blender/source/gameengine/Ketsji/KX_Camera.cpp
Erwin Coumans 2e6d576182 Sorry to break the cvs-closed status, so if you really need to make a new 2.40 build, just disable the game engine if it doesn't compile for a platform. Again, sorry if this breaks non-windows platforms, but I hope people help to get this amazing fix working for all platforms. Armature-fixing contribution from Snailrose. Also lots of cool things from Snailrose and Lagan.
Armatures are back
Split screen
Double sided lightning
Ambient lighting
Alpha test
Material IPO support (one per object atm)
Blender materials
GLSL shaders - Python access
Up to three texture samplers from the material panel ( 2D & Cube map )
Python access to a second set of uv coordinates

See http://www.elysiun.com/forum/viewtopic.php?t=58057
2006-01-06 03:46:54 +00:00

762 lines
19 KiB
C++

/*
* $Id$
*
* ***** BEGIN GPL/BL DUAL LICENSE BLOCK *****
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version. The Blender
* Foundation also sells licenses for use in proprietary software under
* the Blender License. See http://www.blender.org/BL/ for information
* about this.
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): none yet.
*
* ***** END GPL/BL DUAL LICENSE BLOCK *****
* Camera in the gameengine. Cameras are also used for views.
*/
#include "KX_Camera.h"
#include "KX_Python.h"
#include "KX_PyMath.h"
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
KX_Camera::KX_Camera(void* sgReplicationInfo,
SG_Callbacks callbacks,
const RAS_CameraData& camdata,
bool frustum_culling,
PyTypeObject *T)
:
KX_GameObject(sgReplicationInfo,callbacks,T),
m_camdata(camdata),
m_dirty(true),
m_normalised(false),
m_frustum_culling(frustum_culling && camdata.m_perspective),
m_set_projection_matrix(false),
m_set_frustum_centre(false)
{
// setting a name would be nice...
m_name = "cam";
m_projection_matrix.setIdentity();
m_modelview_matrix.setIdentity();
SetProperty("camera",new CIntValue(1));
}
KX_Camera::~KX_Camera()
{
}
MT_Transform KX_Camera::GetWorldToCamera() const
{
MT_Transform camtrans;
camtrans.invert(MT_Transform(NodeGetWorldPosition(), NodeGetWorldOrientation()));
return camtrans;
}
MT_Transform KX_Camera::GetCameraToWorld() const
{
return MT_Transform(NodeGetWorldPosition(), NodeGetWorldOrientation());
}
void KX_Camera::CorrectLookUp(MT_Scalar speed)
{
}
const MT_Point3 KX_Camera::GetCameraLocation() const
{
/* this is the camera locatio in cam coords... */
//return m_trans1.getOrigin();
//return MT_Point3(0,0,0); <-----
/* .... I want it in world coords */
//MT_Transform trans;
//trans.setBasis(NodeGetWorldOrientation());
return NodeGetWorldPosition();
}
/* I want the camera orientation as well. */
const MT_Quaternion KX_Camera::GetCameraOrientation() const
{
return NodeGetWorldOrientation().getRotation();
}
/**
* Sets the projection matrix that is used by the rasterizer.
*/
void KX_Camera::SetProjectionMatrix(const MT_Matrix4x4 & mat)
{
m_projection_matrix = mat;
m_dirty = true;
m_set_projection_matrix = true;
m_set_frustum_centre = false;
}
/**
* Sets the modelview matrix that is used by the rasterizer.
*/
void KX_Camera::SetModelviewMatrix(const MT_Matrix4x4 & mat)
{
m_modelview_matrix = mat;
m_dirty = true;
m_set_frustum_centre = false;
}
/**
* Gets the projection matrix that is used by the rasterizer.
*/
const MT_Matrix4x4& KX_Camera::GetProjectionMatrix() const
{
return m_projection_matrix;
}
/**
* Gets the modelview matrix that is used by the rasterizer.
