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python... pyglet... opengl... scaling

hey, I was experimenting with pyglet, and was trying out their opengl, but cant figure out how to scale images...

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  1. #!/usr/bin/python
  2.  
  3. # $Id:$
  4.  
  5.  
  6.  
  7. '''Demonstrates one way of fixing the display resolution to a certain
  8.  
  9. size, but rendering to the full screen.
  10.  
  11.  
  12.  
  13. The method used in this example is:
  14.  
  15.  
  16.  
  17. 1. Set the OpenGL viewport to the fixed resolution
  18.  
  19. 2. Render the scene using any OpenGL functions (here, just a polygon)
  20.  
  21. 3. Copy the framebuffer into a texture
  22.  
  23. 4. Reset the OpenGL viewport to the window (full screen) size
  24.  
  25. 5. Blit the texture to the framebuffer
  26.  
  27.  
  28.  
  29. Recent video cards could also render the scene directly to the texture
  30.  
  31. using EXT_framebuffer_object.  (This is not demonstrated in this example).
  32.  
  33. '''
  34.  
  35.  
  36.  
  37. from pyglet.gl import *
  38.  
  39. from pyglet import clock
  40.  
  41. from pyglet import image
  42.  
  43. from pyglet import window
  44.  
  45.  
  46.  
  47. # Create a fullscreen window using the user's desktop resolution.  You can
  48.  
  49. # also use this technique on ordinary resizable windows.
  50.  
  51. win = window.Window(fullscreen=True)
  52.  
  53.  
  54.  
  55. # Use 320x200 fixed resolution to make the effect completely obvious.  You
  56.  
  57. # can change this to a more reasonable value such as 800x600 here.
  58.  
  59. target_resolution = 1280, 800
  60.  
  61.  
  62.  
  63.  
  64. class FixedResolutionViewport(object):
  65.  
  66.     def __init__(self, win, width, height, filtered=False):
  67.  
  68.         self.window = win
  69.  
  70.         self.width = width
  71.  
  72.         self.height = height
  73.  
  74.         self.texture = image.Texture.create_for_size(GL_TEXTURE_2D, 
  75.  
  76.             width, height, GL_RGB)
  77.  
  78.         self.texture = self.texture.get_region(0, 0, width, height)
  79.  
  80.  
  81.  
  82.         if not filtered:
  83.  
  84.             # By default the texture will be bilinear filtered when scaled
  85.  
  86.             # up.  If requested, turn filtering off.  This makes the image
  87.  
  88.             # aliased, but is more suitable for pixel art.
  89.  
  90.             glTexParameteri(self.texture.target, 
  91.  
  92.                 GL_TEXTURE_MAG_FILTER, GL_NEAREST)
  93.  
  94.             glTexParameteri(self.texture.target, 
  95.  
  96.                 GL_TEXTURE_MIN_FILTER, GL_NEAREST)
  97.  
  98.  
  99.  
  100.     def begin(self):
  101.  
  102.         glViewport(0, 0, self.width, self.height)
  103.  
  104.         self.set_fixed_projection()
  105.  
  106.  
  107.  
  108.     def end(self):
  109.  
  110.         buffer = image.get_buffer_manager().get_color_buffer()
  111.  
  112.         self.texture.blit_into(buffer, 0, 0, 0)
  113.  
  114.  
  115.  
  116.         glViewport(0, 0, self.window.width, self.window.height)
  117.  
  118.         self.set_window_projection()
  119.  
  120.  
  121.  
  122.         aspect_width = self.window.width / float(self.width)
  123.  
  124.         aspect_height = self.window.height / float(self.height)
  125.  
  126.         if aspect_width > aspect_height:
  127.  
  128.             scale_width = aspect_height * self.width
  129.  
  130.             scale_height = aspect_height * self.height
  131.  
  132.         else:
  133.  
  134.             scale_width = aspect_width * self.width
  135.  
  136.             scale_height = aspect_width * self.height
  137.  
  138.         x = (self.window.width - scale_width) / 2
  139.  
  140.         y = (self.window.height - scale_height) / 2
  141.  
  142.  
  143.  
  144.         glClearColor(0, 0, 0, 1)
  145.  
  146.         glClear(GL_COLOR_BUFFER_BIT)
  147.  
  148.         glLoadIdentity()
  149.  
  150.         glColor3f(1, 1, 1)
  151.  
  152.         self.texture.blit(x, y, width=scale_width, height=scale_height)
  153.  
  154.  
  155.  
  156.     def set_fixed_projection(self):
  157.  
  158.         # Override this method if you need to change the projection of the
  159.  
  160.         # fixed resolution viewport.
  161.  
  162.         glMatrixMode(GL_PROJECTION)
  163.  
  164.         glLoadIdentity()
  165.  
  166.         glOrtho(0, self.width, 0, self.height, -1, 1)
  167.  
  168.         glMatrixMode(GL_MODELVIEW)
  169.  
  170.  
  171.  
  172.     def set_window_projection(self):
  173.  
  174.         # This is the same as the default window projection, reprinted here
  175.  
  176.         # for clarity.
  177.  
  178.         glMatrixMode(GL_PROJECTION)
  179.  
  180.         glLoadIdentity()
  181.  
  182.         glOrtho(0, self.window.width, 0, self.window.height, -1, 1)
  183.  
  184.         glMatrixMode(GL_MODELVIEW)
  185.  
  186.  
  187.  
  188. rotate = 0
  189. kitten = image.load('kitten.jpg')
  190.  
  191. def draw_scene():
  192.     global kitten
  193.  
  194.     # Draw the scene, assuming the fixed resolution viewport and projection
  195.  
  196.     # have been set up.
  197.  
  198.     glClearColor(0, 0, 0, 0)
  199.  
  200.     glClear(GL_COLOR_BUFFER_BIT)
  201.     f=kitten.width
  202.  
  203.     glLoadIdentity()
  204.     glEnable(GL_TEXTURE_2D)
  205.  
  206.     w, h = target_resolution
  207.  
  208.     glTranslatef(w/2, h/2, 0)
  209.  
  210.     glRotatef(rotate, 0, 0, 1)
  211.  
  212.     #glColor3f(1, 1, 0,)
  213.  
  214.     s = min(w, h) / 4
  215.  
  216.     glRectf(s, s, s, s)
  217.     kitten.blit(0,0)
  218.  
  219. viewport = FixedResolutionViewport(win, 
  220.  
  221.     target_width, target_height, filtered=False)
  222.  
  223. while not win.has_exit:
  224.  
  225.     dt = clock.tick()
  226.  
  227.     rotate += dt * 20
  228.  
  229.  
  230.  
  231.     win.dispatch_events()
  232.  
  233.  
  234.  
  235.     viewport.begin()
  236.  
  237.     win.clear()
  238.  
  239.     draw_scene()
  240.  
  241.     viewport.end()
  242.  
  243.  
  244.  
  245.     win.flip()
that is the fixed_resolution.py file that came with it

