The MAT3 routines from SRGP.

Math/MAT3mat.c

@@ -0,0 +1,138 @@
+/* #include "HEADERS.h" */
+/* Copyright 1988, Brown Computer Graphics Group.  All Rights Reserved. */
+
+/* --------------------------------------------------------------------------
+ * This file contains routines that operate solely on matrices.
+ * -------------------------------------------------------------------------*/
+
+#include "mat3defs.h"
+
+/* #include "macros.h" */
+
+/* --------------------------  Static Routines	---------------------------- */
+
+/* -------------------------  Internal Routines  --------------------------- */
+
+/* --------------------------  Public Routines	---------------------------- */
+
+
+/*
+ * Sets a matrix to identity.
+ */
+
+void
+MAT3identity (register MAT3mat mat)
+{
+   register int i;
+
+   bzero (mat, sizeof(MAT3mat));
+   for (i = 0; i < 4; i++)
+      mat[i][i] = 1.0;
+}
+
+/*
+ * Sets a matrix to zero.
+ */
+
+void
+MAT3zero (MAT3mat mat)
+{
+   bzero (mat, sizeof(MAT3mat));
+}
+
+
+/*
+ * Copies one matrix to another.
+ */
+
+void
+MAT3copy(MAT3mat to, MAT3mat from)
+{
+   bcopy (from, to, sizeof(MAT3mat));
+}
+
+/*
+ * This multiplies two matrices, producing a third, which may the same as
+ * either of the first two.
+ */
+
+void
+MAT3mult (result_mat, mat1, mat2)
+MAT3mat result_mat;
+register MAT3mat mat1, mat2;
+{
+   register int i, j;
+   MAT3mat	tmp_mat;
+
+   for (i = 0; i < 4; i++)
+      for (j = 0; j < 4; j++)
+         tmp_mat[i][j] = (mat1[i][0] * mat2[0][j] +
+		       mat1[i][1] * mat2[1][j] +
+		       mat1[i][2] * mat2[2][j] +
+		       mat1[i][3] * mat2[3][j]);
+   MAT3copy (result_mat, tmp_mat);
+}
+
+/*
+ * This returns the transpose of a matrix.  The result matrix may be
+ * the same as the one to transpose.
+ */
+
+void
+MAT3transpose (result_mat, mat)
+MAT3mat result_mat;
+register MAT3mat mat;
+{
+   register int i, j;
+   MAT3mat	tmp_mat;
+
+   for (i = 0; i < 4; i++) 
+      for (j = 0; j < 4; j++) 
+         tmp_mat[i][j] = mat[j][i];
+
+   MAT3copy (result_mat, tmp_mat);
+}
+
+
+/*
+ * This prints the given matrix to the given file pointer.
+ */
+
+void
+MAT3print(mat, fp)
+MAT3mat mat;
+FILE	*fp;
+{
+   MAT3print_formatted(mat, fp, CNULL, CNULL, CNULL, CNULL);
+}
+
+/*
+ * This prints the given matrix to the given file pointer.
+ * use the format string to pass to fprintf.  head and tail
+ * are printed at the beginning and end of each line.
+ */
+
+void
+MAT3print_formatted(mat, fp, title, head, format, tail)
+MAT3mat mat;
+FILE	*fp;
+char	*title, *head, *format, *tail;
+{
+   register int i, j;
+
+   /* This is to allow this to be called easily from a debugger */
+   if (fp == NULL) fp = stderr;
+
+   if (title  == NULL)	title  = "MAT3 matrix:\n";
+   if (head   == NULL)	head   = "  ";
+   if (format == NULL)	format = "%#8.4lf  ";
+   if (tail   == NULL)	tail   = "\n";
+
+   (void) fprintf(fp, title);
+
+   for (i = 0; i < 4; i++) {
+      (void) fprintf(fp, head);
+      for (j = 0; j < 4; j++) (void) fprintf(fp, format, mat[i][j]);
+      (void) fprintf(fp, tail);
+   }
+}