C++ VMatrix类代码示例

//-----------------------------------------------------------------------------
// Purpose: Generates a view matrix based on our current yaw, pitch, and roll.
//			The view matrix does not consider FOV or clip plane distances.
//-----------------------------------------------------------------------------
void CCamera::BuildViewMatrix()
{
	// The camera transformation is produced by multiplying roll * yaw * pitch.
	// This will transform a point from world space into quake camera space, 
	// which is exactly what we want for our view matrix. However, quake
	// camera space isn't the same as material system camera space, so
	// we're going to have to apply a transformation that goes from quake
	// camera space to material system camera space.
	
	CameraIdentityMatrix( m_ViewMatrix );

	RotateAroundAxis(m_ViewMatrix, m_fPitch, 0 );
	RotateAroundAxis(m_ViewMatrix, m_fRoll, 1);
	RotateAroundAxis(m_ViewMatrix, m_fYaw, 2);

	// Translate the viewpoint to the world origin.
	VMatrix TempMatrix;
	TempMatrix.Identity();
	TempMatrix.SetTranslation( -m_ViewPoint );

	m_ViewMatrix = m_ViewMatrix * TempMatrix;

	m_ViewProjMatrix = m_ProjMatrix * m_ViewMatrix;
	m_ViewProjMatrix.InverseGeneral( m_InvViewProjMatrix );
}

void CEngineTool::CreatePickingRay( const CViewSetup &viewSetup, int x, int y, Vector& org, Vector& forward )
{
	// Remap x and y into -1 to 1 normalized space
	float xf, yf;
	xf = ( 2.0f * (float)x / (float)viewSetup.width ) - 1.0f;
	yf = ( 2.0f * (float)y / (float)viewSetup.height ) - 1.0f;

	// Flip y axis
	yf = -yf;

	VMatrix worldToScreen;
	GetWorldToScreenMatrixForView( viewSetup, &worldToScreen );
	VMatrix screenToWorld;
	MatrixInverseGeneral( worldToScreen, screenToWorld );

	// Create two points at the normalized mouse x, y pos and at the near and far z planes (0 and 1 depth)
	Vector v1, v2;
	v1.Init( xf, yf, 0.0f );
	v2.Init( xf, yf, 1.0f );
    
	Vector o2;
	// Transform the two points by the screen to world matrix
	screenToWorld.V3Mul( v1, org ); // ray start origin
	screenToWorld.V3Mul( v2, o2 );  // ray end origin
	VectorSubtract( o2, org, forward );
	forward.NormalizeInPlace();
}

static void SetDepthFlashlightParams( CBaseVSShader *pShader, IShaderDynamicAPI *pShaderAPI, const VMatrix& worldToTexture, const FlashlightState_t& flashlightState ) 
{
	float atten[4], pos[4], tweaks[4];
	atten[0] = flashlightState.m_fConstantAtten;		// Set the flashlight attenuation factors
	atten[1] = flashlightState.m_fLinearAtten;
	atten[2] = flashlightState.m_fQuadraticAtten;
	atten[3] = flashlightState.m_FarZ;
	pShaderAPI->SetPixelShaderConstant( PSREG_FLASHLIGHT_ATTENUATION, atten, 1 );

	pos[0] = flashlightState.m_vecLightOrigin[0];		// Set the flashlight origin
	pos[1] = flashlightState.m_vecLightOrigin[1];
	pos[2] = flashlightState.m_vecLightOrigin[2];
	pShaderAPI->SetPixelShaderConstant( PSREG_FLASHLIGHT_POSITION_RIM_BOOST, pos, 1 );

	pShaderAPI->SetPixelShaderConstant( PSREG_FLASHLIGHT_TO_WORLD_TEXTURE, worldToTexture.Base(), 4 );

	// Tweaks associated with a given flashlight
	tweaks[0] = ShadowFilterFromState( flashlightState );
	tweaks[1] = ShadowAttenFromState( flashlightState );
	pShader->HashShadow2DJitter( flashlightState.m_flShadowJitterSeed, &tweaks[2], &tweaks[3] );
	pShaderAPI->SetPixelShaderConstant( PSREG_ENVMAP_TINT__SHADOW_TWEAKS, tweaks, 1 );

