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/*
* $XFree86: $
*
* Copyright © 2002 University of Southern California
*
* Permission to use, copy, modify, distribute, and sell this software
* and its documentation for any purpose is hereby granted without
* fee, 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 University
* of Southern California not be used in advertising or publicity
* pertaining to distribution of the software without specific,
* written prior permission. University of Southern California makes
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied
* warranty.
*
* UNIVERSITY OF SOUTHERN CALIFORNIA DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL UNIVERSITY OF
* SOUTHERN CALIFORNIA 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.
*
* Author: Carl Worth, USC, Information Sciences Institute */
#include <stdlib.h>
#include <math.h>
#include "xrint.h"
static XrTransform XR_TRANSFORM_DEFAULT = {
{1, 0,
0, 1,
0, 0}
};
void
XrTransformInit(XrTransform *transform)
{
*transform = XR_TRANSFORM_DEFAULT;
}
void
XrTransformInitMatrix(XrTransform *transform,
double a, double b,
double c, double d,
double tx, double ty)
{
transform->matrix[0] = a; transform->matrix[1] = b;
transform->matrix[2] = c; transform->matrix[3] = d;
transform->matrix[4] = tx; transform->matrix[5] = ty;
}
void
XrTransformInitTranslate(XrTransform *transform,
double tx, double ty)
{
XrTransformInitMatrix(transform,
1, 0,
0, 1,
tx, ty);
}
void
XrTransformInitScale(XrTransform *transform,
double sx, double sy)
{
XrTransformInitMatrix(transform,
sx, 0,
0, sy,
0, 0);
}
void
XrTransformInitRotate(XrTransform *transform,
double angle)
{
XrTransformInitMatrix(transform,
cos(angle), sin(angle),
-sin(angle), cos(angle),
0, 0);
}
void
XrTransformDeinit(XrTransform *transform)
{
/* Nothing to do here */
}
void
XrTransformCompose(XrTransform *t1, const XrTransform *t2)
{
double new[6];
new[0] = t2->matrix[0] * t1->matrix[0] + t2->matrix[1] * t1->matrix[2];
new[1] = t2->matrix[0] * t1->matrix[1] + t2->matrix[1] * t1->matrix[3];
new[2] = t2->matrix[2] * t1->matrix[0] + t2->matrix[3] * t1->matrix[2];
new[3] = t2->matrix[2] * t1->matrix[1] + t2->matrix[3] * t1->matrix[3];
new[4] = t2->matrix[4] * t1->matrix[0] + t2->matrix[5] * t1->matrix[2] + t1->matrix[4];
new[5] = t2->matrix[4] * t1->matrix[1] + t2->matrix[5] * t1->matrix[3] + t1->matrix[5];
memcpy(t1->matrix, new, 6 * sizeof(double));
}
void
XrTransformPointWithoutTranslate(XrTransform *transform, XPointDouble *pt)
{
double new_x, new_y;
new_x = (transform->matrix[0] * pt->x
+ transform->matrix[2] * pt->y);
new_y = (transform->matrix[1] * pt->x
+ transform->matrix[3] * pt->y);
pt->x = new_x;
pt->y = new_y;
}
void
XrTransformPoint(XrTransform *transform, XPointDouble *pt)
{
XrTransformPointWithoutTranslate(transform, pt);
pt->x += transform->matrix[4];
pt->y += transform->matrix[5];
}
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