Added scaling and rotation support.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/gui/trunk@2386 72102866-910b-0410-8b05-ffd578937521

Source/PSMatrix.m

@@ -0,0 +1,198 @@
+/*
+   PSMatrix.m
+
+   Copyright (C) 1996 Free Software Foundation, Inc.
+
+   Author: Ovidiu Predescu <ovidiu@net-community.com>
+   Date: August 1997
+   
+   This file is part of the GNUstep GUI Library.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+   
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this library; if not, write to the Free
+   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include <math.h>
+
+#include <AppKit/config.h>
+#include <AppKit/PSMatrix.h>
+
+/* A Postscript matrix look like this:
+
+  /  a  b  0 \
+  |  c  d  0 |
+  \ tx ty  1 /
+
+ */
+
+static const float pi = 3.1415926535897932384626433;
+
+@implementation PSMatrix
+
++ matrixFrom:(float[6])_matrix
+{
+  PSMatrix* m = [[self alloc] autorelease];
+
+  memcpy (m->matrix, _matrix, sizeof (m->matrix));
+
+  return m;
+}
+
+- init
+{
+  [self makeIdentityMatrix];
+  rotationAngle = 0;
+  return self;
+}
+
+- (id)copyWithZone:(NSZone*)zone
+{
+  PSMatrix* new = [isa alloc];
+
+  memcpy (new->matrix, matrix, sizeof(matrix));
+  new->rotationAngle = rotationAngle;
+  return new;
+}
+
+- (void)scaleBy:(float)sx :(float)sy
+{
+  A *= sx; B *= sx;
+  C *= sy; D *= sy;
+}
+
+- (void)translateToPoint:(NSPoint)point
+{
+  float newTX, newTY;
+
+  newTX = point.x * A + point.y * C + TX;
+  newTY = point.x * B + point.y * D + TY;
+  TX = newTX;
+  TY = newTY;
+}
+
+- (void)rotateByAngle:(float)angle
+{
+  float newA, newB, newC, newD;
+  float angleRad = pi * angle / 180;
+  float sine = sin (angleRad);
+  float cosine = cos (angleRad);
+
+  newA = A * cosine + C * sine;   newB = B * cosine + D * sine;
+  newC = -A * sine + C * cosine;  newD = -B * sine + D * cosine;
+
+  A = newA; B = newB;
+  C = newC; D = newD;
+
+  rotationAngle += angle;
+}
+
+- (void)makeIdentityMatrix
+{
+   A = 1;  B = 0;
+   C = 0;  D = 1;
+  TX = 0; TY = 0;
+  rotationAngle = 0;
+}
+
+- (void)setFrameOrigin:(NSPoint)point
+{
+  float dx = point.x - TX;
+  float dy = point.y - TY;
+  [self translateToPoint:NSMakePoint (dx, dy)];
+}
+
+- (void)setFrameRotation:(float)angle
+{
+  float newAngle = angle - rotationAngle;
+  [self rotateByAngle:newAngle];
+}
+
+- (float)rotationAngle
+{
+  return rotationAngle;
+}
+
+- (void)concatenateWith:(PSMatrix*)other
+{
+  float newA, newB, newC, newD, newTX, newTY;
+
+  newA = other->A * A + other->B * C;
+  newB = other->A * B + other->B * D;
+  newC = other->C * A + other->D * C;
+  newD = other->C * B + other->D * D;
+  newTX = other->TX * A + other->TY * C + TX;
+  newTY = other->TX * B + other->TY * D + TY;
+
+  A = newA; B = newB;
+  C = newC; D = newD;
+  TX = newTX; TY = newTY;
+
+  rotationAngle += other->rotationAngle;
+}
+
+- (void)inverse
+{
+  float newA, newB, newC, newD, newTX, newTY;
+  float det;
+
+  det = A * D - B * C;
+  if (!det) {
+    NSLog (@"error: determinant of matrix is 0!");
+    return;
+  }
+
+  newA = D / det;
+  newB = -B / det;
+  newC = -C / det;
+  newD = A / det;
+  newTX = (-D * TX + C * TY) / det;
+  newTY = (B * TX - A * TY) / det;
+
+  NSDebugLog (@"inverse of matrix ((%f, %f) (%f, %f) (%f, %f))\n"
+	@"is ((%f, %f) (%f, %f) (%f, %f))",
+	A, B, C, D, TX, TY,
+	newA, newB, newC, newD, newTX, newTY);
+
+  A = newA; B = newB;
+  C = newC; D = newD;
+  TX = newTX; TY = newTY;
+}
+
+- (NSPoint)pointInMatrixSpace:(NSPoint)point
+{
+  NSPoint new;
+
+  new.x = A * point.x + C * point.y + TX;
+  new.y = B * point.x + D * point.y + TY;
+
+  return new;
+}
+
+- (NSSize)sizeInMatrixSpace:(NSSize)size
+{
+  NSSize new;
+
+  new.width = A * size.width + C * size.height + TX;
+  new.height = B * size.width + D * size.height + TY;
+
+  return new;
+}
+
+- (NSString*)description
+{
+  return [NSString stringWithFormat:@"PSMatrix ((%f, %f) (%f, %f) (%f, %f))",
+				    A, B, C, D, TX, TY];
+}
+
+@end /* PSMatrix */