gecko/gfx/public/nsTransform2D.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* michaelp 09-25-97 1:56pm
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef nsTransform2D_h___
#define nsTransform2D_h___
#include "gfxCore.h"
#include "nsCoord.h"
class NS_GFX nsTransform2D
{
private:
/**
* This represents the following matrix (note that the order of row/column
* indices is opposite to usual notation)
*
* / m00 0 m20 \
* M = | 0 m11 m21 |
* \ 0 0 1 /
*
* Transformation of a coordinate (x, y) is obtained by setting
* v = (x, y, 1)^T and evaluating M . v
**/
float m00, m11, m20, m21;
public:
nsTransform2D(void) { m20 = m21 = 0.0f; m00 = m11 = 1.0f; }
nsTransform2D(nsTransform2D *aTransform2D) {
m00 = aTransform2D->m00;
m11 = aTransform2D->m11;
m20 = aTransform2D->m20;
m21 = aTransform2D->m21;
}
~nsTransform2D(void) { }
/**
* set this transform to a translation
*
* @param tx, x translation
* @param ty, y translation
**/
void SetToTranslate(float tx, float ty) { m00 = m11 = 1.0f; m20 = tx; m21 = ty; }
/**
* get the translation portion of this transform
*
* @param pt, Point to return translation values in
**/
void GetTranslationCoord(nscoord *ptX, nscoord *ptY) const { *ptX = NSToCoordRound(m20); *ptY = NSToCoordRound(m21); }
/**
* apply matrix to vector
*
* @param pt Point to transform
**/
void TransformCoord(nscoord *ptX, nscoord *ptY) const;
/**
* apply matrix to rect
*
* @param rect Rect to transform
**/
void TransformCoord(nscoord *aX, nscoord *aY, nscoord *aWidth, nscoord *aHeight) const;
/**
* add a scale to a Transform via x, y pair
*
* @param ptX x value to add as x scale
* @param ptY y value to add as y scale
**/
void AddScale(float ptX, float ptY) { m00 *= ptX; m11 *= ptY; }
/**
* Set the scale (overriding any previous calls to AddScale, but leaving
* any existing translation).
*
* @param ptX x value to add as x scale
* @param ptY y value to add as y scale
**/
void SetScale(float ptX, float ptY) { m00 = ptX; m11 = ptY; }
};
#endif