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// Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
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#include <testFrustum.h>
#include <ImathFrustum.h>
#include <ImathFun.h>
#include <iostream>
#include <assert.h>


using namespace std;


void
testFrustum ()
{
    cout << "Testing functions in ImathFrustum.h";

    cout << "\nperspective ";

    float n = 1.7;
    float f = 567.0;
    float l = -3.5;
    float r = 2.0;
    float b = -1.3;
    float t = 0.9;

    Imath::Frustum<float> frustum (n, f, l, r, t, b, false);

    assert (Imath::abs<float> (frustum.fovx() -
			       (atan2(r,n) - atan2(l,n))) < 1e-6);
    assert (Imath::abs<float> (frustum.fovy() -
			       (atan2(t,n) - atan2(b,n))) < 1e-6);
    cout << "1";
    assert (Imath::abs<float> (frustum.aspect() - ((r-l)/(t-b))) < 1e-6);
    cout << "2";

    Imath::M44f m = frustum.projectionMatrix();
    assert (Imath::abs<float> (m[0][0] - ((2*n)/(r-l)))	    < 1e-6 &&
	    Imath::abs<float> (m[0][1])			    < 1e-6 &&
	    Imath::abs<float> (m[0][2])			    < 1e-6 &&
	    Imath::abs<float> (m[0][3])			    < 1e-6 &&
	    Imath::abs<float> (m[1][0])			    < 1e-6 &&
	    Imath::abs<float> (m[1][1] - ((2*n)/(t-b)))	    < 1e-6 &&
	    Imath::abs<float> (m[1][2])			    < 1e-6 &&
	    Imath::abs<float> (m[1][3])			    < 1e-6 &&
	    Imath::abs<float> (m[2][0] - ((r+l)/(r-l)))	    < 1e-6 &&
	    Imath::abs<float> (m[2][1] - ((t+b)/(t-b)))	    < 1e-6 &&
	    Imath::abs<float> (m[2][2] - (-(f+n)/(f-n)))    < 1e-6 &&
	    Imath::abs<float> (m[2][3] - -1.0)		    < 1e-6 &&
	    Imath::abs<float> (m[3][0])			    < 1e-6 &&
	    Imath::abs<float> (m[3][1])			    < 1e-6 &&
	    Imath::abs<float> (m[3][2] - ((-2*f*n)/(f-n)))  < 1e-6 &&
	    Imath::abs<float> (m[3][3])			    < 1e-6);
    cout << "3";

    cout << "\nexceptions ";
    Imath::Frustum<float> badFrustum;

    badFrustum.set (n, n, l, r, t, b, false);
    try
    {
	(void)badFrustum.projectionMatrix();
	assert (!"near == far didn't throw an exception");
    }
    catch (Iex::DivzeroExc) {}
    cout << "1";

    badFrustum.set (n, f, l, l, t, b, false);
    try
    {
	(void)badFrustum.projectionMatrix();
	assert (!"left == right didn't throw an exception");
    }
    catch (Iex::DivzeroExc) {}
    cout << "2";

    badFrustum.set (n, f, l, r, t, t, false);
    try
    {
	(void)badFrustum.projectionMatrix();
	assert (!"top == bottom didn't throw an exception");
    }
    catch (Iex::DivzeroExc) {}
    cout << "3";

    cout << "\northographic ";

    frustum.setOrthographic (true);

    m = frustum.projectionMatrix();
    assert (Imath::abs<float> (m[0][0] - (2/(r-l)))	    < 1e-6 &&
	    Imath::abs<float> (m[0][1])			    < 1e-6 &&
	    Imath::abs<float> (m[0][2])			    < 1e-6 &&
	    Imath::abs<float> (m[0][3])			    < 1e-6 &&
	    Imath::abs<float> (m[1][0])			    < 1e-6 &&
	    Imath::abs<float> (m[1][1] - (2/(t-b)))	    < 1e-6 &&
	    Imath::abs<float> (m[1][2])			    < 1e-6 &&
	    Imath::abs<float> (m[1][3])			    < 1e-6 &&
	    Imath::abs<float> (m[2][0])			    < 1e-6 &&
	    Imath::abs<float> (m[2][1])			    < 1e-6 &&
	    Imath::abs<float> (m[2][2] - (-2/(f-n)))	    < 1e-6 &&
	    Imath::abs<float> (m[2][3])			    < 1e-6 &&
	    Imath::abs<float> (m[3][0] - (-(r+l)/(r-l)))    < 1e-6 &&
	    Imath::abs<float> (m[3][1] - (-(t+b)/(t-b)))    < 1e-6 &&
	    Imath::abs<float> (m[3][2] - (-(f+n)/(f-n)))    < 1e-6 &&
	    Imath::abs<float> (m[3][3] - 1.0)		    < 1e-6);
    cout << "1";

    // TODO - There are many little functions in Imath::Frustum which
    // aren't tested here.  Those test should be added.  But this is
    // a start.

    cout << "\nok\n\n";
}