gles_utils.py

#
# ====================================================================
# gles_utils.py - Utility functions for OpenGL ES
#
# Ported from the C++ utils
#
# Copyright (c) 2006 Nokia Corporation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
from gles import *
from math import *
import types

try:
  radians
except NameError:
  def radians(degrees):
    """Convert degrees to radians"""
    return degrees * (pi/180)

try:
  degrees
except NameError:
  def degrees(radians):
    """Convert radians to degrees"""
    return radians * (180/pi)

def int2fixed(i):
  """Convert an integer to fixed point"""
  return i << 16

def float2fixed(v):
  """Convert a float to fixed point"""
  print "float2fixed"
  print type(v)
  print "v = %x" % (v)
  ret = v*pow(2,16)
  print "ret = %x" % (ret)
  return int(ret)

def fixed2float(v):
  """Convert fixed to float"""
  return v * (1/65536.0)
  
def floats2fixed(values):
  """Convert a sequence of floats to fixed point"""
  return [float2fixed(v) for v in values]

def fixed_mul(a, b):
  """Multiply fixed values"""
  return (a >> 8) * (b >> 8)
def fixed_div(a,b):
 return ((a * (1/b)) * 65536.0)

class TVector:
  """A 3D vector that is represented by single-precision floating point x,y,z coordinates."""
  def __init__(self, aX=0.0, aY=0.0, aZ=0.0):
    self.iX = aX
    self.iY = aY
    self.iZ = aZ
  
  def __add__(self, other):
    # + operator
    return TVector(self.iX + other.iX, self.iY + other.iY, self.iZ + other.iZ)
    
  def __iadd__(self, other):
    # += operator
    ret = self + other
    self.iX = ret.aX
    self.iY = ret.aY
    self.iZ = ret.aZ
    return ret
    
  def __sub__(self, other):
    # - operator
    return (self + (other * -1))
  
  def __neg__(self):
    # -self operator
    return (self * -1)
    
  def __mul__(self, other):
    # * operator
    if isinstance(other, TVector):
      return (self.iX * other.iX + self.iY * other.iY + self.iZ * other.iZ)
    if type(other) in (types.FloatType,types.IntType):
      return TVector(self.iX * other, self.iY * other, self.iZ * other)
      
  
  def Magnitude(self):
    # Calculate the magnitude of this vector. Standard trigonometric calculation:
    # sqrt(x**2 + y**2 + z**2)
    return sqrt(self * self)
  
  def Normalize(self):
    # Normalizes this vector, Panics if this vector = (0, 0, 0)
    magnitude = self.Magnitude()
    if magnitude == 0:
      return
    self = self * (1 / magnitude)
   
  def CrossProduct(aVector1, aVector2):
    # Computes the crossproduct of vector aVector1 and vector aVector2.
    iX = aVector1.iY * aVector2.iZ - aVector1.iZ * aVector2.iY
    iY = aVector1.iZ * aVector2.iX - aVector1.iX * aVector2.iZ
    iZ = aVector1.iX * aVector2.iY - aVector1.iY * aVector2.iX
    
    return TVector(iX, iY, iZ)
    
class TVectorx:
  """A 3D vector that is represented by fixed-point x,y,z coordinates."""
  def __init__(self, aX=0, aY=0, aZ=0):
    self.iX = int2fixed(int(aX))
    self.iY = int2fixed(int(aY))
    self.iZ = int2fixed(int(aZ))
  
  def __add__(self, other):
    # + operator
    return TVectorx(self.iX + other.iX, self.iY + other.iY, self.iZ + other.iZ)
  
  def __iadd__(self, other):
    # += operator
    ret = self + other
    self.iX = ret.aX
    self.iY = ret.aY
    self.iZ = ret.aZ
    return ret
    
  def __sub__(self, other):
    # - operator
    return (self + (other * int2fixed(-1)))
  
  def __neg__(self):
    # -self operator
    return (self * int2fixed(-1))
  
