Serious-Engine/Sources/Engine/Math/Projection_Parallel.cpp

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/* Copyright (c) 2002-2012 Croteam Ltd.
This program is free software; you can redistribute it and/or modify
it under the terms of version 2 of the GNU General Public License as published by
the Free Software Foundation
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */
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#include "Engine/StdH.h"
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#include <Engine/Math/Projection.h>
#include <Engine/Math/TextureMapping.h>
#include <Engine/Math/OBBox.h>
#include <Engine/Math/Geometry.inl>
#include <Engine/Math/Clipping.inl>
/////////////////////////////////////////////////////////////////////
// CParallelProjection3D
/*
* Prepare for projecting.
*/
void CParallelProjection3D::Prepare(void)
{
FLOATmatrix3D t3dObjectStretch; // matrix for object stretch
FLOATmatrix3D t3dObjectRotation; // matrix for object angles
// calc. matrices for viewer and object angles and stretch
MakeRotationMatrix(t3dObjectRotation, pr_ObjectPlacement.pl_OrientationAngle); // object normally
MakeInverseRotationMatrix(pr_ViewerRotationMatrix, pr_ViewerPlacement.pl_OrientationAngle); // viewer inverse
t3dObjectStretch.Diagonal(pr_ObjectStretch);
pr_vViewerPosition = pr_ViewerPlacement.pl_PositionVector;
BOOL bXInverted = pr_ObjectStretch(1)<0;
BOOL bYInverted = pr_ObjectStretch(2)<0;
BOOL bZInverted = pr_ObjectStretch(3)<0;
pr_bInverted = bXInverted!=bYInverted!=bZInverted;
// if the projection is mirrored
if (pr_bMirror) {
// reflect viewer
ReflectPositionVectorByPlane(pr_plMirror, pr_vViewerPosition);
ReflectRotationMatrixByPlane_rows(pr_plMirror, pr_ViewerRotationMatrix);
// invert inversion
pr_bInverted = !pr_bInverted;
}
// calculate screen center
pr_ScreenCenter = pr_ScreenBBox.Center();
// if the object is face-forward
if (pr_bFaceForward) {
// apply object stretch only
pr_RotationMatrix = t3dObjectStretch;
} else {
// first apply object stretch then object rotation and then viewer rotation
pr_mDirectionRotation = pr_ViewerRotationMatrix*t3dObjectRotation;
pr_RotationMatrix = pr_mDirectionRotation*t3dObjectStretch;
}
// calc. offset of object from viewer
pr_TranslationVector = pr_ObjectPlacement.pl_PositionVector - pr_vViewerPosition;
// rotate offset only by viewer angles
pr_TranslationVector = pr_TranslationVector*pr_ViewerRotationMatrix;
// transform handle from object space to viewer space and add it to the offset
pr_TranslationVector -= pr_vObjectHandle*pr_RotationMatrix;
// calculate constant value used for calculating z-buffer k-value from vertex's z coordinate
pr_fDepthBufferFactor = -pr_NearClipDistance;
pr_fDepthBufferMul = (pr_fDepthBufferFar-pr_fDepthBufferNear);
pr_fDepthBufferAdd = pr_fDepthBufferNear;
// make clip planes
MakeClipPlane(FLOAT3D(+pr_vZoomFactors(1),0,+pr_vStepFactors(1)), pr_ScreenBBox.Min()(1)-pr_ScreenCenter(1), pr_plClipL);
MakeClipPlane(FLOAT3D(-pr_vZoomFactors(1),0,-pr_vStepFactors(1)), pr_ScreenCenter(1)-pr_ScreenBBox.Max()(1), pr_plClipR);
MakeClipPlane(FLOAT3D(0,-pr_vZoomFactors(2),-pr_vStepFactors(2)), pr_ScreenBBox.Min()(2)-pr_ScreenCenter(2), pr_plClipU);
MakeClipPlane(FLOAT3D(0,+pr_vZoomFactors(2),+pr_vStepFactors(2)), pr_ScreenCenter(2)-pr_ScreenBBox.Max()(2), pr_plClipD);
// find vector in direction of viewing
pr_vViewDirection = FLOAT3D(
pr_vStepFactors(1)/pr_vZoomFactors(1),
pr_vStepFactors(2)/pr_vZoomFactors(2),
-1.0f);
// mark as prepared
pr_Prepared = TRUE;
}
/*
* Project 3D object point into 3D view space, before clipping.