	// Dimensions of screen, used for screen-space noise map sampling
	float vScreenScale[4] = {1280.0f / 32.0f, 720.0f / 32.0f, 0, 0};
	int nWidth, nHeight;
	pShaderAPI->GetBackBufferDimensions( nWidth, nHeight );
	vScreenScale[0] = (float) nWidth  / 32.0f;
	vScreenScale[1] = (float) nHeight / 32.0f;
	pShaderAPI->SetPixelShaderConstant( PSREG_FLASHLIGHT_SCREEN_SCALE, vScreenScale, 1 );

	if ( IsX360() )
	{
		pShaderAPI->SetBooleanPixelShaderConstant( 0, &flashlightState.m_nShadowQuality, 1 );
	}
}

void MatrixBuildOrtho( VMatrix& dst, double left, double top, double right, double bottom, double zNear, double zFar )
{
	// FIXME: This is being used incorrectly! Should read:
	// D3DXMatrixOrthoOffCenterRH( &matrix, left, right, bottom, top, zNear, zFar );
	// Which is certainly why we need these extra -1 scales in y. Bleah

	// NOTE: The camera can be imagined as the following diagram:
	//		/z
	//	   /
	//	  /____ x	Z is going into the screen
	//	  |
	//	  |
	//	  |y
	//
	// (0,0,z) represents the upper-left corner of the screen.
	// Our projection transform needs to transform from this space to a LH coordinate
	// system that looks thusly:
	// 
	//	y|  /z
	//	 | /
	//	 |/____ x	Z is going into the screen
	//
	// Where x,y lies between -1 and 1, and z lies from 0 to 1
	// This is because the viewport transformation from projection space to pixels
	// introduces a -1 scale in the y coordinates
	//		D3DXMatrixOrthoOffCenterRH( &matrix, left, right, top, bottom, zNear, zFar );

	dst.Init(	 2.0f / ( right - left ),						0.0f,						0.0f, ( left + right ) / ( left - right ),
				0.0f,	 2.0f / ( bottom - top ),						0.0f, ( bottom + top ) / ( top - bottom ),
				0.0f,						0.0f,	 1.0f / ( zNear - zFar ),			 zNear / ( zNear - zFar ),
				0.0f,						0.0f,						0.0f,								1.0f );
}

//-----------------------------------------------------------------------------
// Returns the attachment render origin + origin
//-----------------------------------------------------------------------------
void C_VGuiScreen::GetAimEntOrigin( IClientEntity *pAttachedTo, Vector *pOrigin, QAngle *pAngles )
{
	C_BaseEntity *pEnt = pAttachedTo->GetBaseEntity();
	const char* panelName = PanelName();
	vgui::Panel panel = m_PanelWrapper.GetPanel();
		
	if ( Q_strcmp(panelName, "health_screen") == 0 )
	{
		QAngle weapAngles = pEnt->GetAbsAngles();
		Vector weapForward, weapRight, weapUp;
		AngleVectors(weapAngles, &weapForward, &weapRight, &weapUp);
		
		VMatrix worldFromPanel;
		AngleMatrix(weapAngles, worldFromPanel.As3x4());
		MatrixRotate(worldFromPanel, Vector(0, 0, 1), 180.f);
		MatrixRotate(worldFromPanel, Vector(1, 0, 0), -90.f);
		MatrixAngles(worldFromPanel.As3x4(), *pAngles);
	
		// move it right and over
		*pOrigin = pEnt->GetAbsOrigin() + weapRight*1.75 + weapUp*2.3 + weapForward*5;
		
		return;
	}
	
	//todo: set alpha per view ... m_PanelWrapper.GetPanel()->SetAlpha(200);
	
	if (pEnt && (m_nAttachmentIndex > 0))
	{
		{
			C_BaseAnimating::AutoAllowBoneAccess boneaccess( true, true );
			pEnt->GetAttachment( m_nAttachmentIndex, *pOrigin, *pAngles );
		}
		
		if ( IsAttachedToViewModel() )
		{
			FormatViewModelAttachment( *pOrigin, true );
		}
	}
	else
	{
		BaseClass::GetAimEntOrigin( pAttachedTo, pOrigin, pAngles );
	}

