Method invertNonIdentity

src/core/Matrix.cpp:361–404

}

bool Matrix::invertNonIdentity(Matrix* inverse) const {
  TypeMask mask = this->getType();
  // Optimized invert for only scale and/or translation matrices.
  if (0 == (mask & ~(ScaleMask | TranslateMask))) {
    if (mask & ScaleMask) {
      if (values[SCALE_X] == 0 || values[SCALE_Y] == 0) {
        return false;
      }
      float invSX = 1 / values[SCALE_X];
      float invSY = 1 / values[SCALE_Y];
      float invTX = -values[TRANS_X] * invSX;
      float invTY = -values[TRANS_Y] * invSY;
      if (inverse) {
        inverse->values[SKEW_X] = inverse->values[SKEW_Y] = 0;
        inverse->values[SCALE_X] = invSX;
        inverse->values[SCALE_Y] = invSY;
        inverse->values[TRANS_X] = invTX;
        inverse->values[TRANS_Y] = invTY;
        inverse->setTypeMask(mask | RectStayRectMask);
      }
      return true;
    }
    if (inverse) {
      inverse->setTranslate(-values[TRANS_X], -values[TRANS_Y]);
    }
    return true;
  }
  float determinant = values[SCALE_X] * values[SCALE_Y] - values[SKEW_X] * values[SKEW_Y];
  if (FloatNearlyZero(determinant, FLOAT_NEARLY_ZERO * FLOAT_NEARLY_ZERO * FLOAT_NEARLY_ZERO)) {
    return false;
  }
  determinant = 1 / determinant;
  auto sx = values[SCALE_Y] * determinant;
  auto ky = -values[SKEW_Y] * determinant;
  auto kx = -values[SKEW_X] * determinant;
  auto sy = values[SCALE_X] * determinant;
  auto tx = -(sx * values[TRANS_X] + kx * values[TRANS_Y]);
  auto ty = -(ky * values[TRANS_X] + sy * values[TRANS_Y]);
  if (inverse) {
    inverse->setAll(sx, kx, tx, ky, sy, ty);
    inverse->setTypeMask(typeMask);
  }
  return true;
}

void Matrix::mapPoints(Point dst[], const Point src[], int count) const {
  this->getMapPtsProc()(*this, dst, src, count);