QMatrix2x2 QMatrix2x2::Invert() const
{
// We need inverse of determinant in calculus.
const float_q INV_DET = SQFloat::_1 / this->GetDeterminant();
return QMatrix2x2( INV_DET * this->ij[1][1],
-INV_DET * this->ij[0][1],
-INV_DET * this->ij[1][0],
INV_DET * this->ij[0][0] );
}
void VideoViewer::resizeGL(int width, int height)
{
double projectionMatrixValues[4];
double scaleMatrixValues[4];
if(height * _frame->width < width * _frame->height)
{
projectionMatrixValues[0] = (double) height / (double)width;
projectionMatrixValues[1] = 0.0;
projectionMatrixValues[2] = 0.0;
projectionMatrixValues[3] = 1.0;
scaleMatrixValues[0] = (double) _frame->width / (double)_frame->height;
scaleMatrixValues[1] = 0.0;
scaleMatrixValues[2] = 0.0;
scaleMatrixValues[3] = 1.0;
}
else
{
projectionMatrixValues[0] = 1.0;
projectionMatrixValues[1] = 0.0;
projectionMatrixValues[2] = 0.0;
projectionMatrixValues[3] = (double) width / (double)height;
scaleMatrixValues[0] = 1.0;
scaleMatrixValues[1] = 0.0;
scaleMatrixValues[2] = 0.0;
scaleMatrixValues[3] = (double)_frame->height / (double)_frame->width;
}
_matrix = QMatrix2x2(projectionMatrixValues) *
QMatrix2x2(scaleMatrixValues);
glViewport(0, 0, width, height);
}
QMatrix2x2 QMatrix2x2::Transpose() const
{
return QMatrix2x2(this->ij[0][0], this->ij[1][0], this->ij[0][1], this->ij[1][1]);
}