*/
const MT_Matrix4x4& KX_Camera::GetModelviewMatrix() const
{
return m_modelview_matrix;
}
bool KX_Camera::hasValidProjectionMatrix() const
{
return m_set_projection_matrix;
}
void KX_Camera::InvalidateProjectionMatrix(bool valid)
{
m_set_projection_matrix = valid;
}
/*
* These getters retrieve the clip data and the focal length
*/
float KX_Camera::GetLens() const
{
return m_camdata.m_lens;
}
float KX_Camera::GetCameraNear() const
{
return m_camdata.m_clipstart;
}
float KX_Camera::GetCameraFar() const
{
return m_camdata.m_clipend;
}
RAS_CameraData* KX_Camera::GetCameraData()
{
return &m_camdata;
}
void KX_Camera::ExtractClipPlanes()
{
if (!m_dirty)
return;
MT_Matrix4x4 m = m_projection_matrix * m_modelview_matrix;
// Left clip plane
m_planes[0] = m[3] + m[0];
// Right clip plane
m_planes[1] = m[3] - m[0];
// Top clip plane
m_planes[2] = m[3] - m[1];
// Bottom clip plane
m_planes[3] = m[3] + m[1];
// Near clip plane
m_planes[4] = m[3] + m[2];
// Far clip plane
m_planes[5] = m[3] - m[2];
m_dirty = false;
m_normalised = false;
}
void KX_Camera::NormaliseClipPlanes()
{
if (m_normalised)
return;
for (unsigned int p = 0; p < 6; p++)
{
MT_Scalar factor = sqrt(m_planes[p][0]*m_planes[p][0] + m_planes[p][1]*m_planes[p][1] + m_planes[p][2]*m_planes[p][2]);
if (!MT_fuzzyZero(factor))
m_planes[p] /= factor;
}
m_normalised = true;
}
void KX_Camera::ExtractFrustumSphere()
{
if (m_set_frustum_centre)
return;
// The most extreme points on the near and far plane. (normalised device coords)
MT_Vector4 hnear(1., 1., 0., 1.), hfar(1., 1., 1., 1.);
MT_Matrix4x4 clip_camcs_matrix = m_projection_matrix;
clip_camcs_matrix.invert();
// Transform to hom camera local space
hnear = clip_camcs_matrix*hnear;
hfar = clip_camcs_matrix*hfar;
// Tranform to 3d camera local space.
MT_Point3 nearpoint(hnear[0]/hnear[3], hnear[1]/hnear[3], hnear[2]/hnear[3]);
MT_Point3 farpoint(hfar[0]/hfar[3], hfar[1]/hfar[3], hfar[2]/hfar[3]);
// Compute centre
m_frustum_centre = MT_Point3(0., 0.,
(nearpoint.dot(nearpoint) - farpoint.dot(farpoint))/(2.0*(m_camdata.m_clipend - m_camdata.m_clipstart)));
m_frustum_radius = m_frustum_centre.distance(farpoint);
// Transform to world space.
m_frustum_centre = GetCameraToWorld()(m_frustum_centre);
m_frustum_radius /= fabs(NodeGetWorldScaling()[NodeGetWorldScaling().closestAxis()]);
m_set_frustum_centre = true;
}
bool KX_Camera::PointInsideFrustum(const MT_Point3& x)
{
ExtractClipPlanes();
for( unsigned int i = 0; i < 6 ; i++ )
{
if (m_planes[i][0]*x[0] + m_planes[i][1]*x[1] + m_planes[i][2]*x[2] + m_planes[i][3] < 0.)
return false;
}
return true;
}
int KX_Camera::BoxInsideFrustum(const MT_Point3 *box)
{
ExtractClipPlanes();
unsigned int insideCount = 0;
// 6 view frustum planes
for( unsigned int p = 0; p < 6 ; p++ )
{
unsigned int behindCount = 0;
// 8 box verticies.
for (unsigned int v = 0; v < 8 ; v++)
{
if (m_planes[p][0]*box[v][0] + m_planes[p][1]*box[v][1] + m_planes[p][2]*box[v][2] + m_planes[p][3] < 0.)
behindCount++;
}
// 8 points behind this plane
if (behindCount == 8)
return OUTSIDE;
// Every box vertex is on the front side of this plane
if (!behindCount)
insideCount++;
}
// All box verticies are on the front side of all frustum planes.