  def __mul__(self, other):
    # * operator
    if isinstance(other, TVectorx):
      return (fixed_mul(self.iX, other.iX) + fixed_mul(self.iY, other.iY) + fixed_mul(self.iZ, other.iZ))
    if type(other) in (types.FloatType, types.IntType):
      return TVectorx(fixed_mul(self.iX, other), fixed_mul(self.iY, other), fixed_mul(self.iZ, other))
    else:
      raise TypeError("Unsupported type")
  
  def Magnitude(self):
    # Calculate the magnitude of this vector. Standard trigonometric calculation:
    # sqrt(x**2 + y**2 + z**2)
    src = fixed2float(self * self)
    #print src
    return float2fixed(sqrt(src))

  def Normalize(self):
    # Normalizes the vector by dividing each component with the length of the vector.
    magnitude = self.Magnitude()
    #print magnitude
    if magnitude == 0:
      return
    ret = self * float2fixed(1 / fixed2float(magnitude))
    self.iX = ret.aX
    self.iY = ret.aY
    self.iZ = ret.aZ
    
  def CrossProduct(aVector1, aVector2):
    # Computes the crossproduct of vector aVector1 and vector aVector2.
    iX = fixed_mul(aVector1.iY, aVector2.iZ) - fixed_mul(aVector1.iZ, aVector2.iY)
    iY = fixed_mul(aVector1.iZ, aVector2.iX) - fixed_mul(aVector1.iX, aVector2.iZ)
    iZ = fixed_mul(aVector1.iX, aVector2.iY) - fixed_mul(aVector1.iY, aVector2.iX)
    return TVectorx(iX, iY, iZ)
    
class FiniteStateMachine:
  # An abstraction of a finite state machine
  def __init__(self):
    self.iState = None
    self.iPrevState = None
  def SetState(self, aNewState ):
    # Set the current state and trigger OnEnterState.
    if aNewState != -1:
      if aNewState != self.iState:
        if self.iPrevState != -1:
          self.OnLeaveState( self.iState )
        self.iPrevState = self.iState
        self.iState = aNewState
        self.OnEnterState( self.iState )
  
  def OnLeaveState( self, aState ):
    # Empty implementation
    pass
  
  def OnEnterState( self, iState ):
    # Empty implementation
    pass
  
class TFlareConfig:
  # Index of the texture used by this element.
  #iIndex
  # Length scaling.
  #iLengthScale
  # Texture scaling.
  #iImageScale;  
  pass
  
class CLensFlareEffect:
  # An abstraction of a lens flare effect.
  def __init__(self, aTextureNames, aFlareConfigs, aTextureManager, aScreenWidth, aScreenHeight):
    self.iTextures = TTexture(len(aTextureNames))
    
    self.iFlareConfigs = aFlareConfigs
    #self.iFlareConfigCount = aFlareConfigCount
    
    self.iTextureManager = aTextureManager
    
    self.iCenterX = aScreenWidth>>1
    self.iCenterY = aScreenHeight>>1
    
  def DrawAt(self, aLightX, aLightY):
    # Renders the lens flare effect at a given screen coordinates.
    # Uses the CTextureManager::Blit, which in turn draws two triangles (forming
    # a single quad)
    
    # Computing the lens flare vector.
    DirX = aLightX - iCenterX
    DirY = aLightY - iCenterY
    
    #TReal Scale;
    #TReal BlitCenterX, BlitCenterY;
    #TReal BlitWidth_div_2, BlitHeight_div_2;
    
    glEnable( GL_BLEND )
    glBlendFunc(GL_ONE, GL_ONE)
    glEnable( GL_TEXTURE_2D )
    
    for i in range(len(self.iFlareConfigs)):
      TextureIndex = self.iFlareConfigs[i].iIndex
      Scale = self.iFlareConfigs[i].iLengthScale
      
