerySpace() - Returns the Transformation Matrix of a Space
-
-Since the tofract matrix of an XYspace includes the scale factor
-necessary to produce fractpel results (i.e., FRACTFLOAT), this
-must be taken out before we return the matrix to the user. Fortunately,
-this is simple: just multiply by the inverse of IDENTITY!
-*/
-
-void QuerySpace(S, cxxP, cyxP, cxyP, cyyP)
- register struct XYspace *S; /* space asked about */
- register double *cxxP,*cyxP,*cxyP,*cyyP; /* where to put answer */
-{
- double M[2][2]; /* temp matrix to build user's answer */
-
- if (S->type != SPACETYPE) {
- ArgErr("QuerySpace: not a space", S, NULL);
- return;
- }
- MatrixMultiply(S->tofract.normal, IDENTITY->tofract.inverse, M);
- *cxxP = M[0][0];
- *cxyP = M[1][0];
- *cyxP = M[0][1];
- *cyyP = M[1][1];
-}
-
-/*
-:h3.FormatFP() - Format a Fixed Point Pel
-
-We format the pel as "dddd.XXXX", where XX's are hexidecimal digits,
-and the dd's are decimal digits. This might be a little confusing
-mixing hexidecimal and decimal like that, but it is convenient
-to use for debug.
-
-We make sure we have N (FRACTBITS/4) digits past the decimal point.
-*/
-#define FRACTMASK ((1<<FRACTBITS)-1) /* mask for fractional part */
-
-void FormatFP(string, fpel)
- register char *string; /* output string */
- register fractpel fpel; /* fractional pel input */
-{
- char temp[8];
- register char *s;
- register char *sign;
-
- if (fpel < 0) {
- sign = "-";
- fpel = -fpel;
- }
- else
- sign = "";
-
- sprintf(temp, "000%x", fpel & FRACTMASK);
- s = temp + strlen(temp) - (FRACTBITS/4);
-
- sprintf(string, "%s%d.%sx", sign, fpel >> FRACTBITS, s);
-}
-
-/*
-:h3.DumpSpace() - Display a Coordinate Space
-*/
-/*ARGSUSED*/
-void DumpSpace(S)
- register struct XYspace *S;
-{
- IfTrace4(TRUE,"--Coordinate space at %x,ID=%d,convert=%x,iconvert=%x\n",
- S, S->ID, S->convert, S->iconvert);
- IfTrace2(TRUE," | %12.3f %12.3f |",
- &S->tofract.normal[0][0], &S->tofract.normal[0][1]);
- IfTrace2(TRUE," [ %p %p ]\n", S->itofract[0][0], S->itofract[0][1]);
- IfTrace2(TRUE," | %12.3f %12.3f |",
- &S->tofract.normal[1][0], &S->tofract.normal[1][1]);
- IfTrace2(TRUE," [ %p %p ]\n", S->itofract[1][0], S->itofract[1][1]);
-}
projects / rdpsrv / blobdiff