basically i just want to make that kitten picture rotate instead of the red box. i got the picture to rotate, but I cant figure out how to scale it down to match the box size.

i searched for about 2-3 hours tonight for opengl refrences on how to do this but came up empty handed
Dec 24 '07 #1
1 3968
Oops, embarrassing... I put down the wrong code :p

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  1. kitten = image.load('kitten.jpg')
  2. texture=kitten.texture
  3.  
  4. def draw_scene():
  5.     global kitten, texture
  6.  
  7.     # Draw the scene, assuming the fixed resolution viewport and projection
  8.  
  9.     # have been set up.
  10.  
  11.     glClearColor(0, 0, 0, 0)
  12.  
  13.     glClear(GL_COLOR_BUFFER_BIT)
  14.     f=kitten.width
  15.  
  16.     glLoadIdentity()
  17.     glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL)
  18.     glEnable(GL_TEXTURE_2D)
  19.  
  20.     w, h = target_resolution
  21.  
  22.     glTranslatef(w/2, h/2, 0)
  23.  
  24.     #glRotatef(rotate, 0, 0, 1)
  25.  
  26.     glColor3f(1, 0, 1)
  27.  
  28.     s = min(w, h) / 4
  29.  
  30.     glRectf(-s, -s, s, s)
  31.     glBindTexture(GL_TEXTURE_2D, texture.id)
  32.     glBegin(GL_POLYGON)
  33.     glVertex3f (-s, -s, 0.0);
  34.     glVertex3f (s, -s, 0.0);
  35.     glVertex3f (s, s, 0.0);
  36.     glVertex3f (-s, s, 0.0);
  37.     glEnd()
that is what I changed, and all it gives is a gray square
Dec 24 '07 #2

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