'''
(*)~----------------------------------------------------------------------------------
 Pupil - eye tracking platform
 Copyright (C) 2012-2013  Moritz Kassner & William Patera

 Distributed under the terms of the CC BY-NC-SA License.
 License details are in the file license.txt, distributed as part of this software.
----------------------------------------------------------------------------------~(*)
'''
from OpenGL.GL import *
from OpenGL.GLU import gluOrtho2D

def clear_gl_screen():
    glClear(GL_COLOR_BUFFER_BIT)

def adjust_gl_view(w,h):
    """
    adjust view onto our scene so
    that a quad from 0,0 to 1,1 fits into it perfecly
    """
    if h == 0:
        h = 1
    glViewport(0, 0, w, h)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    nRange = 1.0
    if w <= h:
        glOrtho(-nRange, nRange, -nRange*h/w, nRange*h/w, -nRange, nRange)
    else:
        glOrtho(-nRange*w/h, nRange*w/h, -nRange, nRange, -nRange, nRange)
    # switch back to Modelview
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

def draw_gl_polyline((positions),(r,g,b,a),type='Loop'):
    glColor4f(r,g,b,a)
    if type=='Loop':
        glBegin(GL_LINE_LOOP)
    elif type=='Strip':
        glBegin(GL_LINE_STRIP)
    else:
        glBegin(GL_LINES)
    for x,y in positions:
        glVertex3f(x,y,0.0)
    glEnd()

def draw_gl_polyline_norm((positions),(r,g,b,a),type='Loop'):
    glMatrixMode(GL_PROJECTION)
    glPushMatrix()
    glLoadIdentity()
    gluOrtho2D(-1, 1, -1, 1) # origin at the center positive up, positve right
    glMatrixMode(GL_MODELVIEW)
    glPushMatrix()
    glLoadIdentity()
    draw_gl_polyline(positions,(r,g,b,a),type)
    glMatrixMode(GL_PROJECTION)
    glPopMatrix()
    glMatrixMode(GL_MODELVIEW)
    glPopMatrix()


def draw_gl_point((x,y),size=20,color=(1.,0.5,0.5,.5)):
    glColor4f(*color)
    glPointSize(int(size))
    glBegin(GL_POINTS)
    glVertex3f(x,y,0.0)
    glEnd()

def draw_gl_point_norm(pos,size=20,color=(1.,0.5,0.5,.5)):

    glMatrixMode(GL_PROJECTION)
    glPushMatrix()
    glLoadIdentity()
    gluOrtho2D(-1, 1, -1, 1) # origin at the center positive up, positve right
    glMatrixMode(GL_MODELVIEW)
    glPushMatrix()
    glLoadIdentity()

    draw_gl_point(pos,size,color)

    glMatrixMode(GL_PROJECTION)
    glPopMatrix()
    glMatrixMode(GL_MODELVIEW)
    glPopMatrix()



def draw_gl_texture(image):
    """
    We draw the image as a texture on a quad that is perfectly set into our window.
    """

    height, width, channels = image.shape
    if  channels == 3:
        gl_blend = GL_BGR
        gl_blend_init = GL_RGB
    else:
        gl_blend = GL_BGRA
        gl_blend_init = GL_RGBA
    # Create Texture
    glTexImage2D(GL_TEXTURE_2D,
                        0,
                        gl_blend_init,
                        width,
                        height,
                        0,
                        gl_blend,
                        GL_UNSIGNED_BYTE,
                        image)
    glEnable(GL_TEXTURE_2D)
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST) # interpolation here

    # Set Projection Matrix
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluOrtho2D(0, width, height, 0) # origin in the top left corner just like the img np-array
    # Switch back to Model View Matrix
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

    # someday replace with this:
    # glEnableClientState(GL_VERTEX_ARRAY)
    # glEnableClientState(GL_TEXTURE_COORD_ARRAY)
    # Varray = numpy.array([[0,0],[0,1],[1,1],[1,0]],numpy.float)
    # glVertexPointer(2,GL_FLOAT,0,Varray)
    # glTexCoordPointer(2,GL_FLOAT,0,Varray)
    # indices = [0,1,2,3]
    # glDrawElements(GL_QUADS,1,GL_UNSIGNED_SHORT,indices)
    glColor4f(1.0,1.0,1.0,1.0)
    # Draw textured Quad.
    glBegin(GL_QUADS)
    glTexCoord2f(0.0, 0.0)
    glVertex2f(0.0, 0.0)
    glTexCoord2f(1.0, 0.0)
    glVertex2f(width, 0.0)
    glTexCoord2f(1.0, 1.0)
    glVertex2f(width, height)
    glTexCoord2f(0.0, 1.0)
    glVertex2f(0.0, height)
    glEnd()
    glDisable(GL_TEXTURE_2D)