michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef nsTransform2D_h___
michael@0: #define nsTransform2D_h___
michael@0: 
michael@0: #include "gfxCore.h"
michael@0: #include "nsCoord.h"
michael@0: 
michael@0: class NS_GFX nsTransform2D
michael@0: {
michael@0: private:
michael@0:  /**
michael@0:   * This represents the following matrix (note that the order of row/column
michael@0:   * indices is opposite to usual notation)
michael@0:   *
michael@0:   *      / m00   0   m20  \
michael@0:   * M =  |  0   m11  m21  |
michael@0:   *      \  0    0    1   /
michael@0:   *
michael@0:   * Transformation of a coordinate (x, y) is obtained by setting
michael@0:   * v = (x, y, 1)^T and evaluating  M . v
michael@0:   **/
michael@0: 
michael@0:   float     m00, m11, m20, m21;
michael@0: 
michael@0: public:
michael@0:   nsTransform2D(void)                         { m20 = m21 = 0.0f; m00 = m11 = 1.0f; }
michael@0:   nsTransform2D(nsTransform2D *aTransform2D)  {
michael@0:     m00 = aTransform2D->m00;
michael@0:     m11 = aTransform2D->m11;
michael@0:     m20 = aTransform2D->m20;
michael@0:     m21 = aTransform2D->m21;
michael@0:   }
michael@0: 
michael@0:   ~nsTransform2D(void)                        { }
michael@0: 
michael@0:  /**
michael@0:   * set this transform to a translation
michael@0:   *
michael@0:   * @param      tx, x translation
michael@0:   * @param      ty, y translation
michael@0:   **/
michael@0: 
michael@0:   void SetToTranslate(float tx, float ty)    { m00 = m11 = 1.0f; m20 = tx; m21 = ty; }
michael@0:   
michael@0:  /**
michael@0:   * get the translation portion of this transform
michael@0:   *
michael@0:   * @param      pt, Point to return translation values in
michael@0:   **/
michael@0: 
michael@0:   void GetTranslationCoord(nscoord *ptX, nscoord *ptY) const { *ptX = NSToCoordRound(m20); *ptY = NSToCoordRound(m21); }
michael@0: 
michael@0:  /**
michael@0:   * apply matrix to vector
michael@0:   *
michael@0:   * @param    pt Point to transform
michael@0:   **/
michael@0: 
michael@0:   void TransformCoord(nscoord *ptX, nscoord *ptY) const;
michael@0: 
michael@0:  /**
michael@0:   * apply matrix to rect
michael@0:   *
michael@0:   * @param    rect Rect to transform
michael@0:   **/
michael@0: 
michael@0:   void TransformCoord(nscoord *aX, nscoord *aY, nscoord *aWidth, nscoord *aHeight) const;
michael@0: 
michael@0:  /**
michael@0:   * add a scale to a Transform via x, y pair
michael@0:   *
michael@0:   * @param    ptX x value to add as x scale
michael@0:   * @param    ptY y value to add as y scale
michael@0:   **/
michael@0: 
michael@0:   void AddScale(float ptX, float ptY) { m00 *= ptX; m11 *= ptY; }
michael@0: 
michael@0:  /**
michael@0:   * Set the scale (overriding any previous calls to AddScale, but leaving
michael@0:   * any existing translation).
michael@0:   *
michael@0:   * @param    ptX x value to add as x scale
michael@0:   * @param    ptY y value to add as y scale
michael@0:   **/
michael@0: 
michael@0:   void SetScale(float ptX, float ptY) { m00 = ptX; m11 = ptY; }
michael@0: };
michael@0: 
michael@0: #endif