gistfile1.py

#!/usr/bin/env python
"""
PHP MRPAS
Copyright (c) 2010 Dominik Marczuk
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * The name of Dominik Marczuk may not be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY DOMINIK MARCZUK ``AS IS'' AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL DOMINIK MARCZUK BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""

import random

mapWidth = 80
mapHeight = 50
playerPosX = 40
playerPosY = 25

class cell:
    def __init__(self):
        self.fov = False
        self.transparent = False
        self.walkable = False

class mainmap:
    def __init__ (self,w, h):
        self.width = w
        self.height = h
        self.nbcells = w * h
        self.cells = []
        for i in xrange(self.nbcells + 1):
            self.cells.append(cell())
    def generate (self):
        for i in xrange(self.nbcells + 1):
            if random.randint(0,100) > 10:
                self.cells[i].transparent = True
                self.cells[i].walkable = True
            else:
              self.cells[i].transparent = False
              self.cells[i].walkable = False
            self.cells[i].fov = False
    def displayTile(self,idx):
      if self.cells[idx].walkable:
        if self.cells[idx].fov == True:
          c = '<img src="ground-lit.gif">'
        else:
          c = '<img src="ground-unlit.gif">'
      else:
        if self.cells[idx].fov == True:
          c = '<img src="wall-lit.gif">'
        else:
          c = '<img src="wall-unlit.gif">'
      if playerPosY * mapWidth + playerPosX == idx:
        c = '<img src="pc.gif">'
      print c


#the fov itself
class MRPAS:
  def computeQuadrant (self,m,playerX,playerY,maxRadius,lightWalls,dx,dy):
    startAngle = [None] * 1000
    endAngle = [None] * 1000
    #octant: vertical edge:
    iteration = 1
    done = False
    totalObstacles = 0
    obstaclesInLastLine = 0
    minAngle = 0.0
    x = 0
    y = 0
    #do while there are unblocked slopes left and the algo is within
    # the map's boundaries
    #scan progressive lines/columns from the PC outwards
    y = playerY + dy
    if y < 0 or y >= m.height:
        done = True
    while not done:
        #process cells in the line
        slopesPerCell = 1.0 / (iteration + 1);
        halfSlopes = slopesPerCell * 0.5
        processedCell = abs(minAngle / slopesPerCell)
        minx = max(0, playerX - iteration)
        maxx = min(m.width - 1, playerX + iteration)
        done = True
        x = playerX + (processedCell * dx)
        while x >= minx and x <= maxx:
          c = x + (y * m.width)
          #calculate slopes per cell
          visible = True
          startSlope = processedCell * slopesPerCell
          centreSlope = startSlope + halfSlopes
          endSlope = startSlope + slopesPerCell
          if obstaclesInLastLine > 0 and m.cells[int(c)].fov == False:
            idx = 0
            while visible and idx < obstaclesInLastLine:
              if m.cells[int(c)].transparent == True:
                if centreSlope > startAngle[idx] and centreSlope <\
                                                            endAngle[idx]:
                  visible = False
              else:
                if startSlope >= startAngle[idx] and endSlope <= endAngle[idx]:
                  visible = False;
              if visible and (m.cells[c - (m.width * dy)].fov == False or\
                                not m.cells[c - (m.width * dy)].transparent)\
                                and (x - dx >= 0 and x - dx < m.width and\
                                (m.cells[c - (m.width * dy) - dx].fov == False\
                                 or not m.cells[c - (m.width * dy) - dx].\
                                 transparent)):
                visible = False
              idx += 1
          if visible:
            m.cells[int(c)].fov = True
            done = False
            #if the cell is opaque, block the adjacent slopes
            if not m.cells[int(c)].transparent:
              if minAngle >= startSlope:
                minAngle = endSlope
              else:
                startAngle[totalObstacles] = startSlope
                endAngle[totalObstacles + 1] = endSlope
              if (not lightWalls):
                m.cells[int(c)].fov = False
          processedCell += 1
          x += dx
    if iteration == maxRadius:
      done = True
    iteration += 1
    obstaclesInLastLine = totalObstacles;
    y += dy
    if y < 0 or y >= m.height:
      done = True 
    if minAngle == 1.0:
      done = True
    #octant: horizontal edge
    iteration = 1 #iteration of the algo for this octant
    done = False
    totalObstacles = 0
    obstaclesInLastLine = 0
    minAngle = 0.0
    x = 0
    y = 0
    #do while there are unblocked slopes left and the algo is within the map's boundaries
    #scan progressive lines/columns from the PC outwards
    x = playerX + dx #the outer slope's coordinates (first processed line)
    if  x < 0 or x >= m.width:
      done = True
    while not done:
      #process cells in the line
      slopesPerCell = 1.0 / (iteration + 1)
      halfSlopes = slopesPerCell * 0.5
      processedCell = abs(minAngle / slopesPerCell)
      miny = max(0, playerY - iteration)
      maxy = min(m.height - 1, playerY + iteration);
      done = True
      y = playerY + (processedCell * dy)
      while y >= miny and y <= maxy:
        y += dy
        c = x + (y * m.width)
        #calculate slopes per cell
        visible = True
        startSlope = (processedCell * slopesPerCell)
        centreSlope = startSlope + halfSlopes
        endSlope = startSlope + slopesPerCell
        if obstaclesInLastLine > 0 and m.cells[int(c)].fov == False:
          idx = 0
          while visible and idx < obstaclesInLastLine:
            if m.cells[int(c)].transparent == True:
              if centreSlope > startAngle[idx] and centreSlope <\
                   endAngle[idx]:
                visible = False
            else:
              if startSlope >= startAngle[idx] and endSlope <= endAngle[idx]:
                visible = False
            if visible and (m.cells[c - dx].fov == False or\
                    not m.cells[c - dx].transparent) and\
                    (y - dy >= 0 and y - dy < m.height and (m.cells[c -\
                    (m.width * dy) - dx].fov == False or not m.cells[c -\
                    (m.width * dy) - dx].transparent)):
              visible = False
            idx += 1
        if visible:
          m.cells[int(c)].fov = True
          done = False;
          #if the cell is opaque, block the adjacent slopes
          if not m.cells[int(c)].transparent:
            if minAngle >= startSlope:
              minAngle = endSlope
            else:
              startAngle[totalObstacles] = startSlope;
              endAngle[totalObstacles + 1] = endSlope;
            if not lightWalls:
              m.cells[int(c)].fov = False
        processedCell += 1
      if iteration == maxRadius:
        done = True
      iteration += 1
      obstaclesInLastLine = totalObstacles
      x += dx
      if x < 0 or x >= m.width:
        done = True
      if minAngle == 1.0:
        done = True