*/
void CParallelProjection3D::PreClip(const FLOAT3D &v3dObjectPoint,
FLOAT3D &v3dTransformedPoint) const
{
// check that the projection object is prepared for projecting
ASSERT(pr_Prepared);
// rotate and translate the point
v3dTransformedPoint = v3dObjectPoint*pr_RotationMatrix + pr_TranslationVector;
}
/*
* Project 3D object point into 3D view space, after clipping.
*/
void CParallelProjection3D::PostClip( const FLOAT3D &v3dTransformedPoint,
FLOAT3D &v3dViewPoint) const
{
// check that the projection object is prepared for projecting
ASSERT(pr_Prepared);
// multiply X and Y coordinates with zoom factor and add the center of screen
v3dViewPoint(1) = pr_ScreenCenter(1)
+ v3dTransformedPoint(1) *pr_vZoomFactors(1)
+ v3dTransformedPoint(3) *pr_vStepFactors(1);
v3dViewPoint(2) = pr_ScreenCenter(2)
- v3dTransformedPoint(2) *pr_vZoomFactors(2)
- v3dTransformedPoint(3) *pr_vStepFactors(2);
}
void CParallelProjection3D::PostClip( const FLOAT3D &v3dTransformedPoint, FLOAT fTransformedR,
FLOAT3D &v3dViewPoint, FLOAT &fViewR) const
{
// check that the projection object is prepared for projecting
ASSERT(pr_Prepared);
// multiply X and Y coordinates with zoom factor and add the center of screen
v3dViewPoint(1) = pr_ScreenCenter(1)
+ v3dTransformedPoint(1) *pr_vZoomFactors(1)
+ v3dTransformedPoint(3) *pr_vStepFactors(1);
v3dViewPoint(2) = pr_ScreenCenter(2)
- v3dTransformedPoint(2) *pr_vZoomFactors(2)
- v3dTransformedPoint(3) *pr_vStepFactors(2);
fViewR = fTransformedR *pr_vZoomFactors(1);
}
/* Test if a sphere in view space is inside view frustum. */
INDEX CParallelProjection3D::TestSphereToFrustum(const FLOAT3D &vViewPoint, FLOAT fRadius) const
{
ASSERT(pr_Prepared);
const FLOAT fX = vViewPoint(1);
const FLOAT fY = vViewPoint(2);
const FLOAT fZ = vViewPoint(3);
INDEX iPass = 1;
// check to near
if( fZ-fRadius>-pr_NearClipDistance) {
return -1;
} else if( fZ+fRadius>-pr_NearClipDistance) {
iPass = 0;
}
// check to far
if( pr_FarClipDistance>0) {
if( fZ+fRadius<-pr_FarClipDistance) {
return -1;
} else if( fZ-fRadius<-pr_FarClipDistance) {
iPass = 0;
}
}
// check to left
FLOAT fL = fX*pr_plClipL(1) + fZ*pr_plClipL(3) - pr_plClipL.Distance();
if( fL<-fRadius) {
return -1;
} else if( fL<fRadius) {
iPass = 0;
}
// check to right
FLOAT fR = fX*pr_plClipR(1) + fZ*pr_plClipR(3) - pr_plClipR.Distance();
if( fR<-fRadius) {
return -1;
} else if( fR<fRadius) {
iPass = 0;
}
// check to up
FLOAT fU = fY*pr_plClipU(2) + fZ*pr_plClipU(3) - pr_plClipU.Distance();
if( fU<-fRadius) {
return -1;
} else if( fU<fRadius) {
iPass = 0;
}
// check to down
FLOAT fD = fY*pr_plClipD(2) + fZ*pr_plClipD(3) - pr_plClipD.Distance();
if( fD<-fRadius) {
return -1;
} else if( fD<fRadius) {
iPass = 0;
}
// all done
return iPass;
}
/* Test if an oriented box in view space is inside view frustum. */
INDEX CParallelProjection3D::TestBoxToFrustum(const FLOATobbox3D &box) const
{
ASSERT(pr_Prepared);
INDEX iPass = 1;
INDEX iTest;
// check to near
iTest = (INDEX) box.TestAgainstPlane(FLOATplane3D(FLOAT3D(0,0,-1), pr_NearClipDistance));
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if( iTest<0) {