      BlitCenterX = DirX*Scale+self.iCenterX
      BlitCenterY = DirY*Scale+self.iCenterY
      BlitWidth_div_2   = (self.iTextures[TextureIndex].iTextureWidth  * self.iFlareConfigs[i].iImageScale) / 4
      BlitHeight_div_2  = (self.iTextures[TextureIndex].iTextureHeight * self.iFlareConfigs[i].iImageScale) / 4
      
      iTextureManager.Blit(self.iTextures[TextureIndex],
        (BlitCenterX - BlitWidth_div_2), 
        (BlitCenterY - BlitHeight_div_2),
        (BlitCenterX + BlitWidth_div_2), 
        (BlitCenterY + BlitHeight_div_2))
    glDisable( GL_TEXTURE_2D )
    glDisable( GL_BLEND )
    
class T3DModel:
  # Abstraction of a 3D model, represented by a position vector and single-precision floating point Yaw, Pitch, Roll orientation
  def __init__(self, aPosition, aYaw, aPitch, aRoll):
    self.position = aPosition
    self.yaw = aYaw
    self.pitch = aPitch
    self.roll = aRoll
  
  def MakeWorldViewMatrix(aCamera, aPosition, aYaw=0, aPitch=0, aRoll=0):
    # Sets up a world + a view matrix.
    
    glMultMatrixf(aCamera.iViewMatrix)
    
    glTranslatef(aPosition.iX-aCamera.iPosition.iX, aPosition.iY-aCamera.iPosition.iY, aPosition.iZ-aCamera.iPosition.iZ)
    if aRoll:
      glRotatef( aRoll , 0, 0, 1)
    if aYaw:
      glRotatef( aYaw  , 0, 1, 0)
    if aPitch:
      glRotatef( aPitch, 1, 0, 0)
  MakeWorldViewMatrix = staticmethod(MakeWorldViewMatrix)
  def MakeBillboardWorldViewMatrix(aCamera, aPosition):
    # Sets up a billboard matrix, which is a matrix that rotates objects in such a 
    # way that they always face the camera.
    # Refer to the billboard example to see how this method is used.
    
    # Set up a rotation matrix to orient the billboard towards the camera.
    Dir = aCamera.iLookAt - aCamera.iPosition;  	
    
    #TReal Angle, SrcT, SrcB;
    
    SrcT = Dir.iZ;
    SrcB = Dir.iX;
    Angle = atan2( SrcT, SrcB)
    # The Yaw angle is computed in such a way that the object always faces the 
    # camera.
    Angle = -(degrees( Angle ) + 90)
    T3DModel.MakeWorldViewMatrix(aCamera, aPosition, Angle)
  MakeBillboardWorldViewMatrix = staticmethod(MakeBillboardWorldViewMatrix)
    
class T3DModelx:
  # Abstraction of a 3D model, represented by a position vector and fixed-point Yaw, Pitch, Roll orientation
  def __init__(self, aPosition=TVectorx(int2fixed(0),int2fixed(0),int2fixed(0)), aYaw=int2fixed(0), aPitch=int2fixed(0), aRoll=int2fixed(0)):
    # Constructs and initializes a T3DModelx to position aPosition, with 
    # orientation [aYaw, aPitch, aRoll].
    self.position = aPosition
    self.yaw = aYaw
    self.pitch = aPitch
    self.roll = aRoll
  def MakeWorldViewMatrix(aCamera, aPosition, aYaw=0, aPitch=0, aRoll=0):
    # Sets up a world + a view matrix.
    
    glMultMatrixx(aCamera.iViewMatrix)
    
    glTranslatex(aPosition.iX-aCamera.iPosition.iX, aPosition.iY-aCamera.iPosition.iY, aPosition.iZ-aCamera.iPosition.iZ)
    if aRoll != int2fixed(0):
      glRotatex( aRoll , int2fixed(0), int2fixed(0), int2fixed(1))
    if aYaw != int2fixed(0):
      glRotatex( aYaw  , int2fixed(0), int2fixed(1), int2fixed(0))
    if aPitch != int2fixed(0):
      glRotatex( aPitch, int2fixed(1), int2fixed(0), int2fixed(0))
  MakeWorldViewMatrix = staticmethod(MakeWorldViewMatrix)

  def MakeBillboardWorldViewMatrix(aCamera, aPosition):
    # Sets up a billboard matrix, which is a matrix that rotates objects in such a 
    # way that they always face the camera.
    # Refer to the billboard example to see how this method is used.
    