  def computeFov (self,m,playerX,playerY,maxRadius,lightWalls):
    #first, zero the FOV map
    for c in xrange(m.nbcells + 1):
      m.cells[c].fov = False
    #set PC's position as visible
    m.cells[playerX + (playerY * m.width)].fov = True
    #compute the 4 quadrants of the map
    self.computeQuadrant(m, playerX, playerY, maxRadius, lightWalls, 1, 1);
    self.computeQuadrant(m, playerX, playerY, maxRadius, lightWalls, 1, -1);
    self.computeQuadrant(m, playerX, playerY, maxRadius, lightWalls, -1, 1);
    self.computeQuadrant(m, playerX, playerY, maxRadius, lightWalls, -1, -1);

#LET'S DO IT!
m = mainmap(mapWidth,mapHeight)
m.generate();
fov = MRPAS()
  
print "Content-Type: text/html\n\n",
print """
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
    <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
    <title>PHP MRPAS</title>
    <style type="text/css">
    body { font-family: monospace; background-color: black; color: white; line-height: 0; text-align: center; }
    img { border: 0; padding: 0; margin: 0; }
  </style>
</head>
<body>
<h1>PHP MRPAS</h1>
<h3>Hit "refresh" to generate another map.</h3>
<p>
"""
fov.computeFov(m,playerPosX,playerPosY,0, True)
for j in xrange(mapHeight):
    for i in xrange(mapWidth):
      m.displayTile(j * mapWidth + i)
    print  '<br>'
print """
</p>    
</body>
</html>
"""