NazaraEngine/src/Nazara/Graphics/AbstractViewer.cpp

51 lines
1.6 KiB
C++

// Copyright (C) 2024 Jérôme "SirLynix" Leclercq (lynix680@gmail.com)
// 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/Graphics/RenderTarget.hpp>
#include <Nazara/Graphics/ViewerInstance.hpp>
#include <Nazara/Graphics/Debug.hpp>
namespace Nz
{
AbstractViewer::~AbstractViewer() = default;
Vector3f AbstractViewer::Project(const Vector3f& worldPos) const
{
const Matrix4f& viewProj = GetViewerInstance().GetViewProjMatrix();
Vector4f clipspace = viewProj * Vector4f(worldPos, 1.f);
clipspace.x = clipspace.x / clipspace.w;
clipspace.y = clipspace.y / clipspace.w;
clipspace.z = clipspace.z / clipspace.w;
Vector2f screenSize = Vector2f(GetRenderTarget().GetSize());
Vector3f screenSpace;
screenSpace.x = (clipspace.x * 0.5f + 0.5f) * screenSize.x;
screenSpace.y = (clipspace.y * 0.5f + 0.5f) * screenSize.y;
screenSpace.z = clipspace.z;
return screenSpace;
}
Vector3f AbstractViewer::Unproject(const Vector3f& screenPos) const
{
Vector2f screenSize = Vector2f(GetRenderTarget().GetSize());
// Screen space => clip space
Vector4f clipSpace;
clipSpace.x = screenPos.x / screenSize.x * 2.f - 1.f;
clipSpace.y = screenPos.y / screenSize.y * 2.f - 1.f;
clipSpace.z = screenPos.z;
clipSpace.w = 1.f;
// Clip space => projection space => view space => world space
const Matrix4f& inverseViewProj = GetViewerInstance().GetInvViewProjMatrix();
Vector4f unproj = inverseViewProj * clipSpace;
return Vector3f(unproj.x, unproj.y, unproj.z) / unproj.w;
}
}