140 lines
2.8 KiB
C
140 lines
2.8 KiB
C
/* #include "HEADERS.h" */
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/* Copyright 1988, Brown Computer Graphics Group. All Rights Reserved. */
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/* --------------------------------------------------------------------------
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* This file contains routines that operate solely on matrices.
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* -------------------------------------------------------------------------*/
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#include <string.h>
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#include "mat3defs.h"
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/* #include "macros.h" */
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/* -------------------------- Static Routines ---------------------------- */
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/* ------------------------- Internal Routines --------------------------- */
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/* -------------------------- Public Routines ---------------------------- */
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/*
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* Sets a matrix to identity.
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*/
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void
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MAT3identity (register MAT3mat mat)
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{
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register int i;
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bzero (mat, sizeof(MAT3mat));
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for (i = 0; i < 4; i++)
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mat[i][i] = 1.0;
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}
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/*
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* Sets a matrix to zero.
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*/
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void
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MAT3zero (MAT3mat mat)
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{
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bzero (mat, sizeof(MAT3mat));
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}
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/*
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* Copies one matrix to another.
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*/
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void
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MAT3copy(MAT3mat to, MAT3mat from)
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{
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bcopy (from, to, sizeof(MAT3mat));
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}
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/*
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* This multiplies two matrices, producing a third, which may the same as
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* either of the first two.
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*/
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void
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MAT3mult (result_mat, mat1, mat2)
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MAT3mat result_mat;
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register MAT3mat mat1, mat2;
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{
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register int i, j;
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MAT3mat tmp_mat;
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for (i = 0; i < 4; i++)
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for (j = 0; j < 4; j++)
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tmp_mat[i][j] = (mat1[i][0] * mat2[0][j] +
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mat1[i][1] * mat2[1][j] +
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mat1[i][2] * mat2[2][j] +
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mat1[i][3] * mat2[3][j]);
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MAT3copy (result_mat, tmp_mat);
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}
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/*
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* This returns the transpose of a matrix. The result matrix may be
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* the same as the one to transpose.
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*/
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void
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MAT3transpose (result_mat, mat)
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MAT3mat result_mat;
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register MAT3mat mat;
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{
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register int i, j;
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MAT3mat tmp_mat;
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for (i = 0; i < 4; i++)
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for (j = 0; j < 4; j++)
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tmp_mat[i][j] = mat[j][i];
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MAT3copy (result_mat, tmp_mat);
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}
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/*
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* This prints the given matrix to the given file pointer.
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*/
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void
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MAT3print(mat, fp)
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MAT3mat mat;
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FILE *fp;
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{
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MAT3print_formatted(mat, fp, CNULL, CNULL, CNULL, CNULL);
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}
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/*
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* This prints the given matrix to the given file pointer.
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* use the format string to pass to fprintf. head and tail
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* are printed at the beginning and end of each line.
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*/
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void
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MAT3print_formatted(mat, fp, title, head, format, tail)
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MAT3mat mat;
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FILE *fp;
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char *title, *head, *format, *tail;
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{
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register int i, j;
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/* This is to allow this to be called easily from a debugger */
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if (fp == NULL) fp = stderr;
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if (title == NULL) title = "MAT3 matrix:\n";
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if (head == NULL) head = " ";
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if (format == NULL) format = "%#8.4lf ";
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if (tail == NULL) tail = "\n";
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(void) fprintf(fp, title);
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for (i = 0; i < 4; i++) {
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(void) fprintf(fp, head);
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for (j = 0; j < 4; j++) (void) fprintf(fp, format, mat[i][j]);
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(void) fprintf(fp, tail);
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}
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}
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