if (insideCount == 6)
return INSIDE;
return INTERSECT;
}
int KX_Camera::SphereInsideFrustum(const MT_Point3& centre, const MT_Scalar &radius)
{
ExtractFrustumSphere();
if (centre.distance2(m_frustum_centre) > (radius + m_frustum_radius)*(radius + m_frustum_radius))
return OUTSIDE;
unsigned int p;
ExtractClipPlanes();
NormaliseClipPlanes();
MT_Scalar distance;
int intersect = INSIDE;
// distance: <-------- OUTSIDE -----|----- INTERSECT -----0----- INTERSECT -----|----- INSIDE -------->
// -radius radius
for (p = 0; p < 6; p++)
{
distance = m_planes[p][0]*centre[0] + m_planes[p][1]*centre[1] + m_planes[p][2]*centre[2] + m_planes[p][3];
if (fabs(distance) <= radius)
intersect = INTERSECT;
else if (distance < -radius)
return OUTSIDE;
}
return intersect;
}
bool KX_Camera::GetFrustumCulling() const
{
return m_frustum_culling;
}
void KX_Camera::EnableViewport(bool viewport)
{
m_camdata.m_viewport = viewport;
}
void KX_Camera::SetViewport(int left, int bottom, int right, int top)
{
m_camdata.m_viewportleft = left;
m_camdata.m_viewportbottom = bottom;
m_camdata.m_viewportright = right;
m_camdata.m_viewporttop = top;
}
bool KX_Camera::GetViewport() const
{
return m_camdata.m_viewport;
}
int KX_Camera::GetViewportLeft() const
{
return m_camdata.m_viewportleft;
}
int KX_Camera::GetViewportBottom() const
{
return m_camdata.m_viewportbottom;
}
int KX_Camera::GetViewportRight() const
{
return m_camdata.m_viewportright;
}
int KX_Camera::GetViewportTop() const
{
return m_camdata.m_viewporttop;
}
//----------------------------------------------------------------------------
//Python
PyMethodDef KX_Camera::Methods[] = {
KX_PYMETHODTABLE(KX_Camera, sphereInsideFrustum),
KX_PYMETHODTABLE(KX_Camera, boxInsideFrustum),
KX_PYMETHODTABLE(KX_Camera, pointInsideFrustum),
KX_PYMETHODTABLE(KX_Camera, getCameraToWorld),
KX_PYMETHODTABLE(KX_Camera, getWorldToCamera),
KX_PYMETHODTABLE(KX_Camera, getProjectionMatrix),
KX_PYMETHODTABLE(KX_Camera, setProjectionMatrix),
KX_PYMETHODTABLE(KX_Camera, enableViewport),
KX_PYMETHODTABLE(KX_Camera, setViewport),
{NULL,NULL} //Sentinel
};
char KX_Camera::doc[] = "Module KX_Camera\n\n"
"Constants:\n"
"\tINSIDE\n"
"\tINTERSECT\n"
"\tOUTSIDE\n"
"Attributes:\n"
"\tlens -> float\n"
"\t\tThe camera's lens value\n"
"\tnear -> float\n"
"\t\tThe camera's near clip distance\n"
"\tfar -> float\n"
"\t\tThe camera's far clip distance\n"
"\tfrustum_culling -> bool\n"
"\t\tNon zero if this camera is frustum culling.\n"
"\tprojection_matrix -> [[float]]\n"
"\t\tThis camera's projection matrix.\n"
"\tmodelview_matrix -> [[float]] (read only)\n"
"\t\tThis camera's model view matrix.\n"
"\t\tRegenerated every frame from the camera's position and orientation.\n"
"\tcamera_to_world -> [[float]] (read only)\n"
"\t\tThis camera's camera to world transform.\n"
"\t\tRegenerated every frame from the camera's position and orientation.\n"
"\tworld_to_camera -> [[float]] (read only)\n"
