gistfile1.py

def get_filled_path(points):
    from OpenGL.GLU import gluNewTess, gluTessNormal, gluTessProperty,\
        gluTessBeginPolygon, gluTessBeginContour, gluTessEndContour,\
        gluTessEndPolygon, gluTessCallback, gluErrorString, gluTessVertex,\
        GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_NONZERO, GLU_TESS_VERTEX,\
        GLU_TESS_BEGIN, GLU_TESS_END, GLU_TESS_ERROR, GLU_TESS_COMBINE

    tess = gluNewTess()
    gluTessNormal(tess, 0, 0, 1)
    gluTessProperty(tess, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_NONZERO)

    tess_list = []
    tess_style = None
    tess_shape = None

    def tess_vertex(vertex):
        global tess_shape
        tess_shape += list(vertex[0:2])

    def tess_begin(which):
        global tess_style, tess_shape
        tess_style = which
        tess_shape = []

    def tess_end():
        global tess_style, tess_shape
        tess_list.append((tess_style, tess_shape))

    def tess_error(code):
        err = gluErrorString(code)
        pymt.pymt_logger.warning('BezierPath: GLU Tesselation Error: %s' % str(err))

    gluTessCallback(tess, GLU_TESS_VERTEX, tess_vertex)
    gluTessCallback(tess, GLU_TESS_BEGIN, tess_begin)
    gluTessCallback(tess, GLU_TESS_END, tess_end)
    gluTessCallback(tess, GLU_TESS_ERROR, tess_error)

    gluTessBeginPolygon(tess, None)
    gluTessBeginContour(tess)
    for x, y in zip(points[::2], points[1::2]):
        v_data = (x, y, 0)
        gluTessVertex(tess, v_data, v_data)
    gluTessEndContour(tess)
    gluTessEndPolygon(tess)

    return tess_list

def draw_filled_path(points):
    from OpenGL.GL import glVertex2f
    for style, points in points:
        with gx_begin(style):
            for x, y in zip(points[::2], points[1::2]):
                glVertex2f(x, y)

def point_inside_polygon(x, y, poly):
    n = len(poly)
    if n < 2:
        return False
    inside = False
    p1x, p1y = poly[0]
    for i in range(n+1):
        p2x,p2y = poly[i % n]
        if y > min(p1y,p2y):
            if y <= max(p1y,p2y):
                if x <= max(p1x,p2x):
                    if p1y != p2y:
                        xinters = (y-p1y)*(p2x-p1x)/(p2y-p1y)+p1x
                    if p1x == p2x or x <= xinters:
                        inside = not inside
        p1x,p1y = p2x,p2y
    return inside

class Curve(object):
    def __init__(self, points=[], tension=0., precision=1., is_closed=False):
        self._points    = points
        self._tension   = tension
        self._is_closed = is_closed
        self._curve     = []
        self._filledpath = None
        self._precision = precision
        self.update()

    def update(self):
        p = self._points
        self._curve = []
        self._filledpath = None
        if len(self._points) < 2:
            return
        if len(self._points) == 2:
            p0, p1 = p
            self._curve = [p0[0], p0[1], p1[0], p1[1]]
            return
        n = len(p) - 1
        if self._is_closed:
            for i in xrange(n):
                if i == 0:
                    o = self._curve_seg(p[n], p[0], p[1], p[2])
                elif i == (n - 1):
                    o = self._curve_seg(p[n-2], p[n-1], p[n], p[0])
                else:
                    o = self._curve_seg(p[i-1], p[i], p[i+1], p[i+2])
                self._curve += o
            self._curve += self._curve_seg(p[n-1], p[n], p[0], p[1])
        else:
            for i in xrange(n):
                if i == 0:
                    o = self._curve_seg(p[0], p[0], p[1], p[2])
                elif i == (n - 1):
                    o = self._curve_seg(p[n-2], p[n-1], p[n], p[n])
                else:
                    o = self._curve_seg(p[i-1], p[i], p[i+1], p[i+2])
                self._curve += o

    def _curve_seg(self, p0, p1, p2, p3):
        curve   = []
        p       = self._precision
        tension = self._tension
        x       = 0.
        y       = 0.
        xl      = p1[0] - 1.
        yl      = p1[1] - 1.

        t       = 0.
        f       = 1.
        k       = 1.1

        m1x     = (1 - tension) * (p2[0] - p0[0]) / 2.
        m2x     = (1 - tension) * (p3[0] - p1[0]) / 2.
        m1y     = (1 - tension) * (p2[1] - p0[1]) / 2.
        m2y     = (1 - tension) * (p3[1] - p1[1]) / 2.