return -1;
} else if( iTest==0) {
iPass = 0;
}
// check to far
if( pr_FarClipDistance>0) {
iTest = (INDEX) box.TestAgainstPlane(FLOATplane3D(FLOAT3D(0,0,1), -pr_FarClipDistance));
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if( iTest<0) {
return -1;
} else if( iTest==0) {
iPass = 0;
}
}
// check to left
iTest = (INDEX) box.TestAgainstPlane(pr_plClipL);
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if( iTest<0) {
return -1;
} else if( iTest==0) {
iPass = 0;
}
// check to right
iTest = (INDEX) box.TestAgainstPlane(pr_plClipR);
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if( iTest<0) {
return -1;
} else if( iTest==0) {
iPass = 0;
}
// check to up
iTest = (INDEX) box.TestAgainstPlane(pr_plClipU);
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if( iTest<0) {
return -1;
} else if( iTest==0) {
iPass = 0;
}
// check to down
iTest = (INDEX) box.TestAgainstPlane(pr_plClipD);
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if( iTest<0) {
return -1;
} else if( iTest==0) {
iPass = 0;
}
// all done
return iPass;
}
/*
* Project 3D object point into 3D view space.
*/
void CParallelProjection3D::ProjectCoordinate(const FLOAT3D &v3dObjectPoint,
FLOAT3D &v3dViewPoint) const
{
// rotate and translate the point
v3dViewPoint = v3dObjectPoint*pr_RotationMatrix + pr_TranslationVector;
// multiply X and Y coordinates with zoom factor and add the center of screen
v3dViewPoint(1) =
pr_ScreenCenter(1)
+v3dViewPoint(1)*pr_vZoomFactors(1)
+v3dViewPoint(3)*pr_vStepFactors(1);
v3dViewPoint(2) =
pr_ScreenCenter(2)
+v3dViewPoint(2)*pr_vZoomFactors(2)
+v3dViewPoint(3)*pr_vStepFactors(2);
}
/*
* Get a distance of object point from the viewer.
*/
FLOAT CParallelProjection3D::GetDistance(const FLOAT3D &v3dObjectPoint) const
{
// get just the z coordinate of the point in viewer space
return
v3dObjectPoint(1)*pr_RotationMatrix(3,1)+
v3dObjectPoint(2)*pr_RotationMatrix(3,2)+
v3dObjectPoint(3)*pr_RotationMatrix(3,3)+
pr_TranslationVector(3);
}
/*
* Project 3D object direction vector into 3D view space.
*/
void CParallelProjection3D::ProjectDirection(const FLOAT3D &v3dObjectPoint,
FLOAT3D &v3dViewPoint) const
{
// rotate the direction
v3dViewPoint = v3dObjectPoint*pr_RotationMatrix;
}
/*
* Project 3D object axis aligned bounding box into 3D view space.
*/
void CParallelProjection3D::ProjectAABBox(const FLOATaabbox3D &boxObject,
FLOATaabbox3D &boxView) const
{
ASSERTALWAYS( "This is not yet implemented");
}
/*
* Project 3D object plane into 3D view space.
*/
void CParallelProjection3D::Project(const FLOATplane3D &p3dObjectPlane,
FLOATplane3D &p3dTransformedPlane) const
{
// check that the projection object is prepared for projecting
ASSERT(pr_Prepared);
// rotate and translate the plane
p3dTransformedPlane = p3dObjectPlane*pr_RotationMatrix + pr_TranslationVector;
}
/* Calculate plane gradient for a plane in 3D view space. */
void CParallelProjection3D::MakeOoKGradient(const FLOATplane3D &plViewerPlane, CPlanarGradients &pgOoK) const
{
// check that the projection object is prepared for projecting
ASSERT(pr_Prepared);
// ####!!!! use viewer plane or object plane?
