public unsafe void TestGetRecalculatedProjMatrix()
{
Window testWindow = new Window("TestWindow", 800U, 600U);
SceneViewport vp = testWindow.AddViewport(ViewportAnchoring.BottomLeft, Vector2.ZERO, Vector2.ONE, 0.1f, 1000f);
SceneViewport vp2 = testWindow.AddViewport(ViewportAnchoring.BottomLeft, Vector2.ZERO, Vector2.ONE, 10f, 500f);
Camera c = new Camera();
c.Position = Vector3.ZERO;
c.LookAt(Vector3.FORWARD, Vector3.UP);
c.SetHorizontalFOV(MathUtils.PI_OVER_TWO);
Assert.AreEqual(
new Matrix(1f, 0f, 0f, 0f, 0f, 1.333f, 0f, 0f, 0f, 0f, 1f, 1f, 0f, 0f, -0.1f, 0f),
*((Matrix *)vp.GetRecalculatedProjectionMatrix(c))
);
Assert.AreEqual(
new Matrix(1f, 0f, 0f, 0f, 0f, 1.333f, 0f, 0f, 0f, 0f, 1.02f, 1f, 0f, 0f, -10.204f, 0f),
*((Matrix *)vp2.GetRecalculatedProjectionMatrix(c))
);
c.SetHorizontalFOV(MathUtils.DegToRad(70f));
Assert.AreEqual(
new Matrix(1.428f, 0f, 0f, 0f, 0f, 1.904f, 0f, 0f, 0f, 0f, 1f, 1f, 0f, 0f, -0.1f, 0f),
*((Matrix *)vp.GetRecalculatedProjectionMatrix(c))
);
testWindow.SetResolution(1024U, 768U);
Assert.AreEqual(
new Matrix(1.428f, 0f, 0f, 0f, 0f, 1.904f, 0f, 0f, 0f, 0f, 1f, 1f, 0f, 0f, -0.1f, 0f),
*((Matrix *)vp.GetRecalculatedProjectionMatrix(c))
);
testWindow.SetResolution(1000U, 1000U);
Assert.AreEqual(
new Matrix(1.428f, 0f, 0f, 0f, 0f, 1.428f, 0f, 0f, 0f, 0f, 1f, 1f, 0f, 0f, -0.1f, 0f),
*((Matrix *)vp.GetRecalculatedProjectionMatrix(c))
);
c.Dispose();
vp2.Dispose();
vp.Dispose();
testWindow.Close();
}
public unsafe Vector2 WorldToScreen(SceneViewport sv, Vector3 worldCoordinates)
{
Vector2 viewportSizePixels = sv.SizePixels;
Matrix vpMat = *((Matrix *)GetRecalculatedViewMatrix()) * *((Matrix *)sv.GetRecalculatedProjectionMatrix(this));
var clipSpaceCoordinates = worldCoordinates * vpMat;
float halfWidth = 0.5f * viewportSizePixels.X;
float halfHeight = 0.5f * viewportSizePixels.Y;
return(new Vector2(
(clipSpaceCoordinates.X / clipSpaceCoordinates.Z) * halfWidth + halfWidth,
viewportSizePixels.Y - ((clipSpaceCoordinates.Y / clipSpaceCoordinates.Z) * halfHeight + halfHeight)
));
}
/// <summary>
///
/// </summary>
/// <param name="sv"></param>
/// <param name="pixel">Relative to viewport centre</param>
/// <returns></returns>
public unsafe Ray PixelRayCast(SceneViewport sv, Vector2 pixel)
{
Vector2 viewportSizePixels = sv.SizePixels;
Matrix invProjMat = ((Matrix *)sv.GetRecalculatedProjectionMatrix(this))->Inverse;
Matrix invViewMat = ((Matrix *)GetRecalculatedViewMatrix())->Inverse;
Vector4 viewSpaceDir = invProjMat * new Vector4(
((2f * pixel.X) / viewportSizePixels.X), // These two lines are converting the pixel in to NDC ([-1:1, -1:1, -1:1, -1:1])
((2f * pixel.Y) / -viewportSizePixels.Y),
1f, // These two lines are for homogenous clip space. Z=1f is forwards, out of the screen
1f // Perspective divide = W
);
Vector3 worldSpaceDir = (Vector3)(invViewMat * new Vector4(viewSpaceDir, z: 1f, w: 0f)).ToUnit();
return(new Ray(Position, worldSpaceDir));
}