    #if not aPosition:
    #  aPosition = self.position
    
    # Set up a rotation matrix to orient the billboard towards the camera.
    Dir = aCamera.iLookAt - aCamera.iPosition
    
    #TReal Angle, SrcT, SrcB;
    #return
    SrcT = fixed2float(Dir.iZ)
    SrcB = fixed2float(Dir.iX)
    print "SrcT: %x" % (SrcT)
    print "SrcB: %x" % (SrcB)
    angle = atan2( SrcT, SrcB)
    print "Angle = %f" % (angle)
    # The Yaw angle is computed in such a way that the object always faces the camera.
    angle = -(degrees( angle ) + 90)
    print "Angle = %f" % (angle)
    T3DModelx.MakeWorldViewMatrix(aCamera, aPosition, float2fixed(angle))
  MakeBillboardWorldViewMatrix = staticmethod(MakeBillboardWorldViewMatrix)
  
class TCamera:
  # Abstraction of a Camera in 3D space.
  #
  # The camera is represented by the eye point, the reference point, and the up vector. 
  # This class is very useful since it provides an implementation of the gluLookAt method
  # which is not part of the OpenGL ES specification.
  def __init__(self, aPosition=TVector(0, 0, 0), aLookAt=TVector(0, 0, -1), aUp=TVector(0, 1, 0)):
    self.iViewMatrix = []
    self.LookAt(aPosition, aLookAt, aUp)
    
  def LookAt(self, aPosition, aLookAt, aUp):
    #Initializes a TCamera to aPosition, aLookAt, aUp.
    #TVector XAxis, YAxis, ZAxis;
    
    self.iPosition = aPosition
    self.iLookAt = aLookAt
    self.iUp = aUp
    
    # Get the z basis vector, which points straight ahead; the
    # difference from the position (eye point) to the look-at point.
    # This is the direction of the gaze (+z).
    ZAxis = (self.iLookAt - self.iPosition)
    
    # Normalize the z basis vector.
    ZAxis.Normalize()
    
    # Compute the orthogonal axes from the cross product of the gaze 
    # and the Up vector.
    #print ZAxis
    #print self.iUp
    if isinstance(ZAxis, TVectorx):
      XAxis = TVectorx.CrossProduct(ZAxis, self.iUp)
    elif isinstance(ZAxis, TVector):
      XAxis = TVector.CrossProduct(ZAxis, self.iUp)
    XAxis.Normalize()
    if isinstance(ZAxis, TVectorx):
      YAxis = TVectorx.CrossProduct(XAxis, ZAxis)
    if isinstance(ZAxis, TVector):
      YAxis = TVector.CrossProduct(XAxis, ZAxis)
    # Start building the matrix. The first three rows contain the 
    # basis vectors used to rotate the view to point at the look-at point.
    self.MakeIdentity()
    
    self.iViewMatrix[0][0] =  XAxis.iX;
    self.iViewMatrix[1][0] =  XAxis.iY;
    self.iViewMatrix[2][0] =  XAxis.iZ;
    
    self.iViewMatrix[0][1] =  YAxis.iX;
    self.iViewMatrix[1][1] =  YAxis.iY;
    self.iViewMatrix[2][1] =  YAxis.iZ;
    
    self.iViewMatrix[0][2] = -ZAxis.iX;
    self.iViewMatrix[1][2] = -ZAxis.iY;
    self.iViewMatrix[2][2] = -ZAxis.iZ;
    
  def MakeIdentity(self):
    self.iViewMatrix = [
      [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]
    ]

class TCameraX:
  # Abstraction of a Camera in 3D space using fixed-point arithmetic.
  #
  # The camera is represented by the eye point, the reference point, and the up vector. 
  #
  # This class is very useful since it provides an implementation of the gluLookAt method
  # which is not part of the OpenGL ES specification.
  def __init__(self, aPosition=TVectorx(0, 0, 0), aLookAt=TVectorx(0, 0, -1), aUp=TVectorx(0, 1, 0)):
    self.LookAt(aPosition, aLookAt, aUp)
    self.iViewMatrix = []

  def LookAt(self, aPosition, aLookAt, aUp):
    # Initializes a TCamera to aPosition, aLookAt, aUp.
    #TVectorx XAxis, YAxis, ZAxis;
    
    self.iPosition = aPosition
    self.iLookAt = aLookAt
    self.iUp = aUp
    
    # Get the z basis vector, which points straight ahead; the
    # difference from the position (eye point) to the look-at point.
    # This is the direction of the gaze (+z).
    ZAxis = (iLookAt - iPosition)
    
