Method pushMatrix

blocks/Cairo/src/Cairo.cpp:2085–2096

	}

	void	pushMatrix( const mat3 &top ) {
		mat3 m = mMatrixStack.back() * top;
		mMatrixStack.push_back( m );
		// verify the matrix is non-singular
		if( ! isSingular( m ) ) {
			mCtx.setMatrix( m );
			//mCtx.transform( mMatrixStack.back() );
		}
		else {
			mMatrixStackContainsIllegal = true;
		}
	}
	void	popMatrix() {
		mMatrixStack.pop_back();
		mMatrixStackContainsIllegal = false;