	// Msg("%s origin %.1f %.1f %.1f angles %.1f %.1f %.1f \n", PanelName(), pOrigin->x, pOrigin->y, pOrigin->z, pAngles->x, pAngles->y, pAngles->z);

}

//-----------------------------------------------------------------------------
// Purpose: Builds the matrix for a counterclockwise rotation about an arbitrary axis.
//
//		   | ax2 + (1 - ax2)cosQ		axay(1 - cosQ) - azsinQ		azax(1 - cosQ) + aysinQ |
// Ra(Q) = | axay(1 - cosQ) + azsinQ	ay2 + (1 - ay2)cosQ			ayaz(1 - cosQ) - axsinQ |
//		   | azax(1 - cosQ) - aysinQ	ayaz(1 - cosQ) + axsinQ		az2 + (1 - az2)cosQ     |
//          
// Input  : mat - 
//			vAxisOrRot - 
//			angle - 
//-----------------------------------------------------------------------------
void MatrixBuildRotationAboutAxis( VMatrix &dst, const Vector &vAxisOfRot, float angleDegrees )
{
	MatrixBuildRotationAboutAxis( vAxisOfRot, angleDegrees, dst.As3x4() );
	dst[3][0] = 0;
	dst[3][1] = 0;
	dst[3][2] = 0;
	dst[3][3] = 1;
}

void MatrixBuildPerspective( VMatrix &dst, float fovX, float fovY, float zNear, float zFar )
{
	// FIXME: collapse all of this into one matrix after we figure out what all should be in here.
	float width = 2 * zNear * tan( fovX * ( M_PI/180.0f ) * 0.5f );
	float height = 2 * zNear * tan( fovY * ( M_PI/180.0f ) * 0.5f );

	memset( dst.Base(), 0, sizeof( dst ) );
	dst[0][0]  = 2.0F * zNear / width;
	dst[1][1]  = 2.0F * zNear / height;
	dst[2][2] = -zFar / ( zNear - zFar );
	dst[3][2] = 1.0f;
	dst[2][3] = zNear * zFar / ( zNear - zFar );

	// negate X and Y so that X points right, and Y points up.
	VMatrix negateXY;
	negateXY.Identity();
	negateXY[0][0] = -1.0f;
	negateXY[1][1] = -1.0f;
	MatrixMultiply( negateXY, dst, dst );
	
	VMatrix addW;
	addW.Identity();
	addW[0][3] = 1.0f;
	addW[1][3] = 1.0f;
	addW[2][3] = 0.0f;
	MatrixMultiply( addW, dst, dst );
	
	VMatrix scaleHalf;
	scaleHalf.Identity();
	scaleHalf[0][0] = 0.5f;
	scaleHalf[1][1] = 0.5f;
	MatrixMultiply( scaleHalf, dst, dst );
}

//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
AngularImpulse WorldToLocalRotation( const VMatrix &localToWorld, const Vector &worldAxis, float rotation )
{
    // fix axes of rotation to match axes of vector
    Vector rot = worldAxis * rotation;
    // since the matrix maps local to world, do a transpose rotation to get world to local
    AngularImpulse ang = localToWorld.VMul3x3Transpose( rot );

    return ang;
}

void MatrixBuildPerspectiveX( VMatrix& dst, double flFovX, double flAspect, double flZNear, double flZFar )
{
	float flWidth = 2.0f * flZNear * tanf( flFovX * M_PI / 360.0f );
	float flHeight = flWidth / flAspect;
	dst.Init(   2.0f * flZNear / flWidth,						0.0f,							0.0f,										0.0f,
				0.0f,  2.0f  * flZNear/ flHeight,							0.0f,										0.0f,
				0.0f,						0.0f,  flZFar / ( flZNear - flZFar ),	 flZNear * flZFar / ( flZNear - flZFar ),
				0.0f,						0.0f,						   -1.0f,										0.0f );
}

//-----------------------------------------------------------------------------
// Computes the position of the canister
//-----------------------------------------------------------------------------
void CEnvHeadcrabCanisterShared::GetPositionAtTime( float flTime, Vector &vecPosition, QAngle &vecAngles )
{
	float flDeltaTime = flTime - m_flLaunchTime;
	if ( flDeltaTime > m_flFlightTime )
	{
		flDeltaTime = m_flFlightTime;
	}