"\t\tThis camera's world to camera transform.\n"
"\t\tRegenerated every frame from the camera's position and orientation.\n"
"\t\tThis is camera_to_world inverted.\n";
PyTypeObject KX_Camera::Type = {
PyObject_HEAD_INIT(&PyType_Type)
0,
"KX_Camera",
sizeof(KX_Camera),
0,
PyDestructor,
0,
__getattr,
__setattr,
0, //&MyPyCompare,
__repr,
0, //&cvalue_as_number,
0,
0,
0,
0, 0, 0, 0, 0, 0,
doc
};
PyParentObject KX_Camera::Parents[] = {
&KX_Camera::Type,
&KX_GameObject::Type,
&SCA_IObject::Type,
&CValue::Type,
NULL
};
PyObject* KX_Camera::_getattr(const STR_String& attr)
{
if (attr == "INSIDE")
return PyInt_FromLong(INSIDE); /* new ref */
if (attr == "OUTSIDE")
return PyInt_FromLong(OUTSIDE); /* new ref */
if (attr == "INTERSECT")
return PyInt_FromLong(INTERSECT); /* new ref */
if (attr == "lens")
return PyFloat_FromDouble(GetLens()); /* new ref */
if (attr == "near")
return PyFloat_FromDouble(GetCameraNear()); /* new ref */
if (attr == "far")
return PyFloat_FromDouble(GetCameraFar()); /* new ref */
if (attr == "frustum_culling")
return PyInt_FromLong(m_frustum_culling); /* new ref */
if (attr == "perspective")
return PyInt_FromLong(m_camdata.m_perspective); /* new ref */
if (attr == "projection_matrix")
return PyObjectFrom(GetProjectionMatrix()); /* new ref */
if (attr == "modelview_matrix")
return PyObjectFrom(GetModelviewMatrix()); /* new ref */
if (attr == "camera_to_world")
return PyObjectFrom(GetCameraToWorld()); /* new ref */
if (attr == "world_to_camera")
return PyObjectFrom(GetWorldToCamera()); /* new ref */
_getattr_up(KX_GameObject);
}
int KX_Camera::_setattr(const STR_String &attr, PyObject *pyvalue)
{
if (PyInt_Check(pyvalue))
{
if (attr == "frustum_culling")
{
m_frustum_culling = PyInt_AsLong(pyvalue);
return 0;
}
if (attr == "perspective")
{
m_camdata.m_perspective = PyInt_AsLong(pyvalue);
return 0;
}
}
if (PyFloat_Check(pyvalue))
{
if (attr == "lens")
{
m_camdata.m_lens = PyFloat_AsDouble(pyvalue);
m_set_projection_matrix = false;
return 0;
}
if (attr == "near")
{
m_camdata.m_clipstart = PyFloat_AsDouble(pyvalue);
m_set_projection_matrix = false;
return 0;
}
if (attr == "far")
{
m_camdata.m_clipend = PyFloat_AsDouble(pyvalue);
m_set_projection_matrix = false;
return 0;
}
}
if (PyObject_IsMT_Matrix(pyvalue, 4))
{
if (attr == "projection_matrix")
{
MT_Matrix4x4 mat;
if (PyMatTo(pyvalue, mat))
{
SetProjectionMatrix(mat);
return 0;
}
return 1;
}
}
return KX_GameObject::_setattr(attr, pyvalue);
}
KX_PYMETHODDEF_DOC(KX_Camera, sphereInsideFrustum,
"sphereInsideFrustum(centre, radius) -> Integer\n"
"\treturns INSIDE, OUTSIDE or INTERSECT if the given sphere is\n"
"\tinside/outside/intersects this camera's viewing frustum.\n\n"
"\tcentre = the centre of the sphere (in world coordinates.)\n"
"\tradius = the radius of the sphere\n\n"
"\tExample:\n"
"\timport GameLogic\n\n"
"\tco = GameLogic.getCurrentController()\n"
"\tcam = co.GetOwner()\n\n"
"\t# A sphere of radius 4.0 located at [x, y, z] = [1.0, 1.0, 1.0]\n"
