//
// TransformTests.cpp
// tests/shared/src
//
// Copyright 2013-2015 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#include "TransformTests.h"

#include <algorithm>
#include <glm/glm.hpp>

#include <SharedLogging.h>
#include <Transform.h>

#include "../QTestExtensions.h"

using namespace glm;

const vec3 xAxis(1.0f, 0.0f, 0.0f);
const vec3 yAxis(0.0f, 1.0f, 0.0f);
const vec3 zAxis(0.0f, 0.0f, 1.0f);
const quat rot90 = angleAxis((float)M_PI / 2.0f, yAxis);

QTEST_MAIN(TransformTests)

const float EPSILON = 0.001f;

void TransformTests::getMatrix() {

    const vec3 t(0.0f, 0.0f, 10.0f);

    // create a matrix that is composed of a PI/2 rotation followed by a small z translation
    const mat4 m(vec4(rot90 * xAxis, 0.0f),
                 vec4(rot90 * yAxis, 0.0f),
                 vec4(rot90 * zAxis, 0.0f),
                 vec4(vec4(t, 1.0f)));

    // postScale by a mirror about the x axis.
    const mat4 mirrorX(vec4(-1.0f, 0.0f, 0.0f, 0.0f),
                       vec4( 0.0f, 1.0f, 0.0f, 0.0f),
                       vec4( 0.0f, 0.0f, 1.0f, 0.0f),
                       vec4( 0.0f, 0.0f, 0.0f, 1.0f));
    const mat4 result_a = m * mirrorX;

    Transform xform;
    xform.setRotation(rot90);
    xform.setTranslation(t);
    xform.postScale(vec3(-1.0f, 1.0f, 1.0f));
    mat4 result_b;
    xform.getMatrix(result_b);

    QCOMPARE_WITH_ABS_ERROR(result_a, result_b, EPSILON);
}

void TransformTests::getInverseMatrix() {

    const vec3 t(0.0f, 0.0f, 10.0f);

    // create a matrix that is composed of a PI/2 rotation followed by a small z translation
    const mat4 m(vec4(rot90 * xAxis, 0.0f),
                 vec4(rot90 * yAxis, 0.0f),
                 vec4(rot90 * zAxis, 0.0f),
                 vec4(vec4(t, 1.0f)));

    // mirror about the x axis.
    const mat4 mirrorX(vec4(-1.0f, 0.0f, 0.0f, 0.0f),
                       vec4( 0.0f, 1.0f, 0.0f, 0.0f),
                       vec4( 0.0f, 0.0f, 1.0f, 0.0f),
                       vec4( 0.0f, 0.0f, 0.0f, 1.0f));
    const mat4 result_a = inverse(m * mirrorX);

    Transform xform;
    xform.setTranslation(t);
    xform.setRotation(rot90);

    //
    // change postScale to preScale and the test will pass...
    //

    xform.postScale(vec3(-1.0f, 1.0f, 1.0f));
    mat4 result_b;
    xform.getInverseMatrix(result_b);

    QCOMPARE_WITH_ABS_ERROR(result_a, result_b, EPSILON);
}