	VMatrix initToWorld;
	if ( m_bLaunchedFromWithinWorld || m_bInSkybox )
	{
		VectorMA( m_vecStartPosition, flDeltaTime * m_flHorizSpeed, m_vecParabolaDirection, vecPosition );
		vecPosition.z += m_flInitialZSpeed * flDeltaTime + 0.5f * m_flZAcceleration * flDeltaTime * flDeltaTime;

		Vector vecLeft;
		CrossProduct( m_vecParabolaDirection, Vector( 0, 0, 1 ), vecLeft );

		Vector vecForward;
		VectorMultiply( m_vecParabolaDirection, -1.0f, vecForward );
		vecForward.z = -(m_flInitialZSpeed + m_flZAcceleration * flDeltaTime) / m_flHorizSpeed;	// This is -dz/dx.
		VectorNormalize( vecForward );

		Vector vecUp;
		CrossProduct( vecForward, vecLeft, vecUp );
 
		initToWorld.SetBasisVectors( vecForward, vecLeft, vecUp );
	}
	else
	{
		flDeltaTime -= m_flWorldEnterTime;
		Vector vecVelocity;
		VectorMultiply( m_vecDirection, m_flFlightSpeed, vecVelocity );
		VectorMA( m_vecEnterWorldPosition, flDeltaTime, vecVelocity, vecPosition );

		MatrixFromAngles( m_vecStartAngles.Get(), initToWorld );
	}

	VMatrix rotation;
	MatrixBuildRotationAboutAxis( rotation, Vector( 1, 0, 0 ), flDeltaTime * ROTATION_SPEED );

	VMatrix newAngles;
	MatrixMultiply( initToWorld, rotation, newAngles );
	MatrixToAngles( newAngles, vecAngles );
}

VMatrix VMatrix::NormalizeBasisVectors() const
{
	Vector vecs[3];
	VMatrix mRet;


	GetBasisVectors(vecs[0], vecs[1], vecs[2]);
	
	VectorNormalize( vecs[0] );
	VectorNormalize( vecs[1] );
	VectorNormalize( vecs[2] );

	mRet.SetBasisVectors(vecs[0], vecs[1], vecs[2]);
	
	// Set everything but basis vectors to identity.
	mRet.m[3][0] = mRet.m[3][1] = mRet.m[3][2] = 0.0f;
	mRet.m[3][3] = 1.0f;

	return mRet;
}

void CRenderManager::SetupProjectionMatrix( int nWidth, int nHeight, float flFOV )
{
	VMatrix proj;
	float flZNear = ZNEAR;
	float flZFar = ZFAR;
	float flApsectRatio = (nHeight != 0.0f) ? (float)nWidth / (float)nHeight : 100.0f;

	float halfWidth = tan( flFOV * M_PI / 360.0 );
	float halfHeight = halfWidth / flApsectRatio;

	memset( proj.Base(), 0, sizeof( proj ) );
	proj[0][0]  = 1.0f / halfWidth;
	proj[1][1]  = 1.0f / halfHeight;
	proj[2][2] = flZFar / ( flZNear - flZFar );
	proj[3][2] = -1.0f;
	proj[2][3] = flZNear * flZFar / ( flZNear - flZFar );

	CMatRenderContextPtr pRenderContext( g_pMaterialSystem );
	pRenderContext->MatrixMode( MATERIAL_PROJECTION );
	pRenderContext->LoadMatrix( proj );
}

void CBaseVSShader::SetFlashlightVertexShaderConstants( bool bBump, int bumpTransformVar, bool bDetail, int detailScaleVar, bool bSetTextureTransforms )
{
	Assert( !IsSnapshotting() );

	VMatrix worldToTexture;
	const FlashlightState_t &flashlightState = s_pShaderAPI->GetFlashlightState( worldToTexture );

	// Set the flashlight origin
	float pos[4];
	pos[0] = flashlightState.m_vecLightOrigin[0];
	pos[1] = flashlightState.m_vecLightOrigin[1];
	pos[2] = flashlightState.m_vecLightOrigin[2];
	pos[3] = 1.0f / ( ( 0.6f * flashlightState.m_FarZ ) - flashlightState.m_FarZ );		// DX8 needs this

	s_pShaderAPI->SetVertexShaderConstant( VERTEX_SHADER_SHADER_SPECIFIC_CONST_0, pos, 1 );

	s_pShaderAPI->SetVertexShaderConstant( VERTEX_SHADER_SHADER_SPECIFIC_CONST_1, worldToTexture.Base(), 4 );