"\tif (cam.sphereInsideFrustum([1.0, 1.0, 1.0], 4) != cam.OUTSIDE):\n"
"\t\t# Sphere is inside frustum !\n"
"\t\t# Do something useful !\n"
"\telse:\n"
"\t\t# Sphere is outside frustum\n"
)
{
PyObject *pycentre;
float radius;
if (PyArg_ParseTuple(args, "Of", &pycentre, &radius))
{
MT_Point3 centre;
if (PyVecTo(pycentre, centre))
{
return PyInt_FromLong(SphereInsideFrustum(centre, radius)); /* new ref */
}
}
PyErr_SetString(PyExc_TypeError, "sphereInsideFrustum: Expected arguments: (centre, radius)");
Py_Return;
}
KX_PYMETHODDEF_DOC(KX_Camera, boxInsideFrustum,
"boxInsideFrustum(box) -> Integer\n"
"\treturns INSIDE, OUTSIDE or INTERSECT if the given box is\n"
"\tinside/outside/intersects this camera's viewing frustum.\n\n"
"\tbox = a list of the eight (8) corners of the box (in world coordinates.)\n\n"
"\tExample:\n"
"\timport GameLogic\n\n"
"\tco = GameLogic.getCurrentController()\n"
"\tcam = co.GetOwner()\n\n"
"\tbox = []\n"
"\tbox.append([-1.0, -1.0, -1.0])\n"
"\tbox.append([-1.0, -1.0, 1.0])\n"
"\tbox.append([-1.0, 1.0, -1.0])\n"
"\tbox.append([-1.0, 1.0, 1.0])\n"
"\tbox.append([ 1.0, -1.0, -1.0])\n"
"\tbox.append([ 1.0, -1.0, 1.0])\n"
"\tbox.append([ 1.0, 1.0, -1.0])\n"
"\tbox.append([ 1.0, 1.0, 1.0])\n\n"
"\tif (cam.boxInsideFrustum(box) != cam.OUTSIDE):\n"
"\t\t# Box is inside/intersects frustum !\n"
"\t\t# Do something useful !\n"
"\telse:\n"
"\t\t# Box is outside the frustum !\n"
)
{
PyObject *pybox;
if (PyArg_ParseTuple(args, "O", &pybox))
{
unsigned int num_points = PySequence_Size(pybox);
if (num_points != 8)
{
PyErr_Format(PyExc_TypeError, "boxInsideFrustum: Expected eight (8) points, got %d", num_points);
return NULL;
}
MT_Point3 box[8];
for (unsigned int p = 0; p < 8 ; p++)
{
PyObject *item = PySequence_GetItem(pybox, p); /* new ref */
bool error = !PyVecTo(item, box[p]);
Py_DECREF(item);
if (error)
return NULL;
}
return PyInt_FromLong(BoxInsideFrustum(box)); /* new ref */
}
PyErr_SetString(PyExc_TypeError, "boxInsideFrustum: Expected argument: list of points.");
return NULL;
}
KX_PYMETHODDEF_DOC(KX_Camera, pointInsideFrustum,
"pointInsideFrustum(point) -> Bool\n"
"\treturns 1 if the given point is inside this camera's viewing frustum.\n\n"
"\tpoint = The point to test (in world coordinates.)\n\n"
"\tExample:\n"
"\timport GameLogic\n\n"
"\tco = GameLogic.getCurrentController()\n"
"\tcam = co.GetOwner()\n\n"
"\t# Test point [0.0, 0.0, 0.0]"
"\tif (cam.pointInsideFrustum([0.0, 0.0, 0.0])):\n"
"\t\t# Point is inside frustum !\n"
"\t\t# Do something useful !\n"
"\telse:\n"
"\t\t# Box is outside the frustum !\n"
)
{
MT_Point3 point;
if (PyVecArgTo(args, point))
{
return PyInt_FromLong(PointInsideFrustum(point)); /* new ref */
}
PyErr_SetString(PyExc_TypeError, "pointInsideFrustum: Expected point argument.");
return NULL;
}
KX_PYMETHODDEF_DOC(KX_Camera, getCameraToWorld,
"getCameraToWorld() -> Matrix4x4\n"
"\treturns the camera to world transformation matrix, as a list of four lists of four values.\n\n"