        while t <= 1:
            x = (2 * t * t * t - 3 * t * t + 1)  *  p1[0] + \
                (t * t * t - 2 * t * t + t)  *  m1x + \
                (-2 * t * t * t + 3 * t * t) * p2[0] + \
                (t * t * t - t * t) * m2x
            y = (2 * t * t * t - 3 * t * t + 1) * p1[1] + \
                (t * t * t - 2 * t * t + t) * m1y + \
                (-2 * t * t * t + 3 * t * t) * p2[1] + \
                (t * t * t - t * t) * m2y

            #x = round(x)
            #y = round(y)

            if x != xl or y != yl:
                if x - xl > p or y - yl > p or xl - x > p or yl - y > p:
                    t -= f
                    f  = f / k
                else:
                    curve += [x, y]
                    xl = x
                    yl = y
                    if t + f > 1.:
                        t = 1 - f
            else:
                f = f * k
            t += f
        return curve

    @property
    def curve(self):
        return self._curve

    @property
    def filledpath(self):
        if self._filledpath is None:
            self._filledpath = get_filled_path(self.curve)
        return self._filledpath

    def _set_tension(self, value):
        if self._tension == value:
            return
        self._tension = value
        self.update()
    def _get_tension(self):
        return self._tension
    tension = property(_get_tension, _set_tension)

    def _set_points(self, value):
        if self._points == value:
            return
        self._points = value
        self.update()
    def _get_points(self):
        return self._points
    points = property(_get_points, _set_points)

    def _set_precision(self, value):
        if self._precision == value:
            return
        self._precision = value
        self.update()
    def _get_precision(self):
        return self._precision
    precision = property(_get_precision, _set_precision)

    def _set_is_closed(self, value):
        if self._is_closed == value:
            return
        self._is_closed = value
        self.update()
    def _get_is_closed(self):
        return self._is_closed
    is_closed = property(_get_is_closed, _set_is_closed)


if __name__ == '__main__':
    from pymt import *

    w = getWindow()

    class Shape(MTWidget):
        def __init__(self, **kwargs):
            super(Shape, self).__init__(**kwargs)
            self.curve = Curve(precision=10)
            def r():
                import random
                if random.random() > .5:
                    return .5
                return .3
            self.color = map(lambda x: r(), xrange(3)) + [.5]
            self.linecolor = self.color[:3] + [.7]
            self.circlecolor = map(lambda x: x + .1, self.color[:3])

        def collide_point(self, x, y):
            return point_inside_polygon(x, y, self.curve.points)

        def draw(self):
            c = self.curve
            if c.is_closed:
                set_color(*self.color)
                draw_filled_path(c.filledpath)
            set_color(*self.linecolor)
            drawLine(c.curve, width=5.)
            set_color(*self.circlecolor)
            for p in c.points:
                drawCircle(pos=p, radius=3)

        def on_touch_down(self, touch):
            if not self.collide_point(*touch.pos):
                return
            touch.grab(self)
            touch.userdata['controlpoints'] = []
            for idx in xrange(len(self.curve.points)):
                x, y = self.curve.points[idx]
                if Vector(x, y).distance(touch.pos) < 150:
                    touch.userdata['controlpoints'].append(idx)
            return True

        def on_touch_move(self, touch):
            if touch.grab_current != self:
                return
            if touch.dpos == (0, 0):
                return
            p = self.curve.points
            for idx in touch.userdata['controlpoints']:
                d = Vector(touch.pos) - Vector(touch.dpos)
                p[idx] = Vector(p[idx]) + d
            self.curve.update()
            return True


    class Canvas(MTWidget):
        def __init__(self, **kwargs):
            super(Canvas, self).__init__(**kwargs)

        def on_touch_down(self, touch):
            if super(Canvas, self).on_touch_down(touch):
                return True
            shape = Shape()
            self.add_widget(shape)
            touch.userdata['shape'] = shape
            shape.curve.points = shape.curve.points + [touch.pos]
            shape.curve.points = shape.curve.points + [touch.pos]
            return True

        def on_touch_move(self, touch):
            if 'shape' in touch.userdata:
                shape = touch.userdata['shape']
                last = shape.curve.points[-2]
                if Vector(touch.pos).distance(Vector(last)) > 80:
                    shape.curve.points = shape.curve.points + [touch.pos]
                else:
                    shape.curve.points = shape.curve.points[:-1] + [touch.pos]
                return True
            return super(Canvas, self).on_touch_move(touch)

        def on_touch_up(self, touch):
            if 'shape' in touch.userdata:
                shape = touch.userdata['shape']
                if len(shape.curve.curve) < 3:
                    self.remove_widget(shape)
                    return
                shape.curve.is_closed = True
                shape.curve.update()
                return True
            return super(Canvas, self).on_touch_up(touch)


    runTouchApp(Canvas())