# ----------------------------------------------------------------------------
# pymunk
# Copyright (c) 2007-2016 Victor Blomqvist
#
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# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
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# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# SOFTWARE.
# ----------------------------------------------------------------------------

"""This submodule contains helper functions to help with quick prototyping 
using pymunk together with pyglet.

Intended to help with debugging and prototyping, not for actual production use
in a full application. The methods contained in this module is opinionated 
about your coordinate system and not very optimized (they use batched 
drawing, but there is probably room for optimizations still). 
"""

__docformat__ = "reStructuredText"

__all__ = ["DrawOptions"]


import math

import pyglet

import pymunk
from pymunk.vec2d import Vec2d

class DrawOptions(pymunk.SpaceDebugDrawOptions):
    def __init__(self, **kwargs):
        """Draw a pymunk.Space.
        
        Typical usage::
        
        >>> import pymunk
        >>> import pymunk.pygame_util
        >>> s = pymunk.Space()
        >>> options = pymunk.pyglet_util.DrawOptions()
        >>> s.debug_draw(options)
        
        You can control the color of a Shape by setting shape.color to the color 
        you want it drawn in.
        
        >>> c = pymunk.Circle(None, 10)
        >>> c.color = (255, 0, 0, 255) # will draw my_shape in red
        
        You can optionally pass in a batch to use for drawing. Just 
        remember that you need to call draw yourself.
        
        >>> my_batch = pyglet.graphics.Batch()
        >>> s = pymunk.Space()
        >>> options = pymunk.pyglet_util.DrawOptions(batch=my_batch)
        >>> s.debug_draw(options)
        >>> my_batch.draw()
        
        See pyglet_util.demo.py for a full example
        
        :Param:
                kwargs : You can optionally pass in a pyglet.graphics.Batch
                    If a batch is given all drawing will use this batch to draw 
                    on. If no batch is given a a new batch will be used for the
                    drawing. Remember that if you pass in your own batch you 
                    need to call draw on it yourself.
        
        """
        self.new_batch = False
        
        if "batch" not in kwargs:
            self.new_batch = True
        else:
            self.batch = kwargs["batch"]

        super(DrawOptions, self).__init__()


    def __enter__(self):
        if self.new_batch:
            self.batch = pyglet.graphics.Batch()
    def __exit__(self, type, value, traceback):
        if self.new_batch:
            self.batch.draw()

    def draw_circle(self, pos, angle, radius, outline_color, fill_color):
        circle_center = pos
        
        #http://slabode.exofire.net/circle_draw.shtml
        num_segments = int(4 * math.sqrt(radius))
        theta = 2 * math.pi / num_segments
        c = math.cos(theta)
        s = math.sin(theta)
        
        x = radius # we start at angle 0
        y = 0
        
        ps = []
        
        for i in range(num_segments):
            ps += [Vec2d(circle_center.x + x, circle_center.y + y)]
            t = x
            x = c * x - s * y
            y = s * t + c * y
                
        mode = pyglet.gl.GL_TRIANGLE_STRIP
        ps2 = [ps[0]]
        for i in range(1, int(len(ps)+1/2)):
            ps2.append(ps[i])
            ps2.append(ps[-i])
        ps = ps2
        vs = []
        for p in [ps[0]] + ps + [ps[-1]]:
                vs += [p.x, p.y]
            
        c = circle_center + Vec2d(radius, 0).rotated(angle)
        cvs = [circle_center.x, circle_center.y, c.x, c.y]
            
        bg = pyglet.graphics.OrderedGroup(0)
        fg = pyglet.graphics.OrderedGroup(1)
            
        l = len(vs)//2
       

        self.batch.add(len(vs)//2, mode, bg,
                ('v2f', vs),
                ('c4B', fill_color.as_int()*l))
        self.batch.add(2, pyglet.gl.GL_LINES, fg,
                ('v2f', cvs),
                ('c4B', outline_color.as_int()*2))


    def draw_segment(self, a, b, color):
        pv1 = a
        pv2 = b
        line = (int(pv1.x), int(pv1.y), int(pv2.x), int(pv2.y))
        
        self.batch.add(2, pyglet.gl.GL_LINES, None,
                    ('v2i', line),
                    ('c4B', color.as_int() * 2))


    def draw_fat_segment(self, a, b, radius, outline_color, fill_color):
        pv1 = a
        pv2 = b
        d = pv2 - pv1
        a = -math.atan2(d.x, d.y)
        radius = max(radius, 1)
        dx = radius * math.cos(a)
        dy = radius * math.sin(a)
        
        p1 = pv1 + Vec2d(dx,dy)
        p2 = pv1 - Vec2d(dx,dy)
        p3 = pv2 + Vec2d(dx,dy)
        p4 = pv2 - Vec2d(dx,dy)
            
        vs = [i for xy in [p1,p2,p3]+[p2,p3,p4] for i in xy]
            
        l = len(vs)//2
        self.batch.add(l,pyglet.gl.GL_TRIANGLES, None,
                    ('v2f', vs),
                    ('c4B', fill_color.as_int() * l))

    def draw_polygon(self, verts, radius, outline_color, fill_color):
        mode = pyglet.gl.GL_TRIANGLE_STRIP

        l = len(verts)
        mid = len(verts) // 2 
        
        vs = []
        for i in range(mid):
            vs += [verts[i].x, verts[i].y]
            vs += [verts[l-1-i].x, verts[l-1-i].y]

        if l%2:
            vs += [verts[mid].x, verts[mid].y]
            
        vs = [vs[0], vs[1]] + vs + [vs[-2], vs[-1]]

        l = len(vs)//2
        self.batch.add(l, mode, None,
                    ('v2f', vs),
                    ('c4B', fill_color.as_int()*l))

    def draw_dot(self, size, pos, color):
        # todo: optimize this functions
        self.batch.add(1, pyglet.gl.GL_POINTS, grPointSize(size), 
                    ('v2f', pos),
                    ('c4B', color.as_int()*1))

class grPointSize(pyglet.graphics.Group):
    """
    This pyglet rendering group sets a specific point size.
    """
    def __init__(self, size=1.0):
        super(grPointSize, self).__init__()
        self.size = size
    def set_state(self):
        pyglet.gl.glPointSize(self.size)
    def unset_state(self):
        pyglet.gl.glPointSize(1.0)