// create k gradients from the plane equation
FLOAT xn = plViewerPlane(1);
FLOAT yn = plViewerPlane(2);
FLOAT zn = plViewerPlane(3);
FLOAT d = plViewerPlane.Distance();
FLOAT ci = pr_ScreenCenter(1);
FLOAT cj = pr_ScreenCenter(2);
FLOAT fx = pr_vZoomFactors(1);
FLOAT fy = pr_vZoomFactors(2);
FLOAT sx = pr_vStepFactors(1);
FLOAT sy = pr_vStepFactors(2);
FLOAT Div = zn-sx*xn-sy*yn;
FLOAT dkodi = xn/(fx*Div);
FLOAT dkodj = yn/(fy*Div);
FLOAT k00 = d/Div-ci*dkodi-cj*dkodj;
// NOTE: here, k is really used instead ook
pgOoK.pg_f00 = k00;
pgOoK.pg_fDOverDI = dkodi;
pgOoK.pg_fDOverDJ = dkodj;
}
/*
* Clip a line.
*/
ULONG CParallelProjection3D::ClipLine(FLOAT3D &v3dPoint0, FLOAT3D &v3dPoint1) const
{
// check that the projection object is prepared for projecting
ASSERT(pr_Prepared);
// front clip plane is exactly the viewplane
//const FLOATplane3D plFrontClip(FLOAT3D(0.0f,0.0f,-1.0f), 0.0f);
ULONG ulCode0 = LCFVERTEX0(LCF_UNCLIPPED);
ULONG ulCode1 = LCFVERTEX1(LCF_UNCLIPPED);
// clip the line by each plane at the time, skip if some removes entire line
if (ClipLineByNearPlane(v3dPoint0, v3dPoint1, 0.0f, ulCode0, ulCode1, LCF_NEAR)
// if something remains
) {
// return the clip code for both vertices
return ulCode0 | ulCode1;
// if some of the planes removed entire line
} else {
// return the code that tells that entire line is removed
return LCF_EDGEREMOVED;
}
}
/*
* Get placement for a ray through a projected point.
*/
void CParallelProjection3D::RayThroughPoint(const FLOAT3D &v3dViewPoint,
CPlacement3D &plRay) const
{
ASSERTALWAYS("Function not supported");
}
/*
* Check if an object-space plane is visible.
*/
BOOL CParallelProjection3D::IsObjectPlaneVisible(const FLOATplane3D &p3dObjectPlane) const
{
// check that the projection object is prepared for projecting
ASSERT(pr_Prepared);
// the object plane is visible if it is not heading away from the view direction
return (p3dObjectPlane*pr_mDirectionRotation)%pr_vViewDirection<0.01f;
}
/*
* Check if a viewer-space plane is visible.
*/
BOOL CParallelProjection3D::IsViewerPlaneVisible(const FLOATplane3D &p3dViewerPlane) const
{
// check that the projection object is prepared for projecting
ASSERT(pr_Prepared);
// the object plane is visible if it is not heading away from the view direction
return p3dViewerPlane%pr_vViewDirection<0.01f;
}
/*
* Calculate a mip-factor for a given object.
*/
// by its distance from viewer
FLOAT CParallelProjection3D::MipFactor(FLOAT fDistance) const
{
// check that the projection object is prepared for projecting
ASSERT(pr_Prepared);
/* calculated using following formula:
k = log2(1024*z/xratio);
*/
return Log2(1024.0f/pr_vZoomFactors(1));
}
// general mip-factor for target object
FLOAT CParallelProjection3D::MipFactor(void) const
{
// check that the projection object is prepared for projecting
ASSERT(pr_Prepared);
/* calculated using following formula:
k = log2(1024*z/xratio);
*/
return Log2(1024.0f/pr_vZoomFactors(1));
}