100 lines
3.3 KiB
C++
100 lines
3.3 KiB
C++
//========= Copyright Valve Corporation, All rights reserved. ============//
|
|
//
|
|
// Purpose:
|
|
//
|
|
//=============================================================================
|
|
#include "tier2/camerautils.h"
|
|
#include "tier0/dbg.h"
|
|
#include "mathlib/vector.h"
|
|
#include "mathlib/vmatrix.h"
|
|
#include "tier2/tier2.h"
|
|
|
|
// memdbgon must be the last include file in a .cpp file!!!
|
|
#include "tier0/memdbgon.h"
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// accessors for generated matrices
|
|
//-----------------------------------------------------------------------------
|
|
void ComputeViewMatrix( matrix3x4_t *pWorldToCamera, const Camera_t &camera )
|
|
{
|
|
matrix3x4_t transform;
|
|
AngleMatrix( camera.m_angles, camera.m_origin, transform );
|
|
|
|
VMatrix matRotate( transform );
|
|
VMatrix matRotateZ;
|
|
MatrixBuildRotationAboutAxis( matRotateZ, Vector(0,0,1), -90 );
|
|
MatrixMultiply( matRotate, matRotateZ, matRotate );
|
|
|
|
VMatrix matRotateX;
|
|
MatrixBuildRotationAboutAxis( matRotateX, Vector(1,0,0), 90 );
|
|
MatrixMultiply( matRotate, matRotateX, matRotate );
|
|
transform = matRotate.As3x4();
|
|
|
|
MatrixInvert( transform, *pWorldToCamera );
|
|
}
|
|
|
|
void ComputeViewMatrix( VMatrix *pWorldToCamera, const Camera_t &camera )
|
|
{
|
|
matrix3x4_t transform, invTransform;
|
|
AngleMatrix( camera.m_angles, camera.m_origin, transform );
|
|
|
|
VMatrix matRotate( transform );
|
|
VMatrix matRotateZ;
|
|
MatrixBuildRotationAboutAxis( matRotateZ, Vector(0,0,1), -90 );
|
|
MatrixMultiply( matRotate, matRotateZ, matRotate );
|
|
|
|
VMatrix matRotateX;
|
|
MatrixBuildRotationAboutAxis( matRotateX, Vector(1,0,0), 90 );
|
|
MatrixMultiply( matRotate, matRotateX, matRotate );
|
|
transform = matRotate.As3x4();
|
|
|
|
MatrixInvert( transform, invTransform );
|
|
*pWorldToCamera = invTransform;
|
|
}
|
|
|
|
void ComputeProjectionMatrix( VMatrix *pCameraToProjection, const Camera_t &camera, int width, int height )
|
|
{
|
|
float flFOV = camera.m_flFOV;
|
|
float flZNear = camera.m_flZNear;
|
|
float flZFar = camera.m_flZFar;
|
|
float flApsectRatio = (float)width / (float)height;
|
|
|
|
// MatrixBuildPerspective( proj, flFOV, flFOV * flApsectRatio, flZNear, flZFar );
|
|
|
|
#if 1
|
|
float halfWidth = tan( flFOV * M_PI / 360.0 );
|
|
float halfHeight = halfWidth / flApsectRatio;
|
|
#else
|
|
float halfHeight = tan( flFOV * M_PI / 360.0 );
|
|
float halfWidth = flApsectRatio * halfHeight;
|
|
#endif
|
|
memset( pCameraToProjection, 0, sizeof( VMatrix ) );
|
|
pCameraToProjection->m[0][0] = 1.0f / halfWidth;
|
|
pCameraToProjection->m[1][1] = 1.0f / halfHeight;
|
|
pCameraToProjection->m[2][2] = flZFar / ( flZNear - flZFar );
|
|
pCameraToProjection->m[3][2] = -1.0f;
|
|
pCameraToProjection->m[2][3] = flZNear * flZFar / ( flZNear - flZFar );
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// Computes the screen space position given a screen size
|
|
//-----------------------------------------------------------------------------
|
|
void ComputeScreenSpacePosition( Vector2D *pScreenPosition, const Vector &vecWorldPosition,
|
|
const Camera_t &camera, int width, int height )
|
|
{
|
|
VMatrix view, proj, viewproj;
|
|
ComputeViewMatrix( &view, camera );
|
|
ComputeProjectionMatrix( &proj, camera, width, height );
|
|
MatrixMultiply( proj, view, viewproj );
|
|
|
|
Vector vecScreenPos;
|
|
Vector3DMultiplyPositionProjective( viewproj, vecWorldPosition, vecScreenPos );
|
|
|
|
pScreenPosition->x = ( vecScreenPos.x + 1.0f ) * width / 2.0f;
|
|
pScreenPosition->y = ( -vecScreenPos.y + 1.0f ) * height / 2.0f;
|
|
}
|
|
|
|
|