RetroZilla/gfx/thebes/public/gfxMatrix.h

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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 * The Original Code is Oracle Corporation code.
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 * The Initial Developer of the Original Code is Oracle Corporation.
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 * Contributor(s):
 *   Stuart Parmenter <pavlov@pavlov.net>
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#ifndef GFX_MATRIX_H
#define GFX_MATRIX_H

#include <cairo.h>

#include "gfxPoint.h"
#include "gfxTypes.h"

// XX - I don't think this class should use gfxFloat at all,
// but should use 'double' and be called gfxDoubleMatrix;
// we can then typedef that to gfxMatrix where we typedef
// double to be gfxFloat.

class gfxMatrix {
protected:
    cairo_matrix_t mat;

public:
    gfxMatrix() { Reset(); }
    gfxMatrix(const gfxMatrix& m) : mat(m.mat) {}
    gfxMatrix(gfxFloat a, gfxFloat b, gfxFloat c, gfxFloat d, gfxFloat tx, gfxFloat ty) {
        mat.xx = a; mat.yx = b; mat.xy = c; mat.yy = d; mat.x0 = tx; mat.y0 = ty;
    }

    gfxMatrix(const cairo_matrix_t& m) {
        mat = m;
    }

    gfxMatrix& operator=(const cairo_matrix_t& m) {
        mat = m;
        return *this;
    }

    const gfxMatrix& operator *= (const gfxMatrix& m) {
        return Multiply(m);
    }

    gfxMatrix operator * (const gfxMatrix& m) {
        return gfxMatrix(*this).Multiply(m);
    }

    // conversion to other types
    cairo_matrix_t ToCairoMatrix() const {
        return mat;
    }

    void ToValues(gfxFloat *xx, gfxFloat *yx,
                  gfxFloat *xy, gfxFloat *yy,
                  gfxFloat *x0, gfxFloat *y0) const
    {
        *xx = mat.xx;
        *yx = mat.yx;
        *xy = mat.xy;
        *yy = mat.yy;
        *x0 = mat.x0;
        *y0 = mat.y0;
    }

    // matrix operations
    const gfxMatrix& Reset() {
        cairo_matrix_init_identity(&mat);
        return *this;
    }

    const gfxMatrix& Invert() {
        cairo_matrix_invert(&mat);
        return *this;
    }

    const gfxMatrix& Scale(gfxFloat x, gfxFloat y) {
        cairo_matrix_scale(&mat, x, y);
        return *this;
    }

    const gfxMatrix& Translate(const gfxPoint& pt) {
        cairo_matrix_translate(&mat, pt.x, pt.y);
        return *this;
    }

    const gfxMatrix& Rotate(gfxFloat radians) {
        gfxFloat s = sin(radians);
        gfxFloat c = cos(radians);
        gfxMatrix t( c, s,
                    -s, c,
                     0, 0);
        return *this = t.Multiply(*this);
    }

    const gfxMatrix& Multiply(const gfxMatrix& m) {
        cairo_matrix_multiply(&mat, &mat, &m.mat);
        return *this;
    }

    void TransformDistance(gfxFloat *dx, gfxFloat *dy) const {
        cairo_matrix_transform_distance(&mat, dx, dy);
    }

    void TransformPoint(gfxFloat *x, gfxFloat *y) const {
        cairo_matrix_transform_point(&mat, x, y);
    }

    gfxSize GetScaling() const {
        return gfxSize(mat.xx, mat.yy);
    }

    gfxPoint GetTranslation() const {
        return gfxPoint(mat.x0, mat.y0);
    }

    bool HasShear() const {
        return ((mat.xy != 0.0) || (mat.yx != 0.0));
    }
};

#endif /* GFX_MATRIX_H */