genesis-3d_engine/Engine/app/apputil/mouserayutil.cc

/****************************************************************************
Copyright (c) 2009,Radon Labs GmbH
Copyright (c) 2011-2013,WebJet Business Division,CYOU
 
http://www.genesis-3d.com.cn

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****************************************************************************/
#include "stdneb.h"
#include "apputil/mouserayutil.h"

namespace AppUtil
{
using namespace Math;

//------------------------------------------------------------------------------
/**
    Utility function which computes a ray in world space between the eye
    and the current mouse position on the near plane.
    Mouse position is expected in the range 0..1.
*/
line
MouseRayUtil::ComputeWorldMouseRay(const float2& mousePos, float length, const matrix44& invViewMatrix, const matrix44& invProjMatrix, float nearPlane)
{
    // Compute mouse position in world coordinates.
    point screenCoord3D((mousePos.x() - 0.5f) * 2.0f, (mousePos.y() - 0.5f) * 2.0f, 1.0f);
    vector viewCoord = matrix44::transform(invProjMatrix,screenCoord3D);
    point localMousePos = viewCoord * nearPlane * 1.1f;
    localMousePos.y() = -1 * localMousePos.y();
    point worldMousePos = matrix44::transform(invViewMatrix,localMousePos);
    vector worldMouseDir = worldMousePos - point(invViewMatrix.get_position());
    worldMouseDir = vector::normalize(worldMouseDir);
    worldMouseDir *= length;

    return line(worldMousePos, worldMousePos + worldMouseDir);
}

Math::line 
MouseRayUtil::ComputeWorldMouseLine(const float2& mousePos, const matrix44& invViewMatrix, float nearPlaneDist, 
											float nearPlaneWidth, float nearPlaneHeight, Graphic::Camera::ViewType viewType /*= Graphic::Camera::VT_persp*/, float length /*= 10000*/)
{
	float4 camPos = invViewMatrix.get_position();
	// we think invViewMatrix is not including scale information.If it doesn't contain scale information,
	// then the vector would be normalized, If it contains scale information, then the data blow is not right.
	float4 camBackDir = vector::normalize(invViewMatrix.get_zaxis());
	float4 camUpDir = vector::normalize(invViewMatrix.get_yaxis());
	float4 camRightDir = vector::normalize(invViewMatrix.get_xaxis());

	float4 bias = camBackDir * (-nearPlaneDist) 
		+ camUpDir * ((0.5f - mousePos.y()) * nearPlaneHeight) 
		+ camRightDir * ((mousePos.x() - 0.5f) * nearPlaneWidth);

	float4 worldMousePos = camPos + bias;
	float3 dir;
	if (Graphic::Camera::VT_ortho == viewType)
	{
		dir.set(-camBackDir.x(), -camBackDir.y(), -camBackDir.z());
	}
	else
	{
		dir.setFromFloat4(bias);	
		dir.normalise();
	}

	float3 endPos = dir * length;
	return line(worldMousePos, point(endPos.x(), endPos.y(), endPos.z()));
}

//------------------------------------------------------------------------
Math::Ray 
MouseRayUtil::ComputeWorldMouseRay(const Math::float2& mousePos, const Math::matrix44& invViewMatrix, const Math::matrix44& invProjMatrix, float nearPlane,Graphic::Camera::ViewType viewType)
{
	// Compute mouse position in world coordinates.
	point screenCoord3D((mousePos.x() - 0.5f) * 2.0f, (mousePos.y() - 0.5f) * 2.0f, 1.0f);
	vector viewCoord = matrix44::transform( invProjMatrix,screenCoord3D);
	point localMousePos = viewCoord * nearPlane * 1.0f;
	localMousePos.y() = -1 * localMousePos.y();
	point worldMousePos = matrix44::transform(invViewMatrix,localMousePos);
	vector worldMouseDir = worldMousePos - point(invViewMatrix.get_position());
	if(Graphic::Camera::VT_ortho == viewType)
	{
		worldMouseDir = vector(0.0f,0.0f,1.0f);
		worldMouseDir = matrix44::transform(invViewMatrix,worldMouseDir);
	}
	worldMouseDir = vector::normalize(worldMouseDir);

	float3 dir;
	dir.setFromFloat4(worldMouseDir);
	dir = float3::normalize(dir);
	if (float3::isNormalize(dir))
	{	
		return Ray( float3(worldMousePos.x(), worldMousePos.y(), worldMousePos.z() ), dir);
	}
	return Ray( float3(0,100000000,0), float3(0,1,0));

}
//------------------------------------------------------------------------
Math::Ray 
MouseRayUtil::ComputeWorldMouseRay(const Math::float2& mouseScreenPos, const Math::matrix44& invViewMatrix, float nearPlaneWidth, float nearPlaneHeight, float neardistane, Graphic::Camera::ViewType viewType)
{
	float4 camPos = invViewMatrix.get_position();
	// we think invViewMatrix is not including scale information.If it doesn't contain scale information,
	// then the vector would be normalized, If it contains scale information, then the data blow is not right.
	float4 camBackDir = invViewMatrix.get_zaxis();
	float4 camUpDir = invViewMatrix.get_yaxis();
	float4 camRightDir = invViewMatrix.get_xaxis();

	float4 bias = camBackDir * (-neardistane) 
		+ camUpDir * ((0.5f - mouseScreenPos.y()) * nearPlaneHeight) 
		+ camRightDir * ((mouseScreenPos.x() - 0.5f) * nearPlaneWidth);

	float4 worldMousePos = camPos + bias;
	float3 dir;
	if (Graphic::Camera::VT_ortho == viewType)
	{
		dir.set(-camBackDir.x(), -camBackDir.y(), -camBackDir.z());
		dir.normalise();
	}
	else
	{
		dir.setFromFloat4(bias);	
		dir.normalise();
	}

	return Ray( float3(worldMousePos.x(), worldMousePos.y(), worldMousePos.z()), dir);
}

} // namespace RenderUtil