	// Set the flashlight attenuation factors
	float atten[4];
	atten[0] = flashlightState.m_fConstantAtten;
	atten[1] = flashlightState.m_fLinearAtten;
	atten[2] = flashlightState.m_fQuadraticAtten;
	atten[3] = flashlightState.m_FarZAtten;
	s_pShaderAPI->SetVertexShaderConstant( VERTEX_SHADER_SHADER_SPECIFIC_CONST_5, atten, 1 );

	if ( bDetail )
	{
		SetVertexShaderTextureScaledTransform( VERTEX_SHADER_SHADER_SPECIFIC_CONST_8, BASETEXTURETRANSFORM, detailScaleVar );
	}

	if( bSetTextureTransforms )
	{
		SetVertexShaderTextureTransform( VERTEX_SHADER_SHADER_SPECIFIC_CONST_6, BASETEXTURETRANSFORM );
		if( !bDetail && bBump && bumpTransformVar != -1 )
		{
			SetVertexShaderTextureTransform( VERTEX_SHADER_SHADER_SPECIFIC_CONST_8, bumpTransformVar ); // aliased on top of detail transform
		}
	}
}

void CStatueProp::VPhysicsUpdate( IPhysicsObject *pPhysics )
{
	BaseClass::VPhysicsUpdate( pPhysics );

	if ( s_vcollide_wireframe->GetBool() )
	{
		const CPhysCollide *pCollide = pPhysics->GetCollide();

		Vector vecOrigin;
		QAngle angAngles;

		pPhysics->GetPosition( &vecOrigin, &angAngles );

		if ( pCollide )
		{
			Vector *outVerts;
			int vertCount = physcollision->CreateDebugMesh( pCollide, &outVerts );
			int triCount = vertCount / 3;
			int vert = 0;

			VMatrix tmp = SetupMatrixOrgAngles( vecOrigin, angAngles );
			int i;
			for ( i = 0; i < vertCount; i++ )
			{
				outVerts[i] = tmp.VMul4x3( outVerts[i] );
			}

			for ( i = 0; i < triCount; i++ )
			{
				NDebugOverlay::Line( outVerts[ vert + 0 ], outVerts[ vert + 1 ], 0, 255, 255, false, 0.0f );
				NDebugOverlay::Line( outVerts[ vert + 1 ], outVerts[ vert + 2 ], 0, 255, 255, false, 0.0f );
				NDebugOverlay::Line( outVerts[ vert + 2 ], outVerts[ vert + 0 ], 0, 255, 255, false, 0.0f );
				vert += 3;
			}

			physcollision->DestroyDebugMesh( vertCount, outVerts );
		}
	}
}

void MatrixBuildPerspectiveOffCenterX( VMatrix& dst, double flFovX, double flAspect, double flZNear, double flZFar, double bottom, double top, double left, double right )
{
	float flWidth = 2.0f * flZNear * tanf( flFovX * M_PI / 360.0f );
	float flHeight = flWidth / flAspect;

	// bottom, top, left, right are 0..1 so convert to -<val>/2..<val>/2
	float flLeft   = -(flWidth/2.0f)  * (1.0f - left)   + left   * (flWidth/2.0f);
	float flRight  = -(flWidth/2.0f)  * (1.0f - right)  + right  * (flWidth/2.0f);
	float flBottom = -(flHeight/2.0f) * (1.0f - bottom) + bottom * (flHeight/2.0f);
	float flTop    = -(flHeight/2.0f) * (1.0f - top)    + top    * (flHeight/2.0f);

	dst.Init(   (2.0f * flZNear) / (flRight-flLeft),                           0.0f, (flLeft+flRight)/(flRight-flLeft),                            0.0f,
				0.0f,  2.0f*flZNear/(flTop-flBottom), (flTop+flBottom)/(flTop-flBottom),                            0.0f,
				0.0f,                           0.0f,           flZFar/(flZNear-flZFar),  flZNear*flZFar/(flZNear-flZFar),
				0.0f,                           0.0f,                             -1.0f,                            0.0f );
}