"\tie: [[1.0, 0.0, 0.0, 0.0], [0.0, 1.0, 0.0, 0.0], [0.0, 0.0, 1.0, 0.0], [0.0, 0.0, 0.0, 1.0]])\n"
)
{
return PyObjectFrom(GetCameraToWorld()); /* new ref */
}
KX_PYMETHODDEF_DOC(KX_Camera, getWorldToCamera,
"getWorldToCamera() -> Matrix4x4\n"
"\treturns the world to camera transformation matrix, as a list of four lists of four values.\n\n"
"\tie: [[1.0, 0.0, 0.0, 0.0], [0.0, 1.0, 0.0, 0.0], [0.0, 0.0, 1.0, 0.0], [0.0, 0.0, 0.0, 1.0]])\n"
)
{
return PyObjectFrom(GetWorldToCamera()); /* new ref */
}
KX_PYMETHODDEF_DOC(KX_Camera, getProjectionMatrix,
"getProjectionMatrix() -> Matrix4x4\n"
"\treturns this camera's projection matrix, as a list of four lists of four values.\n\n"
"\tie: [[1.0, 0.0, 0.0, 0.0], [0.0, 1.0, 0.0, 0.0], [0.0, 0.0, 1.0, 0.0], [0.0, 0.0, 0.0, 1.0]])\n"
)
{
return PyObjectFrom(GetProjectionMatrix()); /* new ref */
}
KX_PYMETHODDEF_DOC(KX_Camera, setProjectionMatrix,
"setProjectionMatrix(MT_Matrix4x4 m) -> None\n"
"\tSets this camera's projection matrix\n"
"\n"
"\tExample:\n"
"\timport GameLogic\n"
"\t# Set a perspective projection matrix\n"
"\tdef Perspective(left, right, bottom, top, near, far):\n"
"\t\tm = MT_Matrix4x4()\n"
"\t\tm[0][0] = m[0][2] = right - left\n"
"\t\tm[1][1] = m[1][2] = top - bottom\n"
"\t\tm[2][2] = m[2][3] = -far - near\n"
"\t\tm[3][2] = -1\n"
"\t\tm[3][3] = 0\n"
"\t\treturn m\n"
"\n"
"\t# Set an orthographic projection matrix\n"
"\tdef Orthographic(left, right, bottom, top, near, far):\n"
"\t\tm = MT_Matrix4x4()\n"
"\t\tm[0][0] = right - left\n"
"\t\tm[0][3] = -right - left\n"
"\t\tm[1][1] = top - bottom\n"
"\t\tm[1][3] = -top - bottom\n"
"\t\tm[2][2] = far - near\n"
"\t\tm[2][3] = -far - near\n"
"\t\tm[3][3] = 1\n"
"\t\treturn m\n"
"\n"
"\t# Set an isometric projection matrix\n"
"\tdef Isometric(left, right, bottom, top, near, far):\n"
"\t\tm = MT_Matrix4x4()\n"
"\t\tm[0][0] = m[0][2] = m[1][1] = 0.8660254037844386\n"
"\t\tm[1][0] = 0.25\n"
"\t\tm[1][2] = -0.25\n"
"\t\tm[3][3] = 1\n"
"\t\treturn m\n"
"\n"
"\t"
"\tco = GameLogic.getCurrentController()\n"
"\tcam = co.getOwner()\n"
"\tcam.setProjectionMatrix(Perspective(-1.0, 1.0, -1.0, 1.0, 0.1, 1))\n")
{
PyObject *pymat;
if (PyArg_ParseTuple(args, "O", &pymat))
{
MT_Matrix4x4 mat;
if (PyMatTo(pymat, mat))
{
SetProjectionMatrix(mat);
Py_Return;
}
}
PyErr_SetString(PyExc_TypeError, "setProjectionMatrix: Expected 4x4 list as matrix argument.");
return NULL;
}
KX_PYMETHODDEF_DOC(KX_Camera, enableViewport,
"enableViewport(viewport)\n"
"Sets this camera's viewport status\n"
)
{
int viewport;
if (PyArg_ParseTuple(args,"i",&viewport))
{
if(viewport)
EnableViewport(true);
else
EnableViewport(false);
}
Py_Return;
}
KX_PYMETHODDEF_DOC(KX_Camera, setViewport,
"setViewport(left, bottom, right, top)\n"
"Sets this camera's viewport\n")
{
int left, bottom, right, top;
if (PyArg_ParseTuple(args,"iiii",&left, &bottom, &right, &top))
{
SetViewport(left, bottom, right, top);
}
Py_Return;
}