NazaraEngine/src/Nazara/Graphics/AbstractViewer.cpp

67 lines
1.9 KiB
C++

// Copyright (C) 2017 Jérôme Leclercq
// This file is part of the "Nazara Engine - Graphics module"
// For conditions of distribution and use, see copyright notice in Config.hpp
#include <Nazara/Graphics/AbstractViewer.hpp>
#include <Nazara/Renderer/RenderTarget.hpp>
#include <Nazara/Graphics/Debug.hpp>
namespace Nz
{
/*!
* \ingroup graphics
* \class Nz::AbstractViewer
* \brief Graphics class that represents the viewer for our scene
*
* \remark This class is abstract
*/
AbstractViewer::~AbstractViewer() = default;
Vector3f AbstractViewer::Project(const Nz::Vector3f& worldPosition) const
{
Vector4f pos4D(worldPosition, 1.f);
pos4D = GetViewMatrix() * pos4D;
pos4D = GetProjectionMatrix() * pos4D;
pos4D /= pos4D.w;
Rectf viewport = Rectf(GetViewport());
Nz::Vector3f screenPosition(pos4D.x * 0.5f + 0.5f, -pos4D.y * 0.5f + 0.5f, pos4D.z * 0.5f + 0.5f);
screenPosition.x = screenPosition.x * viewport.width + viewport.x;
screenPosition.y = screenPosition.y * viewport.height + viewport.y;
return screenPosition;
}
float AbstractViewer::ProjectDepth(float depth)
{
const Matrix4f& projectionMatrix = GetProjectionMatrix();
float a = projectionMatrix(2, 2);
float b = projectionMatrix(2, 3);
return (0.5f * (-a * depth + b) / depth + 0.5f);
}
Vector3f AbstractViewer::Unproject(const Nz::Vector3f& screenPos) const
{
Rectf viewport = Rectf(GetViewport());
Nz::Vector4f normalizedPosition;
normalizedPosition.x = (screenPos.x - viewport.x) / viewport.width * 2.f - 1.f;
normalizedPosition.y = (screenPos.y - viewport.y) / viewport.height * 2.f - 1.f;
normalizedPosition.z = screenPos.z * 2.f - 1.f;
normalizedPosition.w = 1.f;
normalizedPosition.y = -normalizedPosition.y;
Nz::Matrix4f invMatrix = GetViewMatrix() * GetProjectionMatrix();
invMatrix.Inverse();
Nz::Vector4f worldPos = invMatrix * normalizedPosition;
worldPos /= worldPos.w;
return Nz::Vector3f(worldPos.x, worldPos.y, worldPos.z);
}
}