    # Normalize the z basis vector.
    ZAxis.Normalize();
    
    # Compute the orthogonal axes from the cross product of the gaze 
    # and the Up vector.
    XAxis = TVectorx.CrossProduct(ZAxis, iUp)
    XAxis.Normalize()
    YAxis = TVectorx.CrossProduct(XAxis, ZAxis)
    
    # Start building the matrix. The first three rows contain the 
    # basis vectors used to rotate the view to point at the look-at point.
    self.iViewMatrix = self.MakeIdentity(self.iViewMatrix)
    
    iViewMatrix[0][0] =  XAxis.iX
    iViewMatrix[1][0] =  XAxis.iY
    iViewMatrix[2][0] =  XAxis.iZ
    
    iViewMatrix[0][1] =  YAxis.iX
    iViewMatrix[1][1] =  YAxis.iY
    iViewMatrix[2][1] =  YAxis.iZ
    
    iViewMatrix[0][2] = -ZAxis.iX
    iViewMatrix[1][2] = -ZAxis.iY
    iViewMatrix[2][2] = -ZAxis.iZ
    
  def MakeIdentity(self, aMatrix):
    self.iViewMatrix = [
      [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]
    ]
    aMatrix[0 + 4 * 0] = int2fixed(1); aMatrix[0 + 4 * 1] = int2fixed(0)
    aMatrix[0 + 4 * 2] = int2fixed(0); aMatrix[0 + 4 * 3] = int2fixed(0)
    
    aMatrix[1 + 4 * 0] = int2fixed(0); aMatrix[1 + 4 * 1] = int2fixed(1)
    aMatrix[1 + 4 * 2] = int2fixed(0); aMatrix[1 + 4 * 3] = int2fixed(0)
    
    aMatrix[2 + 4 * 0] = int2fixed(0); aMatrix[2 + 4 * 1] = int2fixed(0)
    aMatrix[2 + 4 * 2] = int2fixed(1); aMatrix[2 + 4 * 3] = int2fixed(0)
    
    aMatrix[3 + 4 * 0] = int2fixed(0); aMatrix[3 + 4 * 1] = int2fixed(0)
    aMatrix[3 + 4 * 2] = int2fixed(0); aMatrix[3 + 4 * 3] = int2fixed(1)
    return aMatrix

class TParticle:
  # This structure is used by the class CParticleEngine. 
  # It is an abstraction of a particle.
  # Position    
  #TVector iPosition
  # Velocity        
  #TVector iVelocity
  # Acceleration
  #TVector iAcceleration
  # Empty implementation
  pass

class CParticleEngine:
  # Abstraction of a particle engine.
  # Particles engines are used to create special effects like Rain, Smoke, Snow, Sparks, etc...
  def __init__(self, aParticlesCount, aPosition):
    # Constructs a CParticleEngine object with aParticlesCount particles at 
    # position aPosition.
    self.iParticlesCount = aParticlesCount
    self.iParticles = [TParticle() for x in xrange(self.iParticlesCount)]
    
    self.position = aPosition
    
  def ResetEngine(self):
    # Resets the particle engine
    for p in self.iParticles:
        self.ResetParticle(p)
  def ResetParticle(self, aIndex):
    # Resets the particle at index aIndex
    pass
  def UpdateEngine(self, aElapsedTime):
    # Updates the engine.
    pass
  def RenderEngine(self, aCamera):
    # Renders the system.
    pass
class Utils:
  # A set of useful functions.
  pass